Update on Diet-Associated Dilated Cardiomyopathy

Last week brought a revealing announcement from the FDA. After frequent and persistent petitioning from Veterinarians, Veterinary Nutritionists, and concerned Caregivers, the FDA finally released a list of the brands that have been linked to cases of diet-associated dilated cardiomyopathy (DCM). Since June 27, my inbox and social media sites have been blowing up with shares, retweets, and emails from concerned friends and family. The story was even picked up by major news outlets, like CNN and ABC, adding to the fervor.

But I’m conflicted about this report. On one hand, certain pet food manufacturers have taken a very cavalier approach to their diet’s role in this preventable and potentially deadly disease. Because only a relatively “small percentage” of dogs develop diet-associated DCM on their foods, they insist that there is no problem, ignoring the overwhelming evidence to the contrary.  On the other hand, the FDA’s report paints a broad stroke over specific brands and is being interpreted (at least by the concerned friends and owners I’ve talked to) as an indictment of all “grain-free” or of certain manufacturers, which is a less than helpful oversimplification of a complex problem. As I advised in my post last fall (and this bears repeating here) I would urge caution before panicking and rushing to change your dog or cat’s food without considering what to change to. By all means if you are feeding a diet that has been associated with heart disease in other dogs then a change is warranted, but before jumping to another potentially problematic diet (just because it is not on the list) it is important to step back and look at what we know and don’t know to date.

 

Not a diet-associated DCM case, but could have been if we didn’t get him on the right diet for his breed and health status.

Recap of the Problem …

In 2017 Veterinary Cardiologists began noticing an increased incidence of DCM in Golden retrievers. This is a breed (along with other large breed dogs) with an increased risk of DCM in general, but the number of cases and age at onset of disease was not typical. This prompted a closer look at potential contributing factors and Veterinary Cardiologists then reached out to the larger veterinary community for information on other cases of unexpected or atypical DCM in any dog. Initially, the common thread was the feeding of a diet marketed as “grain-free.” Since that time the FDA Center for Veterinary Medicine (FDA-CVM) and researchers at both Tufts University and University of California, Davis, Veterinary Schools have been collecting data and working on finding a root cause of this potentially fatal disease. They have found that not only were Veterinarians seeing cases of DCM in dogs fed diets marketed as “grain free”, but also in dogs eating diets that use uncommon animal proteins (like kangaroo and bison, whether grain-inclusive or not) or that were made by smaller manufacturers that may or may not be adequately formulated for long-term feeding.

From the FDA update June 27, 2019.

So what do we know?

  1. Not all cases are taurine deficient. Many of the dogs diagnosed with diet-associated DCM in the last 2 years had low taurine levels, but not all. Whether low or normal taurine levels were measured, most dogs if caught early had improvement in clinical signs and reversal of cardiac changes when their previous diet was stopped and taurine was supplemented.
  2. Not all dogs eating “grain-free” diets are affected. There are an estimated 20 million dogs eating diets marketed as “grain-free” that include some combination of legumes (peas, lentils, chickpeas, pinto, etc.) or potato (sweet or white), or both, and only (only?!) 515 reported cases of diet-associated DCM in dogs since 2017.
  3. Large breed dogs are at an increased risk, but even small dogs are affected. Large breed dogs account for 338 out of the 515 reported cases, but Shih tzus and Shetland Sheepdogs are on the list, too.
  4. Dry dog foods are the predominant type reported, but raw and home-cooked make the list, too. This probably has more to do with the relative popularity of these diet types rather than some inherent risk/benefit of a particular food type.
  5. “Grain-Free” is a marketing ploy and not based on any scientific or nutritional studies. There is no proven health benefit to avoiding grains in your dog’s diet unless they have a documented food allergy (which is actually very uncommon). Grains play a lot of roles in the diet, and most of these roles are pretty helpful at optimizing health.

Meeting with Dr. Weeth to make sure we are keeping our hearts and whole bodies healthy.

What don’t we know?

  1. We don’t know the true scope of the problem. In people, underreporting of adverse drug effects is a well-known problem with some reviews indicating that as high as 95% of adverse reactions go unreported. Which means we may be seeing only the  5% of actual cases that were reported to the FDA and it could be closer to 10,000 dogs that are affected. It takes time to report a suspected adverse food event and Veterinarians and Caregivers may not realize the value of this reporting. Additionally, many owners may contact the pet food manufacturer if there is a problem rather than the FDA assuming that the information is getting relayed to the government agency.
  2. We don’t know where the problem is coming from. All grain-free diets are being targeted by media outlets and some enthusiastic pet “advocates”, but we don’t know if this is a problem with all grain-free diets (probably not), peas and legumes (maybe, especially at high amounts), and/or questionable formulations and manufacturing processes (probably, yes). When peas are included at relatively low levels in the diet (less than 20% of the total recipe) or as occasional treats they do not appear to cause a problem, but none of the diets from any of the brands on the FDA’s recent list have gone through controlled feeding and digestibility trials to prove that they are safe and healthy for dogs at the level of legume inclusion they use, which can be over 40% of the recipe when all types and portions are added up.
  3. We don’t know if this is an ingredient, dog, or manufacturer problem (or maybe all three). I suspect we will find that peas and potatoes in the hands of experienced formulators and experienced pet food manufacturers and for the majority of dogs are not the problem. The problem will be (like it was in the early 2000s when poorly formulated lamb and rice dog foods were causing DCM in dogs) a failure of certain manufacturers to account for variation in ingredient quality, changes in digestibility with processing, and individual variation in the dog population. Do affected dogs have low taurine production? Do they have increased loss from their gut? Do they have normal production and gut handling, but a low total food intake and are just getting inadequate intake overall? Meeting minimum nutrient levels on paper is not enough. Pet food manufacturers must know or hire knowledgeable individuals with an understanding for how nutrient levels vary in the raw materials, how they are affected by other ingredients or nutrients in the mix, the effect of cooking (or lack of cooking) on nutrient stability and bioavailability, and the wide range of variability in genetics and food intakes in the dog population. Basing diet formulations on market trends rather than nutritional science is a recipe for disaster.
  4. We don’t know if the percentages of the brands reported simply represent their popularity and market share or an underlying problem with these companies.  Maybe the three most frequent brands reported are really no better or worse than the least frequent three brands, they are just better at marketing their diets so more people buy them. I don’t have access to those market insights to know whether this is true or not, but I bet these companies do.

At the end of the day, diet-associated DCM is a preventable condition and manufacturers who are selling foods that are labeled as “complete and balanced” have an ethical and fiduciary obligation to meet that label promise. Having an idea about pet foods, being a dog trainer/breeder/owner, inheriting a family pet-food business, and/or writing a book about dogs and cats (even if it’s about food) does not qualify a person to know what it takes to keep a large population of dogs and cats healthy. No free passes because you didn’t know what you didn’t know, no matter the sincerity, especially if it ends up with disease and death.

And if you are a Veterinarian who is seeing cases of suspected diet-associated DCM or are a Caregiver with a dog or cat who has been diagnosed with suspected diet-associated DCM, please report it by following the link here so we can help the FDA get to the bottom of this problem before more dogs and cats get sick.

 

Dr. Weeth keeping dogs and their hearts healthy!

Happy (and Safe) Feeding,

 

Dr. Weeth

 

Your Pet’s Pancreas and You

Ah, the pancreas… an often overlooked and misunderstood part of the digestive system that only gets noticed by veterinarians and caregivers when it’s not working well.  But the pancreas shouldn’t just get attention when it is inflamed and painful (from Pancreatitis), or not producing enough insulin (from Diabetes Mellitus), it deserves recognition for doing its job well and not causing problems on a day-to-day basis. Today’s post is to familiarize you with the pancreas and (hopefully) give you a few tips to help you keep it happy for years to come.

stock-footage-portrait-of-mature-couple-petting-dog

Happy Pancreas = Happy Dog

Anatomy of the Pancreas

This part gets a bit technical, so bear with me. The pancreas is a glandular organ that sits behind the stomach and extends across the length of the stomach to the upper small intestinal (the duodenum). It connects to the duodenum via the pancreatic duct, which serves at the pathway for release of digestive enzymes and other essential compounds into the intestinal tract. This part of the pancreas’ job is called its exocrine function. This is in addition to the pancreas’ other, probably more familiar role, the production and release of insulin into the blood stream (i.e., its endocrine function). The endocrine pancreas will be covered in my next post on Diabetes Mellitus; I’m not completely ignoring that topic, just pushing off for now.

Pancreatic enzyme release is triggered by the hormone cholecystokinin (CCK) that is secreted from the intestinal cells in response to the intake of certain food components, specifically protein and fat. Both protein and fat will stimulate CCK release, but fat has a much more pronounced effect even at lower intakes. Irrespective of trigger, the secretion of CCK causes the pancreas to contract and squeeze pancreatic enzymes down the pancreatic duct and into the duodenum to begin the breakdown of dietary macronutrients (macronutrients = dietary protein, fat and carbohydrate). There are a few other functions of CCK, such as stimulating contraction of the gall bladder and creating a feedback on the brain to slow food intake, but it’s CCK’s effect on the pancreas that I am focusing on for management (and minimization) of pancreatitis.

knitted digestive tract

Your key digestive organs, without the actual blood and guts

The Exocrine Pancreas

The primary exocrine enzymes produced by the pancreas are trypsin and chymotrypsin (both used for protein digestion), lipase (required for fat digestion), and amylase (essential for starch digestion). These enzymes are produced in their inactive forms, which must be activated by other enzymes in the presence of bicarbonate (also made in the pancreas). For example, trypsin is actually made and stored in the pancreas as trypsinogen. Trypsinogen is packaged into zymogen granules within the pancreas and kept separate from bicarbonate. This isolation of enzymes and activators protects both the integrity of the digestive process and the pancreas itself.  If trypsin becomes activated too early not only will it not get into the duodenum where it is needed for food digestion, but it will start to digest the proteins in the pancreas instead. And this is painful. Very, very painful.

Sparky PN

One of my former patients on IV nutritional support, fluid support and pain meds because of severe pancreatitis.

 

What Causes Inflammation of the Pancreas?

The clinical name for inflammation in the pancreas is pancreatitis (pancreas- = pancreas + -itis = inflammation). Pancreatitis can either be acute (vomiting and pain within hours) or chronic (low smoldering illness with vague signs that can be confused with other medical conditions).

In dogs, one of the most common dietary causes of acute pancreatitis is eating a non-food item (like 2 lb of bird seed) or eating fatty table scraps (either intentionally fed or found by rooting through the garbage). The exact mechanism of pancreatitis isn’t known but it is believed that the higher than normal fat intake causes the rapid increase in circulating blood fats and then “activation” of pancreatic enzymes within the pancreas. Other risk factors for acute pancreatitis include being a miniature Schnauzer or Yorkshire terrier (sorry pups), or any other dog breed that has a genetic predispositions to hypertriglyceridemia (the term for high circulating levels of triglyceride in the blood); being on medication such as potassium bromide and phenobarbital (two common anti-seizure medication); and being more than 20% over your ideal weight (yep, being a fat dog isn’t a cosmetic issue). Chronic pancreatitis in dogs is a bit more challenging to identify as the clinical signs can be vague and are often confused with other chronic medical conditions, because of this chronic pancreatitis is thought to be an under-diagnosed and under-reported condition. One study out of the UK conducted post-mortem evaluations of 200 dogs that had died from a variety of different causes (none of which were reported to be either acute or chronic pancreatitis in the medical records by the way) and found evidence of chronic pancreatitis in one-third of them.

Cats on the other hand like to be different. Genetics, medications, obesity, and high fat meals are not often associated with pancreatitis in cats. Instead stressful events, like introduction of a new animal into the household or having work done at your home, seem to be the more common histories among cats that present to their veterinarian with signs of acute pancreatitis. Many of these cats may also be diagnosed with what veterinarians like to call triaditis, (triad- = three + -itis = inflammation), meaning they are found to have evidence of inflammation in the pancreas (pancreatitis), in the liver (hepatitis), and in the intestinal tract (enteritis) all at the same time. Chronic pancreatitis can also be seen along with diabetes mellitus in cats, though just like with triaditis it often becomes a chicken-or-the-egg game to figure out which came first.

 

What Does Pancreatitis Look Like?

Animals, both dogs and cats, with mild cases of pancreatitis may vomit, refuse food, or seem quieter than usual at home. Dogs and cats with chronic, low-grade pancreatitis may have vague signs such as an intermittently poor appetite and weight loss. Severe pancreatitis can cause not only vomiting, food refusal, and lethargy, but diarrhea, fever, and abdominal pain. Severe pancreatitis, if left untreated, can also result in shock, circulatory collapse, and death. So pancreatitis is basically badness, followed by more and more severe badness if not caught and treated.

P1030573

Signs of pancreatitis aren’t always obvious. 

 

 

What Can We Do About It?

Supportive treatment for dogs and cats with pancreatitis is very similar: IV fluids to keep them hydrated, anti-nausea meds to stop them from vomiting, and pain control (whether they are acting overtly painful or not) will be on the list. Dietary therapy on the other hand is less consistent so here is where I’d like to provide some general guidelines to caregivers, vet techs, and veterinarians when treating dogs and cats with known or suspected pancreatitis.

The two most important features of a diet for an animal with pancreatitis are (in order of important): 1) feeding a diet that is LOWER in fat than what was being fed before and 2) feeding a diet that is MORE digestible than what was fed before. If you don’t know what is causing the GI signs you’re seeing and you have pancreatitis as one of the possible causes on the list, err on the side of caution and just feed a lower fat, more digestible diet. Seems straight forward but I see a lot of confusion in practice about how to translate this to an actual diet so I give you…

 

Dr Weeth’s Dietary Consideration for Feeding Animals with Pancreatitis

dog and food bowl

What is in that bowl is as important as the rest of the medical treatment

  1. Dietary fat is a wonderful thing for healthy animals, except when it’s not. Fat can enhance the palatability of the food (I much prefer half and half in my coffee to skim milk); in the right amounts and with the right fatty acid profile can improve coat glossiness and decrease shedding (and big dogs can shed a lot!); fat also provides more calories per gram than either protein or carbohydrates, so feeding a higher fat diet relative to a moderate or low fat diet will increase energy density, reducing the overall volume of food needed each day; and with this reduction in volume in, so, too, do you see a reduction in the volume of poop coming out. The end result of feeding a higher fat food is often that the dog or cat readily eats their food, has a lovely shiny coat, doesn’t shed very much, and has a low stool volumes. Sounds perfect (and a lot like the reasons people give for feeding raw … hhmmm… maybe it’s not the “raw” part of those diets that is doing anything?…). Perfect unless you are a dog or cat with pancreatitis. When the pancreas is inflamed dietary fat can stimulate CCK release, contraction of the pancreas and release of digestive enzymes… into the pancreas. This promotes continued autodigestion of the pancreas and surrounding tissues, malabsorption of nutrients, and pain. Cats and dogs with abdominal pain can be very stoic, but if you or a human loved one has experienced pancreatitis you know it is not fun. Fat is sometimes your friend, but sometimes your dog or cat’s worst enemy.
  1. Digestibility is important for everyone. In general, over-the-counter (OTC) adult maintenance dog and cats food will be less digestible than the therapeutic intestinal support diets sold by veterinarian. This means that more of the OTC diet you feed (yes, even the “premium” priced ones) becomes poop rather than getting absorbed by your dog or cat. There is some variability in OTC diets and a number of the newer “premium” marketed foods, especially ones that are frozen/freeze-dried raw or fresh pasteurized, can be as digestible as intestinal support diets. BUT, before you think that sounds like a great option for animals with pancreatitis, many OTC diets (especially “premium” marketed foods), will have fat contents that exceed 50% of the calories in the diet. These types of diet would be very harmful for a dog with a history or an active case of pancreatitis. OTC diets marketed as “light” or “lean” will have lower fat contents compared to standard adult maintenance foods, but as the fat dropped in OTC diets, so does the digestibility. What about home-cooked foods you may ask? Some combinations of home-prepared foods, like cottage cheese and white rice or chicken breast and white rice, can be as digestible, if not more digestible, than the therapeutic intestinal support diets, but there is going to be a lot more variability depending on the way they are cooked and specific ingredients selected. Also, many home-prepared diets are rarely balanced for long-term feeding ( and if used should only be fed during the recovery stages of pancreatitis (about 2-3 weeks) before your dog or cat is transitioned to a balanced diet whether it is a commercial diet or you have the home-prepared foods balanced for long-term feeding.
  1. Diet History is key to finding the right diet the first time around. Whenever possible the decision of what to feed and the degree of fat restriction needed should be based on the previous diet intake. This is where diet and treat history are very important. Did your dog (that lovable furry fiend) get into the BBQ remains or a container of bacon grease you’ve been meaning to throw out? In these types of case your dog could have eating a whoppingly high fat intake and as such feeding a moderate fat contenting diet (one that provides between 20-35% fat calories) would be fine. Or did they develop pancreatitis or hyperlipidemia, or both, while eating a diet that was already at 25% fat calories? In this situation, feeding a diet with a similar fat content would not help, and could potentially make them worse. These dogs should be fed a diet that provides less than 20% of the calories from fat. Basically, you want to find out how much fat the dog is eating now and decease it by about half while still staying above the minimum requirement for fat. As I mentioned earlier, cats are a bit different and you want to find a diet that manages whatever concurrent medical conditions your veterinarian finds. Fat triggers and subsequent fat restriction are less important in most cases, but (and I feel like there is always a but) this is not true 100% of the time. I have definitely seen cats in practice that acted more like fat-responsive pancreatitic dogs and needed to fed a highly digestible, fat restricted diet.

 

The optimal long-term diet choice for a dog or cat with pancreatitis will depend on the inciting cause (genetics, medication, hypertriglyceridemia, or high fat intake) and additional medical issues (diabetes mellitus, IBD, etc). Irrespective of underlying cause, dogs with a history of pancreatitis should never be fed diets or treats with more than 45% of the calories coming from fat due to the risk of recurrent pancreatitis.

 

Happy and Healthy Feeding!

 

Lisa P. Weeth, DVM, MRCVS, DACVN

 

Magic Beans? The Wonderful World of Dietary Supplements, Part 2 of 2

If you walk into any pet supply or grocery store you will find an aisle (maybe more) filled with products promising to make your dog or cat smarter, faster, leaner, prettier, more energetic, better smelling, etc. The list of advertised benefits of any given supplement or nutraceutical goes on and on.

 

As you read in Part 1 of this series the supplement industry is heavy on business, but can be light on science and regulation. That doesn’t mean that there isn’t a place for supplements on your kitchen or clinic shelves. Today’s commercial pet foods (even those at the economy price point) provide all of the known essential nutrients your dog or cat needs without anything being added, but there are a few condition where adequate may not the same as optimal.

I’ve put together a list of what I consider to be my Top 5 Dietary Supplements for health and wellness. Not all of them (or maybe any of them) will be right for your dog or cats, but they are worth getting to know a little better.

So without further ado…

Dr. Weeth’s Top 5 Dietary Supplements

IMG_3190

If only we all had a coat that glistened in the sun…

 

1. Essential Fatty Acids (EFAs): A balance of linoleic acid (LA; an 18-carbon length essential omega-6 fatty acid) and alpha-linolenic acid (ALA; an 18-carbon length essential omega-3 fatty acid) is necessary in dogs to maintain the normal water barrier function of skin and to maintain the suppleness of the hair coat.

Dogs that aren’t getting enough of one or both EFAs can have dull, dry, hair coats, with skin flakes (dandruff) and excessive shedding. These are the dogs that seem to shed a whole other dog when you brush them out. Yes, shed happens, but it happens more robustly when your dog isn’t getting the right amounts or ratio of EFAs in the diet.

The specific amounts required by an individual animal will depend on the overall balance of fats and fatty acids in the diet as well as breed differences in coat texture and length, which means that even diets marketed as “complete and balanced” may miss the EFA mark for optimal skin and coat health in a given individual. Supplementing higher levels of ALA has been shown to help improve skin and coat quality in otherwise healthy dogs and may help decrease itchiness in those with allergic or atopic dermatitis.

  • Who would benefit? Otherwise healthy dogs with dry, flaky skin or with excess shedding; dogs with dermatitis caused by an allergic reaction (e., abnormal and excessive immune reactions to food, flea, environmental triggers) or atopy (i.e., abnormal and excessive immune reactions to an unknown trigger).
  • How to get it? Many of the powders, pills, and chew that are marketed to “complete” a commercial diet for dogs and cats are simply dressed up ground flaxseed, a source of the essential omega-3 fatty acid ALA. Corn on the other hand (an oft demonized, but utterly delicious cereal crop) is high in the essential omega-6 fatty acid LA. Adding ground flaxseed doesn’t have magic fairy dust-like properties, it simply balances the LA:ALA ratio in most commercial diets, which supports a healthier skin barrier and allows the shedding fur to slip past each other instead of “felting” and coming out in clumps.
  • Use with caution in dogs with a history of pancreatitis or other fat intolerances (hyperlipidemias or diarrhea). Care should also be taken in animals with suspected or document allergies as many of these flaxseed-based multivitamin/multimineral/fatty acid supplements contain additional proteins that could trigger or exacerbate an allergic response.

 

P1010072

SAMe and the liver, a happy pair.

2. S-Adenosyl-Methionine (SAMe): SAMe is normally made in the liver of all animals. It serves as a precursor to taurine (an amino acid) and glutathione (an antioxidant); supports liver cell regeneration; and helps the liver metabolize a number of different compounds and drugs.  All features that make SAMe an attractive supplement for animals with liver disease when SAMe production is decreased.

Scientific evidence for SAMe’s use in dogs and cats with primary liver disease is largely anecdotal or based on in vitro (cell culture) tests, though SAMe supplementation has been shown to protect the liver from toxic side effects of CCNU (a type of chemotherapy drug) in dogs undergoing cancer treatment and may improve behavioral traits in dogs experiencing age-related declines in cognitive function (old dogs that start to act like old dogs). Similar cancer treatment and geriatric studies have not been published in cats, but SAMe supplementation has been shown to limit the effects of acetaminophen (the active ingredient in the pain reliever Tylenol) toxicity.

 

  • Who would benefit? Dogs with congenital or acquired liver disease; dogs undergoing cancer treatment; older dogs in general; and cats exposed to acetaminophen. Cat with liver disease and geriatric cats may benefit form SAMe supplementation as well, but without published evidence on its use, SAMe for cats falls into the category of “not harmful, possibly helpful” so worth a try if you can give pills to your cat.
  • How to get it? There are a number of commercial SAMe supplements sold for both veterinary and human use and either type may work for your dog or cat. When selecting supplements (marketed for pets or people) it is important to know that SAMe is prone to degradation during manufacturing and storage so capsules and enteric coated pills are better than chewable wafers.
  • Another key consideration when supplementing SAMe is that it undergoes a significant first-pass metabolism with approximately 50% of the ingested SAMe being metabolized by the liver before it can be used as SAMe itself. Additionally, the presence of food in the stomach can decrease absorption of SAMe even further, meaning that SAMe supplements should be given on an empty stomach at least 1 hour before a meal to have maximal absorption.

 

everyone poops

Everybody poops, but maybe probiotics could help them poop better.

3. Probiotics: Probiotics are beneficial bacteria, such as Lactobacillus, Bifidobacter, and Enterococcus, that may help support normal colon cell health and normal gut-associated and whole-body immunity. They do this by inhibit growth of more pathogenic intestinal bacteria strains; enhancing immune function at the level of the gut; and exerting a trophic (growth-like) effect on the intestinal cells themselves.

In otherwise healthy animals, probiotic supplementation may not give your dog or cat perfect poops or make them extract more nutrients from their diet (both marketing claims I’ve seen), but it may help swing the balanced of colonic bacteria away from potentially pathogenic strains such as Clostridia perfringens.

Clostridia overgrowth is associated with acute diarrhea in dogs and cats so theoretically reducing their numbers may have longer-term health benefits. In dogs and cats with acute diarrhea or in dogs with chronic intestinal diseases probiotic supplementation may actually help normalize the colonic bacterial environment (what is called the gut microbiome) and improve clinical signs of soft stool and diarrhea more rapidly than when medical treatments (antibiotics and immune-modifying medications) are given alone. The beneficial effects of probiotics may also extend beyond the gut itself. For example, probiotic supplementation may improve clinical signs of atopic dermatitis in dogs.

 

  • Who would benefit? Dogs and cats experiences chronic or acute diarrhea; dogs with atopic or allergic dermatitis.
  • How to get it? Probiotics marketed for pets or people can be used to provide a source of beneficial intestinal bacteria, though certain veterinarian strains may be more effective in cats and dogs than the human counterparts. There is also variability between product strains and in manufacturing and stabilization processes, so I recommend using a probiotic supplement from a reputable manufacturer.
  • Unfortunately, the amounts of probiotic bacteria found in fermented foods like yogurts and kefirs are relatively low compared to what is found in a supplements capsule or wafer so you are better off with giving a good quality probiotic supplement rather than relying on a daily yogurt treat. It is also important to know that even the best probiotic supplement won’t be enough to correct diarrhea by itself. If your dog or cat is having diarrhea that lasts for more than 24 hours you should seek veterinary care and treatment sooner rather than later. Your pet and your floors will thank you.

 

dog with salmon

This old dog has the right idea.

4. Fish Oils: Fatty fishes like salmon, cod, and menhaden are high in the long-chain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

DHA is incorporated into the fatty insulation of nervous tissue and is essential for normal eye and brain development of puppies. EPA on the other hand isn’t essential in the diet (meaning your dog or cat will survive if fish oils are left out), but in adult animals increased intake of EPA can help decrease production of pro-inflammatory mediators and help manage arthritis pain, atopy, kidney disease, heart disease,  lymphoma treatment, and may help support brain health in older dogs and cats .

  • Who would benefit? Older dogs and cats, especially those with chronic diseases, such as heart or kidney disease, or that are being managed for inflammatory conditions, such as skin or intestinal allergies.
  • How to get it? Fish oils can be given as either a liquid or capsule, but manufacturer quality control is essential. Supplements should be checked to be free of environmental contaminants (e.g. mercury or PCBs) or excess levels of vitamins A and D, which can be toxic to dogs and cats. Product quality and testing should be done by every fish oil manufacturer, so it is worth spending a little time looking into manufacturers before spending your money.
  • Caution should be used when adding fish oil to cat diets as platelet abnormalities and bleeding disorders have been reported in cats receiving high dosages of EPA. Additionally, increased intake of EPA and DHA will increase the requirement for vitamin E in the diet. Without enough vitamin E cats fed high fish oil diet are at risk of developing painful inflammation in their fatty tissues (called pansteatitis).
  • Added Note: Fish oil should not actually smell “fishy”; this odor change occurs when the fatty acids in fish oil begin to break down from improper handling or storage. You should also be forewarned, as the long-chain fatty acids from fish oil are incorporated into every cell in your pet’s body they will eventually be incorporated into skin oils, which will begin to oxidize giving your dog or cat a distinct fishmonger aroma.

 

 

Raider2

Old dogs have old joints. Could supplements keep those joints young?

5. Glucosamine/Chondroitin Sulfate: Synovial joints (ones that allow movement between bones) are composed of cartilage matrix (the proteoglycans hyaluronic acid and glucosaminoglycans -or GAGs for short), collagen, and water. Inflammation in the joint (arthritis = arthr– joint + –itis inflammation) can result in damage to the joint tissues and potential loss of chondrocytes (the cells that line the joint and product the matrix proteins).

 

Oral glucosamine and chondroitin sulfate supplements have been theorized (and marketed) to provide precursors to matrix GAGs and help improve mobility in animals with arthritis, but results of clinical trials on glucosamine and chondroitin sulfate supplements have been mostly disappointing. Lack of efficacy in controlled clinical trials could mean that these supplement just don’t work, or maybe failure of a response is related to the severity of existing damage to the joint and degree of chondrocytes loss rather than complete futility of glucosamine and chondroitin sulfate supplements in all animals.

I wonder if we have been looking at these supplements the wrong way. Maybe oral glucosamine and chondroitin sulfate supplements are more chondroprotective rather than chondroreplacive (I think I just made up a new word), and should be started before damage (or at least significant damage) has occurred. This would be a very difficult to prove or disprove in clinical trials, but since glucosamine and chondroitin sulfate supplements appear to be relatively safe for both dogs and cats, they  fall into the “possible helpful, but not harmful” category.

  • Who would benefit? Canine athletes, feline athletes (if such a creature existed), and possibly every middle age to geriatric dog or cat.
  • How to get it? Veterinary and human glucosamine and chondroitin sulfate supplements are available. Veterinary supplements are often flavored to increased acceptance by dogs and cats, but a number of human supplements products may contain comparable amounts of glucosamine and chondroitin sulfate.
  • Caution should be used if you are considering giving a human supplements as some joint health products may include additional nutrients (like high levels of vitamin D) or herbal mixtures that have not been safety tested in dogs and cats. Occasionally  vomiting has been reported in dogs given glucosamine and chondrointin sulfate supplements, but this appears to be caused by stomach irritation rather than any innate harmful effects of the supplement.

 

The reality of nutrition is that it is not one-size-fits-all. Needs will vary based on breed, life stage, health status, and activity level. Even though commercial pet foods from good quality manufacturers (check out this link to help define “good quality manufacturers”) will provide all of these essential nutrients at levels adequate for survival, what is adequate for day-to-day living in one animal may not be the same as what optimizes health and wellness in another. This is where supplements come in.

And one last note: Supplements should never replace proven medical treatments for your dog or cat, but when added to a balanced diet, regular exercise, and preventative veterinary care, could help keep them feeling good for years to come.

 

Happy Feeding!

Lisa P. Weeth, DVM, MRCVS, DACVN

 

Nutrition and Cancer: What We Can and Can’t Do

In case you were wondering what a typical day in the life of a Veterinary Nutrition Specialists is like, my working days are mostly filled by those with chronic diseases: diabetic cats with kidney disease; dogs with food allergies and pancreatitis; maybe a diabetic dog with food allergies, history of pancreatitis, kidney disease, AND a picky appetite just to make it interesting. But on one particular day a few years back my first appointment of the morning was a little different. The reason for the visit as listed in the medical chart was “questions about preventing cancer” and my soon-to-be patient was a 4 month old Golden Retriever puppy full of happy, healthy, fluffy, puppy cuteness.

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Not an actual picture of my patient, but just as cute.

After introducing myself to the puppy and his people I quickly learned what brought them in seeking cancer prevention advice. Turned out that this particular puppy was the fourth in a series of GoldenS cared for by the owners over the previous 20+ years. The first died at 10 years of age from hemangiosarcoma (an aggressive cancer of blood vessels that usually starts in the spleen and quickly spreads in the body), the second at age 6 from osteosarcoma (an aggressive cancer of the bone that usually starts in one bone and can spread throughout the body), and the third died at 2 years of age from lymphoma (an aggressive cancer of one of the white blood cell families, that can go and do whatever it wants). Their most recent loss was less a year before our appointment, so needless to say, this couple was very concerned about losing this new puppy too soon. They wanted to know if there was anything they could do diet and supplement-wise to prevent cancer from striking another four-legged family member.

 

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Another gratuitous puppy picture.

If any of my readers were wondering that same thing, the short answer was no. There are no proven dietary changes or nutritional supplements that have been definitively shown to prevent cancer in dogs and cats. Cancer is a leading cause of death in dogs and cats with genetics, viruses, environmental toxins, age, and neuter status all having a direct or indirect role in the development of certain types of cancer.

So what do dog and cat caregivers need to know about cancer and possible nutritional prevention/treatments?

#1: What causes cancer?

Cancer results from damage to DNA (the genetic code of every cell) that 1) allows that cell to replicate itself unchecked, 2) to avoid normal housekeeping systems that would otherwise destroy an abnormal cell, 3) to induce new blood vessels growth to supply the cancerous cells with nutrients, and 4) to spread either locally or distantly (or both).

Cancer incidences are higher in certain pure-bred dogs than in mixes; viruses such as feline leukemia virus (FeLV) and transmissible venereal tumors (TVT) can induce cancer development and are acquired by close contact with infected animals; unneutered male dogs can develop testicular tumors just as unneutered females can develop uterine cancer (the risk of these two tumor types is virtually eliminated with neutering); cats and dogs living in households with heavy smokers have an increased risk of oral and nasal cancers due to environmental tobacco exposure. Additionally dogs and cats today are living longer thanks to vaccines, complete and balanced commercial diets, and advances in medical prevention/treatment of other diseases. Essentially, by preventing other potentially fatal diseases we have opened up the playing field for cancer in older aged dogs and cats.

Breed predispositions play an especially important role in cancer occurrence in Golden Retrievers. Goldens are beautiful, smart, dedicated family dogs, steadfast companions, but they are also a breed that has among the highest risk for cancer development at any age. This is one of the primary reasons for the development of Golden Retriever Lifetime Study. This study enrolled 3000 young Goldens and will track the genetics, environment and diet of each individual dog to help identify risk factor and possible prevention strategies for cancer as well as other chronic disease. This is a huge undertaking not only by the researchers, but the family committing their beloved canines and their own time to this study. At the time of my puppy appointment, the Golden Retriever Lifetime Study had not yet been launched and it will be at least a decade, if not longer, before we have any inkling of results.

What can dog and cat caregivers do about these risks? If you are adopting a purebred dog or cat, learn about the breed and what conditions can typically affect that breed. Do your research on any potential breeders as well. Find out what steps (if any) they are taking to screen their breeding pairs for known and potential health problems. Is the breeder tracking disease incidences (including cancer occurrence) in their lines? Once that cat or kitten is in your care, vaccinate for FeLV, if they are considered to be at-risk for this disease. Since FeLV is a “social” virus that required direct contact with an infected cat, indoor only cats in a FeLV-free household don’t typically need annual boosters. But talk to your veterinarian about your individual cat’s risk before stopping any vaccine regime. Canine TVT is a sexually transmitted disease, and both testicular and uterine tumors require intact reproductive tracts so the best way to prevent all of these is by neutering your dog. And if you are a smoker who hasn’t/can’t/doesn’t want to end their habit, at least smoke outside away from your dog or cat.

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Old age happens, but it’s better than the alternative.

 

#2: What about specific foods and cancer risk?

If you are reading my posts, you are interested in canine and feline nutrition and have likely read other websites that claim that “kibble causes cancer” or that there are “cancer causing preservatives in pet food”, but scientific evidence for these claims is very much lacking. These claims are also almost always made by either a distraught pet owner looking for someone to blame for unexpected cancer diagnosis or by a person or business trying to market their own special line of “miracle cure-alls.” Our old Labrador, Maggie, lived 14 ½ years eating primarily dry dog food (with the occasional pizza or bread roll stolen from the counter when we weren’t looking), and ultimately died from a stroke-like event that hit her one morning. My 18-year-old cat Oliver is asleep next to me right now, has eaten dry commercial food his whole life and, other than his arthritis, is the picture of geriatric health; while our 3-year-old cat Cosette had eaten a variety of canned and dry foods over her short life, loved eating cat grass (that I grew myself) every day, and just died from transitional cell carcinoma in her left kidney (a rare cancer in cats, let alone in one so young). I don’t blame Cosette’s once-a-day cat grass habit for her developing cancer nor do I attribute Oliver’s longevity and health to dry food; cancer happens even to good cats and dogs.

But what does the vet literature say? There are some published veterinary studies that have tried to find an association between specific food intakes and cancer risk. One study looked at feline oral squamous cell carcinoma and another looked at thyroid adenomas in cats, but both of these studies relied on owners to report frequency and types of foods given over years to decades prior to the cancer diagnosis. Another study in dogs tried to draw a connection between intake of fresh fruits and vegetables with lowered risk of transitional cell carcinoma in Scottish Terriers. Again, these researches relied on owners to recall types and amount of fresh produce fed over the previous years. Most people can’t recall how much fruit and veg they fed themselves over the last week, let along how much they fed their dogs. I’ve worked with people who can’t even remember the name of the food they use (“it’s the purple bag with black writing”) or live in household with multiple feeders (intentional and unintentional). Recall bias is essentially the over- or under-reporting of foods and lifestyle habits that a responder thinks may be associated with a particular disease state. Recall bias is a significant enough problem in human health studies that nutritional epidemiologists have almost completely abandoned this method of data collection, yet for some reason veterinary researchers still rely on it. Food recall is always faulty in my clients, and they are highly motivated to remember their dog or cats food intake. To date, any veterinary study using only caregiver food recall to draw conclusions about diet and cancer risk in dogs and cats should be taken with a heavy dose of skepticism.

What do cat and dog owners need to know about commercial diets and cancer risk: Improvements in disease prevention, nutritional needs, medical care, and diagnostics mean that today’s cats and dogs are living to ages when accumulated DNA damage can result in cancer. Feed a complete and balanced diet that meets your individual animal and family’s lifestyle needs. If you want to feed a varied diet or a portion of fresh foods on a regular basis, that is no problem, as long as the overall diet still meets your dog or cats nutritional needs, they tolerate it well, and the foods selected are not harmful (no toxic foods like garlic or grapes, and avoid feeding foods that contain Salmonella or Campylobacter).

vegetarian dog

The wild ‘carnivore’ back from the hunt.

 #3: What about the role of obesity in cancer development?

This may be the one area of nutrition and health that could impact disease prevalence. In people, obesity has been shown to increase risk of specific cancers, such as uterine, liver, and post-menopausal breast cancer. These same associations haven’t been seen in dogs or cats, but calorie restriction has been shown to decrease cancer risk in rodent and primate models. The only published prospective (meaning they started with healthy dogs and followed them forward in time) study in dogs to date that looked at lifetime intakes and disease prevalence showed an equal number of cancer occurrences in lean and overweight dogs, but the small sample size (only 48 dogs in total) make this comparison almost meaningless. The results of the Golden Retriever Lifetime Study may give us more insight into this question.

 

What do cat and dog owners need to know about obesity and cancer risk: Lack of scientific data doesn’t mean that there is not an association between obesity and cancer development in companion dogs and cats, it just means that we don’t have a study that could answer this question. Even in the absence of a clear link between obesity and cancer, excess weight is a proven risk factor for other problems in dogs, and cats including joint disease, diabetes, skin disease, breathing difficulties, and at least in dogs has been shown to decrease longevity.

 

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There may be less to love, but you can love them longer.

#4: What about the role of carbohydrates and cancer?

A quick Google search on “carbohydrates and cancer” will give pages of websites claiming to prevent or cure cancer by avoiding carbohydrates, and especially carbohydrates that include GMOs and gluten (the “evil” ingredients du jour). And there is big money in making these kinds of diet claims. Just look at the recent Belle Gibson story. Her fake cancer and food cure story garnered her hundreds of thousands of followers (and dollars), spawned a book, an app, and stories in international magazines, until she was recently exposed as a fraud and a thief.

There is one veterinary study that the anti-carb people like to point to and shout, “See, carbohydrate influence cancer!” It was published in 2000 and looked at response to cancer treatment in dogs with lymphoma fed a low carbohydrate (18% of the calories) diet supplemented with fish oil and arginine. Low carb advocates (including one of the lead authors) have cherry-picked the results of this study to make claims like “dogs with cancer should be fed a low carbohydrate diet” and “carbohydrates feed cancer” (emphasis is mine), yet when you read the entirety of the paper you learn that the control diet (the non-supplemented diet used as a comparison for the supplemented diet) had the exact same carbohydrate content as the study diet, just no fish oil and extra arginine. And the low carb control diet had absolutely no influence on cancer progression relative to expected outcomes. Again, feeding a low carbohydrate diet alone made no difference in disease free interval or survival time in these dogs with lymphoma. Yes, cancer cells utilize blood sugar (glucose) more rapidly than the surrounding normal cells, but this happens whether the individual consumes carbohydrates directly in their diet or if the blood glucose is produced from glycogen (a type of carbohydrate stored in the muscle and liver) or from gluconeogenesis (production of glucose in the liver) from metabolism of fatty acids and amino acids (building blocks of protein). The body of an adult, non-reproducing, non-lactating animal is very good at maintaining blood sugar levels, even when fed a carb-free diet. Additionally, there is not a single veterinary study that has demonstrated that dogs or cats fed low to no carbohydrate diets have less cancer incidence than dog or cats fed moderate to high carbohydrate diets. Not that I am advocating that dogs and cats should be fed lots of starches and simple sugars, I just don’t want people to wave the cancer prevention/treatment flag when touting the “benefit” of a carbohydrate-free diet.

 

What do cat and dog owners need to know about carbohydrates and cancer risk: At this time there is no evidence that a diet with a low (less than 20% of the calories), moderate (20-40% of the calories), or high (greater than 40% of the calories) carbohydrate content has any bearing on cancer development in dogs and cats. There may be other reasons to feed a reduced carbohydrate diet, like management of feline diabetes, and animals with insulin secreting tumors (insulinomas) will often benefit from a reduction in overall carb intake, but like for all conditions the specific diet selected for your dog or cat should encompass their whole health needs.

 

Porkchop and corn

Psst, no one told her she wasn’t supposed to like corn.

 

#5: What about antioxidants for cancer protection?

 

The most common supplements marketed for “cancer prevention” or “cancer treatment” include combinations of antioxidant compounds, such as vitamin C, vitamin E, carotenoids, and selenium. On the surface this may seems to make sense. Antioxidants exist within each cell to balance and prevent the accumulation of reactive oxygen species (ROS) that are formed during normal cellular metabolism. These ROS can have damaging effects on nearby DNA, effects that could potentially end up in cancer development. The balance between formation of ROS and antioxidant capacity of the cell is dependant on dietary intake of antioxidants compounds, as well as the demand on the antioxidant systems through exposure to oxidative damage. So supplementing antioxidants seems like a smart thing, right? Maybe not. In people increased intake of antioxidants may influence cancer development, but not in the way we want. Prospective studies in people have shown that supplementing beta-carotene and vitamin A may increase the risk of lung cancer in smokers; high dosage vitamin E may increase prostate cancer risk; and women (but not men) taking high dosages of vitamins C and E, selenium and zinc, may actually be at an increased risk of skin cancers.  And there are a number of other studies looking at different cancer that have shown no effect (good or bad) of antioxidant supplementation. It is important to note that these studies in people were based on longer term (5-15 year studies) using tens of thousands of individuals. Veterinary medicine hasn’t done anything like this, until the Golden Retriever Lifetime Study and even that would be considered small by human study stanards.  There are no published studies evaluating specific antioxidant supplementation and cancer prevention in dogs and cats, though increased antioxidant intake in older dogs may help protect cognitive ability.

What do cat and dog owners need to know about antioxidants and cancer risk: There is no evidence that increased intake of antioxidants will prevent cancer in dogs and cats, and if anything, the studies in people have demonstrated that megadoses (10-100X normal dietary requirements) of certain antioxidants may actually increase risk of certain cancers. Antioxidants consumed as part of a healthy, balanced diet are fine, as are naturally occurring antioxidants found in fresh fruits and vegetables (non-toxic ones of course). There may also be some benefit to cognitive function with moderate increases in antioxidant intake in middle age to older dogs and cats.

 

food scale

It is all about finding the right balance (and avoiding known risks).

The bottom line…

There are no proven dietary strategies or techniques to prevent cancer development in dogs and cats. Defects in tumor suppressor genes, exposure to environmental toxins, obesity, and chronic inflammation have been proposed as causes of tumor development in people and many of these same mechanisms may occur in dogs and cats. Genetic factors and environmental toxins may not be avoidable or preventable, but avoiding obesity and feeding a complete and balanced (no deficiencies, no excesses) are within every caregiver’s control.

 

 

 

Happy Feeding!

Lisa P. Weeth, DVM, MRCVS, DACVN

 

 

What you see isn’t always what you get: The potential for undeclared ingredients in pet food

As a Veterinary Nutrition Specialist, one of the more common reasons pet owners would seek out my help was to manage suspected or proven food allergies. In my last post I explained the definition for some ingredients that can be used in commercial dog and cat foods, but when it comes to knowing what is actually in that bag or can you may still be guessing. A recent scientific study on undeclared ingredients in commonly available pet foods pointed out that pet owners may be getting more that they wanted in certain over-the-counter (OTC) foods and treats.

The prevalence (that’s statistics-speak for the number of cases identified each year) for true food allergies in dogs and cats is unknown, but veterinarians and caregivers alike are often quick to blame a food allergy when presented with a dog or cat with itchy skin or diarrhea. Sometimes these cases are a true allergy (i.e., a food protein interacts with an immune cell and causes an exaggerated response), while others are the results of inadequate essential fatty acids (skin problems) or poor digestibility of a food +/- a lack of dietary fiber (diarrhea). The only proven way to diagnose a food allergy is with a dietary elimination and challenge trial. This involves making a list of every food protein (plant and animal) that has ever been fed to the patient; finding a diet (commercially- or home-prepared) that does not include those ingredients; feeding that limited ingredient diet exclusively for 8-10 weeks to see resolution of signs (8-10 week is for skin disease, gastrointestinal signs usually clear up much sooner); and then challenging the patient with either the previously fed diet or individual proteins (plant or animal) and watching for recurrence of sign. One of my own dogs, Raider, had an allergy to beef and was a great example to me of what could happen with re-exposure to an offending protein. I knew that within 12 hours of eating even a single piece of drop hamburger (the reality of life with young kids and dogs) his ears would flare-up bright red and he would start to scratch them almost nonstop. Sometimes this would progress to an overt ear infection and other times it would go away on its own after a day or two. Avoidance was the key to management of his allergies.

People with food allergies on the other hand can develop life-threatening and potentially fatal anaphylaxis when exposed to an offending food protein and because of this on January 1, 2006, the Food Allergen Labeling and Consumer Protection Act (FALCPA) went into effect in the US. This required human food manufacturers to list not only the ingredients they intentionally added to a particular food or supplement, but any potential cross-contamination of outside ingredients that could occur during the manufacturing process. This is why you see labels that look ridiculously obvious like this…

egg warning

I should hope that “egg” is included!

But also ones with potentially hidden allergens like this…

allergy warning

That is a whole lot of foods other than “rice” to worry about.

Which brings me back to the study out of Chapman University on undeclared ingredients in pet foods. There are two ways that unlisted ingredient can find their way you’re your pet’s food:

  • #1: The less sinister explanation is that this is simply a side-effect of the manufacturing process. The reality of pet food manufacturing is that one production line will process a number of different foods, potentially for different companies and brands on the same day. These manufacturing facilities do not close down and clean out the equipment between runs of different foods. A cleaning and sterilization process happens at the end of the production day and it would be too expensive, both from the cost of labor and lost production, to do it after every single food or treat run. Which means that if a “lamb and rice” diet follows a “chicken and rice” diet during processing, little bits of residual chicken will end up in the “lamb and rice” food. Additionally, if any powdered protein ingredients (i.e., “meals”) are in the recipe, small amounts of these powders can end up on the equipment. Think about what happens when you bake at home. I don’t know about you, but as careful as I try to be, I always end up with at least a little bit of flour on the counter (and me!). Cross-contamination of ingredients is a very common occurrence in OTC pet foods and treats and is one of the reasons why limited ingredient diets sold exclusively through veterinarians are more expensive. These prescription-only therapeutic diets are made in a way that prevents cross-contamination of other protein sources so that you as the caregiver know exactly what you are feeding.
  • #2: The second reason undeclared ingredients may find their way into your dog or cat’s food is the more nefarious route, intentional (and illegal) substitution of ingredients. This means that the manufacture or raw material provider may have decided to use “Poultry” (a potential combination of chicken and turkey) as a less expensive alternative to individual “Chicken” or “Turkey”; “Chicken” as a less expensive alternative to “Beef”; or “Meat” (a potential combination of beef, pork, lamb, and goat) as a less expensive alternative to individual “Beef”, “Lamb”, or “Venison”. I’m not saying that this happened with any of the foods tested in this study nor that it happens at all in pet food manufacturing, but if I’m being completely cynical I think it would be fairly easy to pass off one non-descript animal protein ingredient for another. “Poultry meal” (a yellowish-tan powder) looks a lot like “turkey meal” (another yellowish-tan powder); “meat” (reddish-brown muscle protein) can look a lot like “venison”, “beef”, or “lamb” (all reddish-brown muscle proteins). When I look at the details of the DNA results in this article I noticed that a few diets that listed “Turkey” as an ingredient also tested positive for chicken and vice-versa; a few with “Beef” as an ingredient also tested positive for pork, lamb, and/or goat; and one that listed “Venison” was found to have no venison at all. Some of these may have been unintentional cross-contamination that occurred during manufacturing, while others (like the absence of venison in a diet that listed venison) may have been a purposeful substitutions. Irrespective of whether these were intentional or not, this study highlighted some of potential gaps in quality control of the OTC pet food supply chain.

For caregivers who are living with dogs and cats with food allergy, having undeclared proteins can lead to unnecessary discomfort and pain for the dog or cat as well as unnecessary medication and visits to the vet’s office. Allergen warning labels are not required on foods and treats for dogs and cats, so if you want to know what is potentially in your dog or cat’s OTC food, you need to look at every single product that particular brand sells and mentally add them to the List of Ingredients. The veterinary therapeutic diets are easier to figure out; what’s on the List is what’s in the food. Every pet food company big or small is trying to make a profit, the challenge is figuring out which ones are also trying to improve dog and cat health and which ones are solely trying to claim a piece of the $20 billion a year prize.

Happy Feeding!

Lisa P. Weeth, DVM, MRCVS, DACVN