The fearsome Eastern Massasauga rattlesnake is considered the most dangerous snake in Ontario. But what happens if one of these venomous creatures actually bites you?

Inland Ontario is devoid of the dangerous animals found in warmer regions of the world. However, Canada’s most populous province is still home to a number of potentially deadly animals. The massasauga probably tops most people’s lists.

Although the massasauga is often mistakenly referred to as Ontario’s only venomous snake (there is one), it is in fact the only species of rattlesnake found in the province. It is also the only serpentine animal found in Ontario that is powerful enough to kill a human.

However, there have only been two massasauga bite fatalities in the province, and no fatalities in the past forty years.

Still, it’s good to know how to respond if you’re ever bitten by a rattlesnake.

Experts first stress that victims should not panic. A bite does not necessarily mean that they have been poisoned. A hasty movement can increase your heart rate and cause the poison to enter your bloodstream more quickly.

The West Parry Sound Health Centre (WPSHC), which acts as the province’s poison control centre, explains that a quarter of all rattlesnake bites are ‘dry’ bites, so there’s a good chance you’ll come away unscathed.

Still, chances are the bite wasn’t dry, and limiting movement is your most important tool for limiting the spread. Next, WPSHC says bite victims should clean the wound with soap and water and remove any jewelry from the affected limb — which is helpful if swelling occurs.

In this case, WPSHC advises that you call 911 and get to the hospital “as quickly and safely as possible.” Under no circumstances should you apply a tourniquet, ice, or suction to the bite.

What happens if you decide to postpone medical treatment?

A 2018 scientific paper on the effects of massasauga venom addresses exactly this scenario.

The study, titled “Severe coagulopathy following a massasauga rattlesnake bite,” examines the case of an otherwise healthy 25-year-old man who was bitten on his left big toe while walking in open sandals at night in Ontario’s Eastern Georgian Bay region.

The man decided to delay medical treatment for a whopping 22 hours, and this is what happened next.

Photos included in the study show extreme swelling in the man’s left foot 12 hours after the untreated bite, along with a bloody blister at the bite site with two visible puncture wounds. A massive 12 by 6 cm hematoma, or blood clot, was found near his groin area.

Laureano, M., & Crowther, M. (2018). Severe coagulopathy following a massasauga rattlesnake bite. CMAJ: Canadian Medical Association Journal, 190(7), E191.

The man was treated with a total of ten vials of antidote and his symptoms resolved.

However, this is only one possible outcome in a range of symptoms that appear to be unpredictable and associated with venom-related coagulopathy.

According to the 2018 study, venom-related coagulopathy can affect virtually any part of the hemostatic system, and snakebites have been associated with platelet dysfunction, vascular wall breakdown, prothrombin overactivation, and fibrinogen degradation.