Food allergies can have severe consequences.

Safira

Safira is a delightful 2 year old female neutered Bengal who originally came to Vet HQ to check a wound on her face. Safira had previously been on a premium commercial dry food and had recently changed to a home prepared meal with human grade tuna, beef and chicken, yoghurt and cheese.

The original wound on the face was approximately 2cm by 2cm just to the side of the right eye and extending up towards the ear. There was also evidence of self trauma from her scratching at her face with the hind legs – as claw marks were seen in the wound.

Food allergies in cats present slightly differently to dogs – in that most of the itch is localized to the face and neck regions. Often it can start as a minor itch, then be accompanied by hair loss and subsequent skin infection.

Safira went home with a recipe for a home-prepared meal which was mainly chicken based in the hope that if it were preservatives in the food, that the itch would start to resolve. However, she was back in a week’s time as the infection had taken over the right side of her face and the wound was much larger than initially seen.

At this point the lesion was as below (figure 1), and the self trauma was very evident with deep scratch marks (3 parallel lines through the centre of the lesion). The infection in the skin was also affecting the right eye as there was inflammation of the conjunctiva and she was not opening the eye completely.

There are four main categories that allergies fall into:

• Food allergy – commonly linked in with atopy. The usual suspects are chicken and beef as they are present in most commercial foods.
• Atopy (environmental pollens and allergens such as grass, mould, dust mites and can be likened to hayfever in people)
• Flea allergy – more localized to the lower back and tail base regions.
• Contact allergy – commonly seen on the feet and especially in the interdigital spaces.

To rule out food allergy, animals usually go onto what we call an elimination diet – which is either one of the premium diets (Hills Science z/d low allergen which is made with hydrolysed proteins; or Waltham response FP which is a fish and potato diet). The other option is to prepare the meals at home yourself – with ONE novel protein (so a protein source your animal hasn’t been exposed to previously such as kangaroo, fish or rabbit) to make 1/3 of the diet, and 2/3 of a carbohydrate (usually pumpkin, sweet potato or potato). Food trials are conducted for a minimum of 6 weeks with no additional treats unless they are of the protein source they are been trialed on and with NO preservatives. At the end of 6 weeks, animals are reintroduced to their previous food stuffs and we monitor to see if their symptoms reappear or whether they remain stable.

Food allergies on their own are not particularly common, but elimination diets are always one of the stepping stones in allergic animals who are candidates for the intradermal skin testing in diagnosing Atopy or environmental allergies.

Due to the infection of the wound on the face, Safira was started on a course of antibiotics (an injectable antibiotic Convenia was given which lasts for 14 days), and she was also started on prednisolone tablets which is a corticosteroid. Corticosteroids are usually avoided but in cases where the lesions are so intensely itchy, they help to alleviate the itch and disrupt the cycle of self trauma and subsequent infection.
The wound was cleaned with an antibacterial wash and an Elizabethan collar was applied to stop her self-traumatizing herself.
As the scratches she had made were so deep there was also a risk that the entire area could become necrotic (where the flesh loses circulation and begins to slough). Safira came back daily for a few days to clean the wound and ensure that it was starting to heal.

After a few days, we could see that the wound was starting to heal slowly. We also started applying duoderm, which can act in 2 ways – either absorbing the excess moisture from wounds or release moisture to aid healing. The duoderm worked fantastically in this case to absorb the excess moisture and the wound started to contract so that it was much smaller in size and a scab was forming in the central region.

Figure 3 shows the face after 3 weeks of treatment – she had another injection of the antibiotic at the 2-week mark, as although it was starting to clear, it still had some pus-like discharge around the edges and skin infections generally take 3-6 weeks to clear.

The skin looks much improved at the 3-week stage but the real test will be when the corticosteroid is finished, and whether the low allergen food will be enough to control her allergies. There is always a risk that she may become even itchier after the cortisone is finished, and that she may require long term treatment – with either antihistamines, cortisone, or immunosuppressive medications.