Warm weather months often include run-ins with bees, wasps, and mosquitoes. Very often bites and stings produce an allergic reaction that adds to our misery. This is also true with our pets. Allergic reactions are just as common in our pets and can occur in dogs of any age, breed, or sex. It generally takes several exposures before a reaction occurs, and reactions can vary from mild to severe. Mild. Mild reactions include fever, sluggishness, and loss of appetite. Mild reactions are probably also related to an immune reaction from a vaccination. They usually resolve without treatment.
Moderate. Urticaria is a moderate vascular reaction of the skin marked by hives or wheals and rapid swelling and redness of the lips, around the eyes, and in the neck region. It is usually extremely itchy. Urticaria may progress to anaphylaxis and is considered life-threatening. This is the most common reaction in dogs.
Severe. The most severe reaction is anaphylaxis, a sudden, severe allergic response that produces breathing difficulties, collapse and possible death. Symptoms usually occur within minutes following an insect bite or sting and proceed rapidly. Symptoms usually include sudden onset of vomiting, diarrhea, staggering, rapid drop in blood pressure, swelling of the larynx leading to airway obstruction, seizures and cardiovascular collapse or death. This reaction is life-threatening for your dog.
Both anaphylaxis and urticaria are triggered by antibodies that the immune system has made to some portion of the insect venom. The antibodies cause inflammatory cells like basophils and mast cells to release substances that cause the allergic reaction. Most dogs allergic to insect stings will develop swollen face and hives and not anaphylaxis.
There is no diagnostic test for anaphylaxis or urticaria, but your veterinarian can determine the presence of an allergic reaction by doing a quick physical examination. A history will reveal recent exposure to stinging insects.
Anaphylaxis is an extreme emergency and it occurs soon after being stung. Your veterinarian will begin immediate emergency life support. This will include establishing an open airway, administering oxygen, and intravenous fluids to increase blood pressure. He will probably administer drugs such as epinephrine and corticosteroids. Animals that survive the first few minutes usually return to normal health.
If your dog is known to be allergic to stinging insects, your veterinarian may recommend that you administer Benadryl® (diphenhydramine) in the early stages of the allergic reaction. Unfortunately, oral medication may not be sufficient, and you will have to take your dog in for examination and treatment.
In general, there is no way to predict if your dog will have an allergic reaction. If he has had a reaction before, make sure your veterinarian knows about it and it is in your pet's records. Since each reaction becomes more severe you should keep epinephrine available and know how to use it in case a reaction occurs. Ask your veterinarian about an "epi-pen" to keep on hand or take with you when you travel. This is a special syringe and needle filled with a single dose of epinephrine.