Help with Explaining the Clinical Signs of Allergy in Dogs and Cats to Clients

There are several common clinical signs associated with allergy in dogs or cats, but what is the best practise for veterinary professionals when explaining them to pet owners?

Pet Allergy Week was launched on Monday and over 500 veterinary practices, up and down the country, have signed up to join in the campaign to increase clients’ awareness of the clinical signs of allergies within companion pets, whether it be from environmental factors, food or signs associated with secondary bacterial and yeast infections where a little encouragement is needed to help owners hunt for an underlying cause.

As part of the campaign Avacta Animal Health developed a dog and cat character (named in our BSAVA competition as Fred and Ginger) to help veterinary professionals educate pet owners as to what to look out for if they suspect their pets has an allergy.

A challenge of all professionals is how to explain complex problems to clients in layman’s terms, especially when the diagnostic process and treatment is also far from simple as well as being time consuming and costly. Even if you missed out on signing up to PAW, the following information may come in handy for future consultations with your clients.

When and how?

The first thing pet owners need to consider is when and how the clinical signs occur. Allergic disease in dogs usually first appears between 6 months to 3 years of age. In both species the clinical signs may start seasonally which can give clues to the potential allergens involved, but might then progress to become a year round problem and it is possible for signs to both increase and decrease in severity over time.

Gastrointestinal signs


Gastrointestinal signs associated with food allergens can be allergic (IgE mediated) or could be an intolerance or occur through another non-immune mediated mechanism. Reactions can manifest themselves in many forms from a softening of stools and the excretion of mucus to any of the other listed clinical signs below. It’s worth probing to get as detailed a general and dietary history as possible, as many owners will refer to any GI upset as just diarrhoea or vomiting, which could be easily attributed to many other commonly seen conditions (these do need to be ruled out first).

    • Colitis
    • Gastroenteritis
    • Tenesmus
    • Borborygmi
    • Weight loss
    • Reduced appetite

Ear problems

Ear problems are usually one of several presenting clinical signs when hypersensitivity to an allergen is present, however some dogs present with only recurrent otitis externa. Owners may not think of allergy as a potential cause when all they see are itchy, sore and hot ears or notice certain behavioural changes in their dog such as constantly rubbing their ear on the ground.

Skin problems

Itchy, hot, red skin is often how owners describe their pet especially when secondary infections or ectoparasite infestations are present. However, the itchiness is only the tip of the iceberg. If left untreated, chronic cases can develop alopecia, excoriations, lichenification and hyperpigmentation.

For cats, some of the signs of allergic skin problems are very different to dogs and less predictable so owners may be less likely to make the connection to allergy. Symmetrical alopecia (which can also be caused by stress), lesions on the lips and erosions or ulcerations on the chin or neck (sometimes caused by eosinophilic granulomas) can all be seen.

Paw chewing, over grooming and constant face rubbing are all behaviours of self-trauma also associated with skin problems which can cause secondary damage.

Secondary bacterial and yeast infections

Secondary bacterial and yeast infections, commonly caused by Malassezia and Staphylococci, can cause pyoderma and the variety of skin lesions associated with this (e.g. pustules, papules, and epidermal collarettes). Clients may simply describe this as smelly, spotty or scabby skin.

Respiratory signs in cats

If an owner’s cat is suffering from a persistent cough, wheezing, sneezing or is having difficulty breathing it is worth keeping feline asthma high on the list of differential diagnoses.

Of course, as most of the clinical signs listed above can also be caused by other conditions it should be explained to clients that the alternatives to allergy should be eliminated before allergy testing commences.

Free blood storage

Avacta Animal Health provide a free storage service for blood/serum samples for up to 3 months if other causes need to be ruled out before allergy testing commences. This allows blood to be taken when the animal is most symptomatic before any medication has been given or a food trial is commenced. For further information contact customer services.

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