Your veterinarian will need to conduct a thorough physical exam of your cat in order to accurately diagnose pollen allergies. Since most allergies present with similar symptoms, your vet will need to rule out other potential aggravating environmental, food or toxins they may have come in contact with. It will be important for you to provide your vet with a thorough physical and medical history of your cat. If your cat has recently had any changes in food, bedding or has been exposed to unusual chemicals, this information could help differentiate between allergies to pollen and something else. You should also document the progression of the symptoms, including whether your cat has always suffered from the condition and whether the symptoms improve or worsen at certain times of the year or after certain activities, such as being outside.
Next your vet will want to rule out common conditions that may have similar symptoms. These may include infections or minor colds. Your vet will collect a blood sample which will be sent to a lab to rule out the possibility of any serious systematic sickness. A blood sample can also identify the presence of certain antibodies that are indicative of pollen allergies. Skin allergy tests, similar to those in humans, are also available for cats. In these tests, your cat is injected with a tiny amount of many common types of allergens directly into the skin and then reexamined after several days to determine if any of the substances caused an allergic reaction.
Your vet may also take a small smear from the tissue inside your cat’s nose and mouth. This will allow them to analyze the cells for any inflammatory responses that would indicate allergies. In order to rule out allergies to other substances, your vet may order short term food trials. This will involve modifying your pet’s diet to special prescription foods that contain minimal ingredients in order to test whether food is the potential culprit.