A vaccine allergy may occur when your cat's body rejects one or many of the ingredients contained in a particular vaccine. A vaccine is intended to prevent certain types of infections or diseases by stimulating the immune system using antibodies that resemble that particular infection or disease. This process is intended to "train" the immune system to become aware of, and fight off any later encounter with the same condition. This stimulation of the immune system may cause a reaction, symptoms or side-effects to occur, causing a vaccine allergy diagnosis. Symptoms of vaccine allergy in cats vary depending upon the breed of cat, type of vaccine used and the reaction associated with that particular vaccine.
Mild Vaccine Allergy
Mild symptoms associated with vaccine allergy in cats are the most common and can usually resolve themselves without further treatment. Mild symptoms of vaccine allergy include fever, sluggishness, loss of appetite, or soreness and swelling at the site of the injection. Occasionally, neurological, respiratory or eye disorders will develop.
Moderate Vaccine Allergy
Moderate symptoms may include sneezing, itching, or rapid swelling. One particular moderate side-effect of vaccine allergy in cats is called urticaria, commonly known as hives. Urticaria in cats is a vascular reaction of the skin. Hives will appear, as well as rapid swelling and redness of the lips, eyes and neck. Hives are extremely itchy and this condition should be treated with antihistamines. In more serious cases, steroids may be used for treatment.
Severe Vaccine Allergy
In rare cases, severe symptoms may accompany vaccine allergy in cats. If left untreated, urticaria may progress to anaphylaxis, a more severe reaction to the vaccine. Anaphylaxis is considered life-threatening and is an extreme emergency. Symptoms of anaphylaxis include breathing difficulties, vomiting, diarrhea, rapid drop in blood pressure, seizures, cardiovascular collapse, swelling of the larynx, or death. Steroids and antihistamines will be given, as well as possible oxygen administration and intravenous fluids.
Another rare, but possible severe side-effect of vaccine allergy in cats is sarcoma, a type of aggressive cancer. The most common sign of sarcoma is the discovery of a lump at the site of injection. A biopsy should be performed and aggressive action will be taken if the lump continues to increase in size, persists after a few months, or is larger than 2 centimeters in size. Normal cancer treatments will be performed, including possible amputation of the limb, chemotherapy and/or radiation therapy.
Know Your Cat's Breed
It is important to research any common vaccine allergy side-effects that typically affect your breed of cat. One particular example affects the Ragdoll breed. Ragdoll owners and breeders should be aware that Ragdolls will commonly react adversely to the 4-in-1 distemper vaccine. The 3-in-1 distemper vaccination is recommended for this breed. While vaccinations are important and can prevent countless diseases and infections in your cat, it is also important to be informed to help avoid adverse reactions to vaccine if at all possible.