The Animal Doctor by Dr. Michael W. Fox

Anti-Flea Treatments Raising Environmental Concerns

DEAR READERS: The use of flea-control insecticides on pets needs closer examination, considering the recent discovery of some of insecticides in water sources. Widely used anti-flea topical insecticides, including fipronil and imidacloprid, have been found in wastewater (from bathing pets) and in rivers and streams (from allowing treated dogs into the water) in both the U.K. and the U.S. Both the British and American Veterinary Medical Associations (I am a member of both) have reported these concerns in their professional journals.

These insecticides are highly toxic to aquatic invertebrates and pollinators in parts-per-trillion concentrations, and the toxic degradates have half-lives of up to several hundred days. The U.S. Environmental Protection Agency needs to take action.

Dog owners and groomers bathing dogs, and hunters allowing dogs to enter freshwater ecosystems, should not do so if these animals have been given topical insecticides or are wearing repellant insecticide collars. In addition, the feces of dogs given oral insecticides and antiparasitic drugs should always be picked up and disposed of with other household waste.

DEAR DR. FOX: We have a small 6-year-old dog who was vomiting a lot. Our veterinarian said he was allergic to either chicken or beef, so we changed his food to lamb and duck. It was mostly kibble and a bit of canned food. He still had allergies, but wasn’t vomiting anymore, so the vet put him on Apoquel.

As time went on, his allergies got worse and our vet had us switch to venison (still kibble and some wet food). He still has allergies; he licks his one paw continuously. He is still on the Apoquel.

We are using Hill’s Science Diet now. The fresh food you recommended is all chicken recipes. I would love to get him off the meds, but have no idea what to feed him. -- J.M., Naples, Florida

DEAR J.M.: I have expressed my concerns over many veterinarians prescribing the immune system-suppressing drug Apoquel on my website (

In my opinion, it is no remedy for your dog’s apparent food allergy. There are so many additives and byproducts in many manufactured dog foods, including the costly (and generally unpalatable) prescription diets, that could cause digestive problems and the so-called “leaky gut” syndrome and irritable bowel disease. Apoquel could make things worse.

Try my home-prepared diet (posted on my website) and vary the main protein every three to five days. This “rotational” diet will enable you to identify which major protein/animal product is causing problems. It is quite likely that transitioning to a home-prepared diet with known ingredients could resolve his various health issues.

There may be other environmental allergens affecting your dog, so I would give him 1 teaspoon of local bee pollen daily with his food.

Do keep me posted as to your dog’s progress, and stop the Apoquel. If he is on any anti-flea insecticides, which could cause sickness, discontinue them. Visit to find a veterinarian in your area who can offer a more holistic approach to your dog’s health and well-being.


About 1 in 10 adults in the U.S. between 50 and 80 years old adopted a pet between March 2020 and the end of the year, according to researchers at the University of Michigan. As of January 2021, pet ownership was 12 points higher than in 2019 among people in that age group who live alone, according to the National Poll on Healthy Aging. (Full story: HealthDay News, March 24)

It is my hope that when the COVID-19 pandemic subsides, and families spend less time at home, that the shelters will not fill up with dogs who suffer from separation anxiety. Such animals may house-soil, bark and howl, disturbing neighbors and destroying things in the home. There are ways to prevent these problems, and all dog owners should consult with their veterinarians and animal behaviorist referrals.

(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.

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