Antishistamines are a godsend in the spring and fall for people, but it’s contested whether or not they have the same effect on dogs who have allergies. If your dog is experiencing environmental allergies, will anthistamines like chlorpheniramine help their symptoms?
How do I know if my dog has allergies?
Dogs who have allergies have symptoms very similar to that of humans and include:
- Itchy skin
- Hair loss
- Frequent rashes or redness
- Frequent, recurring ear infections
- Skin infections
- Clear eye discharge
It’s important to note that the majority of dogs with allergies experience skin-related symptoms like itchiness and hair loss although rhinitis symptoms are still fairly common.
What symptoms will antihistamines relieve?
If you tell any layperson that your dog has allergy-symptoms, they’ll tell you to give your dog a Benadryl and it will magically cure them. What most people don’t know, however, is that science has found that histamine isn’t the cause of the vast majority of allergy skin symptoms, meaning antihistamines are very unlikely to help most allergy dogs.
If your dog is part of the smaller population that is experiencing the rhinitis symptoms, an antihistamine could provide a small amount of relief. Histamine plays a moderate role in things like sneezing and eye discharge.
However, you shouldn’t expect to see much–if any–relief in itch with an antihistamine. These dogs require other allergy control options such as allergy testing and associate immunotherapy (“allergy shots”).
Is chlorpheniramine a good choice for my dog?
Chlorpheniramine is commonly recommened by veterinarians because it helps alleviate eye discharge, redness, or itchiness caused by environmental allergies. It may also help with sneezing, runny noses, or coughing.
Is chlorpheniramine safe for dogs?
This is a safe antihistamine for the vast majority of healthy dogs. It isn’t recommended in dogs who:
- Have liver or kidney disease
- Are experiencing high blood pressure
- Have been diagnosed with glaucoma
- Have urine retention problems
- Are taking sedative medications like acepromazine or trazadone
Are there any side effects associated with this medication?
As with any antihistamine, there are very few side effects associated with chlorpheniramine. Drowsiness and dry mouth are the most common reported side effects.
If your dog is given too much chlorpheniramine, it can lead to severe lethargy and even respiratory depression. It’s very important to dose your dog carefully.
What is the chlorpheniramine dosage for dogs ?
You should always check with your veterinarian before giving your dog any medication, especially one that has the potential to cause severe, potentially dangerous sedation.
The dose range also varies depending on the dog and how severe their allergies are. Dogs with more severe symptoms may need a slightly higher dose, but this is something that should be left up to your general practice veterinarian or your veterinary dermatologist who specializes in canine allergies. Other dogs may be very sensitive to antihistamines (much like some humans are) and need a signifcantly lowered dose to avoid excessive sleepiness.
The generally accepted dose is 0.25mg/lb every 8 hours. Do not increase the dose or frequency without explicit instruction from your veterinarian.
If your dog is miserable this season with runny, itchy eyes and sneezing, it may be worth it to give him an antihistamine like chlorpheniramine and see if you notice any relief in your pup’s allergies.