All about pet vaccinations

This week on the Pat Kenny Show, we discussed vaccinations: what are the latest recommendations for pets?

Over the past two hundred years, scientists have created vaccines that have prevented – and, in some cases, eradicated – diseases in humans and animals. Yet if you talk to pet owners online, the question of the need to vaccinate is one that keeps cropping up. People worry that vaccines may even be causing illnesses, and sadly, they sometimes feel that they cannot trust the advice from their vet, because the vet benefits financially from the sale of the vaccine.

There is a danger here that pet owners may stop vaccinating their pets, and if they do, it’s likely that they may well get away with doing this so for a number of years. Vaccines have caused serious illnesses to become rare, so that there may not be an immediate threat to most pets. The problem is that if people choose not to vaccinate, there will be a growing population of unprotected animals that are vulnerable to viral disease when an epidemic does eventually occur.

Vaccination & Measles

It’s useful to compare the situation with measles in humans.

Before the introduction of measles vaccination in the UK in 1968, about half a million people caught measles each year of whom about 100 died. The introduction of the MMR vaccine in 1988 led to a dramatic reduction in measles, with only two human deaths in UK from the disease in the past twenty years.

False claims in the late 1990′s that MMR could cause autism led many parents to refuse to vaccinate their children. Vaccine rates dropped and there are now over to two million young people who remain unvaccinated: they are at risk of the disease.

A few years ago there was a major outbreak of measles in Wales – this would not have happened if people had continued to vaccinate their children.

The last major outbreak in Ireland was in 2000, with over 1600 cases in children, and 3 deaths. The same principles apply to pet vaccination.

There have been similar false claims about dangers associated with vaccinations in the pet world, and as a result, there is a risk of the gradual development of a large unvaccinated population of pets. This would create the potential for an outbreak of one of the nasty viral diseases of pets in a similar way to the human measles situation.

Can adverse reactions happen to vaccines?

It is true that there is a low incidence of adverse reactions to vaccines. Like humans who feel a little under the weather after some vaccines, pets can suffer mild signs of illness as their immune system reacts to the vaccine. This is part of the same immune reaction that causes the body to produce antibodies against the virus, so it’s nothing to worry about. More serious adverse reactions, such as allergic or autoimmune diseases, do happen, but they are exceptionally rare.

Overall, the reported incidence of any type of problem is less than one in five thousand; the risk of a serious reaction is much lower than this.

Are boosters necessary?

The aspect of pet vaccines that seems to worry owners most is the traditional model of “once yearly boosters”. People don’t understand why this is necessary, when in humans, childhood vaccines often confer lifetime immunity. Why do pets need so many vaccines?

The answer to this is complicated: when vaccine regimes were first devised, back in the 1970′s, there was a high mortality rate from diseases like Parvovirus and Distemper. Duration of immunity after vaccines had not been clearly established, and the safest option was the once yearly booster. In recent years, more studies have been done, with many vaccines now promising immunity for three to five years for some diseases after the annual booster at fifteen months of age.

In the face of this changing information about vaccines, the challenge for vets has been to recommend a reduced vaccine schedule while still ensuring that no vulnerable animals slip through the loop. Much as pet owners may appreciate the opportunity to go to the vet less often, if even one animal died of a preventable viral disease, vets would feel that they had failed.

Recent Recommendations

The veterinary profession has tackled this on a global scale, by setting up expert groups, using independent scientists to assess the evidence and to provide guidelines for the vaccination of pets. A simple set of recommendations have now been issued to vets across the world by the World Small Animal Veterinary Association, and these offer the safest approach to pet owners.

Vaccines are now classified as “core” and “non-core”.

Core vaccines include those which all animals need to receive, which means Distemper, Hepatitis and Parvovirus for dogs.

Non-core vaccines are those that are required by only those animals whose geographical location, local environment or lifestyle places them at risk. Examples include Leptospirosis, Kennel Cough and Rabies, although the prevalence of rats in Ireland is so high that many people would regard Leptospirosis as a core vaccine in this country.

The aim of the veterinary profession is to vaccinate every animal with core vaccines and to vaccinate at-risk individuals against non-core vaccines if they are seen to be at risk.

Frequency of Vaccination

The WSAVA guidelines also address the recommended frequency of vaccination: for the main core vaccines, after puppy shots followed by a booster at fifteen months of age, it’s now regarded as safe to repeat the vaccine every three years. If dogs need to be protected against certain other illnesses- including Leptospirosis and Kennel Cough – immunological studies have demonstrated that once yearly vaccines are still needed.

This can all become over-complicated for the average pet owner, which is why it’s still recommended that the safest answer is a once yearly health check by your vet. The vet will review your pet’s health and lifestyle, and will then only give the vaccines which are judged to be necessary.

In Ireland, for most dogs, the recommendation is likely to be a once yearly vaccine against Leptospirosis, with a booster against Distemper, Hepatitis and Parvovirus every three years. Other vaccines, such as Kennel Cough and Rabies, may also need to be given, depending on the dog’s activities.

There is plenty more to discuss on this subject, including widely-disseminated but unproven claims that over-vaccination is the cause of a wide spectrum of illnesses in the dog world. Perhaps that’s for another day?

Questions from listeners:

1) My Chihuahua has put on weight and has stopped wanting to go for walks. I have to leave at home a lot because I work. How can I help her get back to her trim, energetic self? She doesn’t like other people or pets so doggy daycare would be a challenge?

2) Our dog (an Australian Shepherd) has severe social anxiety. We cannot take him to public places i.e. Parks. People playing on a pitch, two or more men walking towards us, children playing set him off. He is also afraid of loud noises. He is 4 years old. We have had him 5 months. He was previously a show dog but unsuitable for breeding because he scored low for elbow displaying. Please help! Trish