Vaccines for Cats (part 2)

Giardiasis (Giardia)

This protozoan single-celled parasite of the gut was formerly called Giardia lamblia, but now is termed Giardia intestinalis or duodenalis. Bloating, diarrhea, gas and putrid feces of soft, mucoid or watery, gassy and sometimes bloody composition may occur, or affected cats may be normal. Kittens tend to develop the most pronounced signs. Sometimes still termed “beaver fever”, traditionally the source of infection was waterways. Now, some water supplies are contaminated so even the urban cat can become infected. Vaccines do not prevent infection generally, but do produce a protective effect against more serious disease and reduce cyst shedding, which is important for environmental control. Medications can frequently cure the cat, but elimination of exposure to sources of contamination is the only sure-fire way to permanently clear the cat.

Ringworm (Dermatophytosis)

This condition is usually caused by Microsporum canis in cats. Many cats are carriers of this fungus (it’s not a worm)—they contaminate the environment with very resistant spores which can then infect other cats. Named for the bullet-like “ring” lesion produced in people, dermatophytosis in the feline is often not visible, especially in longhaired cats. Culture is necessary to diagnose ringworm. The vaccine is sometimes used in catteries or shelter environments where the diagnosis of active ringworm has been made. A vaccine is available in the US but not in Canada at the present time. The vaccine reduces clinical signs and is a non-core vaccine. Control of ringworm may require significant household treatments, in addition to individual cat treatments.

Bordetellosis

This is a respiratory condition caused by the bacterium Bordetella bronchiseptica, and in cats can lead to many signs. Cough, nasal discharge, pneumonia, eye discharge, fever and lethargy may be seen. It can be transmitted from dogs with a kennel cough due to Bordetellosis. About 30-50% of cats test positive for the bacterium, but only a small percentage go on to develop disease. Transmission via cat-to-cat contact, nasal discharge, or aerosols is the most likely means of transfer. Cats in contact with affected cats in shelters, multi-cat environments, feral cats, and travelling cats are good candidates for vaccination.

FIV (Feline AIDS, Feline Immunodeficiency Virus)

Cats are often affected with FIV if they are bitten by an infected cat. Other modes of transmission also occur. This virus is related to the human AIDS virus (HIV) but cross infection between species does not apparently occur. Cats with FIV experience a slow drop in immune system function, so that they develop chronic infections of all sorts. Dental disease, skin disease, and many other general health problems may ensue. Many cats do not show signs of illness until very late in the disease process, or never. This means that cats may live a full life, or develop problems over the course of years. As with human AIDS there is no cure so preventing exposure to infected cats is the best measure. The vaccine is a supportive effort. If a cat goes outdoors and is fighting, or in close contact with cats of uncertain FIV status, this is a really helpful measure, but not fully protective against disease!

Knowing the FIV status of cats is really important since it can help your veterinarian manage the cat’s health problems much more effectively. The FIV-positive kitties require longer treatment and more aggressive treatment of infections for example, due to their immune system dysfunction. Unfortunately, vaccination interferes with the testing kits used to diagnose cats with this condition, so your veterinarian will need to decide what to do when assessing risk versus benefit for this vaccine.

How are vaccines given?

Most vaccines are given by injection, either under the skin or into the muscle. Some vaccines may be administered as drops into the nostril.

What vaccines does my cat need?

Although some vaccines (core vaccines) are recommended for all cats, your veterinarian can assist you in selecting vaccines for your pet based on the unique set of risks faced by your cat. Some factors to be considered include the number of pets in the household, exposure to pets or wild animals out- of-doors, age and health status of your cat, and travel and kenneling considerations.

It is important to re-evaluate vaccination options with your veterinarian should your pet's circumstances change.

How often should my cat receive vaccination?

Your veterinarian can assist you in developing a vaccination protocol suitable for your cat depending on the vaccines he/she deems necessary. Generally, all cats receive a series of vaccinations as kittens that are completed by 6 months of age, and their first booster is given a year later. How long vaccination immunity will last in cats is highly variable between the different diseases and vaccines, and is subject to intense research and debate in the veterinary community at this time and current protocols may change with time. It appears that customization of the protocol is needed for each and every cat.

No matter what vaccination protocol is followed, the Canadian Veterinary Medical Association (CVMA) recommends an annual physical examination as the basis for preventive care for your cat, and twice a year examination for the senior cat. Cats age much faster than people in the same amount of time; a regular check up allows your veterinarian to detect and manage illnesses, such as dental disease, diabetes, heart problems 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 care of your pet.

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 small number of pets. Most commonly, cats will feel tired, may run a fever for 24 to 48 hours after vaccination, and may not eat. In some cats, a small, non-painful lump may form at the site where the vaccine was injected; usually disappearing 4 weeks later. Rarely, a cat will develop facial swelling or a severe allergic reaction (anaphylaxis), accompanied by vomiting, diarrhea, breathing difficulties and collapse. Intense facial itchiness may also occur. Anaphylactic reactions are rarely fatal if treated immediately and appropriately.

There is some limited evidence that vaccines may be implicated in some immune-mediated disorders in dogs and cats. Vaccines are probably only one of many causes for these disorders, which are still uncommon.

What are vaccine-associated sarcomas?

Since 1991, researchers and veterinarians have discovered life-threatening tumours forming at previous vaccine and medication injection sites in cats. Estimated to occur in 1 in 10,000 cats, these tumours were originally thought to have been most commonly attributed to rabies and feline leukemia vaccines. More recent data supports a general inflammation in the area of any injection and genetic susceptibility as factors favoring tumour formation. New investigations are currently looking at preventing this unfortunate reaction. Newer vaccines are formulated to reduce inflammation. Recent vaccine recommendations suggest splitting vaccines so different vaccines are not administered at the same injection site and only those required by animal risk be administered. Any persistent lump developing in or under the skin of your cat following a vaccination or other injection should be examined by your veterinarian.

Are there alternatives to vaccination?

NO.
Despite the occasional risks associated with vaccination, it is universally accepted that vaccination plays an important role in protecting pets. However, some owners may be disinclined to have their pet vaccinated frequently. For some repeat vaccines, blood samples can measure antibody titres. Though these may not always provide solid evidence of immunity, some clinicians use them as an indicator, along with low risk, that vaccines may be administered at a longer than annual revaccination interval. At this time, not all laboratories are standardized to allow accurate interpretation of results, nor can immunity to all diseases be tested this way. Community health does require vaccination as a strategy to control disease outbreak.

What is the future for pet vaccination?

Vaccines will continue to play a very important role in protecting pets from important diseases. Vaccine companies will continue to develop new technologies to provide safer and more effective forms of protection and new vaccines for existing or emerging infectious diseases in pets. Current research into duration of immunity and side effects from vaccination will assist in developing the very best protection possible for cats in Canad