FELINE ALLERGY

FELINE ASTHMA

Feline asthma is a common inflammatory disease of the lower airway affecting approximately 1-5% of the cat population.¹ The median age of presentation is 4-5 years of age, although it is thought many cats presenting at this time will already have a long-term history of the disease, so the actual age of onset could well be significantly younger.¹ Breeds found to be at an increased risk include: Balinese, Korat, Oriental, Seychellois and Siamese.²

Feline asthma has been defined as “an eosinophilic inflammatory disease affecting the bronchioles and leading to reversible bronchoconstriction and airway remodelling, manifested by acute respiratory distress or chronic coughing and expiratory wheezing, and that may be associated with IgE antibodies to inhaled allergens”.³

Cats with feline asthma present with a range of clinical signs including:

• • Episodic severe respiratory distress on expiration (acute cases)
  • Persistent wheezing (chronic cases)
  • Coughing (sometimes only seen on gentle tracheal palpitation)
  • Vomiting or paroxysmal hacking (may be mistaken for hairballs)

FELINE ATOPIC SKIN SYNDROME (FASS)

Formerly described as feline atopic dermatitis or non-flea non-food-induced hypersensitivity dermatitis, FASS is defined as “an inflammatory and pruritic skin syndrome of cats manifested by a spectrum of reaction patterns, none of which are specific for this syndrome, and that may be associated with IgE antibodies to environmental allergens. Food allergy and flea allergy can both either mimic and/or contribute to this syndrome and their potential role must be assessed before deciding on the therapeutic approach”.³

FASS is estimated to affect up to 10-20% of cats⁴ and generally presents under the age of three,⁵ with a later onset more likely to be attributed to a food allergy. Domestic breeds (all hair lengths) along with the Devon Rex, Abyssinian, Persians, Himalayans and Maine coons are found to be at an increased risk of the condition.^5,6

CLINICAL SIGNS OF FASS

Cats with FASS present with a range of clinical signs which are classically differentiated into four reaction patterns, as detailed below. These patterns may occur alone, or in combination, and can be associated with all pruritic allergic conditions of the feline skin or results from non-allergic conditions including dermatophytosis and staphylococcal infections.

1. Miliary dermatitis
2. Eosinophilic granuloma complex (eosinophilic plaques, eosinophilic granulomas (also termed linear granuloma) or indolent ulcers)
3. Symmetrical (barbered) alopecia
4. Erosions and ulcerations of the head, face and neck

FLEA ALLERGIC DERMATITIS (FAD)

The presence of recurrent dorso-lumbar pruritus with lesion distribution favouring the rump, tail, flanks and dorsum, particularly if seasonal, is highly suggestive of this condition. Flea allergic dermatitis can however, present with any of the four reaction patterns listed above for FASS, including indolent ulcers. Visualisation of fleas or flea faeces can be difficult in very pruritic, overgrooming animals. Trial flea therapy is advised in all cases of suspected allergy, with symptoms usually resolving with diligent flea control.

For more information on feline allergic disease, which incorporates the most recent ICADA guidance, please see our Feline Allergic Disease Overview by Professor Richard E W Halliwell.