An allergy to flea saliva is the most common allergy we see in cats. Cats allergic to fleas groom more than normal and some develop large ulcers on their lips or in their mouths. Some scratch furiously around their head and ears, others develop pimple-like lesions on their rumps and trunks, or red lines on their legs and bellies. Cats are so fastidious with grooming that we frequently find no trace of the fleas.
After a thorough check for other parasites and problems we treat the affected cat, any other pets in the household and the house for fleas before we go on to allergies that are more difficult to treat and diagnose.
As usual cats love to confuse their vets - cats with food or pollen allergies may show all or any of the same signs as flea allergic cats! Food allergies are the least common type of allergy but we prick our ears up if a cat has intermittent vomiting or diarrhoea as well as skin signs.
We prescribe a special low allergy diet if we suspect food allergy. If the signs go away on the diet then we trial different proteins until we find the one the cat is allergic too.
Atopy, which is the proper name for allergies to pollens, dust mites and other inhaled allergens, is more common than food allergy, but more difficult to diagnose and treat.