Dogs can suffer from serious allergic reactions to common allergens such as food, mould or pollen. According to Drsfostersmith.com, allergy medications have been shown to control symptoms of allergies in 30 per cent of affected dogs. If the medication is used with other treatment methods, such as eliminating the allergen or adding fatty acids to a dog's diet, that percentage increases.
Cetirizine is an antihistamine more commonly known by the brand name Zyrtec. Antihistamines are medications that provide allergy relief and control symptoms in humans; they can be used in canines when prescribed by a veterinarian.
Cetirizine is used to control canine allergy symptoms, including itching and scratching on the body, chewing on the feet, rubbing of the face on objects, and hair loss.
A study on the effects of cetirizine in dogs, done by the Department of Clinical Studies at Cornell University, found that only two out of 23 dogs suffered from side effects. Side effects included vomiting and an increase in salivation.
Zyrtec comes in tablet form and must be taken orally. Veterinarians who prescribe Zyrtec for a dog will designate a proper dosage for the dog's weight class and give specific instructions on how often the medication can be administered.
If Zyrtec is ineffective in the dog, alternative medications may be prescribed. Alternative treatments for allergies in dogs include benadryl, fatty acid supplements, Chlor-Trimeton, steroids or a change in diet.