A bite from a poisonous (venomous) snake or lizard requires emergency care. If you have been bitten by a snake or lizard that you know or think might be poisonous, call 911 or other emergency services immediately. Do not wait for symptoms to develop.
If you are not sure what type of snake or lizard bit you, call your provincial poison centre immediately to help identify the snake or lizard and find out what to do next. Medicine to counteract the effects of the poison (antivenom) can save a limb or your life.
It is important to stay calm.
Poisonous snakes or lizards found in North America include:
Pit vipers are found in the provinces of Ontario, British Columbia, Alberta, and Saskatchewan.
Symptoms of a pit viper snakebite often appear from minutes to hours after a bite. Severe burning pain at the site usually begins within minutes, and then swelling starts spreading out from the bite.
Things that affect the severity of a poisonous snake or lizard bite include the:
If you do not develop symptoms within 8 to 12 hours, it is possible that no venom was injected; this is called a dry bite. At least 25%, and perhaps up to 50%, of bites are dry. If poison is released in the bite, about 35% of the bites have mild injections of poison (envenomations), 25% are moderate, and 10% to 15% are severe.
It is important to remember that a snake only injects part of its venom with each bite, so it is still dangerous after the first strike. A bite from a young snake can be serious. And a dead snake, even one with a severed head, can still bite and release venom by reflex action for up to 90 minutes after it dies. Even if you do not develop symptoms within 8 hours, continue to watch for symptoms for 2 weeks or more.
Most snakes and lizards in North America are not poisonous. Bites may be frightening, but most do not cause serious health problems. A bite from a small non-poisonous snake might leave teeth marks, a minor scrape, or a puncture wound without other symptoms. Home treatment often relieves symptoms and helps prevent infection.
Although most non-poisonous snakebites can be treated at home, a bite from a large non-poisonous snake (such as a boa constrictor, python, or anaconda) can be more serious. In North America, these snakes are found in the Florida Everglades and zoos, but they may also be kept as exotic pets. The force of the bite can injure the skin, muscles, joints, or bones. Other problems can occur with a non-poisonous snake or lizard bite even if the reptile is small. A snake or lizard's tooth may break off in a wound or a skin infection may develop at the site of the bite.
Check your symptoms to decide if and when you should see a doctor.
Many things can affect how your body responds to a symptom and what kind of care you may need. These include:
You have answered all the questions. Based on your answers, you may be able to take care of this problem at home.
Pain in adults and older children
Pain in children under 3 years
It can be hard to tell how much pain a baby or toddler is in.
Symptoms of infection may include:
Certain health conditions and medicines weaken the immune system's ability to fight off infection and illness. Some examples in adults are:
Symptoms of a severe allergic reaction (anaphylaxis) may include:
A severe reaction can be life-threatening. If you have had a bad allergic reaction to a substance before and are exposed to it again, treat any symptoms as an emergency. Even if the symptoms are mild at first, they may quickly become very severe.
You may need a tetanus shot depending on how dirty the wound is and how long it has been since your last shot.
Shock is a life-threatening condition that may quickly occur after a sudden illness or injury.
Symptoms of shock (most of which will be present) include:
Shock is a life-threatening condition that may occur quickly after a sudden illness or injury.
Symptoms of shock in a child may include:
Symptoms of difficulty breathing can range from mild to severe. For example:
Based on your answers, you may need care soon. The problem probably will not get better without medical care.
Based on your answers, you may need care right away. The problem is likely to get worse without medical care.
Based on your answers, you need emergency care.
or other emergency services now.
If you were bitten by a snake or lizard that you know or think is poisonous, call 911 or other emergency services immediately. Do not wait for symptoms to develop. Symptoms may progress from mild to severe rapidly.
If you are not sure what type of snake or lizard bit you, take a picture of it. But do not do this if it will delay treatment or put someone at risk for more bites. Do not waste time or take any risks trying to kill or bring in the snake. Only trap a poisonous snake if the chances are good that it will bite more people if you let it go. It is important to remember that a snake only injects part of its venom with each bite, so it can still hurt you after the first strike. And a dead snake, even one with a severed head, can bite and release venom by reflex action for up to 90 minutes after it dies.
Medicine (antivenom) to counteract the effects of the poison can save a limb or your life. Antivenom is given as soon as a doctor determines it is needed, usually within the first 4 hours after the snakebite. Antivenom may be effective up to 2 weeks or more after a snakebite.
Immediate home treatment should not delay transport for emergency evaluation.
Avoid doing anything that might cause more problems with the snake or lizard bite.
If you are certain the snake or lizard was not poisonous, use home treatment measures to reduce symptoms and prevent infection.
Call your doctor if any of the following occur during home treatment:
Snakebites are more likely to occur in warm-weather months when both snakes and people are more active outdoors. Most snakebites occur on the fingers, hands, and arms when someone is working with or trying to catch a snake. The legs and feet are also common bite sites; these bites usually occur when a person (especially a child or a hiker) accidentally disturbs a snake.
Snakes and lizards are popular exotic pets, so the risk for being bitten has increased.
Many snake and lizard bites can be prevented.
If you are often in an area where there are poisonous snakes, consider carrying a first aid kit. Carry a cellular phone, if you have one, to call for help if you are bitten.
To prepare for your appointment, see the topic Making the Most of Your Appointment.
You can help your doctor diagnose and treat your condition by being prepared to answer the following questions:
ByHealthwise StaffPrimary Medical ReviewerWilliam H. Blahd, Jr., MD, FACEP - Emergency MedicineAnne C. Poinier, MD - Internal MedicineAdam Husney, MD - Family Medicine
Current as ofMarch 20, 2017
Current as of: March 20, 2017
William H. Blahd, Jr., MD, FACEP - Emergency Medicine
& Anne C. Poinier, MD - Internal Medicine & Adam Husney, MD - Family Medicine
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