Dogs react to venomous insect stings much like people do — with great variation. Some dogs have little or no reaction, while others have severe, even life-threatening responses. Obviously, one sting is less likely to cause a significant problem than an attack from many stinging insects.
The stinger of a bee, wasp, or hornet usually remains in the dog’s skin and may continue to emit poison, so remove it as soon as possible. Squeezing the stinger with a pair of tweezers will cause even more venom to be released. Instead, scrape the surface of the skin with the edge of a plastic credit card, which should remove the stinger.
Watch your dog carefully for a reaction. Mild swelling, redness, and pain at the site of the sting are normal, and should go away on their own, usually without treatment. Severe swelling and pain, hives (large swollen bumps around the sting or on other parts of the body), difficulty breathing, or sudden weakness are all signs of a more severe reaction to the sting, and you should pursue veterinary care immediately.