Vaccination – Keeping your pets healthy
As vets, we often get excited
about the emergency surgery, or the intensive care case, of the heroic medical treatment that we do – and we do save animals’ lives. But for all of us, we probably make a bigger difference to more animals with “simple” preventative care – flea treatment may not save lives, but it massively improves the dog’s or cat’s quality of life; the same goes for worming in most cases.
But there’s one thing we do day in, day out, that saves lives without most people realising it – vaccination (plus we get to play with cute puppies and healthy animals which is great!).
In this blog, we’ll briefly look at how vaccines work, and then look in more detail at what we use them for.
What is a vaccine?
A vaccine is, basically, a way of teaching the immune system how to fight an infection. The body’s immune system is fantastically powerful, but bugs are also clever at adapting to it, so it takes the body a while to learn how to kill an infection – and sometimes, that’s too long. A vaccine allows the immune cells to “practise”, without the risk of causing the real disease. It doesn’t weaken the immune system, or overload it – it triggers exactly the type of response that a real infection would, without the same risk.
If you like, you can consider it similar to a pilot learning to fly in the simulator – they can make as many mistakes as they need to learn how to do it for real, without crashing the plane and killing the passengers!
What diseases are we protecting our pets against?
There are a HUGE range of vaccines available now! The most important ones protect against the following diseases:
DOGS:
- Distemper
- What does it do? The virus attacks the nose, lungs, stomach, intestines, brains, eyes and skin; the skin symptoms are why it is sometimes called “hardpad”, as the pads become thickened and crusted.
- How bad is it? This is a fatal disease of dogs (50% mortality rate) closely related to measles. It can also cross over to seals, where it is nearly 100% fatal.
- Interesting fact: It can sometimes affect humans… but the measles vaccine protects us.
- Canine Infectious Hepatitis
- What does it do? A really nasty virus, called CAV1, that breaks down the blood vessels supplying the dog’s liver and often eyes.
- How bad is it? Some dogs fight it off, others may die within hours – it’s frighteningly variable.
- Interesting fact: Vaccination against CAV1 prevents infection with CAV2 – a cause of Kennel Cough!
- Parvovirus
- What does it do? The virus attacks the gut lining, causing bloody diarrhoea, severe vomiting, massive dehydration and then shock and death. It is usually most severe in puppies, but any unvaccinated dog is susceptible.
- How bad is it? IF the dog survives long enough to get into intensive care at the practice, only one in five will die. Any delay, however, increases that risk
- Interesting fact: The virus can survive in the environment for many months and still be infectious.
- Leptospirosis
- What does it do? The bacteria are spread in urine (from infected dogs and from rats and cows) and when absorbed, infect the kidneys and liver.
- How bad is it? Many dogs will survive infection with suitable treatment, but may shed the bacteria in their urine for months afterwards.
- Interesting fact: Humans can contract the disease, it is an important “zoonosis”. In humans, we call it “Weil’s Disease”.
- Kennel Cough
- What does it do? As you would expect, it causes a severe cough! In severe cases, it can also cause pneumonia.
- How bad is it? In most cases, the disease is self-limiting; however, infected dogs are highly contagious, and may continue coughing for several weeks.
- Interesting fact: There are several different organisms that can cause Kennel Cough; the most important are CAV2 (blocked by the Hepatitis vaccine), Parainfluenza and Bordetella bronchiseptica, first cousin of Whooping Cough in humans.
- Rabies
- What does it do? The virus attacks the brain causing manic and violent behaviour, and then death.
- How bad is it? 100% fatal – and easily spread in bites to humans and other animals. Fortunately, not found in dogs in the UK, although our bats can carry it.
- Interesting fact: There have been about 3 recorded cases of humans who recovered from rabies – ever. But 50,000 people a year die from the disease.
- Lyme Disease
- What does it do? The bacteria are spread by ticks and cause a wide range of symptoms, typically a skin rash, arthritis and lethargy.
- How bad is it? Treatment is a long process (weeks or months of antibiotics) but is usually effective.
- Interesting fact: Ticks can also spread Lyme’s to humans – and in us, it seems to be harder to diagnose and to treat.
- Leishmania
- What does it do? A parasitic disease spread mainly by sandflies, this usually causes crusty skin, damage to the eyes, fever and chronic weight loss.
- How bad is it? The infection is incurable, although it can often usually be controlled with medication.
- Interesting fact: The sandflies that spread Leishmania are found throughout southern Europe, but not in the UK.
CATS:
- Feline
Panleukopenia- What does it do? The virus attacks the gut (causing vomiting and diarrhoea) and the immune system.
- How bad is it? The mortality rate is similar to parvo in dogs.
- Interesting fact: The virus is actually a cat-specific version of parvovirus – just like in dogs!
- Cat Flu
- What does it do? As you’d expect, cat flu viruses (feline herpesvirus and calicivirus) cause sneezing, runny nose, sore eyes, and, rarely pneumonia.
- How bad is it? Very few cats will die of cat flu – although it causes a lot of suffering – but there are a few lethal strains of calicivirus around.
- Interesting fact: Cats who are infected with herpesvirus never clear it – the virus is always hiding in their system, ready to reemerge if they become stressed or ill later in life.
- Feline Leukaemia Virus
- What does it do? This is an oncornovirus, that inserts itself into the cat’s DNA and replicates there. This results in collapse of their immune system, and the development of cancer.
- How bad is it? Over 90% of infected cats will be dead within 3 years.
- Interesting fact: This virus preferentially targets and destroys the genes that prevent cancers from starting – because by turning them off, it increases its own reproduction rate inside the cell.
- Feline Chlamydia
- What does it do? Unlike in humans, in cats Chlamydia attacks the eyes.
- How bad is it? In most cases, the cat will fight off the infection in 2-4 months – but meanwhile, they’re shedding it for all their friends!
- Interesting fact: This bacterium is another cause of the Cat Flu complex.
- Rabies
- See above!
RABBITS:
- Myxomatosis
- What does it do? The virus attacks the junctions between the skin and the mucous membranes, causing swelling and discharge of the eyes, nose, mouth, anus and genitals.
- How bad is it? Unvaccinated rabbits will almost always die – but it may take several weeks of suffering first.
- Interesting fact: The virus is much more severe in European rabbits than the species found in South America, where it originated.
- Viral Haemorrhagic Disease
- What does it do? This virus attacks the blood vessels, causing massive bleeding and death – there is no effective treatment.
- How bad is it? Pretty much 100% fatal in unvaccinated rabbits; the most common symptom is sudden death.
- Interesting fact: There is now a new strain of the virus (VHD2) in the UK – fortunately, we now have a vaccine against this strain as well!