How to address the frustrating problem of allergies in dogs and cats

Itchy dog
Megan V. Winslow/Town Crier
Environmental factors like grass can contribute to canine and feline allergy problems.

Few problems can be as frustrating for pet owners – and veterinarians – as allergies.

For dogs and cats, the itchy feeling can cause severe irritation and self-mutilation. Treating allergies can be as simple as an effective flea control. However, in severe cases, gaining complete control of allergies can be elusive and necessitate multiple treatments. They are nearly always a lifelong problem that can be expensive to control.

Generally, if a dog or cat has an allergy to one thing, then to some degree it is allergic to many things. The primary causes for allergies:

• Fleas. Flea allergies are a reaction to flea saliva.

• Environmental factors. Allergies include dust mites, grasses, weeds and trees.

• Food. Such allergies can be due to many different dietary ingredients.

Sorting out which allergy or combination of causes is responsible for a pet’s itchy feeling is best done with a strict, systematic approach.

The location of biting, chewing, rubbing, etc., can be helpful, as well as knowledge of the breed, age and whether it is a seasonal problem. The possibility of mites cannot be overlooked, and at least a cursory evaluation for mites must be done first. Bacterial and malassezial (yeast) infections can mimic allergies and are a frequent complication of the biting and chewing associated with them. These infections must be controlled and kept under control when dealing with allergies.


The easiest allergy to control is an allergic reaction to flea saliva. Even the bite of one flea can cause an allergic reaction. Effective flea control on all dogs and cats in the household will control this allergy. Unfortunately, many products claim to be effective but are not. Consult with your veterinarian.

Environmental (atopy) and food allergy symptoms are similar, and distinguishing between the two can be difficult. In dogs, both can cause rubbing or scratching the face, chewing the paws and recurrent ear infections. While food allergies generally start at less than 1 year of age or older than 5 years, atopy generally starts between 3 and 6 years of age. Atopy can be seasonal, at least at first, while food allergy symptoms are usually year-round. In cats, atopy and food allergies are much less common than flea allergies, and occur with equal frequency and without a unique pattern.

Corticosteroids generally control atopy, but long-term use is associated with undesirable side effects. Newer immune system modulating drugs such as Apoquel (oclacitinib) and Atopica (cyclosporine) also can be effective, with Apoquel generally effective in reducing the itch resulting from atopy and/or food allergies. Both medications also may have long-term side effects, which must be monitored for. For atopic dogs, an injectable monoclonal antibody (Cytopoint) that blocks the protein interleukin-23 – which results in the itch – is highly effective and safe.

Long-term therapy is best done with multiple therapies, including immunotherapy, based on blood or skin allergy testing; antimicrobial therapy, with shampoos and other topical products; and skin barrier therapy, with topical products and essential fatty acid supplementation.

Food allergies are treated by avoiding the offending food allergens. While beef, poultry, chicken and wheat are commonly implicated, the adverse reaction can be to any food or food additive.

There is no accurate blood test for food allergies. To make a definitive diagnosis, one must feed his or her pet a dietary trial for three months, and if improvement is seen, then feed the former diet to see if an adverse response is seen. While a home-prepared diet is best, prescription veterinary diets are easier – but no single one will work in every case. Usually improvement will be seen in four to five weeks, but if no improvement is seen in 12 weeks, then try another; 100% compliance is essential, and this means no treats, table food or flavored medications. All skin infections also need to be eliminated by the end of the trial, as a common complication with any allergy is skin infections.

Allergies are a lifelong problem and tend not to just disappear. When dealing with allergies, a systematic and disciplined approach is key. Trying a little of this or that generally is ineffective and leaves one frustrated and having to start all over again. Patience is needed. While flare-ups will likely occur, allergies can be controlled by a systematic approach and close monitoring by your veterinarian.

Dr. Kenton Taylor is a veterinarian with Miramonte Veterinary Hospital, 1766 Miramonte Ave., Mountain View. For more information, call 962-8338.

election news button

HalloweenCC 100720 crop

Schools »

Read More

Sports »

Read More

People »

Read More

Special Sections »

Special Sections
Read More

Photos of Los Altos

Browse and buy photos