Thanks to Kim and Pranav for their unsettling suggestions for this episode! I swear the reason I decided to do this episode this week was to celebrate getting over my cold, but then I realized I needed to address the virus everyone is talking about right now. I hope you all stay well and safe out there!
The Hawaiian monk seal OMG LOOK YOU CAN SEE ITS BELLY BUTTON, SO CUTE:
Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.
I’m finally over my cold, so to celebrate let’s do a little bit of an unusual episode. Last year Kim suggested we do an episode about zoonotic diseases and diseases found in polar ice, and Pranav suggested an episode about what happens after humans go extinct. Those two topics seemed to go together, muahahaha.
Zoonotic diseases are diseases that humans can catch from other animals. Rabies is a good example, since it affects all mammals and is passed from one animal to another. In fact, let’s learn a little bit about rabies since naturally people are afraid of catching it but most people don’t know much about it.
Rabies is caused by a virus, specifically the lyssavirus. It acts on the body’s central nervous system, eventually infecting the brain. After that, it infects the salivary glands in order to be transmitted to other animals through a bite wound.
When an animal is infected with rabies, it may not show symptoms for a long time—sometimes years, although it’s more usually a few days to a few months. It starts as a fever and a headache, which are also symptoms of many other diseases. But within a few days of the first symptoms, the animal becomes aggressive, attempting to bite any other animal that it encounters. It has difficulty swallowing, which is why in cartoons animals with rabies are shown foaming at the mouth. This actually happens, but it doesn’t look like shaving cream and you’re not fooling anyone. The foam is just saliva that the animal can’t swallow. In the old days, rabies was called hydrophobia, which means fear of water, because in addition to not being able to swallow, the infected animal actually shows a fear of water. This all happens because the virus wants to be transmitted to other animals, and it does so through contact with infected saliva. If an infected animal could swallow its saliva and drink water, it would be much less likely to transmit rabies. So the virus hijacks the central nervous system to make the animal afraid of water and unable to swallow.
Of course, mammals can only live a few days without water, so once an animal reaches this stage it dies within a few days. Occasionally a human who contracts rabies and starts showing symptoms is rushed to the hospital and treated, but once they’ve reached the final stages of hydrophobia, it’s extremely rare that they survive even with the best medical care available.
So that’s horrifying. Some species of mammal are resistant to rabies and while they may get sick, they don’t usually die from it, including the vampire bat and the Virginia opossum. Birds can catch rabies but usually don’t show symptoms and recover without spreading it. Rabbits and hares, and many small rodents like guinea pigs and rats, almost never catch rabies and as far as researchers know, don’t pass the disease to humans.
And, of course, a vaccine was developed as long ago as 1885, with a more effective vaccine developed in 1967. The vaccine is mostly given to dogs, cats, and other pets, but humans who work with certain wild animals, like bats, are also given the vaccine. In some areas with widespread rabies among wild animals, vaccine-laced baits left for animals to find and eat have helped limit the spread of the disease.
If you are bitten by an animal, even if the animal doesn’t show symptoms of rabies, you should get the rabies vaccine and treatment ...