C.S.I Ewingsdale – Hendrix Goes Down

It’s a dangerous world out there and when pets go roaming, things can turn nasty. One of the most famous of all threats in nature are venomous snakes, of which Australia has some of the most deadly. Our Eastern Brown is way more dangerous than it’s famous cousin, the Cobra. It’s short-tempered, fast, territorial, aggressive, and overpopulating our local landscape.  Having grown up in New Zealand, Hendrix had no idea about any of this when he went out to play……

Hendrix was observed out playing one Thursday morning; climbing trees and chasing bugs in the paddocks of Bay Vista Lane. That evening he seemed unusually quiet for a few hours after coming in for dinner about 6pm. By 8.30pm something was definately wrong: he was wobbly, and couldn’t stand at full height. Walking looked more like waddling. Hendrix’s vocal muscles were unaffected  – his ‘meow’ sounded normal.

These symptoms superficially look like those of a tick-affected animal, but the suddenness of onset and normal voice were more characteristic of a snake bite victim.  In the hospital his urine and blood were checked for tell-tale clues of snake envenomation.

Black and Tiger snake venoms cause red blood cells to pop, releasing their hemoglobin into circulation, staining serum and urine pink. Hendrix’s urine had not-a-whiff of haemoglobin.

In  contrast, the venom of a Brownsnake activates the coagulation cascade, using up all the cells and proteins needed for blood clotting. A blood sample collected from these patients will fail to clot in the usual 60-90 second period. Here’s a video of Hendrix’s blood, 36 hours after collection, still liquid.

Rat-bait poisoning and a few rare blood diseases like haemophilia and thrombocytopenia can cause clot-failure like this, but such conditions don’t cause the loss of muscle strength that Hendrix was suffering.  It appeared Hendrix was bitten by a Brownsnake, just before dinner, and was in early Phase 2.

Blood testing kits used for identifying the type of snakebite in humans are expensive and unreliable in animals. Looking for the bite site is often time consuming and doesn’t offer extra information about the type of snake, so vets in Australia rarely waste time with this, and jump to simpler, cheaper blood tests instead.

TWO PHASES OF SNAKE ENVENOMATION

PHASE ONE: Post-Envenomation Phase

This starts minutes after being bitten and may last up to half an hour. The patient may seem disorientated, wobbly, collapse, tremble, drool, vomit, or even die. This phase is often missed as it may be mild enough to pass unrecognised, or occur while a pet is home alone or unaccompanied in the garden.

If a pet-owner does observe it, the miraculous recovery to full normality is a short-term victory: patients who have significant phase one symptoms will more commonly suffer a severe and possibly life-threatening phase two.

Early administration of antivenom can often prevent the onset of Phase 2 altogether. Tragically, a pet owner may be tricked into believing their pet survived a snake bite, only to find them dead in bed the following morning.

PHASE TWO: Paralytic, Haemolytic, Haemorrhagic Phase.

This usually starts 3-12 hours after phase 1, but can be up to 24 hours after a snakebite. It’s characterised by progressive weakness that initially looks like drunkenness, short-stepping or waddling gait,  fatigue and sitting frequently, inability to leap to height, and eventually complete, ‘rag-doll’ paralysis.

Bleeding from gums, in urine, stool, vomit or anywhere is also common. Death during this phase is due to inability to breathe or haemolytic and/or haemorrhagic complications.

Tough Decisions

Kane and Ash were now presented with a difficult decision. The important considerations are:

The chance of survival when given antivenom early is about 90%. A single dose of antivenom and a stay in hospital on IV fluids was going to cost $800 or more. (Note: Black Snake treatment costs at least double this)

The chance of survival for cats that don’t receive anivenom is about 70% (P.Best, 2000). These animals will usually have slower recoveries and saving on antivenom could end up spent on longer hospital stays on a drip. (Note: The survival rates for dogs left untreated are lower. Cats are faster and don’t typically get bitten as badly as dogs)

Antivenom can only neutralise venom still floating free, unbound to tissue receptors, and is most potent when given early. Waiting to see if he’s going to survive, and then changing your mind at the last minute, is risking the worst possible outcome: death and a big bill. This same principle applies to all antivenoms and tick serum given when a dog is crashing, days after a tick is removed, is also of questionable benefit.

Treatment

It didn’t take long to decide. Hendrix was  given antivenom. Placed on a drip and  premedicated  with adrenaline to prevent anaphylaxis to serum derived from a horse, he stayed in hospital that night. The intravenous fluids supporting perfusion during the coagulation storm in his bloodstream.

The next morning Hendrix was already improving. Antivenom couldn’t reverse the symptoms that he has already developed, and he wasn’t yet walking normally, but he was stable enough able to go home. Hendrix started eating that night, and was back to full power  2 days later.

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RECOMMENDATION

  • If your pet suddenly develops symptoms of tick paralysis but you can’t find it, think snake, call vet.
  • If you see your pet encounter a snake, don’t get hysterical. Pay close attention to it’s colour or markings. If  a poor, dead reptile is presented to you like a trophy, bring it with you to the vet for identification. A positive ID can save you money – less need for blood tests, and possibly no expensive antivenom if it’s non-venomous.
  • If your pet has signs of phase one envenomation and then miraculously recovers, don’t be fooled. Prompt administration of antivenom early may save your pet’s life in 3-12 hours time by preventing phase 2.
  • Some animals survive a snakebite without treatment, so don’t lose hope if things are tight and you have to draw the line.  For more on a case of spontaneous survival see CSI Belongil – Backyard Forensics

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5 Responses to “C.S.I Ewingsdale – Hendrix Goes Down”

  1. Lesa Corrine says:

    Great article Matt..The hot months in this area i see many brown snakes, great to see this info for the pet lovers out there, my little cat came face to face with a brown recently, luckily for her we intervened…Wonderful to see Hendrix recovered.

    Lesa Corrine
    Pets for Life

  2. Sue Chakos says:

    Hi Matt,

    We used to live in Bay Vista Lane and the population of Browns in that area – compared to our place in Ewingsdale now – was phenomenal. They were often on the doorstep when we walked out and several times we nearly trod on them in the yard . One reason we didn’t buy in that street!!!! We have never seen a brown at our house in Tahra Cres though ; Bandy bandys, lots of pythons and whip snakes… which is nice.

    cheers sue
    companion animals welfare inc. CAWI

  3. Jayne says:

    After having a couple of dogs bitten a couple of times by a couple of brown snakes and various other encounters with same, I think it’s important for people to know that young brown snakes (even LARGE young brown snakes) often have a black “crown” or dark markings around their heads. This is not as commonly known as it should be.
    Regards, Jayne

  4. matt says:

    hi jayne, yes the simplification of ‘brown snake’ totally confuses the process of identification. juvelies will can also have banding (image) and george the snake man one stated the only definative feature is brown spots running down the underside, which you can see here.

    the local grey whipsnakes often have a reddish tinge and are brought in to the clinic after spade decapitation on the misaprehension its a baby brown. too tragic.

    m

  5. antonia staff says:

    Dear Matt, thanks for that good informative article. I remember one of Wofti’s puppies met her end exactly as you describe – a bit wobbly and then recovered to be found dead the next morning. I often find large and small snake skins in the garden and on the veranda and wonder if are all pythons. there is a large resident python in the roof – I call him Josephus the Historian as I am sure he catalogues all movement in the house. It is the little skins that worry me. Antonia

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