Insect Stings and Snake Bites in Dogs

The stings of bees, wasps, and yellow jackets, and the bites of ants all cause painful swelling and redness at the site of the sting, usually on a hairless area such as the nose or feet. The swelling may include the face and neck, even if the dog was not stung on the face. If the dog is stung many times, he could go into shock as a result of absorbed toxins. Occasionally, anaphylactic shock develops in a dog who has been stung in the past.

The bites of black widow and brown recluse spiders are toxic to animals. The first sign is sharp pain at the site of the bite. Later the dog develops intense excitability, fever, weakness, and muscle and joint pains. Seizures, shock, and death can occur, especially with the bite of the black widow spider. An antivenin is available to treat these bites.

The stings of centipedes and scorpions cause a local reaction and, at times, severe illness. These bites heal slowly.


  • Identify the insect.
  • If the stinger is found (a small black sac), remove it by scraping it out with your fingernail or a credit card. Do not squeeze or use tweezers, as this can inject more venom. (Only bees leave their stingers behind.)
  • Make a paste of baking soda and water and apply it directly to the sting.
  • Apply an ice pack to relieve the pain and swelling.
  • Apply calamine lotion to relieve the itching.
  • Your veterinarian may prescribe an antihistamine.

If the dog exhibits signs of hypersensitivity to the venom (agitation, face scratching, drooling, vomiting, diarrhea, difficulty breathing, collapse, or seizures), take him at once to the nearest veterinary facility for treatment of anaphylactic shock.

If your dog has a severe reaction to a bee sting, you should consult your veterinarian about keeping an Epi Pen kit available (the Epi Pen is a prepackaged injection of epinephrine used to counteract an anaphylactic reaction) and discuss the proper dose for your dog.

Pit Vipers (Rattlesnakes, Cottonmouths, and Copperheads)

You can identify these species by their large size (4 to 8 feet, 1.2 to 2.4 m, long), triangular heads, pits below and between the eyes, elliptical pupils, rough scales, and the presence of retractable fangs in the upper jaw.

The bite: You may see one or two bleeding puncture wounds in the skin; these are fang marks. These marks may not be visible because of the dog's coat. The pain is immediate and severe. The tissues are swollen and discolored due to bleeding at the site of the bite.

Note that 25 percent of poisonous snakebites lack venom and thus do not produce a local reaction. While absence of local swelling and pain is a good sign, it does not guarantee the dog won't become sick. Severe venom poisoning has been known to occur without a local reaction.

The dog's behavior: Signs of envenomation may take several hours to appear because of variables such as time of the year, species of the snake, toxicity of the venom, amount injected, location of the bite, and size and health of the dog. The amount of venom injected bears no relationship to the size of the snake. Signs of venom poisoning include extreme restlessness, panting, drooling, vomiting, diarrhea, uncoordinated gait, respiratory depression, shock, and sometimes death.

Coral Snakes

Identify this snake by its rather small size (less than 3 feet, .9 m, long), small head with black nose, and brightly colored alternating bands (red, yellow, and black) fully encircling the body. The fangs in the upper jaw are not retractable.

The bite: The puncture wounds from a bite are small and the pain is mild. There is little local reaction.

The dog's behavior: Coral snake venom is neurotoxic, meaning it affects the nerves and causes weakness and paralysis. Signs may be delayed for several hours. They include muscle twitching, pinpoint pupils, weakness, difficulty swallowing, shock, and collapse. Death is by respiratory paralysis.