Vaccinations for Cats

Vaccinating your adult cat or growing kitten is one of the most important steps you take to prevent disease in your pet.

The American Association of Feline Practitioners (AAFP) and their Advisory Panel on Feline Vaccines developed recommendations for the selection and administration of vaccines for cats.

Feline vaccinations fall into two basic categories, the "core" vaccines, that are recommended for healthy cats, and the “non-core” vaccines, that are recommended for healthy cats at specific risk.

Although feline veterinarians are familiar with both groups of vaccines and how and when they should be administered, it is also important for cat owners to educate themselves about these diseases. Note that administration of vaccines does not guarantee protection against infection, or prevention of disease. Some products are highly protective in a large proportion of the vaccinated cats (rabies, parvovirus), and other vaccines tend to decrease severity of disease rather than prevent infection or disease (ringworm).

Feline Panleukopenia (parvovirus)

Feline panleukopenia (also known as feline distemper) is caused by feline parvovirus. This virus can remain contagious in cages, litter boxes, and bowls for months to years. Cats are infected with this virus after ingesting the virus orally, usually from a surface contaminated with another cat’s stool. Viruses are microscopic and because they can be in the environment long after the cat that shed them is gone, the only way to protect is to vaccinate.

Recently, studies have shown that a canine parvovirus subtype 2b can also be contagious to cats, but the current feline vaccines are fairly effective against this threat. The vaccines available for protection against feline panleukopenia offer excellent long lasting immunity to the virus and can be injected or instilled in the nostrils. Younger cats are more susceptible to infection with this virus, and clinical signs include fever, loss of appetite, vomiting, diarrhea, weakness, low cell counts, and even death. Infection of the fetus during pregnancy can lead to brain malformation (cerebellar hypoplasia). Vaccination (injection, intranasal) is highly recommended for all cats, with kittens receiving a set of boosters, then another one year later, then usually every 3 years.  

Feline Viral Rhinotracheitis (herpesvirus-1) and Feline Calicivirus

Many cases of infectious upper respiratory disease in cats are caused by either feline herpesvirus (the cause of viral rhinotracheitis) or by the calicivirus. These viruses are transmitted from cat to cat by nose-to-nose contact, by sneezing, or via objects such as water or food bowls. Although most cats recover from the infections on their own, there are some cats that develop a chronic form of the disease. These cats have periods where they appear healthy, but during times of stress will develop the sneezing and runny nose and eyes associated with these viruses. Persistently infected cats will also shed the virus for months to years, and therefore can act as a source of infection for other cats.

Unlike the panleukopenia vaccine, the rhinotracheitis and calicivirus vaccines only induce relative protection. Therefore, even vaccinated cats may get a mild respiratory infection. Mild respiratory disease may occur post-vaccination in some cats. It is recommended that all cats be vaccinated against these viruses. Kittens are given a series of boosters, then a booster one year later, then usually every three years. Very young kittens that may be born into a contagious environment (catteries, boarding facilities, or shelters) may be vaccinated earlier than usual.

Rabies

Rabies is mainly transmitted via the bite wounds of infected mammals, and in recent years more cats than dogs have been reported with rabies. Although rare in mice and voles, commonly bats, raccoons, foxes and skunks harbor the virus, with distribution of the virus varying according to the geographic location. Cats can be potential source of infection for humans and there is no treatment available for any species once disease signs have begun. According to the AAFP Vaccine 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 ." Vaccination for indoor cats is also recommended due to the potential for exposure due to a bat or other animal entering the home uninvited, or because Kitty decided to sneak out an open door. Newer formulations are specially formulated (canary-pox virus vector recombinant, no adjuvant) to reduce local reactions, and are licensed for cats at a younger age than the traditional vaccine formulations—they are for annual administration.

Feline Leukemia Virus

The feline leukemia virus commonly transfers between cats via saliva or nasal discharge, or shared food and water dishes. The feline leukemia virus can also be transmitted from a mother cat to her kittens. This virus attacks the immune system and clinical signs include anemia, respiratory and other infections, weight loss, 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 it does not produce full protection against the virus in all cats, the best way to prevent infection is to prevent any exposure to infected cats.

Veterinarians recommend testing for the virus (a quick procedure requiring only a small amount of blood) to identify infected cats. Cats should be tested for feline leukemia infection before their first vaccination, and can be tested at the first visit. A series of boosters is given to kittens at risk, then given a booster one year later, then annually for those at risk. Vaccine can be given by injection or trans-dermally, whereby it is injected into the skin without using a needle.

Chlamydiosis

Chlamydophila felis (formerly Chlamydia) is a bacterium 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 is generally recommended for cats that are in environments where infections associated with clinical disease have been confirmed such as in catteries or shelters. Injectable vaccines are given annually to those at risk after an initial booster of 2 injections.

Feline Infectious Peritonitis (FIP, Coronavirus)

Crowded, multiple cat environments such as large catteries have the highest rate of infections. Virus is transmitted easily where feces contaminate the environment. Not all infected cats get clinical disease but those clinically affected cats (1-5% of those infected) rarely survive even in the face of aggressive treatment. Many studies have been conducted on the FIP intranasal vaccine and evidence is equivocal. Consult with your veterinarian about this vaccine—it is not a core vaccine. If given, two doses are followed by annual vaccination.

Ringworm

Dermatophytosis is caused by a fungus, most frequently Microsporum canis. It is not a worm so the label of ringworm is a bit of a misnomer. Ringworm is a term that derives from the ring shape of the lesions seen in people. Although eliminating the infection from individual cats and households can be accomplished with difficulty, treating multiple cats can be very expensive and difficult. Although a vaccine is available, it is used for cats with ringworm, or for those in an environment where the infection is known to be actively spreading.

Bordetellosis (Bordetella bronchiseptica)

This bacterium can infect the respiratory tract of many animals and can cause fever, discharge from the eyes or nose, sneezing, and coughing / pneumonia. Although most cats are exposed to this bacterium during their lives, up to 1/3 of all cats test positive. Cats in shelters and multiple cat households are most often clinically infected. Carriers are common, and transfer is cat-to-cat. The intranasal cat vaccine is used in circumstances where there is risk of exposure such as entry into multiple cat environments with documented disease.

Giardiasis

Giardia intestinalis (formerly G. lamblia) is a protozoan parasite that attacks the intestinal tract causing a range of clinical signs. The kitten may not develop any signs, or get a gassy bloated belly, and watery to mucousy diarrhea. Cats are usually infected via contaminated water, or from environmental contamination due to feces from infected cats. An injecable vaccine is available which is frequently used to treat cats that have already been infested in order to reduce severity of the illness and reduce shedding. The best method to eliminate the parasite permanently is to treat infected cats with proper medication, limit access to contaminated water, and to carry out thorough hygiene measures.

Feline Immunodeficiency Virus (FIV)

This slow acting virus, commonly referred to as "feline AIDS" causes the immune system to weaken. Affected cats can have many disorders, including oral infections, eye disease, cancer, and bone marrow disease. Feline veterinarians recommend that all cats be tested for FIV before they are introduced to a household. There is no cure, and cats may take years to develop the signs, and then take years to succumb.

The commercial vaccine protects against the B strain which is the most common one in the USA, even though the vaccine contains only strains A and D. Unfortunately, cats that have been vaccinated react to the same commonly used screening tests that infected cats do and this complicates disease management. The decision to vaccinate is far from straightforward, so consult your veterinarian.

It is important that all cat owners develop a good working relationship with a veterinarian whom they trust to discuss their cat’s vaccination schedule. It is recommended that a licensed veterinarian perform all vaccinations. Vaccines from different manufacturers vary considerably and only a veterinarian can direct you to the vaccine that will work best for your cat.

Vaccines must be kept in a strict and precise state of refrigeration for them to be effective, an important aspect that is often overlooked by feed and pet stores selling "over-the-counter" vaccines. More importantly, the site of administration, whether nasal, intra-dermal, intramuscular, or subcutaneous can be best determined by a veterinarian who is aware of the current recommendations.

The AAFP panel "discourages the use of polyvalent (multiple component) vaccines other than those containing combinations of feline panleukopenia virus, feline herpesvirus, and feline calicivirus, exclusively…as the number of antigens in a vaccine increases, so too does the probability of associated adverse events."

Vaccine reactions are rare. According to a recent roundtable report, an animal health company representative shared that systemic reaction rates requiring medical care for the core vaccine (trivalent) runs at 8 reactions in 100,000 doses. That is a very low rate! A journal survey of practitioners reporting notable, though not necessarily serious reactions, published a rate of 12 reactions per 10,000 vaccinations, (for all vaccine types, not just core multivalent injection-type).

Vaccine reactions can occur and range in severity. Mild general lethargy, fever and injection site soreness and swelling are not uncommon and usually disappear in a few days. Sometimes, benign swellings stay a while (granulomas).

Immediate vaccine-induced allergic reactions can also occur. With these types of reactions within minutes to hours, vomiting, diarrhea, facial swelling, severe itchiness, and signs of shock may develop, and must be treated immediately by a veterinarian.

Rarely, a limping syndrome or chronic oral inflammation may follow calicivirus vaccination or natural calici illness.

Tumors, called sarcomas may occur as a long-term complication of vaccination or other injections—see our other article on that subject.

Although vaccine reactions are frightening to the owner, they are rarely serious or life threatening. For cats, the risk of contracting infections is far greater than the risk of a vaccine reaction. The benefit of properly scheduled vaccination programs far outweighs the risk of any vaccine reaction.

Disclaimer: This website is not intended to replace professional consultation, diagnosis, or treatment by a licensed veterinarian. If you require any veterinary related advice, contact your veterinarian promptly. Information at Cathealth.com is exclusively of a general reference nature. Do not disregard veterinary advice or delay treatment as a result of accessing information at this site.