Grass Allergy in Cats

Grasses, like flowers, pollinate during specific times of the year, which is why symptoms of a pollen allergy, often called hay fever, appear during spring and summer months. Pollen particles are the male spores of a flowering plant that are needed for fertilization, and are transported from plant to plant by insects or on the wind. These airborne microscopic grains are often released from unmown grasses, and can be carried for miles, where they can inadvertently be inhaled by your cat. While many grasses can produce pollens that can cause problems for sensitive felines, Bermuda grass pollen seems to be the most common.

A grass allergy in your cat can cause respiratory and skin issues if he is exposed to grass pollen. While generally inhaled, pollen can also come into contact with your cat’s skin. Coughing and nasal discharge, or skin inflammation and severe itching, often termed atopic dermatitis, can be signals that your cat is having an allergic response to grass pollen.

Since the symptoms of a grass allergy coincide with grass pollination, you may only see them for a few weeks at a time. While many of us are most familiar with seasonal allergies causing respiratory issues, many cats can also suffer from severe itching that causes them to groom excessively. This action only irritates the skin more, and can cause rashes and scabs. While any parts of the body can manifest these skin problems, they are most common on the face, ears, and above the eyes, as well as the abdomen, legs and feet. Symptoms include:

• Excessive grooming
• Excessive scratchingRubbing face on objects 
• Scabby skin
• Reddened skin
• Lip ulcers
• Leathery skin
• Skin rashes
• Multiple bumps or scabs on the neck and rear areas
• Skin papules, pustules, or crusts 
• Thinning hair
• Hair loss
• Coughing
• Sneezing
• Wheezing
• Nasal or eye discharge
• Overabundance of hairballs 
• Excessive ear wax production 
• Cracked paw pads

The cause of a grass pollen allergy in your cat is the development of a sensitivity to the pollen by your cat’s immune system. Once sensitized, the immune system overreacts to a repeated exposure to grass pollen by producing an overabundance of antibodies to attack the foreign invaders. These antibodies then release large quantities of the chemical histamine, which causes the symptoms seen in an allergic reaction.

Exposure to grass pollen is most often through the inhalation of the airborne grains. Pollen can also gain access to your cat by being absorbed through the skin or ears.

A diagnosis for a grass pollen allergy can be challenging, as many of the symptoms can be indications of other conditions. Your veterinarian will examine your cat and will likely inquire about his eating habits and diet, history of the symptoms and if they reoccur seasonally, and if there has been exposure to fleas or other animals. A diagnosis can be easier if the symptoms appear during times of grass pollination, then disappear until next season. More often, though, your veterinarian will run tests to rule out other causes and confirm an allergy to grass pollen. 

Tests can include a urinalysis and bloodwork, which can rule out parasites, bacteria or viruses. If a food allergy could be a cause, your veterinarian may recommend putting your cat on a special diet for a set amount of time to see if the symptoms disappear. Skin biopsies may be taken and analyzed. An allergy test may reveal the specific allergen your cat may be sensitive to and can be in the form of a blood or skin test.

While removing grass pollen from your cat’s environment is the best treatment, it may not always be possible. Reducing your cat’s exposure to the allergen may reduce symptoms, and can be as simple as keeping your cat indoors with the windows closed during times of high pollen counts in the air.

Your veterinarian may prescribe certain medications to help your cat by reducing the allergic response mediated by the immune system. These can include corticosteroids which can be quite effective but are not recommended for long term use due to the risk of side effects, such as the development of diabetes. Immunosuppressive drugs like cyclosporine are often used when steroids either do not work or cannot be used, but can also cause side effects involving appetite and bone marrow production. Antihistamines can be administered, but are often ineffective in cats due to their lower levels of histamine containing cells. 

Immunotherapy involves a specially formulated injection that is based on the results of diagnostic allergy testing. These injections target the specific allergens your cat is sensitive to, and over time, can reprogram the response of the immune system when exposed to grass pollen. Given weekly, these injections can continue for many years. 

Other treatments are supportive, and can include adding omega-3 fish oils to the diet. Anti-inflammatory medications, an ear cleaning solution, or a change in your cat’s diet may help chronic ear conditions. Itchy skin can be soothed with medicated or hypoallergenic shampoos. These special baths can also reduce the amount of pollen on your cat’s fur and skin.

Allergies to grass pollen are a lifelong condition, and cannot be cured. However, they can be managed through treatments that may be needed throughout your cat’s life. Your veterinarian may prescribe medications to administer at home, as well as recommend soothing baths with special shampoos to ease your cat’s itchy skin. 

To help prevent an allergic response to grass pollen in your cat, use these simple strategies:

• Mow the grass on your property often to prevent pollination
• Keep your cat indoors, especially during pollen season
• Keep windows closed, and wash windowsills of those left open
• Vacuum often
• Place HEPA filters in air cleaners and filtration systems in your home to catch airborne pollens
• Wipe your cat’s paws after an outdoor excursion