Feline Vaccines

For the first article on canine vaccines, and a discussion of rabies, click here.

Cats are not just small dogs that will agree to relieve themselves on ground-up clay. They have their own medical (among other) quirks, their own diseases, and with the exception of rabies, their own unique vaccination needs. This article discusses those vaccines and the disease they prevent. Rabies vaccination is recommended (and legally required) for cats as well; we discussed that in the prior article on canine vaccines so I won’t repeat myself here.

• Feline Viral Rhinotracheitis (Herpes) and Calicivirus:These are two separate diseases, but they are so similar in how they affect cats that we tend to lump them together. Both primarily cause transient upper respiratory symptoms – sneezing, nasal discharge, lethargy and the like (rhinotracheitis = inflammation of the nose & windpipe). Infection is permanent, and both viruses may flare up temporarily any time the animal is stressed – just like cold sores in people. Herpes commonly causes ulcers on the eyes, while calicivirus more often causes oral ulcers. Both are highly contagious between cats, so it’s no surprise that many cats are infected as kittens. So why vaccinate everyone then? Well, if you don’t have it you don’t want it – and equally important, vaccinating everyone reduces viral spread through the population in the long run.

• Panleukopenia (Feline Parvovirus or Feline Distemper): Yeah, this one has too many names. Here’s the scoop – this is very closely related to canine parvovirus, and typically produces the same sort of disease – vomiting, diarrhea, etc. In kittens it also is very effective at damaging white blood cells, hence “panleukopenia,” which translates to “all white cells decreased.” That’s important because that means their immune system is suppressed and thus they become very likely to get secondary diseases. And, in neonates, the disease may damage the nervous system, resulting in problems similar to canine distemper. So that’s where all the names and confusion come from. Fortunately, a very effective vaccine comes from your veterinarian so your cats hopefully never need to worry about those details.

Non-Core Vaccines

• Feline Leukemia Virus (FeLV): This disease primarily affects white blood cells, potentially turning them cancerous (leukemia). However, the most common effect is a depression of the immune system, leading other illnesses to be more severe and predisposing to secondary infections when sick. It is transmitted via saliva, and cats are most susceptible when young. Thus, an initial series is recommended for all kittens, and adult boosters are recommended for cats that spend time outdoors – potentially exposed to other cats. Since cats may be infected for years before showing signs, testing is also recommended for all cats when young.

• Feline Immunodeficiency Virus (FIV): In many ways similar to FeLV, FIV is basically the feline equivalent of AIDS. It is capable of dramatically depressing the immune system, leading to potentially fatal opportunistic infections. The virus must enter the bloodstream directly, making bite wounds the most common manner of transmission. Vaccinated animals will test positive, meaning there’s no way to differentiate vaccination from a sick animal in the future. Considering the efficacy of FIV vaccines is somewhat questionable, vaccination is recommended only on a case-by-case basis, primarily for outdoor male cats – since guys, as always, are more likely to fight.