A couple of days ago, over on Facebook, I posted a few pieces about snake bites on dogs.
One post on Copperhead snake bites (links at bottom) attracted a few Facebook experts with very confident opinions on the subject.
Cool.
More on that later, but let’s review the Copperhead basics to start.
While Copperheads account for *far* more venomous snakebites than any other species in the United States, their venom is quite mild, and fatalities of both humans and dogs are quite rare.
Even prior to the development of antivenin, the human fatality rate for Copperhead snake bites was approximately 1 in 10,000 bites (0.01 percent).
For comparison, Bee stings have a far higher human fatality rate; an average of 62 to 72 deaths per year in the United States compared to just 1 fatality every five years for Copperheads.
Compare that to Rattlesnakes, which account for over 90 percent of fatal snakebites in the US.
Eastern Diamondback bites — the flavor of Rattlesnake in my area — have a 20-40% human mortality rate if left untreated.
What about Copperhead bites on dogs?
Whether people or dogs, Copperhead venom is still the weakest of any administered by a US venomous/poisonous snake.
In Virginia and Maryland, where I have lived for over 40 years, Copperheads are common, and the likelihood of a dog getting bitten by a snake increases substantially in the warmer months.
If a dog comes in to a vet’s office with a venomous snake bite, there’s a 99.9 percent chance it’s a Copperhead bite.
OK, that’s the basics.
Now let’s go to the published experts and see what they say.
At the Journal of the American Animal Hospital Association four veterinary experts write that:
“Copperhead envenomation is common within the US, and no studies exist describing the clinical course of copperhead envenomation in dogs. Almost all treatment decisions regarding those bites are extrapolated from retrospective studies evaluating the clinical course of rattlesnake bites. Because copperheads and rattlesnakes produce venom with different potency, assumptions that treatment of the different envenomations should be similar may be incorrect.”
Excellent.
But did you notice what was implied in the opening statement?
Copperhead envenomination of dogs and cats in the US is very common (the majority of the 150,000 dogs and cats bit by venomous snakes in the US every year), but there are NO clinical studies describing Copperhead envenomination in dogs.
Huh.
Serious problems generally get studied. If Copperhead bites are killing a lot of dogs, you’d think there would be stacks of published data demonstrating the scope of the problem, if only to sell a putative cure.
But there isn’t.
OK.
Now re-reead the next sentence.
Copperhead envenomination is NOT parallel to or even slightly similar to rattlesnake envenomination.
OK. That sounds right.
But can we put some numbers on that?
Yes, it turns out we can.
From the same article in the Journal of the American Animal Hospital Association:
“Medical records of 52 dogs treated for copperhead envenomation were reviewed, and owners were contacted regarding outcome. The most common clinical signs associated with copperhead envenomation included swelling, pain, and ecchymosis [ed: a fancy word for bruising]. Clinicopathological abnormalities (e.g., thrombocytopenia, elevated clotting times, leukocytosis) were mild, and red blood cell morphology changes and coagulopathies were rare. Most dogs were treated with antimicrobials, analgesics, and fluid therapy. No dogs in this study required the use of antivenin and all survived to discharge. This study found that the clinical course after copperhead envenomation is generally limited to local rather than systemic illness. Copperhead envenomation in dogs is largely self-limiting and responsive to supportive care with hospitalization for monitoring.”
Huh.
So scores of thousands of dogs are bitten by Copperhead snakes every year, but a review of documented medical interventions over 8 years found very few of them treated by veterinarians, and *none* of those treated by veterinarians were fatal even without antivenin treatment?
Huh.
Scores of thousands of bites a year.
Little veterinary intervention.
No deaths even without antivenin of any kind.
In my previous post on Copperhead bites, I noted that the proper treatment protocol was not antivenin, but the administration of 2 mg of Benadryl per pound of dog every 12 hours.
But, says veterinarian Sherrie Hartke in the comments section of my original post, Benadryl does not deal with the systemic reaction of Copperhead venom.
And guess what? She’s correct, but not exhaustively so. You see, there is little or no systemic reaction from Copperhead bites.
As the AAHA article notes: “This study found that the clinical course after copperhead envenomation is generally limited to local rather than systemic illness. Copperhead envenomation in dogs is largely self-limiting and responsive to supportive care with hospitalization for monitoring.”
Huh. Self-limiting. That means the dog gets better on its own.
OK, but Copperhead bites DO cause a medical reaction. What is it?
And the answer is localized swelling.
Ms. Hartke says “Giving benadryl is a complete waste of time. Swelling is due to cytotoxic effects and not histamine.”
OK. Big words. Sounds like science. But is it?
I asked Ms. Hartke whether a Bee sting was cytotoxic, and what the go-to treatment for a Bee sting was.
No answer.
Can you guess why?
Yes, that’s right. Bee stings are also cytotoxic, and yes Benadryl is the go-to remedy for Bee stings.
What’s the story? Simple: One of the primary agents in both Bee stings and Copperhead bites is Melittin, which is a peptide that causes immediate pain and tissue irritation. Benadryl does not neutralize Melittin directly, but it blocks the histamines that your body releases, effectively reducing localized swelling.
Swelling is the primary effect of Bee stings and the primary effect of Copperhead bites as well. If swelling gets too bad in a very small dog (like mine), it can impact breathing. Reducing the swelling with a 2 mg per pound dose of Benadryl works.
Oddly, none of the experts in the comments section said they themselves had a dog struck by a Copperhead. The two that did have actual experience with their own dog said antivenin was not necessary. I have had dogs bitten by Copperheads three times over 25 years. No antivenin, and no deaths.
I was told, in the comments section, that I needed to go to a Facebook page on snake bites where the real experts were to be found.
Cool, but perhaps folks could just as easily point me to actual data on Copperhead bites in dogs published by the AVMA, AAHA or some other reputable numbers- and science-based publications? Had any of the experts on the Facebook page written anything about Copperhead bites in dogs that had been published in these kinds of veterinary publications? Please post a link!
No responsive links about Copperhead bites in dogs was forthcoming. Instead links were provided where rattlesnake data was co-mingled with Copperhead data, human data was presented (no dog data at all), or generalized fear mongering was presented with no data and often — again — a conflation of Rattlesnake and Copperheads as if they were the same.
In my original post, I had noted the incredible cost of Crofab antivenin.
Ms. Hartke offered that there were cheaper treatments now, and she quoted wholesale prices of Venom Vet, and Rattler of under $300.
Cool, I replied. Could she give me the actual *total* cost of Venomvet treatment at a vet’s office, including multiple vials of antivenom, administered on a slow IV drip, and overnight care from vet staff, etc.?
No answer.
OK. No problem. I had the answer as reported by a reporter for the Roanoke, Virginia Times: $4,000 to $6,000.
Ouch.
And guess what?
Most pet owners cannot afford that kind of financial hit, and most turn down that costly Copperhead “treatment” protocol as a result.
And guess what? None of those dogs die if they are otherwise healthy, and if they are given 2 mg of Benadryl per pound every 12 hours.
What? How is that possible?
Well, let’s review the basics again: a Copperhead bite is not a Rattlesnake bite. The comparative toxicity of the venom delivered is so vastly different it cannot be graphed.
Though Copperhead venom is hemo-toxic (i.e. destroying red blood cells), that’s a word that translates into little more than swelling and perhaps a little localized (and temporary) tissue loss at the bite location.
Benadryl to reduce swelling, and over-the-counter antibiotics to prevent bite infection, is all that’s needed.
But hey, if you want to shell out $5,000 or more to “Rescue Ranger” your dog, I’m OK with it. So too is every vet fanning the flames of worry about a Copperhead bite.
Just don’t ask to see the epidemiology numbers. They have numbers, of course, but those numbers are the veterinary bill.
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▪️Original Facebook Post >>
https://www.facebook.com/share/p/1CwnxzjKrD/?mibextid=wwXIfr
▪️Copperhead (Agkistrodon contortrix) Envenomation of Dogs: 52 Cases (2004–2011), 2014 in the Journal of the American Animal Hospital Association
https://jaaha.kglmeridian.com/view/journals/aaha/50/5/article-p338.xml
▪️ Copperhead bites can cost you thousands in vet bills, Roanoke Times >>
https://roanoke.com/news/state-regional/business/article_78d3c25d-8802-565b-b1bd-41b326b067c7.html
▪️ Epidemiology of fatal snakebites in the United States 1989–2018, Science Direct >>
https://www.sciencedirect.com/science/article/abs/pii/S0735675720307774?via%3Dihub
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