Translate This Blog

Thursday, February 19, 2015

Rabies Testing--A Gruesome Job

Rabies is a serious, scary disease.  We have done a great job of significantly reducing the number of cases in the US through extensive, legally mandated vaccination programs, but we haven't eliminated it.  Nowadays most vets and virtually every American will go their entire lives without seeing a case or being exposed to it.  That rarity has the potential to breed complacency about the disease and risks.
A couple of weeks ago a young puppy was rushed in for odd neurological signs that had started the night before.  We had just seen him two days prior to that for a routine checkup and vaccinations, and he had been fine at the time.  His history was a bit "sketchy".  The owners had gotten him from someone through a Craig's List add, and the mother had died (the new owner didn't know how or why).  So there were some questions about his background and environment that couldn't be answered.
When he came in it was quickly obvious that he was having some kind of seizure activity.  It wouldn't resolve without IV medications, and even then he had one break-through seizure.  He was salivating heavily, wouldn't swallow, and was having some kind of severe neurological disorder.  The owner said that there was no toxin or medication exposure, so the origin of the seizures was mysterious, especially given the severity.  Due to the costs in stabilizing and treating, as well as the strong possibility of something that might not be treatable, the owner elected euthanasia.
When we're in vet school we are told to treat every neurological case as possible rabies until proven otherwise.  The vast majority of those cases will not be rabies, but we take appropriate precautions just to be safe.  Rabies is an incurable disease that causes severe, permanent brain damage.  Any animal or person who contracts it will in all likelihood die, and if they somehow live they will probably be in a vegetative state.  It is transmitted through bodily fluids, primarilly saliva, and can pentrate through any wound, abrasion, or mucous membrane.  Because of the severity and incurable nature we are very careful about human exposure.  This is also why the vaccine is legally mandated in every state, and why most countries are so careful about importing animals.
The chances of this puppy having rabies were very low, but not impossible.  The symptoms certainly could fit, and the questionable background wouldn't allow us to rule out prior exposure.  Due to the fact that there was human exposure and the owner had children, I made the decision to be absolutely certain and have the puppy tested for rabies.
Unforunately there is only one way to definitively test for it.  Brain tissue needs to be examined for the virus.  So there is no way to confirm or rule out rabies in a living animal.  We have to get to the brain.
This is one of the worst jobs I've had to do, and I've had to do it several times over my career.  Laboratories won't accept an entire corpse, so we have to submit only the head.  This means that we have to cut off the head.  Putting it bluntly, we have to decapitate the animal.  I can't think of a more gruesome procedure, and when I've had to do it I'm typically more subdued than normal.  I can perform a necropsy without problem and while still cracking jokes, finding the appearance of the internal organs interesting as I search for causes of disease and death.  But there is something psychologically different about having to separare the head from the body, and I try not to look at the animal's face or think too much about what I'm doing.  It's absolutely necessary to do, as part of our oath as veterinarians is to protect the public health, so I can't ignore the risks of disease transmission to families, my staff, or myself.
Thankfully the test came back negative.  We still don't know what caused the problems, but we do know that it wasn't something as serious as rabies.