Photo by Dr. Teri Ann Oursler
"An uncommon complication of snakebites is massive tissue destruction in the area of the bite. This tissue damage is often not apparent for several days after the bite, and would appear as areas of skin that are pale in color, and the hair may fall off. If this happens, management may vary from long-term antibiotics to surgery to grafting new skin onto the area. Please call the hospital if Mabel appears to be having any problems."
I wrote these discharge instructions when I was an intern. Recently, as I scanned the list of discharge instructions I'd written for various diseases I noticed that one topic popped up with more versions than many others on the list: snakebites.
The practice where I interned was in the foothills of central California, and we saw snakebite cases regularly. I don’t remember how many, but I would estimate we saw two or three cases every week. The cases usually had similar elements: dog goes out and sniffs around the woodpile, then blammo; he gets hit, usually in the face or front paws. We saw the odd cat who had been bitten, but in most cases it was dogs, usually terriers of the sort that have been bred to relentlessly go down holes after small prey.
Snakebites are painful; this is one way that we could differentiate them from garden-variety bee stings and allergic reactions. These patients were usually in excruciating pain, and touching them anywhere near the region of the bite was a one-way ticket to getting bitten yourself. Pain control was always one of the first priorities for these unfortunates.
There is a lot of lore, and not that much science, surrounding the medical therapy of snakebites. Articles on snakebite management list scores of potential therapeutic interventions, and in online discussion forums, such as the Veterinary Information Network, doctors treating them trade tips and tricks on how to treat these patients and what sorts of interventions are in vogue this week. Use of antibiotics, antihistamines, steroids, anti-inflammatory drugs and antivenin all get tossed around as options. Few scientific papers exist to help guide us to just the right mix of meds for the envenomated pet.
Some of the problem comes from the many different types of snakes scattered all over the globe that could inject you with their venom. In California, we were dealing with snakes of the subfamily Crotalinae. These nasty but efficient little guys are also known as pit vipers (a name that for some reason always conjures up an image of a snake with a green eyeshade and a deck of cards). Pit vipers strike hard and fast. Their venom digests tissues and causes red blood cells to pop in a process called lysis. You can almost hear the snake, sitting under a log and waiting for the unsuspecting dog to amble by: I am about to bite and cause some serious lysisssssssssssss.
In Florida, they deal with more exciting types of snakes, like coral snakes of the family Elapidae – these guys produce a witches’ brew of neurotoxins that can paralyze the muscles of breathing and the bitten body ends up on a ventilator before you can utter "what’s that hissing thing under that there log? I think I’ll touch it, here hold my beer." At upwards of $1000 a day for the ventilator alone, these cases require the highest level of intensive care that veterinarians can provide, and survival is not guaranteed.
The worst snakes of all, in my estimation, live in Australia. For example, the large Eastern or mainland tiger snake has four types of venom. There is something in that country that takes the already bowel-shaking concept of a living, slithering hypodermic that injects Drano into your unsuspecting hide and turns that concept on its scaly little head. The Aussies don’t do anything halfway – witness the latest sport of shark wrestling.
When an Australian snake sinks its teeth into you, you pretty much just explode into a pile of hairy strawberry gelatin, all set to Wagner’s Ride of The Valkyries. No mild-mannered lysis, no paltry and low-key respiratory paralysis, not even the tender touch of liquefied muscle and connective tissue. Just ... *poof*splat*. The actual number of Australian fatalities is not that high, as the Aussies have also managed to find impressive ways to treat these cases. Plus, they have a healthy flight-or-flight attitude towards snakes that can be summed up as follows: RUN!!! (Incidentally, Asia leads the world in fatalities – estimates from the World Health Organization [WHO] are 15,000 to 60,000 fatal snakebites per year; the Aussies suffer two to four fatalities per year, similar to U.S. numbers).
Blanche got bit in the face. Photo by Maribeth Johnson.
Estimates in the U.S. for dogs include about 15,000 bites per year, with a mortality rate around 20%. There is no central organization like WHO to tabulate doggy data, so no one really knows; I don’t remember all that many dogs dying of snakebites when I was treating them. Luckily, although venomous snakes are found in all 50 states, Indiana has a blessedly low number of them, so I have yet to see one in the 2.5 years I have been teaching at Purdue.
Pain control and administering the specific antivenin are the cornerstones of treatment for you or your dog. Antivenin can run you hundreds of dollars per dose, so many owners unfortunately, but understandably, opt out of this intervention. I remember the patients who received antivenin recovering faster and feeling better than the ones that didn’t get it. In people bitten by venomous snakes, they may give you 8 to 10 vials of the stuff. I think in a canine patient, the most I ever gave was two. This is another sad example of how finances can come between what is best for treating a pet and what is realistic for most pet owners.
There is nothing you can do at home or in the field to manage a snake bite. If your dog gets fangs in his flesh, make headway to the nearest veterinary hospital or ER and let them know you are coming. In some cases, they may have to scramble to get the antivenin from a human hospital, so as much heads-up as you can give them will help you out. Adapt the age-old Australian adage of RUN!!! and get them in for medical care as soon as you can, and if you can spring for antivenin, I would give it strong consideration.
Since prevention is so much easier than treatment, keeping inquisitive dogs away from tried-and-true snake hidey holes like woodpiles is a wise move. Not all dogs tend to take the RUN!!! advice to heart (which is living proof of the adage "One dog, one brain; two dogs, no brains"), so some avoidance training may be helpful as prevention planning.
July 7, 2019
VIN News Service commentaries are opinion pieces presenting insights, personal experiences and/or perspectives on topical issues by members of the veterinary community. To submit a commentary for consideration, email email@example.com.