The Animal Doctor

DEAR DR. FOX: I have been reading about feeding dogs vegan diets, or vegetarian ones (including no meat, but still eggs and dairy). What is your opinion on this?

I am concerned about the environment and animal welfare, so I am a vegan, and I must say I feel better since I changed my diet. I know vegan diets are wrong for cats, but what about my dogs? -- R.F., Washington, D.C.

DEAR R.F.: Many dogs, especially German shepherds, get pancreatic insufficiency (run out of starch-digesting enzymes) when on a high-grain/starch diet. Some other breeds develop irritable and inflammatory bowel diseases and colitis, along with associated allergies from the secondary leaky gut syndrome.

Dysbiosis -- an unhealthy population of gut bacteria associated with biologically inappropriate diets -- can lead to other health problems that can be rectified by dietary corrections and supplements. Corn and wheat can cause seizures in dogs, and soy causes bloating and indigestion, indicative of food intolerance. A high-fiber diet can lead to constant hunger and malnutrition, while a high-carbohydrate diet can lead to obesity, diabetes, arthritis and other health problems.

Alternative dietary inclusions such as potato, pea flour and lentils (pulses) have been recently linked with dilated cardiomyopathy in dogs. High levels of lectins in these ingredients may interfere with uptake of taurine, which is an added supplement in most manufactured dog and cat foods. Deficiencies in omega-3, DHA and EPA fatty acids, and high levels of omega-6 from corn in vegan and vegetarian diets (for both dogs and people), are also a major concern. These fatty acids are essential for the neurological and visual development of puppies (so pregnant dogs, especially, should not be given vegetarian diets), and may also slow down cognitive decline in aging animals and help sustain cardiac health. Deficiencies can underlie serious skin disorders and inflammatory conditions.

Dogs and cats are often allergic to eggs and dairy products, or have varying degrees of dietary intolerance to them. Adding synthetic supplements to vegan and vegetarian diets in order to correct deficiencies can be problematic, as per recent recalls of dog foods containing excessive, toxic levels of vitamin D. (One recent example:

My ultimate concern is that dogs (and cats) on biologically inappropriate diets may present clinical problems that some veterinarians will address primarily, and possibly exclusively, believing that the animals are being fed an adequate diet. Treating the symptoms and consequences of improper nutrition, rather than addressing the root cause, has happened in many instances -- especially with dogs and cats being fed manufactured pet foods sold by the veterinarians, along with profitable prescription diets.

These concerns and others about many conventional manufactured pet foods with “junk” and hazardous plant and animal ingredients condemned for human consumption are documented in the book that I co-authored with two other veterinarians, “Not Fit for a Dog: The Truth About Manufactured Cat and Dog Foods.” For more details and home-prepared recipes for dogs and cats, visit

DEAR DR. FOX: I was reading this 2014 column of yours, about behavioral changes associated with flea and tick treatments, with great interest:

I have an 18-month-old Lab/golden mix who has shown aggressive behavior after receiving flea and tick medicine. Last year, we used a topical treatment and it totally changed her behavior. I called the vet and asked about this, and they said to wash it off of her and not to use it again. This year, we decided to use an oral medication (Bravecto) from the vet. Now, I read this article and realize that we have really harmed her for three months. She just got her first dose two weeks ago, and the behavior has restarted.

She is such a sweet girl, but right now I fear when other dogs come towards her, as she gets protective and aggressive. She usually loves everyone and everything.

My question: Is there any way to detox her body? -- M.G., West Palm Beach, Florida

DEAR M.G.: Your letter is important, and I am impressed that you found the reference to my earlier article on this issue.

I would like to hear from other readers whose dogs (and cats) have shown behavioral changes after application or oral treatment with insecticides to kill ticks and fleas. I am opposed to the routine preventive use of these drugs for animal health and environmental reasons, as documented on my website ( I also provide an integrative and safer approach to help prevent these and other external insects from infesting companion animals. It is only a matter of time before they evolve drug resistance.

Your dog will naturally detoxify and rid her body of these chemicals, a process you may facilitate by encouraging plenty of water intake with chicken- or beef-bouillon flavored water and a daily (human) dose of vitamin E, vitamin B complex, and milk thistle for seven days. These will support liver function, the main detoxifying organ of the body.

(Send all mail to or to Dr. Michael Fox in care of Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106. The volume of mail received prohibits personal replies, but questions and comments of general interest will be discussed in future columns.

Visit Dr. Fox’s website at

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