Wednesday, June 25, 2014

Black whipsnake envenomation in dogs

Molly the day she presented with a black whipsnake bite (note bite on her right arm). The bandage is to hold the IV line in place. The two-toned style was because we ran out of blue so had to add pink. We weren't being fancy with the dressing!
Australia is famous for its deadly venomous snakes. Companion animals are often bitten when they are interacting with (chasing, playing with, attacking) snakes. There are plenty of reports of dogs and cats being bitten by brown and black snakes (elapid species), but until recently nothing published in the peer-reviewed literature on bites from Black whipsnakes (Demansia papuensis species group). As my co-author, herpetologist Glenn Shea, says, “Black whipsnakes are venomous, and similar in size to the ‘traditional’ dangerously venomous species, such as black snakes and brown snakes.

During a locum stint in Darwin I treated a 9-year-old Jack Russell terrier, Molly, who sustained a bite from a Greater black whipsnake. There were a number of interesting things about this case.

Poor little Molly 72 hhours after envenomation. Note extensive bruising and swelling. (Also a yellow bandage this time because we can out of pink and blue). Fortunately she made a full recovery.
First is that the bite wound caused severe, painful local necrosis, swelling and tissue damage that progressed from the time of initial presentation. Whilst there is no direct evidence that the venom is fatal, the site of the bite and subsequent swelling may cause life-threatening complications (for example a bite to the neck or chest which causes swelling that may affect the airways).

Second, Molly required treatment (pain relief, anti-inflammatories and supportive care) even though it is anecdotally reported that these snakes aren’t harmful (humans that have been bitten say that it really, really hurts).

Third, the dog tested negative on a snake venom detection kit which suggests (although N=1) that these kits cannot be used to rule out whipsnake envenomation.

A Black Whipsnake in the NT (note this snake was deceased when found).
Of course not all snakes are to be feared - just treated with caution and good care. All snakes are deserving of respect. Including this little cutie-pie here.


Reference

Fawcett A, Shea G and Cutter SM (2014) Black Whipsnake (Demansia papuensis species group) envenomation in a Jack Russell terrier. Australian Veterinary Practitioner 44(2):627-630.