Pete Wedderburn
2nd January 2020 - 3 min read

Needles, shots,  jags, or injections –vaccinations are given many different names in our daily lives. Everyone knows how important they can be, especially for young animals. But what are vaccines and why are they given? 


cat in vets

Vaccines are the best way that modern medicine has found to deal with viruses. Viruses are microscopic lifeforms that can be very difficult to eradicate from the body. When an animal is infected with a virus, there is no drug that will quickly and efficiently destroy the virus. In most cases, the best treatment is simply to keep the animal warm and comfortable and to hope that its own immune system can deal with the virus. This approach works very well with mild viral infections.

For more severe illnesses (such as parvovirus in dogs), other treatments are given, including intravenous drips and antibiotics. However none of these treatments have a direct effect on the virus itself – they simply help the body deal with the damaging effects of the virus. The aim is to keep the animal alive until its own body has managed to overcome the virus. All too often, this does not happen. The virus wins the battle. The animal’s body cannot eradicate the virus, and after a severe illness, the animal dies. 

Preventing Viral Infections

So far, so depressing. It is a sad fact that even the best brains on the planet have not yet found an effective way of curing serious viral infections. This is where vaccines come in. Vaccines are a highly effective way of preventing a viral infection from starting. If a young animal is given a full course of vaccinations, its immune system is primed and ready, so that if it is faced with a viral infection, it is able to rapidly and effectively eliminate it from the body. 

How Vaccines Work

The science behind vaccines is simple: a disease-causing strain of the virus is modified in the laboratory so that it can no longer cause disease. This modified virus is carefully packaged as a sterile solution that can be injected into animals. Once introduced into the animal’s body, it does not cause disease: instead, it stimulates the animal’s immune system to produce antibodies and other defence mechanisms, so that the animal is protected from a “wild” viral infection.

puppy brown and white

Nowadays, most puppies are given a full vaccination course when they are young, given them excellent protection against Distemper and Parvovirus, as well as Canine Hepatitis and Leptospirosis.

Kittens are vaccinated against Cat Flu, Feline Enteritis, and Leukaemia. As a result of widespread vaccination, these diseases are much less common than in the past, although there is a steady, continual flow of cases across the country. I still see around one dog a month dying of Parvovirus.

Adult dogs and cats are supposed to have annual “booster” vaccinations every year: many vet clinics send out reminders to pet owners to let them know. Your dogs and cats may not enjoy them, but those needles/shots/jags/injections could well save their lives.