Canine Cancer Nutrition

Rin getting chemoI have 2 Bernese Mountain Dogs.  I was devastated when one of our dogs, Rin (pictured getting a chemo treatment), was diagnosed with cancer (lymphoma).  A cancer diagnosis is devastating.  Various thoughts flood our mind when we hear these words.  My thoughts were flooded with why, how, what can be done, I don’t want him to die…I cried often.  I opted for chemotherapy.  Rin was only 4 and I felt he had a lot more life in him.  I was right.  I was told with chemo there was a 2 year life expectancy.  Today Rin is going on 3 years cancer free.

In my work with human patients there doesn’t seem to be any rhyme or reason why we get cancer.  Some patients are young, some old, some have lived healthy lives and some should have paid more attention to their health and diet.  There is a genetic component to cancer that we can’t do anything about to reduce the risk.

Besides the treatments offered by the veterinarian, there may be a nutritional aspect which can enhance your dog’s quality of life and possibly survival time.  The recommendations below are generalizations.  Further nutrition consultation should be sought for your dog’s individualized needs.

Most nutritional advice is based on human studies which may or may not be applicable for your dog.  Human nutrition has been highly researched considering the variability of our diet.  It has been shown that certain dietary regimens may decrease cancer risk in humans.  Unlike humans, beloved dogs are fed a more balanced diet.  Human studies also show a correlation with obesity and some cancers.  There is a lack of clinical data to show the same correlation in dogs.  From my functional nutrition training, it is estimated that 95% of human cancers can be prevented with nutrition.

The focus of dietary treatment should be on providing food that is highly digestible and provides sufficient calories, especially with weight loss (anorexia or cachexia).  Without adequate calorie intake the body breaks down skeletal muscle (cachexia) to meet the body’s metabolic needs.  Choosing diets high in fat and protein and low in carbohydrate may be helpful.  As a guideline:  35% protein and ≥25% fat (on a dry matter basis).

Many premium dry and canned products or specialty foods for active or stressed dogs fit these guidelines.  There are also some specialty foods for dogs living with cancer.  They generally have higher quality and quantity of protein and fat compared to maintenance diets.  Be aware that canned food is about 70-75% water (as fed).  With water removed the percentage of nutrients will be lower, e.g.  ≥12% protein and ≥10% fat. Adequate vitamins and minerals are present in most dog foods so there is no need to provide more.

Despite our best efforts, weight loss may still occur even when we provide adequate calories.  With anorexia and cachexia palatability is very important.  Some dogs find moist food more palatable.  These soft foods are also easier to swallow and ideal if swallowing is an issue.

Up to 2% of dietary protein can be provided as arginine (an amino acid which are building blocks of protein).  Arginine may slow tumor progression.  Be careful as more is not better.  Other protein/amino acids have not been significantly studied in dogs, unlike human studies, so the addition of other amino acids is not recommended.

Omega 3 fatty acid is an anti-inflammatory fat and can increase survival times and reduce cancer growth.  The balance of omega-3 fatty acid to omega-6 fatty acid is very important.  Premium foods are supplemented with omega 3 fatty acids to achieve a balance of omega 3 to omega 6.  This balance is imperative to proper functioning and adding more omega 6 fatty acids is not recommended.

During treatment (chemo or radiation) the use of antioxidants may be contraindicated and a survival advantage to the cancer cell.  Fish oil (source of omega 3 fatty acid) and arginine are unlikely to be detrimental.  Fish oil may result in better radiation recovery and less inflammation to surrounding tissue and promote cell death of cancer cells.

Fibre is beneficial for the health of the digestive tract and possibly prevention of colon cancer.  During cancer treatments it may be beneficial if GI symptoms are severe.  However, fibre does increase fullness so if your dog has trouble eating enough calories a lower fibre diet may be more beneficial.

Be cautious of using diets found on the internet designed for canine cancer patients.  They are more often grossly imbalanced in vitamins and minerals.  For example, raw meat diets are usually nutritionally unbalance and reduced nutrient balance can increase the incidence of cancer.  Focus on providing complete and balanced meals to ensure the supply of vitamins and minerals for your dog.

Protein in Dog Food

Protein is one of the most important components of dog foods.  The quality of protein sources can vary greatly and not all protein sources are used by the body to the same degree.  When purchasing a dog food, the first 3 ingredients should be from animal sources.  This is a characteristic of a high quality pet food.

What are the animal sources of protein?

Protein can come from the meat (poultry, beef, fish, lamb, duck, and rabbit), meat by-product, meat meal, and meat by-product meal.  Meat by-products and meat by-product meals are less expensive and less digestible than meat or meat meal. Below is an explanation of the animal protein sources.

Meat includes the clean combination of flesh, skin, nerve and blood vessels, overlying fat, and possibly bone.  There are no feathers, heads, feet, or entrails.  Meat has a high water and fat content.  This may place meat as the first ingredient on the ingredient list as ingredients are listed in descending order according to weight…water and fat increases the weight of the meat.  But this would contributes little to protein and may even be a more substantial source of fat in the food, which increases palatability.

By-products are secondary products and includes clean parts not used in human food such as bone, lungs, spleen, liver, ligaments, blood, fat trimmings, stomach, intestines, head, and feet. Nutritional quality varies.  Hands and feet, if included, are lower in nutritional value but the nutrient rich intestines or organs may compensate for this.  Super-premium, natural and organic varieties do not usually use by-products in their foods.

Meal is a common ingredient in dry foods.  It is produced by rendering the meat…the process that separates fat and removes water.  Bacteria, viruses, and parasites are killed by high temperatures.  Then the meat is ground or reduced in particle size.  For example, chicken meal is the dry, ground, whole chicken exclusive of head, feet, entrails, and feathers.  Bone may or may not be included.  When meat meal is included in foods they are high on the ingredient list because of the low moisture and fat content.

By-product meal is the same process of producing meal from meat except by-products are used instead.

Is Gluten Free A Healthy Option?

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Eating gluten-free (GF) has been one of the biggest diet fads over the past couple of years.  Books with catchy titles, writings by otherwise legitimate experts and celebrity endorsements give the impression that GF diets improve health.  Since many people humanize their dog it’s no wonder that we also humanize their nutritional needs or want our dog to eat the same type of diet we eat.  Commercial dog food companies play into this.  But are GF diets for our dogs necessary?

Gluten is found in wheat, barley, rye, spelt and some varieties of oats.  In dogs with celiac disease or gluten sensitivities, the body reacts negatively to the protein component of gluten, prolamine.  Wheat, the major source of gluten in the diet, contains the prolamine gliadin.  In dog food, gluten is added to increase the protein and carbohydrates content.  For dog treats, the gummy texture of gluten helps bind the ingredients and keep it from falling apart.

Celiac disease, an autoimmune disorder, causes inflammation and damages the villi of the small intestine preventing uptake of certain vitamins, minerals, and eventually other nutrients such as carbohydrates and fat the longer the disease remains untreated.

Less is known about non-celiac gluten sensitivities, which is not an autoimmune disorder.  In people, the symptoms are similar to those with celiac disease and may be more prevalent than celiac disease.  The exact prevalence of celiac disease in dogs is unknown. There is no breed, sex or age predilection, although some breeds are commonly affected.

Symptoms associated with gluten sensitivity include weight loss, diarrhea, vomiting, excessive gas and poor appetite.  A dog could also exhibit allergy symptoms such as itchiness and dermatitis.

A reliable diagnosis can only be made by removing gluten from the diet with a subsequent challenge trial.  The dog will be diagnosed with celiac disease if symptoms improve.  If symptoms don’t improve either the dog wasn’t on the diet long enough (it could take several weeks or longer to see an improvement), there could be extensive inflammatory changes/atrophy (steroids may be needed), or the dog doesn’t have celiac disease.

Refraining from gluten helps heal intestinal damage.  Treatment involves following a GF diet for the rest of the dog’s life.  Specialty food can be provided by the veterinarian or the owner will need to read food labels to ensure food and treats do not contain gluten.

Be wary of breeders, pet store owners, and trainers who try to convince you that gluten needs to be eliminated from the dog’s diet.  This is based on marketing at the expense of what we know scientifically to be best for our dogs.  Eliminating gluten, carbohydrate, or any category of food without medical justification may put the dog’s health at risk and potentially set the dog up for nutrient deficiencies.  Avoiding gluten doesn’t necessarily improve health if there are no symptoms of celiac disease or gluten sensitivities.

GF doesn’t mean grain free.  Keep carbohydrates in the diet.  Look for source such as rice instead of gluten containing carbohydrates.  Many brands are now using potato and even other less common healthy grain sources like barley, tapioca, millet, quinoa, and even garbanzo beans.

Dogs and their owners fight the battle of the bulge

untitledOver the past decade, the waistline of most Canadians has increased – dramatically.  Man’s best friend is following suit.  The number of overweight dogs is increasing and most dog owners are unaware of the problem.  They view their overweight dog as being a normal weight.  A recent survey of 1000 veterinarians says that 45% of the dogs in their care are overweight or obese.

Dogs gain weight for the same reasons humans do – too many calories and too little exercise.  Pet owners can unknowingly over feed their dogs by as much as 25% more calories a day.  Many owners don’t know how much they should feed their dog and if they do they don’t measure the amount they provide.  In such a case a measuring cup is a valuable tool.  However, treats take most of the blame for excess calories.  Approximately 90% of dog owners give their pets treats.  Experts say treats should account for no more than 10% of the dogs’ total calories.  Give a dog an extra chew or cookie a day and at 50 calories each this can add up to a weight gain of 1-2 lb a year.  For comparison, a pig ear given to a 40 lb dog is like humans drinking six 12oz colas and giving a 10 lb dog a small dog bone is like feeding them 2 donuts.  Rarely do we stop with one treat.  Treats are usually given out of guilt, for example when we’ve left our dog home alone all day.  In the dog world, they would rather have more interaction and attention than a treat.

Pet obesity is a big health threat and will reduce life expectancy.  The risks of excess weight include pancreatitis, cancer, arthritis, high blood pressure, diabetes, hip dysplagia, heart disease, kidney disease and respiratory disease.  As well, modern day treats are rewiring the dogs’ behavioural responses and creating cravings that are beyond what’s normal in many pets.  Attending to your dogs’ weight issue will help them live longer and decrease pain and suffering.  When fed a calorie restricted diet a medium sized dog could increase their life expectancy by 2.5 years.  An added benefit is a decreased vet bill.

To improve your dogs’ diet, reduce calories, especially calories from treats.  If you give treats to your dog look for ones without omega-6 fatty acids (such as vegetable and corn oil) as they increase risk of inflammation and disease.  To increase the nutritive quality of a dog’s diet, buy dog foods with meat listed witin the first few ingredients, containing 75% insoluble and 25% soluble fibre.  A prebiotic added to pet food can improve gut health although more research is needed as to appropriate amounts.

Don’t forget exercise, since it is also important for weight loss in dogs.  Since overweight pets are less mobile and less willing to play, you will need to start slow.  A good activity is swimming.  A 20 minute swim is the same as a 5-km hike without the stress on the hips and knees.

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