The antihistamine Chlorpheniramine® is primarily used for dogs when treating allergic reactions. Using Chlorpheniramine® for dogs can ease the itching, inflammation, and irritation associated with skin, ear, and eye problems. This drug is also sometimes used as an anti-anxiety or anti-depressant medication and to prevent motion sickness. Veterinarians often choose Chlorpheniramine® for dogs when treating allergy issues, because it has a weaker sedative effect than some other antihistamine drugs.
When a dog reacts to an allergen, its system is often flooded with histamine, depending on how strong the reaction is. This natural substance typically causes inflammation and itching as it dilates capillaries in the affected area, allowing white blood cells to fight off an irritating substance. An allergic reaction is often triggered mistakenly by the body when it comes in contact with food, plants or other allergens. An antihistamine like Chlorpheniramine® for dogs suppresses the output of histamine, reducing swelling and itching.
Chlorpheniramine® causes drowsiness, decreases itching, and keeps nausea at bay. It is often used as a treatment for snake and insect bites, reactions to blood transfusions and vaccinations, and to relieve the itch of contact dermatitis and other skin problems. As Chlorpheniramine® for dogs has a mildly sedative effect, it is sometimes used to manage anxiety and depression. This drug is sometimes administered to dogs during travel to counteract motion sickness due to its anti-nausea effects.
This antihistamine works well for humans, less so for animals. Though it does show positive effects in cats in over 70 percent of cases, it is less viable for treating dogs. Chlorpheniramine® for dogs is often used by veterinarians as a first resort, however, because the side effects are so few compared to similar drugs.
Dosages typically come in 2-, 4-, 8-, or 12-milligram portions, administered two to three times a day in tablet, injection, and oral syringe forms. Chlorpheniramine® designed for human use is not typically recommended for use with dogs, since human-grade versions usually contain additional ingredients not intended for animals. This drug should not be used in conjunction with other sedatives since this can produce unpredictable side effects. Using Chlorpheniramine® for dogs can interfere with dermatological testing to determine allergens affecting the dog, so its use should be stopped before testing starts.
Like almost all medications, Chlorpheniramine® can have unwanted side effects. A dry mouth and a loss of appetite may result from its use. Nausea and vomiting may also occur, as well as difficulty urinating or moving the bowels. In rare cases, dogs may experience vision problems. Dogs that are allergic to this antihistamine can have extreme reactions, including seizure, stroke or even coma.