Allergic Disease in Dogs & Cats

Allergen avoidance

Allergen avoidance can be an effective form of management and should always be attempted. If your pet tests positive for pollen antibodies, allervet® will provide illustrations of the offending plants to help you to identify and attempt to avoid them.

Unfortunately some dogs and cats have antibodies against many grass, weed and tree pollens, these are airborne and cannot be avoided altogether.


When antibodies are detected against environmental allergens, and allergen avoidance is either not possible or does not help, a desensitisation programme called allergen-specific immunotherapy (ASIT) maybe beneficial. This involves injecting modified preperations of the appropriate allergens (identified with the allervet® test) in an attempt to create tolerance, and abolish clinical signs. Boosters are given every 4 weeks to maintain this state of tolerance.

Desensitisation produces a good clinical response in up to 80% of animals. It is an economic way to manage the signs of allergy and often reduces or entirely removes the need to rely on drugs with potentially serious side effects such as corticosteroids.

In cases of FAD your vet will be able to discuss the most appropriate methods of flea control to suit your pet and household.

If antibodies are detected against particular foods it seems sensible to remove these foods from the diet. allervet® food test results can be used to select an appropriate home-made or commercially available diet to use in a dietary trial. Everyone must be committed to helping your pet stay on this special diet. This will mean no chews, snacks, table scraps or sneaking anyone else’s food! If your pet has a problem with foods there ought to be a significant improvement in his condition within 6-8 weeks of starting a dietary trial.

Take the next step…

If you suspect your pet is suffering from an allergy, talk to your vet as soon as possible to discuss investigation, testing and treatment options.

The allervet® service is offered exclusively in the UK by NationWide Laboratories, leaders in veterinary clinical pathology for over 30 years.

Allergic Disease

Many people suffer from allergies such as hayfever, asthma, eczema, rhinitis and conjunctivitis, and are all too familiar with the misery they can cause. Unfortunately similar symptoms frequently develop in dogs and cats.

What causes allergy?

Allergy develops when the body’s immune system over-reacts to common substances in the environment called allergens. Examples include pollens – from grasses, trees and weeds, dust mites, moulds, insects and certain foods.

Allergens enter the body following skin contact, inhalation or ingestion.

When an allergic animal is exposed to an allergen it manufactures a specific class of antibodies known as IgE’s. These antibodies bind to mast cells in the skin, respiratory tract or intestinal tract; following repeated exposure to the allergen the mast cells become activated and release a variety of unpleasant chemicals which are responsible for the signs of allergy.

How can I tell if my pet is suffering from an allergy?

The most common signs (symptoms) of allergic disease are:

  • Scratching
  • Foot licking
  • Facial rubbing
  • Rashes/sores
  • Watery eyes
  • Respiratory disease
  • Vomiting/diarrhoea

What are the most common allergies?

Flea allergic dermatitis

The most common allergy diagnosed in dogs and cats is caused by fleas and known as flea allergic dermatitis (FAD). When a flea bites a cat or a dog it injects saliva into the animal which can trigger an allergic reaction. If an animal is allergic to fleas just one or two bites can result in an enormous amount of discomfort. Fleas are a common problem and it is important to realise that not all pets with fleas will develop FAD. Nevertheless good routine flea control is very important.

Atopic dermatitis

This is a complex condition characterised by long term inflamed and itchy skin. It is an inherited condition in dogs with certain breeds being more at risk, particulary terriers, Retrievers, Boxers and Shar peis. Clinical signs in dogs usually develop between 1-3 years of age and onset is rare beyond the age of 7. Atopy may develop in cats of any age. Initially affected animals present with signs of itch (scratching, licking, rubbing, pulling out hair) with no obvious sores but with time and repeated self trauma lesions will develop. Disease may be seasonal, occurring during the summer months when pollen counts are high, or present all year round for animals allergic to house dust mites, moulds or food. Eventually some seasonally allergic pets display symptoms throughout the year. Animals suffering from atopic dermatitis often develop secondary skin infections.

Cutaneous adverse food reactions (CAFR)

CAFR include food allergy and food intolerance and may cause signs similar to atopic dermatitis or result in gastro-intestinal disease. CAFR can develop at any age, even when the same diet has been fed for many years. If an adverse food reaction is suspected, your vet may recommend a dietary trial. This involves feeding a simple home-made diet, or a hypoallergenic prescription diet, in an attempt to avoid potentially problematic ingredients. Your vet may advise a blood test (see later) to help select the most appropriate diet for a food trial.

How is allergy diagnosed?

Making a diagnosis of allergy is complicated and includes a thorough evaluation of the animals history, physical examination and tests to rule out other potential causes of skin irritation such as fleas, lice, mites, ringworm, bacterial and fungal infection.

If allergy still seems likely your vet may recommend more specific testing.

allervet® is an allergy test designed especially for veterinary use, a small blood sample is all that is required. The test is able to detect antibodies (IgE) against a variety of environmental allergens (pollens, moulds, mites) which are recognised as common causes of allergy in the UK.

If your vet suspects an adverse food reaction an allervet® food test may be helpful before starting a trial diet.

allervet® testing is an important step on the way to helping your pet get better.

Test results are positive – what next?

Identification of the allergens which may be causing your pets problems has two major advantages. It may allow you to avoid those allergens, alternatively the results can be used to make a desensitising vaccine.

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