Antihistamines for Skin Allergies in Dogs

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Antihistamines can be of significant benefit in controlling skin allergies in dogs. Although
not as universally effective as cortisone type medications (prednisone), they have fewer
side effects and significantly help up to half of dogs with skin allergies. They are well
worth trying in order to avoid or even reduce the level of prednisone needed to control
itching. In any individual patient, one antihistamine may be significantly more effective
than another. Therefore, it is important to try several until one is found that does help,
before determining that they are not effective in your dog.
Please try the following antihistamines for a minimum of 2-3 weeks. If effective, continue
to give them if your dog is itchy (frequently needed only certain times of year, but they
can be used year-round). If one is not effective, proceed to the next one on the list.

Diphenhydramine (Benadryl): 1mg per pound (one 25mg tablet for a 25lb dog) twice
Cetirizine (Zyrtec): ¼ – ½ mg per pound (one 10mg tab per 30-40 lbs) twice daily.
Loratadine (Claritin): ¼ mg per pound (half of a 10mg tablet per 20 lbs) once daily.
Clemastine (Tavist-1, Antihist-1): 0.02mg per pound (one 1.34mg tablet per 65lb dog)
twice daily.
Hydroxyzine: 1mg per pound (one 25mg tablet for a 25lb dog) twice daily. (Prescription
product – Available at Fairhaven Vet)
Omega-3, Fish-oil Fatty Acids (“Welactin”), at fairly high doses, can really help reduce skin itch
and inflammation and are healthy for the rest of the body. All Fish-Oil products should be dosed
based on their combined dose of the two main Omega-3 Fatty Acids, EPA and DHA
• Dogs less than 30 lbs: 75mg PER POUND of combined EPA and DHA daily
• Dogs 31-60 lbs: 60mg PER POUND of combined EPA and DHA daily
• Dogs > 60 lbs: 50mg PER POUND of combined EPA and DHA daily.
Please work up to these doses gradually over about 2-weeks to allow your dog’s digestive tract to
adjust. Using a high-potency product will minimize the amount of Fish Oil actually needed – We
recommend “Welactin” due to it’s high-potency and purity.