Snake Bite in Cats and Dogs

Snake season is upon us again, and if you are a pet owner you should be aware of the signs.
An animal that has been bitten by a snake can present in many ways.  The presentation or signs depend on the species of snake, the age of the snake, the yield and contact of venom with the victim and whether its a cat or a dog.  Therefore it is unlikely that all clinical signs will be portrayed in your pet if bitten by a snake but as soon as one sign is recognized you should present them to a vet as soon as possible.
There are two stages of clinical signs seen in animals bitten by a snake, pre-paralytic syndrome, and the paralytic syndrome, you may not see both stages but once there is suspicion of snake envenomation the sooner treatment is given the better likelihood of a successful recovery.
Clinical Signs
Pre- Paralytic Syndrome –  usually occurs 10-15 minutes after a snake bite and involves an acute collapse, vomiting, increased salivation, urination, defecation, trembling, and increased respiration. This stage may be followed by an apparent recovery where the animal gets up after a few minutes and walks around as per normal. However, if this occurs it means a definite envenomation has occurred.
Paralytic Syndrome – may occur immediately or up to 2 hours after envenomation.  This generally develops as paralysis in animals starting from the back legs and moving towards the head
Signs include : Sudden death, increased salivation, vomiting, dilated pupils, elevated temperature, discoloured urine (red/brown) wobbly gait, weakness/paralysis in back legs that progresses to front legs over time which progresses to paralysis of the chest, neck, tongue muscles often noticed as change in bark.  Animals that are not treated may eventually die from suffocation as their chest and throat muscles no longer permit normal breathing pattern, animals will become depleted in oxygen (seen as a blue tinge in the gums and tongue).  Another indication of envenomation is a prolonged clotting time and you may see continual bleeding from the site of envenomation or blood in stools, vomit, phlegm (from cough) or urine.
Some signs may take some time to develop, for example dilated pupils may take up to 2-6 hours from snake envenomation and often does not occur in cats.  Therefore do not rely on one simple sign of envenomation to disclude your pet from being bitten by a snake.

Once taken to your vet – the vet will carry out a physical exam, and confirm snake envenomation has occurred. A clotting time test to confirm or exclude envenomation may also be performed however as previously mentioned this may not be apparent at time of presentation.  Once confirmed a snake envenomation has occurred, the vet will place a intravenous catheter into the dog/cat’s foreleg and start administering fluids and the anti-venom.  The anti-venine is given in a diluted form slowly over a period of 30 minutes, occassionaly dogs may have an allergic reaction to the ant-vinene, the vets do everything possible to avoid this reaction by using anti-inflammatories and anti-histamines, however sometimes regardless of these efforts a reaction may still occur.

After intial treatment with anti-venine the dog/cat is left in peace and quiet with a fluid drip until ready to go home.  Additional medication throughout the course of treatment in hospital depends on a case by case basis, animals that shoul clotting defects will be given Vitamin K to aid platelet formation, and antibiotics to prevent infection.

Depending on the severity of the case at presentation to the vet often depends on the prognosis of the envenomation and depicts the duration of stay (thus cost of treatment).  Animals that are left until they show obvious signs of paralysis 12-24 hours after envenomation can expect a lengthier stay in hospital compared to those where envenomation has occurred immediately prior to presentation to the vet.  Obviously the type of snake also plays an important role, as does size of animal and amount of venom; for example: a small dog bitten by a large king brown that has a large amount of venom stored may produce a fatal bite compared to a bite to a larger dog with same size snake and venom.

If my dog has been treated for snake bite this year I won’t need to bring it in again if he get’s bitten again?  False.  The antivenom is not a vaccination, there is no lasting protection with previous treatments thus if your dog seeks out snakes and is bitten again after being treated for snake bite the dog will need to be presented again to the vet for another course of treatment.

If I have a bottle of Vitamin C at home and my dog is bitten by a snake I should be able to treat it myself if I give it a shot of Vitamin C.  False. Vitamin C is ascorbic acid, which is proven to be useful as an anti-oxidant and scavenger of free radicals (molecules released into the blood during periods of inflammation).  It is commonly used in practice when treating snake bites as an additive to the antivenin.  It is given under the skin or into the vein to prevent further break down of muscle cells and red blood cells which occurs during envenomation and paralysis.  As a single treatment it would not prevent the dog becoming paralysed from the snake bite and dying.

If my dog has been bitten by a snake or numerous snakes in it’s lifetime it is likely to suffer from chronic kidney problems? Providing your pet is brought to a vet clinic as soon as possible there will be minimal long term effects of snake envenomation.  When animals are not brought into the clinic and not placed on intravenous fluids they may likely experience renal / kidney disease later on in life.

Once bitten, and treated for snake bite, my pet won’t need any after care attention when it is sent home? Dogs and cats that are bitten by snakes and treated successfully at a veterinary clinic may experience some weakness and lethargy for some days to weeks after treatment.  Once that animals can eat and drink on their own they are usually sent home, however they may still have some deficits in their capabilities, thus may not run around as per normal for some time.  You may also have repeat episodes of envenomation if a pocket of venom forms soon after the bite (this commonly occurs when bitten in the mouth) and isn’t released into the blood stream until some time later after appropriate treatment.

My pet won’t die if it is bitten by a snake and treated at the vets.  Unfortunately this not a guarantee that can be given, each patient is treated on a case by case basis, severe cases often have a worse prognosis particularly victims of Taipans, however we aim to ensure all snake bite victims are monitored closely and treatment initiated as soon as possible to achieve a good result.

  • In the event of a snake envenomation
  • remove all people and pets from the area the snake was last seen
  • advise of appropriate authorities if human envenomation has occurred – ( dial OOO )
  • ring Gray St Veterinary Clinic to advise if your pet has been bitten
  • if snake is deceased – and you are not sure if the snake is poisonous bring snake with you to the clinic – We do not advise to seek out the snake. 
  • Remember if you have noticed the snake bite the dog or see the above signs that is all the confirmation we need that envenomation has occurred.