Feline Vaccinations

Feline viral rhinotracheitis and feline calicivirus: Most infectious upper respiratory disease in cats is caused by either feline herpesvirus (the cause of viral rhinotracheitis) or by the calicivirus. These viruses are transmitted from cat to cat through nose-to-nose contact or by fomites (objects such as water or food bowls). Although most cats recover from the infection on their own, similar to humans with the common cold, there are some cats that can develop a chronic form of the disease. These cats can have periods where they appear healthy, but during times of stress will develop the sneezing and runny nose and eyes associated with this virus. Persistently infected cats will also shed the virus for months to year, and therefore can act as a source of infection for other cats. Vaccines against these viruses come in intranasal, conjunctival (applied to the eye), and injectable forms. Unlike the panleukopenia vaccine, the rhinotracheitis and calicivirus vaccines only induce relative, not complete, protection. Therefore, even vaccinated cats may get a mild respiratory infection. It is recommended that all cats be vaccinated against these viruses, usually at 12 weeks of age with the injectable form. A booster should be given in 2-4 weeks (3-4 weeks is ideal) then again in one year, then every three years. Very young kittens that may be born into a contagious environment (catteries, boarding facilities, or shelters) can be vaccinated at younger than 12 weeks with the conjunctival vaccine. However, these vaccines produce more side effects than the injectable form and should be used with caution.

Rabies: Rabies is mainly transmitted through the bite wounds of infected mammals. Although rare in rodents such as mice and voles, there can be large populations of infected bats and skunks and other animals depending on the geographic location. Although cats are relatively resistant to rabies, they can be potential source of infection for humans and there is no treatment available. According to the AAFP Advisory Panel "rabies virus vaccination is highly recommended for all cats, and is required by law in some states and municipalities; products approved for use every year or every 3 years are available. Statutes governing the administration of rabies virus vaccines vary considerably throughout the United States; veterinarians should comply with the legal requirements of their area." Vaccination for indoor cats is also recommended due to the potential for exposure from a bat or other animal that has entered the house. Also the cat could possibly get out of the house.

Feline Leukemia virus infection: The feline leukemia virus can infect cats by saliva or nasal discharge, biting, or sharing food and water dishes. Unlike other viruses, the feline leukemia virus can also be transmitted from a mother cat to her kittens while they are still in the uterus or in the milk while they are nursing. This virus attacks the immune system and clinical signs are most often anemia, secondary respiratory infections, weight loss, lethargy, anorexia, cancer, and even death. Kittens under 16 weeks of age and cats living in households or catteries with infected cats are the most susceptible to this virus. Vaccination against feline leukemia is recommended for cats at risk of exposure (those who go outdoors or are living with an infected or potentially infective cat). Because not all vaccines produce total protection against the virus in all cats, the best way to prevent infection is to prevent exposure to infected cats. Most veterinarians recommend testing for the virus (a quick 10 minute procedure requiring a small amount of blood) to identify any infected cats. Cats should be tested for feline leukemia infection before initial vaccination and can be tested as early as 6 weeks. There are some potentially serious side effects from the leukemia vaccine that need to be taken into consideration when deciding to vaccinate a cat. Adverse effects from vaccination can include local swelling or pain, transient lethargy or fever, post-vaccination granuloma formation (a gathering of inflammatory cells that cause a benign lump), and most seriously, vaccine associated sarcomas. A sarcoma is a type of a mass that is comprised of cancerous cells. Sarcomas can spread from the site of the injection down into surrounding connective tissue, muscle, and bone. Even with chemotherapy, radiation, and surgical removal some cats have died from vaccine-associated sarcomas. Although sarcomas have been reported from vaccines other than the feline leukemia virus (rabies is thought to be associated with possible sarcoma formation), current scientific research links sarcoma formation most often with feline leukemia vaccination. It is important to realize that incidents of sarcomas are very rare, and seem to be from vaccines that were mostly administered in previous years before the use of the current, more refined vaccines. For most cats, the risk contacting the virus is far greater than the risk of a vaccine reaction. It is recommended that cats receive the first vaccination at 8-12 weeks, a booster in 2-4 weeks (3-4 weeks is ideal), and a booster one year later then every 3 years after that.

Chlamydiosis: Chlamydia psittaci is a bacteria that can infect the eye membranes and respiratory tract of cats. Treatment with an appropriate antibiotic is usually curative. Cats that are vaccinated are not protected from infection, but will get less severe clinical signs. The vaccine itself can cause lethargy, depression, anorexia, and fever, and is there fore only recommended for cats that are in environments where infections associated with clinical disease have been confirmed.

Feline infectious peritonitis: Feline infectious peritonitis, or FIP, is a disease caused by the feline coronavirus. Crowded, multiple cat environments have the highest rate of infections where the virus is passed from the feces of one cat to the mouth of another. Affected cats rarely survive even in the face of aggressive treatment. Many studies have been conducted on the vaccine currently available for FIP. At this time, the vaccine is not recommended due to the lack of evidence that the vaccine induces protection from the virus.