The most common sign that your cat is suffering from an allergy can be itching of the skin, with or without hair loss and either localized (one area) or generalized (all over your cat). Often your cat will display "hyperesthesia" highly sensitive skin . Scabby crusts and bumps can develop into open sores if left untreated. Your cat may also show signs of coughing, sneezing, and/or wheezing. Severely affected cats can have asthma attacks.
Sometimes, there may be an associated nasal or ocular (eye) discharge. Some cats have vomiting or diarrhea. Cats that have noticeable hair loss, especially at the tail base may have a flea bite allergy. Food allergy often shows up as severe itching at the face, rashes around the anus and inconsistent stool quality.
The treatment required for a cat's allergies will depend upon the type of allergy and the causative agents responsible for the hypersensitivity reactions. For example, contact allergies generally only require preventing exposure to the antigen. Similarly, in the case of food allergies, removing the triggering food from the cat's diet will often be enough to solve the problem. However, with respect to environmental antigens, treatment may be more complex. Diagnostic testing is not reliable and costly.
Since there is no actual cure for allergies, reducing exposure and managing the symptoms are the main goals of treatment. In the case of environmental antigens, it can be difficult to reduce exposure sufficiently to prevent the occurrence of troubling symptoms. For instance, if the triggering antigen is airborne pollen, it's practically impossible to completely eliminate exposure. However, certain actions such as using an air filter, keeping windows closed, and rinsing your pet's feet when it comes in from outside can help to reduce the impact of environmental antigens.
There are also several forms of medical treatment available whose primary aim is to reduce allergy symptoms. In some cases, allergy shots may be used but have a very low benefit. To be safe, consult one of our veterinarian for guidance.