Should I get my cat vaccinated?
In the vast majority of cases the answer is yes, around the world there are a number of life-threatening and life-changing diseases which your cat can be protected from with the help of a vaccine. Depending on where you live in the world these vaccines may vary slightly, but they may also help protect you too!
What are vaccines?
Vaccines are a type of medication designed to ‘teach’ the immune system all about different pathogens (disease causing organisms). They cleverly inform the system regarding various types of bacteria and viruses, building recognition regarding their size, shape, and nature. This is so, if encountered in the future, the immune response is faster and better equipped to prevent the animal from becoming sick.
Vaccines typically use either pieces of the pathogen, or a modified version of the bacteria or virus where the dangerous parts have been removed, still allowing the immune system to learn how to recognise them. The immune system then produces memory cells which stay in the blood stream for a long time. However, these do not last forever, which is why vaccines need to be refreshed and is the reason ‘booster’ vaccines are required at set time intervals.
Does my cat need every type of vaccine?
The World Small Animal Veterinary Association (WSAVA) has performed an abundance of research into animal vaccines and has produced a set of guidelines for countries to follow around the world. They classify vaccines as ‘core’ and ‘non-core’ vaccines, with the vaccines included in these categories varying from country to country. The core vaccines are recommended for all animals in every country, and the non-core vaccines are situational so may be recommended by your local veterinarian depending on how frequent certain diseases are in your area. Not all vaccines are required every year either, as some vaccines induce a better immune response than others, with some only needing to be given every third year.
What about adverse effects?
Just like with human vaccines, animals can have adverse reactions to some vaccinations which can range from minor to serious in severity. Severe side effects happen very infrequently, because of this it is widely accepted that the benefits from vaccines outweigh the potentiality of adverse effects. Milder side effects of vaccines can include pain and slight swelling at the injection site and feeling under the weather and more tired for the next few days. Serious side effects, which happen very infrequently (less than 1 in 10,000 cats), can include anaphylactic type reactions and induction of immune mediated issues, however if these occur and are noticed quickly, they can be treated.
Unlike dogs, in very rare circumstances, cats can have a longer-term reaction to any injection which results in a type of cancerous growth called an ‘injection site sarcoma’. Whilst it has not been proven exactly how these arise, it is thought that some types of vaccination may cause this growth to occur. To minimise issues related to this some veterinarians will choose to administer certain vaccines in different areas (e.g., over one of the back legs instead of in the scruff over the back of the neck) to improve treatability of this growth should one arise. It is important that if you notice a swelling in the area of your cat’s vaccination that does not start to reduce in size over 1-2 weeks then you should take your cat back for a re-examination with your veterinarian.
What are the core vaccines for cats?
Across the world the core vaccines recommended for cats include feline parvovirus (or panleukopenia virus), feline herpesvirus-1, feline calicivirus, and in areas of the world where rabies is endemic (found in wild animal populations) it is also considered a core vaccine.
Feline Parvovirus
This is a virus that is closely related to the canine parvovirus, and mainly attacks the intestines and immune system resulting in signs of vomiting, diarrhoea, and lethargy. It is often a virus which causes severe disease and can be life-threatening. It is spread through most bodily fluids, however as one of the main clinical signs is diarrhoea the main spread is through faeces and contamination of the environment. There is no specific treatment for feline parvovirus, so care is mainly focused on supporting your cat through the infection and treating any effects of the virus, such as dehydration and a suppressed immune system.
Feline Herpesvirus-1
This is a virus that causes what we term ‘cat flu’ alongside calicivirus and is extremely contagious. It mainly causes signs of upper respiratory tract infection (sneezing and nasal discharge), fever, lethargy, and problems with the eyes including conjunctivitis, discharge from the eyes and eye ulcers. In cases where major eye ulcers occur cats will sometimes have permanent scarring to the surface of the eye which can lead to problems with vision long term. Cats pick up herpesvirus from direct contact with an infected cat, from the environment an infected cat has been in, or by sharing food and water bowls. Similarly, to herpes viruses in humans (e.g., cold sores), feline herpesvirus-1 can remain latent, and can cause clinical signs during times of stress or illness. There are specific anti-viral treatments for feline herpesvirus-1, however these are not always successful and many other treatments including antibiotics and supportive care (cleaning away discharge, anti-inflammatory medications and nursing) are required to treat these cats.
Feline Calicivirus
This is the second type of virus that results in ‘cat flu’ signs, and like feline herpesvirus is extremely contagious. It causes signs of upper respiratory tract infection (sneezing and nasal discharge), some signs related to the eyes (conjunctivitis and discharge from the eyes), fever, and lethargy, but also causes very painful ulcerations on the tongue and gums, meaning these cats really do not want to eat. Just like feline herpesvirus, calicivirus is also transmitted through direct contact with infected cats and indirect contact through the environment and food and water bowls. There is no specific anti-viral treatment for calicivirus, and so treatment mainly revolves around supportive treatment, pain relief and sometimes antibiotics.
Rabies
Possibly the most well-known virus on this list, rabies virus is found all over the world and mainly works by infecting the neurological system of cats, causing behavioural changes making them extremely aggressive, before leading to depression and paralysis which leads to death. In addition to being lethal in cats, it can also be very dangerous in humans which is why it is such an important vaccination in countries where rabies can be found in wild animals. Rabies is transmitted primarily through the saliva of an infected animal when they bite another animal or person. In people exposed to rabies there are a number of treatment options to prevent rabies causing problems, however we do not have these for cats and usually dogs showing clinical signs of rabies need to be euthanised.
What are the non-core vaccines for cats?
Depending on where you live in the world some of these diseases may be more prevalent, and therefore it may be recommended that you vaccinate your cat against them. The non-core vaccines for cats include feline leukaemia virus, feline immunodeficiency virus, and Chlamydophila felis.
Feline Leukaemia Virus
As suggested by the name, feline leukaemia virus is one that affects the immune system of cats, and can lead to many blood cell disorders, including cancers, and increased susceptibility to other disease because of a weakened immune system. Initially, cats infected with feline leukaemia virus may not show any signs at all, however as infected cats get older and their immune systems weaken, or as cancer develops as a result of the virus, they will begin to show clinical signs. These are often vague or related to infection with illnesses the immune system would normally be able to fight off, and can include loss of appetite, weight loss, picking up infections (of the skin, bladder, nose, and throat), inflammation around the teeth and gums, diarrhoea, and neurological signs. Just like the ‘cat flu’ viruses, feline leukaemia virus is spread through close contact with infected cats and their environments. As with the other diseases on this list, feline leukaemia virus does not have a specific treatment, and when cats start to show clinical signs related to progression of the disease, the only thing that can be done is supportive treatment for these conditions.
Feline Immunodeficiency Virus
There are a lot of similarities between feline immunodeficiency virus (FIV for short) and human immunodeficiency virus (HIV) in both name and how the disease affects the body. FIV lives in, and destroys, the white blood cells in infected cats, initially causing vague signs of a fever, lethargy, and a lack of appetite. Infected cats will usually recover and return to their normal behaviours whilst the virus spreads through the immune system, and when the immune system becomes weakened because of the spread, other clinical signs will become evident. Similarly to feline leukaemia virus, most of the signs will be infections the immune system would normally be able to prevent, including infections of the skin, bladder, nose and throat, and also inflammation in the mouth and of the gums, before lying dormant in the white blood cells and as the disease progresses this results in clinical signs related to a weakened immune system. FIV is spread most commonly by fighting between cats, however friendly close contact does not seem to spread the virus anywhere near as much. In cats we do not have a specific antiviral treatment for FIV as they do for humans, so treatment is focused on preventing and treating infections that the immune system cannot deal with.
Chlamydofila felis
This bacterial infection is specifically targeted to the membranes around the eyes of cats, leading to conjunctivitis and therefore clinical signs of ocular pain (usually seen by cats holding their eyes more closed than usual), ocular discharge, sneezing, and sometimes mild nasal discharge. These signs may only be present in one eye to start with but will very quickly spread to both. Transmission mainly occurs through direct contact with an infected cat, as the bacteria do not survive well in the environment. Fortunately, Chalmydophila felis can be treated with antibiotics, however vaccination is useful in controlling outbreaks, especially when there are large numbers of cats involved.
Conclusion
As you can see, based on the aforementioned list of core vaccines, these are all vaccines against serious conditions with no specific cure and long-term side effects, and the only treatments we have for them involve supporting your cat through the clinical signs caused by these diseases. In these cases, preventing your cat from getting these diseases through vaccination is much safer for them, and much more effective than a treatment that is not able to treat the disease specifically. In the case of the non-core vaccines, it is more dependent on the disease prevalence in your local area, whether your cat goes outdoors, and the recommendations of your local veterinarians.