OTC [over the counter] ANTIHISTAMINES FOR YOUR PET
How they work? : Histamine is a chemical that binds to cells to cause inflammation [itchiness]
– it’s commonly associated with allergies. Antihistamines are drugs that compete with
histamine to bind to cells histamine receptors. That lessens the inflammation and “itch” that
allergens cause. Their effectiveness is determined by their ability to bind to the histamine
receptors on cells. The better/stronger they bind - the better they work. The most effective
antihistamine is different for every pet. We recommend a “trial and error” approach – try an
antihistamine with your pet for 2 weeks – IF it doesn’t help – then try another….
How effective are they? : In dogs they work pretty well, in cats they seem to be less effective.
DON’T GIVE TO A PET WITH A HEART PROBLEM or HYPERTENSION – CHECK WITH YOUR
VETERINARIAN FIRST!
WHAT TO NEVER FORGET? : ONLY GIVE PLAIN ANTIHISTAMINE !! There should be NO other
active ingredient on the package label. The other drugs sometimes added to certain
formulations of antihistamines can be lethal to your pet. Some newer formulations have
artificial sweeteners – be careful --- NO XYLITOL !!!!!!
DOGS:
Benadryl [diphenhydramine HCl] is usually dosed at 1 mg/lb orally every 8 – 12 hrs. May
cause drowsiness, sometimes used to sedate your dog on a long car ride.
Zyrtec [Ceterizine 10 mg] OR Claritin [Loratidine 10mg ]
For dogs less than 30 lbs = ½ tablet by mouth once every 24hrs
For dogs 30- 75 lbs = 1 tablet by mouth once every 24hrs
For dogs greater than 75 lbs = 1 tablet by mouth once every 12hrs
CATS:
Chlorpheniramine maleate 4mg [ Chlor-trimetron] given at 2-4 mg per cat [1/2 to 1 tab]
every 12 hrs
Loratadine 10mg [Claritin] given at a dose of 2.5-5 mg per cat [1/4 to ½ tab]every 12 hrs