Zoonotic diseases are diseases that are common to both humans and animals. There are a lot of these, but it's always surprising to find that people don't understand which is which.
There are a lot of jokes about distemper, but the reality is that you can't get distemper from your dog or cat.
In fact, canine distemper is a nervous system disease and feline distemper is a gastrointestinal problem—not even closely related other than by name.
And while there has been some talk that canine distemper may cause problems in humans, this has been proven to be false.
Rabies is probably the most serious zoonotic disease in North America. It can affect most mammals and pass between them, which is something to be very aware of.
This virus travels along nerves, so a bite on the hand, while very serious, isn't as serious as a bite on the face. And the animal (human) has to be shedding the virus in the saliva to pass it on.
The animal also has to survive the bite. Yes, squirrels can get rabies, but they wouldn't likely survive the attack of a larger animal to develop the disease in the wild.
The Journal of the American Medical Association features artwork on its weekly cover that highlights one of the articles. Years ago, they had a painting of a squirrel to highlight an article on zoonotic disease and rabies.
They later printed an apology since there has never been a recorded case of rabies in a squirrel.
Some parasites are zoonotic.
I once diagnosed a mite problem in a small dog. I couldn't get a good skin scraping from the dog, but noticed that his human held him in the crook of her arm and she had a rash there.
I did a quick skin scraping on her and there was the mite. She was completely horrified, but it solved the problem nicely.
I once caught the same mite myself while treating a pig. I did a nice job of clearing up the pig, but took a lot of jokes about infecting myself.
Many people think of the common cold as a simple infection. It can be, but it can also be much more serious, since it actually is a physical syndrome of several hundred infectious agents.
These are specific to humans and very annoying at best, but that's why you can get a cold and then get another soon after. They're caused by different bugs.
Dogs have much the same thing—a whole host of agents that make them sick and can come back.
Humans get colds. Dogs and cats get colds. But it's very unlikely that you'll catch one from your pet, or that you'll give one to your pet.
A good example of this is kennel cough.
This is a term for a respiratory infection in a dog that is caused by one of many bugs. You can't vaccinate for all of them, and you wouldn't want to.
But one in particular can be more serious, so the vaccine is against one specific bacterium.
You can vaccinate your dog and have it come down with kennel cough soon after. It's not that the vaccine didn't work. You protected against one agent and the dog caught a much milder one.
Feline leukemia is rare in most areas. I have seen two cases in Yukon, but it is more often a disease of large groups of cats. It also doesn't pass from cats to humans.
In my former life, we had a cat colony attached to a hospital that treated cancer patients. I had to test every cat for feline leukemia and vaccinate them when the hospital administrator wouldn't believe that it was a cat-specific disease.
Ringworm is another zoonotic disease. Ringworm actually isn't a worm at all, but a fungus.
As it infects the skin, it tends to spread out with the centre gradually healing. As this happens, it can leave a distinctive ring-shaped lesion. Hence the name confusion.
There are a number of types of fungus, and while some are pretty mild, there are a few that can be pretty nasty.
Shaving, topical creams, systemic drugs are all used, depending on the type and the severity.
A vet who once worked for me had been treating rabbits and absent-mindedly scratched his back. His very cute technician ended up with ringworm on her hands and arms, while he had it on his back...
Try explaining that one.