could food be the culprit of your pet's itching?
Cutaneous adverse reactions to food (CARF) is the new way of saying “food allergy.” In simplest terms, CARF refers to the condition experienced by some pets that eat something and begin itching. Along with the sparkly new name, I thought I’d share the current thoughts and typical treatment of food allergies, er, CARF, in pets.
For starters, we still don’t know exactly how many pets suffer from CARF. The latest estimates guess 1% to 6% of all veterinary skin cases are due to CARF. About 10% to 49% of all pets diagnosed with “allergies” have food to blame. In the past, we used age of onset to help determine if food was to blame for a pet’s itchiness. We now understand that CARF should be considered as a cause of itching at any age.
CARF can occur in any gender or breed, too. While it’s true certain breeds such as Labs, Cocker Spaniels, Golden Retrievers, Soft-Coated Wheaten Terriers, Dalmatians, West Highland Whites, Collies, Shar-Peis, Lhasa Apsos, Springer Spaniels and Miniature Schnauzers appear to have more CARF than other breeds, the latest research has not found a direct genetic link or cause.
Symptoms of CARF
Most pets with CARF scratch around their face, ears, stomach and legs. In my experience, any cat itching around the head and neck should be considered to have CARF until proven otherwise. Pets with CARF often viciously chew and claw until their skin looks like someone blowtorched and then raked over it with a fork. (I’m only exaggerating a little.)
Pets that itch year-round are more likely to have CARF. These pets may see spikes in skin issues during warmer months, but even when it’s cold outside, they agonize from itching. If I see a patient with “allergies” more than twice a year, CARF goes to the top of my list of probable causes. Another hint that CARF is guilty is that traditional steroid treatment doesn’t relieve the reaction and redness or the symptoms quickly return. CARF patients also often fail to improve with antihistamines, cyclosporine and fish oils.
Making the diagnosis
CARF can only be diagnosed by conducting an eight- to 12-week, single-protein, limited-ingredient diet trial. If the patient fails to get better within eight weeks, CARF is innocent. If partial improvement is seen, go an additional four weeks before acquittal. Even if a patient improves only 30% to 40%, I’ll advise the owner to feed a limited antigen diet forever. If a patient improves during the trial, we return to the original food and note what happens. When the itching usually worsens, that confirms diet as the perpetrator.
Most pets with CARF will do best on a homemade or special limited-ingredient diet. Pet food choices continue to expand, and it seems a new therapeutic diet is introduced every few months. I’m amazed at how much happier my CARF patients are when fed the proper diet for their body. Even CARF pets with seasonal allergies (atopy) suffer less in the spring and fall when their diet is controlled. If you find your pet has frequent bouts of allergies year-round, be sure to ask your vet about CARF.