Potential side effects of the canine rabies vaccination

Here in the UK, rabies is considered to have been eradicated, meaning that we are one of just a few countries in the world where rabies does not pose a risk to our pets. However, rabies is still present and prevalent in many other countries of the world, including in parts of Europe, which can pose a problem for dogs that are going on holiday with you outside of the UK, or that need to be brought into the UK from further afield.

In order to permit the free transport of dogs in and out of the UK without the need for long periods of quarantine, dogs (and other animals including cats and ferrets) can be awarded a special pet passport, which allows them to travel freely into and out of the UK, with some caveats. One of the conditions of issue for a pet passport is that your dog be vaccinated against rabies, and that they have regular boosters and in some cases, blood tests before your pet can travel.

Due to this, a significant number of dogs in the UK now receive the rabies vaccine as part of preparations to go abroad, although this vaccine is part of the pet passport scheme and is not one of the standard vaccines given to all dogs. If you are considering taking your pet abroad and so, having them vaccinated against rabies, it is of course important to find out about the vaccine in more detail, how it works, and the potential side effects that it may have on your dog. Read on to learn more.

How the rabies vaccine works

The rabies vaccine is classed as an immunising agent, which involves injecting a deactivated strain of the virus into the pet, which in turn prompts the dog’s immune system to produce antibodies to the virus, thereby protecting them against later contracting an active strain of the disease.

Potential side effects of vaccination

There is no chance at all of your dog catching rabies from the vaccine itself, as the vaccine uses a dead or deactivated strain of the virus. However, in rare cases, injection can lead to an allergic reaction called anaphylaxis, which generates a range of almost immediate issues including shock, breathing difficulties and an irregular heart rate. In order to counteract this effect, epinephrine, a form of adrenalin, must be administered to the dog ASAP.

Generally, for the few dogs who will prove to have a severe reaction to the vaccine, they will become symptomatic within just a few minutes of injection, and will always show a reaction within a day of the injection.

Potential symptoms that you might notice at home include vomiting and diarrhoea, shock, elevated heart rate, a weak pulse, and respiratory distress, all of which will require urgent veterinary attention. Some dogs may have a mild, localised allergic reaction to the shot at the site of the injection, without any other problems, but this will generally go away on its own.

Long term risks

While the benefits of administering the rabies vaccine to dogs that need it far outweigh the potential risks, the rabies vaccine is one that does pose a higher risk of long term complications than most other vaccines, and so unless you are planning to take your dog abroad or have another good reason for needing the vaccine, it should not simply be given to UK dogs as standard.

In rare cases, side effects can take anything from a few days up to several months to become apparent, and so it is important to keep an eye on your dog’s health and condition in order to quickly identify any potential problems.

Some of the more serious potential long term side effects of the vaccine that present in a very small number of dogs include:

• Tumour formation at the site of the injection.
• Epilepsy or other seizure disorders.
• Digestive problems.
• Muscle weakness.
• Autoimmune conditions and a weakened immune system.

In some cases, a rabies reaction can manifest as a behavioural problem too, so keep a special eye out for issues such as sudden onset aggression, and speak to your vet if you have any concerns.

Preparing in advance

If you are confident that your dog needs the rabies vaccine and that their chances of reacting badly to the vaccine are low, it is still wise to plan ahead for the vaccine, remaining aware of potential problems.

• If your dog has ever had a reaction to another vaccine or undergone complications as the result of a prior vaccination, let your vet know about this so that they can decide upon the best way to proceed, which may involve keeping your dog in the clinic for a day or so after vaccination in order to keep an eye on them.
• Do not administer other vaccinations or treatments at the same time as the rabies vaccine, as this can both increase the chances of generating a bad reaction in the dog, and also make it harder to identify what caused the problem.
• Keep a note of when your dog was vaccinated and the serial number of the vaccine with you when you are travelling too, in case you need to see a vet in the country that you are visiting when abroad.