Bad news for dog parents is that summer is snake season, which means that humans and dogs are at risk of snake bites. While the prospect of being bitten, no matter the snake, is not a happy one, the fact that venomous snakes abound across the entire continental US makes it somewhat worse (Alaska is not plagued by snakes – they have the sense to avoid the extreme cold).

Timber_Rattlesnake snake bitesThe different species of poisonous snakes in the US can be separated into 4 broad categories:

  1. Rattlesnakes
  2. Copperheads:
  3. Cottonmouths or water moccasins
  4. Coral snakes

There are several species within each category, for example:


  • Banded rock rattlesnake
  • Diamondback rattlesnake
  • Mojave rattlesnake
  • Pacific rattlesnake
  • Sidewinder rattlesnake
  • Timber rattlesnake
  • And more


  • Broad-banded copperhead
  • Northern copperhead
  • Osage copperhead
  • Southern copperhead
  • Trans-Pecos copperhead


  • Eastern cottonmouth
  • Florida cottonmouth
  • Western cottonmouth

Coral snakes

  • Arizona coral snake
  • Eastern coral snake
  • Texas coral snake
  • Western coral snake

About snake venom

The venom in snake bites contains several different toxins that are designed to paralyse and kill prey – and enemies. There are two types of venom:

  1. Neurotoxic, which affects the nervous system
  2. Hemotoxic, which affects the blood system

One snake can have both neurotoxins and hemotoxins.

Effects of snake venom

In addition to pain, which is rather obvious, snake venom can cause:

Northern copperhead snake

  • Cells to shut down
  • Numbness
  • Impaired bodily functions
  • Amputation to prevent the spread of the poison
  • Damage to blood vessels
  • Impaired blood clotting
  • Localised tissue damage
  • Neurotoxicity and paralysis
  • Death

The severity of the effects depends on several factors, including:

  • Age of the snake – younger snakes have more toxic venom
  • Species of the snake
  • The time since the last bite – snakes that haven’t bitten in a while have more concentrated venom.
  • Aggressiveness of the attack – the more aggression (the greater the threat) the more toxic the venom.
  • Depth of the bite – deeper snake bites are more dangerous.
  • Number of bites – more snake bites = more venom
  • Amount of venom injected – dry snake bites don’t have any venom at all
  • Location of the snake bite – bites to the torso can be especially dangerous as the poison can reach the heart quickly. Snake bites to the head or limbs are less dangerous.
  • Size of the dog – the smaller the dog the worse the symptoms
  • Movement post-bite – the more your dog moves, the quicker and further the venom spreads
  • The time until treatment – the sooner your dog gets treated for the snake bite, the less severe the symptoms are allowed to become and the better the prognosis.

What are the signs of a venomous snake bite?

Some symptoms depend on the type of venom, but in general if you see any of the following signs you should take your dog to your veterinarian immediately:

  • Yelp of pain – obviously, especially if it’s accompanied by a leap back from a high-risk area.
  • Pain remains intense
  • Puncture marks – rapid swelling, bleeding and discharge may obscure bite marks
  • Swelling and skin discoloration in the affected area
  • Excessive drooling
  • Vomiting and diarhea
  • Bloody urine and urinary incontinence
  • Rapid breathing or difficulty breathing
  • Dilated pupils
  • Pale gums
  • Disorientation and confusion
  • Weakness
  • Tremors
  • Collapse
  • Paralysis
  • Shock
  • Death

It can take up to 10 – 18 hours for symptoms to appear after a snake bite attack.

How are venomous snake bites treated?

Cottonmouth_SnakeThe best way to treat venomous snake bites is with medication and rest.

Medications include:

  • IV Fluids to prevent blood pressure dropping
  • Oxygen if breathing difficulties present
  • Antihistamines
  • Antibiotics to prevent secondary infections
  • Anticonvulsants if your dog has seizures
  • Pain medication, often with a sedative effect to keep dogs still
  • Blood transfusion in extreme cases when blood doesn’t clot
  • Antivenin (anti-venom) may be given at the discretion of the veterinarian. It should be given as soon as possible after the snake bite to be effective; within 4 – 6 hours is best. (It is very expensive, however, costing between $450 and $750 per vial. Depending on the size of your dog, it can take up to 10 vials for treatment to be successful.)

Some medication is delayed to prevent complications; for example, anti-inflammatory meds may be delayed by 24 hours, steroids may also be delayed until the risk of infection has been eliminated. Alternatively, steroidal medication can be combined with antibiotics to counter the immunosuppressive action of steroids.

Your dog is likely to be hospitalised so her condition can be closely monitored, this period can be as short as 12 hours or as long as 72 hours. One of the primary reasons for keeping dogs overnight is to ensure that there is no damage to the organs.

Most pets (95%) survive with proper treatment, but note that it can take several weeks for your dog to recover fully.

What can you do to prevent snake bites?

You can try a snake bite vaccination, but note that no controlled studies have been carried out, so there’s no scientific evidence that it works. Note also that the vaccine doesn’t make your dog immune to snake bites; she will still require treatment. At best the vaccine can lessen the severity of the symptoms and improve recovery time.

You can consider snake aversion training but make sure you go to a trainer who doesn’t use shock collars. Not only are shock collars cruel and inhumane, but they often teach dogs exactly the opposite of what was intended, and as a result, the emotional and behavioral fallout can be monstrous. Ethical animal societies don’t endorse shock collars in snake aversion training, but that doesn’t mean training can’t help.

Ethical snake avoidance trainers use sight, sound, smell and simulations to train dogs to avoid certain species. For example, the sound of a rattlesnake or the smell of cottonmouth can be the cue for your dog to come straight to you. Also, you should never underestimate a solid recall and a steak-proof leave-it.

The best way to prevent snake bites is to manage your dog’s environment when at home and out on walks.

  • Keep your dog on-leash on walks
  • Choose your walks carefully and try to avoid high-risk areas, including high grass, rocky outcrops, streams, and marshes
  • Keep your dog’s nose out of holes in the ground and under rocks and tree branches
  • Stick to open paths instead of overgrown routes; it’ll be easier to spot snakes sunning themselves
  • Don’t walk at night because most snakes are nocturnal
  • If you see or hear a snake, slowly walk away
  • Make sure your yard isn’t overgrown and that walkways are clear
  • Don’t leave food around that will attract rodents, which will attract snakes
  • Store firewood away from the house
  • Fortify your fence
  • Learn as much as you can about snakes in your area.

What to do if your dog is bitten

  • Stay calm, not only will your dog pick up on your emotions but you also need to act quickly and carefully, which is difficult when you’re panicking.
  • Try to identify the snake, as this will help with treatment. Pay attention to color, size and patterns.
  • Examine your dog’s body and don’t stop if you find a puncture wound; there could be more than one.
  • Clean the wound with cold water, this also controls swelling.
  • If you’re on a walk, try carrying your dog back to the car.
  • Once in the car, keep your dog as quiet and warm as possible.
  • Try to immobilize the limb without wrapping it up tightly.
  • Get to a veterinarian ASAP.

What NOT to do

Coral snake

DO NOT do the following:

  • Cut the wound to squeeze out the venom and definitely don’t try to suck out the venom, as you could cause an infection.
  • Apply a tourniquet, as it can cause tissue damage.
  • Ice the wound, as it constricts the blood vessels and concentrates the venom, increasing the risk of muscle damage.
  • Apply topical treatment.

As with so many things in life, information is your best form of protection. Find out what snakes live in your area, train yourself to recognise them and make sure you have a mini-emergency treatment kit in your car, including clean water, a blanket, and a strap to immobilize your dog. Above all, avoid high-risk areas and if you think there are risky elements in the environment, put your dog on leash. Being on lead may annoy your dog, but it could save her life.