If a dog develops hives, identify the allergen as quickly as possible and remove it, according to WebMD. If it seems to be triggered by food, modify the dog's diet. If the hives appear after contact with shampoo or an insecticide, bathe and rinse the dog's coat thoroughly. If a dog has a flea allergy, eliminate the fleas and give it a medicated bath to control and alleviate itching.
For both types of allergies cases, vets can prescribe antihistamines or corticosteroids for a few days to reduce itching. WebMD suggests always contacting a veterinarian before administering Benadryl.
The Bark, a dog magazine, states that allergies among dogs are rarely cured. Instead, most owners seek to diminish the severity of the reaction. Research has shown that early supplements of high-potency probiotic bacteria decrease the likelihood of a dog developing skin allergies later in life. Most dogs can improve their allergies through their diet. The Bark lists fish oils, nutritional yeast, alfalfa and freshly milled flaxseed as useful additions, although improvements can take up to three months to appear.
If a dog is regularly groomed, The Bark also recommends using lower heat to dry its coat and switching to plain water for baths. If shampoo is necessary, use a moisturizing type followed with conditioner.