Vaccination and Your Cat

Apr 25, 2017

What are Vaccines?

Vaccines are designed to protect against organisms that cause infectious diseases. Cat vaccines contain viruses that have been killed or altered in some way to make them safe. Vaccines stimulate the body's immune system to form disease fighting cells and antibodies (also known as circulating proteins) to protect against disease. 

Most fully vaccinated animals will be resistant to the disease for which they are immunized. When given to young kittens, protection from their mothers (via antibodies in the milk) interferes with the vaccine, so multiple doses of vaccine need to be given. 

For some diseases, this protection declines until 20 weeks of age, making it important to boost the vaccine every three to four weeks until five months of age. 

Protective response to vaccines can be reduced in any cat with poor health, due to an uncompleted series of boosters, and in animals taking drugs that can suppress the immune system. 

The effectiveness of vaccines is also determined by the particular manufacturer’s formulation and the nature of the particular disease against which the vaccine is designed to protect.

From What Diseases Can Vaccines Protect my Cat?

The veterinary community agrees all cats should be vaccinated against diseases that are widespread, cause serious illness, and/or are highly contagious (termed “core” vaccines). 

Other vaccines may be recommended based on the risk a particular disease poses to an individual cat (non-core vaccines). While many pet owners believe vaccines produce 100 per cent protection in all pets, this is not always true. Some vaccines will protect most pets, but others may only reduce the severity or duration of clinical signs. 

Core Vaccines for Cats

Feline Panleukopenia (Cat flu/cat distemper)
Panleukopenia is a potentially fatal viral disease that causes vomiting, diarrhea, severe dehydration, fever, and sudden death. Kittens born to infected cats may suffer permanent brain damage. Vaccines against panleukopenia provide excellent protection.

Feline Viral Rhinotracheitis (Herpes virus) and Calicivirus
These organisms infect the airways of cats, cause runny eyes and nose, sneezing, mouth ulcers, and sometimes a reduced appetite. Vaccines against these “cold” viruses may help increase resistance to infection and reduce severity of disease.

All mammals including humans are at risk of contracting rabies, which is almost invariably fatal. Rabid pets may display a "dumb" form that is characterized by listlessness, weakness and paralysis, or the "furious" form of rabies characterized by abnormal aggression. In some parts of Canada, where risk is high, vaccination of pets is mandatory.

Non-core Vaccines for Cats

Feline Leukemia Virus 
This virus causes a multitude of disorders from tumours, (including leukemia), to bone marrow suppression, to silent infection, although some infected cats may not show clinical signs for several years. All kittens under one year of age should be vaccinated against feline leukemia virus (FeLV) because they are at greatest risk for infection. Adult cats that go outside or that live with any FeLV-infected cat should be vaccinated.

Frequently Asked Questions

How are Vaccines Given?
Most vaccines are given by injection under the skin. Some vaccines may be administered as drops into the nose.

What Vaccines Does My Cat Need?
Although core vaccines are recommended for all healthy cats, your veterinarian can assist you with selection of vaccines for your cats based on their unique set of risks. Some factors to be considered include the number of cats in the household, exposure to feral cats or wild animals, age and health status, travel, cattery life, and boarding or showing. It is important to re-evaluate vaccination options with your veterinarian should your pet's lifestyle circumstances change.

How Often Should My Cat Receive Vaccination?
Your veterinarian will develop a vaccination protocol suited to your pet. Generally, all cats receive a series of vaccinations as kittens that are completed by four to five months of age, and their first booster is given a year later. Subsequent boosters may be given every year or every three years, depending on the vaccine. 

Regardless of your cat’s infectious disease risk, the Canadian Veterinary Medical Association (CVMA) recommends an annual physical examination and consultation as the cornerstone of preventive care for your cat, with twice yearly examinations for senior cats. More frequent examinations may be needed for cats with special needs or disease conditions. 

Pets age much faster than people in the same amount of time; an annual “check-up” allows your veterinarian to early detection and management of illnesses such as dental disease, diabetes, hyperthyroidism and kidney failure that may develop as your cat ages. Certain breeds may be predisposed to health problems even at an early age. In addition, an annual visit gives you an opportunity to discuss other topics such as behaviour, nutrition, parasite control and home care of your cat.

Are Vaccines Safe?
Although vaccines must undergo safety trials to receive licensing in Canada and are considered very safe, vaccines can still cause reactions in a very small number of pets. 

Most commonly, cats (like kids!) may feel tired, may run a fever for 24 hours after vaccination, and may not eat as well. Treatment is seldom required. In some cats, a small, non-painful lump may form at the site where the vaccine was injected; usually disappearing within four weeks. Again, treatment is usually not needed.  

If a lump persists for three months, grows larger than 2 cm in diameter or continues to grow beyond one month after injection, ask your veterinarian to evaluate it. Injection site sarcomas are very rare, but should be identified early. 

Very rarely, a cat will develop facial itchiness, or a generalized allergic reaction (anaphylaxis), accompanied by vomiting, diarrhea, breathing difficulties, and extremely rarely, collapse. Should any of these occur, contact your veterinarian immediately. Anaphylactic reactions are rarely fatal if treated in a timely fashion. 

Veterinarians agree that appropriate vaccination by far outweighs any rare risks. 

Are There Alternatives to Vaccination?
No. Despite the very occasional risks associated with vaccination, it is widely accepted that vaccination plays an important role in the protection of cats from these serious diseases. However, we know that in rare cases, owners may be unwilling to have their pet vaccinated. 

For some infectious diseases, blood samples can be used to measure antibody levels (titres). Though these tests do not provide evidence of protective immunity, some clinicians use high titre results as an indicator, along with low disease exposure risk that vaccines might be administered at a longer than usual revaccination interval. This can be discussed, and decisions made with the help of your veterinarian. Titres are not recommended for rabies to assess vaccine protection as they are far less reliable, except for those tests used for export. 

What is the Future for Pet Vaccination?
Vaccines will continue to play a very important role in the protection of pets against these significant diseases. New technologies have provided even safer and more effective forms of vaccine protection. In addition, vaccine companies will continue to develop new vaccines for existing or emerging infectious diseases in cats. Current research into duration of immunity and side effects from vaccination helps ensure the very best protection possible for cats in Canada. 

Unvaccinated cats are a risk to the general cat community by serving as a source of infection for other cats, including young kittens. Remember that vaccination doesn’t just protect your cat, it protects vulnerable kittens and cats around too, and in some cases such as with rabies, you and your family. 

April 25, 2017

Dr. Kathleen Cavanagh, Consulting Online Editor, CVMA

Dr. Margie Scherk, Specialist Editor
DVM, DABVP (Feline)

Further reading:
2013 AAFP Feline Vaccination Advisory Panel Report at: http://www.Catvets.Com/Guidelines/Practice-Guidelines/Feline-Vaccination-Guidelines (Accessed April 25, 2017)