Ask Elizabeth: May 2012

Q. Dear Elizabeth: I’m hoping that you can help me solve a very frustrating problem. My cat Jessica is a six-year-old Siamese. Her skin has become very dry and flakey, and I think it must be very itchy. She’s constantly scratching at herself, sometimes so roughly that little clumps of her coat fall out. I haven’t taken her to see a veterinarian yet, but a neighbor told me that I should be giving Jessica omega-3 supplements. But omega-3 comes from fish oil, and I think that Jessica is allergic to fish, so I’m afraid to do that. Are there any other sources of omega-3? What other ingredients in her food could be making her so uncomfortable?

A. Based on what you have described, it’s clear to me that you must seek veterinary medical attention for Jessica without delay. How long has this skin problem been going on? Has it been bothering Jessica for the past month or two? Or have you been observing it for a year or more? Timing plays an important role in helping to determine the source of her discomfort!

It’s quite possible  that Jessica is allergic to fish. But this could be a sign that she’s especially sensitive and might be prone to harbor other food allergies, as well. Or she might have concurrent environmental allergies to such irritants as dust mites, molds and mildews. In humans, these allergies tend to manifest themselves in sniffling and sneezing, but in cats and dogs, they are likely to cause itchy skin. It’s also possible that Jessica may have developed an allergy to flea saliva, in which case a single bite from a flea that occurred weeks or months ago can set off a chain reaction leading to these signs.

But perhaps the main reason for having Jessica evaluated is that a skin issue can also be the external manifestation of a serious internal ailment. For instance, middle-aged or older cats that develop an overproduction of thyroid hormone (hyperthyroidism) or a decreased ability to produce or use insulin (diabetes mellitus) will often exhibit the clinical signs that Jessica is showing. Both conditions are treatable, but any delay in addressing them can be very risky.

In my opinion, your neighbor’s recommendation that Jessica be given a daily dose of omega-3 as a dietary supplement does have merit, and your veterinarian is likely to agree. Among other things, this so-called essential fatty acid encourages the maintenance of a cat’s healthy skin and fur. Cats are unable to produce it in sufficient quantity, so it must be obtained either in the food they eat or in daily doses of a dietary supplement. If it turns out that Jessica is indeed allergic to fish — which is a rich source of omega-3 — she may have to be given a specially formulated, vegetable-based type of supplement that does not use fish oil as an ingredient. 

These substances seem to reduce joint inflammation that leads to arthritis and are thought to slow the progression of various cancers. However, I urge you to seek medical attention for Jessica prior to adding any nutritional supplements to her diet. You’ll want to make sure that no systemic illness needs to be addressed first; and if your veterinarian does recommend giving her a daily supplement, you’ll want to discuss which ones, and the proper daily amount.

The veterinarian will begin with a complete physical exam, possibly beginning with baseline bloodwork to rule out any serious systemic disorders. The focus of the exam will then shift to Jessica’s skin, with the veterinarian performing a variety of tests and other procedures aimed toward ruling out parasitic, bacterial or fungal infections and other frequent causes of skin problems. If a food allergy is suspected, you may be asked to prepare a “novel diet,” in which proteins and carbohydrates that Jessica has habitually consumed are totally removed from her daily and are replaced by, for example, chicken or potatoes. For two months or so, Jessica will consume nothing but water and the foods in this novel diet. If her allergic signs eventually disappear, you can conclude that the cause of her skin problems has been one of the foods that you have withdrawn.

At that point, you may be asked to reintroduce the withdrawn foods, one by one, and see what happens. If the allergy signs suddenly recur after she ingests one of these ingredients, there’s a good chance you’ve identified the offending substance. From then on, of course, you’ll be sure never again to include that ingredient in Jessica’s food. Most important, however, is that you take Jessica in for a thorough veterinary exam without delay! Love, Elizabeth