Vaccine Reaction
My cat has
developed a small hardened lump in the area where she received her rabies
vaccine two and a half weeks ago. Is this a cause of concern?
Veterinarians see a variety of vaccination reactions in dogs and cats. Fortunately, most are mild and non-consequential. A hard lump, or induration, may occur at the site of injection of any medication, including vaccines. This is the body's reaction to the foreign chemical. The immune system sends in special cells to investigate the invasion. These immunocytes cause the hardening of the skin. For vaccinations, it indicates a good reaction to the vaccine, and optimum protection for the diseases for which the vaccine was intended is expected. Most of these lumps peak in size and hardness in one to two weeks, then gradually reduce and disappear over the following weeks. No treatment is necessary. In the worst case scenarios, the small capillary blood supply to the lump skin may be damaged, and that section of skin may slough.
If the lump is under the skin, becomes increasingly tender and large, an abscess is possible. Pain and size increase should be evaluated after one week from the time of injection.
Your veterinarian would be happy to examine your cat and give you an instant determination of the lump. This is often the best solution, for it provides the immediate answer, and gives the doctor feedback on the injection given.
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