Most veterinarians would agree that allergies are being diagnosed more frequently in their four legged patients. These conditions make life miserable for dogs and cats, and their constant scratching eventually becomes annoying to their owners too. Who likes to cuddle up on the couch with an itchy, fidgeting companion?

Your dog’s immune system is designed to protect him from bacteria and other invaders, and it does this very well. However, sometimes it gets it wrong and over-reacts to substances that are harmless, such as pollen, or an ingredient in his kibble. The result is an allergic reaction.

The main allergies in our dogs and cats are flea allergy, food allergy and atopy.

Flea Allergy

Virtually all dogs suffer from a flea bite or two, and they are mildly annoying. Allergic dogs have a severe reaction to the flea saliva. They can scratch and bite at their skin until it is red, and they lose their hair. It’s common for a secondary bacterial infection to develop on the traumatized skin, which makes the itch even worse.

Flea allergy usually appears on a dog’s back, tail and down the hind legs. Cats are affected in similar areas, but they may also develop small scabs all over their body. It tends to be worse in summer, when the flea population is higher.

Food Allergy

The most common symptoms of food allergy in our pets are itchy skin, ears and feet.

Dogs and cats that develop a food allergy have been eating the food for at least two years before they become sensitive to it. We can use this to our advantage when we are working out exactly what our pet is reacting to.

Common food allergens include beef, dairy, wheat and corn. These ingredients are found in most commercial brands of dog food, so changing your dog’s kibble isn’t likely to make any difference.

To properly diagnose a food allergy, you need to feed your dog a food they have never eaten before, for at least 8 weeks. Because they haven’t eaten it before, they can’t be allergic to it so during the treatment period, their skin itching should ease. Your veterinarian can help you work out an appropriate diet for your dog.

Atopy

Atopy in pets is a bit like hay fever in us; it is an allergy to dusts and pollens in the environment. Affected dogs will scratch their skin, rub their face on the ground and chew their feet. They may also sneeze and suffer from conjunctivitis and repeated ear infections. Cats also itch all over, and they may pull their hair out as they scratch.

This allergy is usually seasonal, so is worse at certain times of the year when there is more pollen in the air.

A veterinary dermatologist can perform allergy tests to identify what your dog is reacting to. This involves injecting tiny amounts of different substances into his skin, and watching for swelling around the injection site.

Diagnosis and Treatment

Your veterinarian will suspect that your dog has an allergy based on his symptoms, the distribution of his skin irritation and whether it is seasonal. However, to be sure, they may recommend that a skin biopsy be done.

There are three ways of treating allergies in dogs and cats. Firstly, we can prevent our pet coming in contact with the offending substance. In the case of flea allergy, this involves using an effective flea control program to not only kill the fleas on your dog, but to stop them breeding in the environment. With food allergies, a food trial can identify the ingredients your dog is allergic to, and you can then avoid feeding them to him. It is not easy to keep an atopic dog away from pollens, so we need to tackle this allergy in other ways.

The second way of managing allergies is to give your pet medication to stop his immune system reacting to an allergen. Drugs such as corticosteroids and antihistamines are used for this, but they can have side effects. They are also not very effective in the case of food allergies.

The last way of controlling your dog’s allergic symptoms is with desensitizing injections. After allergy testing to identify exactly what is making him itch, injections of tiny amounts of these substances are injected into his body, to encourage his immune system to tolerate it. This should result in a reduction in his symptoms.  These desensitising injections are most useful in cases of atopy and flea allergy.  They can be expensive but they’re usually quite effective.

Your pet needn’t suffer from itchy allergic skin. Your veterinarian will work out a treatment plan that is appropriate for your dog or cat, so you can both enjoy a peaceful snuggle on the couch.

 

Written by Dr. Audrey Harvey © September 1, 2011

Dr. Audrey Harvey is an Australian veterinarian who has looked after dogs and cats for 20 years.