A SPATE of recent snakebite cases serve as a timely reminder that these spring days are warm enough to enliven our local reptile population.
Two dogs were successfully treated for brown snake bite with anti-venom, while one died before we could treat it, despite having been bitten only twenty minutes earlier.
Deterioration of that speed is not unheard of but it's very unusual, with most cases progressing over hours rather than minutes.
A young woman bitten by a tiger snake in 2003 took 32 hours to start showing signs, after which a precipitous decline ensued.
Dogs and cats often have delays of 24 hours or more before onset of clinical signs such as paralysis following snakebite.
It depends on the blood and lymphatic supply in the area of the bite.
Compared to a red-bellied black, the venom of an eastern brown snake is gram for gram over sixty times more lethal!
Its venom has a range of components with different effects different speeds of action.
One interesting feature is that, unlike black snake venom, there is no local tissue damage, pain, swelling or bruising at the bite site. This means the bite it usually invisible.
The fastest acting brown snake venom component is one that causes failure of the blood clotting mechanism and this starts working within minutes of the bite.
We can use blood clotting tests to determine whether or not an animal has been envenomed.
The other components are a combination of paralysing neurotoxins and these usually take at least one to two hours or more to start working.
An important feature of brown snake envenomation in dogs is what we call the "pre-paralytic signs".
These include transient collapse, vomiting, salivation and lethargy.
If you see these signs after a bite then you know your dog has received a potentially lethal dose of venom.
This is very important because an envenomed dog can show these signs, and ten minutes later look ostensibly completely normal. They are not!
If treatment with anti-venom is given after the pre-paralytic signs but before the paralysis sets in, then lower doses are needed and the odds of survival are much better.