Yes, allergy shots are available for people allergic to cats. Called subcutaneous immunotherapy (SCIT), these injections gradually expose your immune system to cat allergen proteins in increasing doses until your body learns to tolerate them. The treatment typically takes three to five years but can produce lasting relief from sneezing, itchy eyes, congestion, and asthma symptoms triggered by cat dander. Separately, cats themselves can also receive allergy shots for their own environmental allergies.
How Cat Allergy Shots Work
Cat allergy shots retrain your immune system at the cellular level. When you’re allergic to cats, your body mounts an exaggerated inflammatory response to proteins found in cat saliva, skin, and urine. This triggers the release of histamine from mast cells, which causes the familiar symptoms of itching, swelling, and congestion.
Immunotherapy works by shifting your immune response away from this overreaction. Over time, the injections reduce the recruitment of inflammatory cells to your nose, lungs, and eyes. Your body also starts producing blocking antibodies that intercept cat allergens before they can trigger a reaction. The net effect is that your immune system gradually stops treating cat dander as a threat.
What the Treatment Schedule Looks Like
Cat allergy shots follow two phases. During the buildup phase, you receive injections once or twice per week, with each dose containing a slightly higher concentration of cat allergen extract. This phase typically lasts three to six months.
Once you reach your target dose, you move into the maintenance phase. Injections drop to once every two to four weeks and continue for three to five years. Most allergists require you to wait in the office for 20 to 30 minutes after each shot so they can monitor for reactions. Some people choose to continue maintenance injections beyond five years if their symptoms return after stopping.
Which Conditions Allergy Shots Treat
Cat allergy shots are most commonly prescribed for allergic rhinitis (chronic nasal symptoms) and allergic asthma triggered by cat exposure. These are the conditions with the strongest evidence supporting immunotherapy. There is also emerging data suggesting that people with atopic dermatitis, a form of eczema made worse by cat dander, may benefit from the treatment, particularly those with severe skin symptoms who also have respiratory allergies and cannot fully avoid cat exposure.
How Effective They Are
Immunotherapy doesn’t work for everyone. Data from veterinary immunotherapy studies, which use similar principles, suggest roughly half of treated patients have an excellent response, about 25% see moderate improvement, and about 25% don’t respond at all. Human studies of cat-specific immunotherapy show comparable variability. Most people who do respond notice gradual improvement over six to twelve months, though some take longer. The benefit often persists for years after stopping treatment.
Side Effects and Safety
Most side effects are local: redness, swelling, or itching at the injection site. In a study of patients receiving cat allergen immunotherapy, 80% of all adverse reactions were local, and the vast majority of those were mild or moderate. Local reactions were more common during the buildup phase than during maintenance.
Systemic reactions, where symptoms spread beyond the injection site, are uncommon. In the same study, all systemic reactions were mild (limited to hives or nasal symptoms) and resolved without needing to adjust treatment. Severe anaphylaxis is rare but is the reason allergists require that in-office observation period after each injection.
Sublingual Drops as an Alternative
If you don’t want weekly injections, sublingual immunotherapy (SLIT) is an option. This involves placing drops or tablets containing cat allergen extract under your tongue daily at home. The mechanism is essentially the same: gradual exposure that shifts your immune response. SLIT tends to have fewer systemic side effects than shots, though local reactions like mouth itching are common. The trade-off is that some studies suggest SLIT may be slightly less potent than injections for certain allergens, and it requires daily adherence rather than periodic office visits.
What About Allergy Shots for Cats Themselves?
Cats can also receive immunotherapy for their own environmental allergies. Feline atopic skin syndrome, where cats develop itchy, inflamed skin from allergens like dust mites, pollen, or mold, is the primary condition treated. Feline asthma triggered by environmental allergens is another candidate.
Before starting treatment, a veterinary dermatologist needs to identify which allergens are causing the problem. Intradermal skin testing, where small amounts of allergens are injected into the skin and the reaction is measured, is considered the gold standard in cats. Blood tests that measure allergen-specific antibodies are more convenient but less reliable. One study comparing the two methods in cats found that serum testing had a sensitivity of only about 35%, with poor agreement between the two tests across a panel of 34 allergens.
The response rates for cats mirror those in humans and dogs: roughly half respond well, a quarter see partial improvement, and a quarter don’t benefit. Treatment typically involves injections given at home by the owner, starting with a buildup phase and transitioning to maintenance injections every few weeks. Sublingual drops are also available for cats and can be easier for owners who are uncomfortable giving injections. Improvement usually takes several months to become apparent, and most cats need to stay on maintenance therapy long-term.
Cost Considerations
For humans, the cost of allergy shots depends heavily on insurance coverage and how many allergen serums you need. Co-pays of $20 per visit are common, and since some patients require two separate injections per session (to keep certain allergen extracts from degrading each other), costs can reach $40 per visit. Over a full three-year course with weekly visits, that adds up to $3,000 to $6,000 in co-pays alone, not counting the initial allergy testing.
For cats, veterinary immunotherapy typically costs $300 to $600 per year for the serum and injections, though the initial allergy testing (particularly intradermal testing with a dermatologist) can run $300 to $700. Since cats often need lifelong maintenance, these costs are ongoing.