Oh, you love your pet? Hope you enjoy loving it IN YOUR EARLY GRAVE. Here's all the gross diseases it can give you.
Dogs: Heartworms
Humans can get heartworms when a mosquito bites an infected dog then bites you. Yuck. Usually, the human body can ward off heartworm parasites, but in rare cases, the worms travel to your lungs and make lesions.
Source: images.retecool.com
Cats: Toxoplasmosis
Toxoplasmosis is a parasite from cat poop that crawls into human brains and literally changes how you think. It literally makes you LOVE CATS. And eats your brain.
Birds: Parrot Fever
Psittacosis, a.k.a. parrot fever, is form of chlamydia that parrots get that they can pass to humans without eve having sex with them Messed up and totally true.
Racoons: Roundworms
Bet you thought I was gonna say rabies, right? If you're sick enough to keep a pet raccoon, have fun when roundworms from it infect your eyes. Nasty.
Source: fuckyeahrabies