Canine Vaccines

Almost everyone has their pets vaccinated against a variety of diseases. I’m always surprised how few questions I get about what all those needle-pokes are for. Well, if you’ve ever wondered about the whole story on all those tiny little vials – this series is for you. The first two articles will cover what diseases we vaccinate in dogs, then cats. Then, we’ll cover the questions I do get asked on a regular basis – like how often to vaccinate, how vaccines differ, and potential reactions to vaccines.

Rabies Virus
It’s the big one that everyone is familiar with, thanks to the fact that rabies is pretty much 100% fatal once it becomes symptomatic – and therefore your pet is legally required to be vaccinated against it. Transmitted by saliva into open wounds, it travels to the brain where it causes neurological effects ranging from stupor and loss of coordination (the “dumb” form) to violent outbursts (the “vicious” form). The time from infection to symptoms can vary from weeks to several months; after symptoms develop it progresses to death fairly quickly, though.

Pretty much any mammal can get it and give it – to your dog, cat, ferret, or you. Fortunately, human and pet infections are rare in the US nowadays – thanks largely to vaccination. It is very present in the US, however; every state except Hawaii reports anywhere from a handful to hundreds of cases in wild animals annually. The most common carriers are bats, raccoons, skunks and the like.

“Parvo” Vaccine Complex
Pretty much all veterinarians use a combination vaccine that includes parvo, distemper, and hepatitis. These are discussed individually below. Some combo vaccines also include parainfluenza, which is discussed below under “kennel cough.”

• Parvovirus: Most folks have heard of this one too, as it is the only disease we routinely vaccinate against that’s still relatively common. The virus very efficiently destroys the cells lining the intestines; this leaves the dog unable to digest food, retain water, or keep intestinal bacteria from entering the bloodstream. A malnourished, dehydrated, septic puppy is generally a dead puppy without treatment. On the bright side, if caught early and treated aggressively dogs generally respond well – if they live long enough, they’ll generally clear the virus on their own. However, several days in the hospital on intravenous fluids and antibiotics gets costly fast, and is by no means a guarantee.

• Distemper Virus: About 50% of dogs who catch distemper will experience mild general malaise and/or respiratory disease. Unfortunately, the others will develop a potentially fatal infection of the brain and spine; those that survive often have serious long-term neurological problems. All affected dogs will experience severe suppression of the immune system – the virus first attacks white blood cells – and potentially life-threatening secondary infections often occur in any affected dog. You may not hear a lot about it, but it’s out there – and it’s not a disease to be trifled with.

• Infectious Canine Hepatitis (Canine Adenovirus Type-1): This is a disease that primarily damages the liver, potentially fatally, but it may also affect the eyes, kidneys and other organs, or turn into a chronic, low-grade infection. Fortunately, it’s very rare nowadays because of routine vaccination. Interestingly, the vaccine is actually CAV-2, a related virus that causes transient respiratory disease and is part of the “kennel cough” complex discussed below. CAV-2 vaccine provides good cross-protection against the more serious CAV-1, and the old CAV-1 vaccines had more frequent side effects.

Other, Non-Core Vaccines

• “Kennel Cough” – Bordetella bronchiseptica & Parainfluenza Virus: “Kennel cough” is the common term for a group of upper respiratory infections that are generally self-limiting. They generally don’t hang around in the environment long, and instead are passed between dogs in close quarters – most commonly, in kennels, at dog parks, or at events like shows or agility contests. Bordetella & parainfluenza are two of the more common culprits, and the primary ones we vaccinate against. They aren’t consider “core” vaccines, since many dogs never board at a kennel and have minimal contact with other pets – but they are highly recommend for those who do, and required to stay at kennels.

• Leptospirosis: Lepto is a bacterial disease that can shut down the kidneys and may damage other organs like the liver. That’s bad. It’s also something you can get, though good oral hygiene minimizes risks (making it mostly a concern for children). The majority of mammals can carry it, sometimes without major symptoms, and transmit it via urine. We all know what dogs do when they find urine, hence why they’re prone to it. Risk levels vary from area to area, so talk to your veterinarian. However, if you travel with your pets it is a good idea regardless.

• Lyme Disease: This bacterial disease is most commonly associated with severe arthritis, though it can also seriously damage organs such as the kidneys. It’s transmitted by ticks, and is also known as borreliosis after the bacteria that causes it. This is another fairly region-specific disease, with the east coast and Great Lakes regions being at greatest risk, so talk to your vet.