Coronavirus in dogs and cats

With all the media coverage of the new strain of coronavirus affecting people, I figured I’d touch on the types of coronavirus that dogs and cats get. Why not.

First of all, the coronavirus is not new – many species (including humans!) have had their own coronaviruses circulating for decades. The virus tends to keep each strain specific to the species, and it doesn’t like to go changing species. So the kind of coronavirus dogs get won’t infect a person or a cat, it just infects dogs. But wait – you’re thinking about the dog that the news reported tested positive, right? The dog did not HAVE the virus. The dog was WEARING the virus. If you have a virus and are in your house coughing away, anything in the house, if swabbed and tested, is likely to be positive. Your chair, your refrigerator, your fish tank, your pets. And why is it called Corona – does it live in beer? Nope! If you look at the virus with an electron microscope, it has little spikes, like a little crown, which led to the Latin name Coronavirus (think of the word “coronation”).

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Coronavirus in dogs is not exciting – at all! In vet school it was mentioned as an aside, but we focused on the viruses that actually require treatment. If a dog gets Coronavirus, he’ll have diarrhea for a few days and then get over it. It isn’t deadly, and doesn’t really even require treatment! It typically affects puppies or dogs who are in close quarters that aren’t the cleanest (think puppy mill). Of course, puppies tend to have immune systems that aren’t quite up to snuff, so they are more commonly affected than adult dogs.

There’s no test for coronavirus in dogs that can easily be done. There is a vaccine available for it. Interestingly, the vaccine is considered NOT RECOMMENDED by the American Animal Hospital Association. (Here’s my article on vaccines). I personally don’t know any vets that give it. Apparently there are some vaccine manufacturers that still make it. If your dog gets a distemper vaccine that’s a DHPP-C or DAPP-C or any other variation that ends in C, that means coronavirus is added to the mix. Thirty years ago vets used it, but no modern vets really use it today. Why? The disease is out there, but it doesn’t really cause significant sickness, so why stimulate the immune system and risk a vaccine reaction for a disease that the dog will get over on its own anyway!

Coronavirus in cats is WAY different! Coronavirus is associated with FIP – Feline Infectious Peritonitis. This is a big bad disease that is 100% fatal. Total opposite of the coronavirus in dogs! (There are some experimental treatments out there now for FIP with mediocre success – but there’s hope!).

FIP is still a disease that we don’t fully understand. It typically affects kittens, but adult cats can get it too. The thing is, no one knows what makes one cat get sick with FIP and the next cat doesn’t get it!

Up to 90% of cats in the country, when tested, will test positive for exposure to coronavirus. Many cats are infected with Coronavirus and never show symptoms. One version of the virus can cause diarrhea for a few days. Other versions can simply infect a cat, the cat then is shedding virus throughout the environment, but never shows any symptoms! In fact, of all the cats infected with Coronavirus, less than 5% will develop FIP. Everyone else has their coronavirus and lives a normal life.

The current theory for why some cats get FIP and others don’t is the “mutation theory.” Pretty much every cat has their own coronavirus they’ve been exposed to, and the virus hangs out in their intestinal cells. In a small percentage of cats, this virus mutates for reasons no one knows. It turns into a very aggressive version of the virus that causes the disease FIP. There are two main forms of FIP: wet and dry. The wet form is easiest to diagnose, as these cats/kittens present with a belly full of fluid. When we tap the fluid, we get a characteristic yellow fluids than can only be cause by FIP. The dry form is harder to diagnose, but neurologic symptoms, high fever, a thorough eye exam, and some abnormalities on blood work can clue us in. Either way, the disease is generally fatal, and euthanasia is often the most humane option. What makes this disease so heartbreaking is it typically affects kittens. And in one litter of kittens, one might get FIP, and the others won’t. No one knows why. They all got exposed to the same Coronavirus. Life’s not fair.

Can we test cats for Coronavirus? Sure! Is it helpful? Not at all! Since 90% of cats have been exposed to or are already infected with coronavirus, if we test a cat we suspect has FIP and it comes back positive….so what? We can test 100 healthy cats and 90 of those will come back positive – and none of them might have FIP!

There is (or used to be?) a vaccine for FIP/Coronavirus, but it is completely ineffective, and is not recommended by the American Association of Feline Practitioners. I’ve never heard of anyone giving this shot…ever. But you might read about it somewhere, so worth mentioning.

So Coronavirus is frustrating for vets too! For dogs, it barely gets mentioned and is generally ignored. In cats, it’s a big deal that has many scientists actively researching what makes some cats develop FIP while others don’t, and ways to potentially treat it. Both have vaccines available (somewhere?) that are useless. Neither has a specific treatment. And both types of Coronavirus will stay in their species.

So please don’t put a mask on your dog or cat – it just looks silly!