Hello, my name is***** and I have over 20 years of experience as a veterinarian. I'm sorry to hear that your fellow Harper has red, swollen, inflamed tissue around his eyes. I suspect that his conjunctiva (the pink tissue between the whites of the eye and the eyelids) are affected.
Dogs can get infectious conjunctivitis (Pink eye) but more commonly we see conjunctivitis from an allergic reaction or secondary to immune mediated disease (body attacks itself).
If this is a repeated problem for him one possible underlying problem is KCS or dry eye. This is an autoimmune like condition in which the body attacks the tear glands and scarring results with decreased tear production. This can be very uncomfortable for them. With poor tear production the eyes don't get dirt and bacteria flushed out as it should be, his eyes will be itchier, they would get red, and he will rub them more, thus predisposing toward infections/irritation.
KCS is diagnosed by measuring tear production with a special test called a Schirmer tear test, which measures the amount of liquid tears in the eyes at the time they are tested. Sometimes if a dog is stressed or excited we get normal levels, when most to the time they are not. So with a normal test level if I have a strong suspicion that tear production is poor I will ask to retest them at a later date.
Ideally with KCS we would use an immunosuppressive eye drop to knock down his immune system's reaction and allow his tear glands to start functioning again. Common immunosuppressive medications include Tacrolimus or Cyclosporine eye drops. These drops or the oil vehicle that they are in can be very irritating, especially when his eyes are already so sensitive. We often need to start with medication at a lower percentage concentration level to acclimate the eyes and then increase the percentage in the product.
Unfortunately the other problem is that these drops can take several weeks to start working. If you stop too soon then he won't respond, and if you stop them completely after he improves the immune system will attack the tear glands again, and his symptoms will return. In the meantime while we wait for the drops to fully work I often will recommend using artificial tears too to keep their eyes more comfortable. You can use any artificial tear product while waiting for the immunosuppressive drug to work, but the drops rather then the gel formulations seem to be a little more soothing.
For now I would warm compress his flush his eyes and then flush them thoroughly with sterile saline. Then you can use artificial tears to soothe his eyes every 3-4 hours.
If there is a yellow or greenish colored discharge you can apply Polysporin ointment (available at the drug store) to his eyes once then have been cleaned and flushed and he has artificial tears applied. Apply a 1 inch line of ointment to his eyes every 6-8 hours. Use for 3-4 days past any evidence of green or yellow colored discharge.
If he isn't improving and he needs to see his veterinarian do stop both medications for 24 hours before his appointment so they can accurately measure his levels of tear production.
Another possible cause of irritation as I mentioned are allergies, which make his face very itchy, and when he rubs his face he accidentally irritates his eyes and the area around them and may introduce bacteria into his eyes.
These dogs benefit from artificial tears too.
They also benefit from a combination of antihistamines and high doses of omega-3 fatty acids to help combat the symptoms of allergy. In combination fatty acids and antihistamines work synergistically, much better than either one alone. If his symptoms worsen during a particular season I would think that inhaled allergens are a part of his problem.
Antihistamines to try include:
1)Benadryl (diphenhydramine only don't use the combination products with acetaminophen or decongestants as they can be toxic for dogs) at 1mg to 2mg per pound of body weight or one 25mg capsule per 15 to 25 pounds of body weight orally every 8 hours.
OR 2)Claritin (loratidine) at 5mg per 25 pounds of body weight once or twice daily.
OR 3)Hydroxyzine at 1mg per pound of body weight orally every 8 hours.
OR 4) Chlorpheniramine at 4mg to 8mg per dog once or twice daily.
OR 5) Zyrtec (Cetirizine hydrochloride) at 1/2 mg per pound of body weight orally every 24 hours. That would be one 10mg tablet per 20 pounds of body weight. Make sure it is NOT the formulation with a decongestant (such as Zyrtec-D) because dogs cannot tolerate decongestants.
Some dogs do better on one antihistamine rather than another. Give the one you pick a week trial and if it isn't working try another. Be aware antihistamines can cause sleepiness or hyperactivity in some dogs. These side effects do wear off with repeated use.
Omega-3 fatty acids are fish oil products. 3V by DVM or Derm Caps ES are good brand name products. Use the high end of the dosing schedule for your pup's weight. I recommend a dose based upon the EPA portion (eicosapentanoic acid) of the supplement as if we do that the rest of the supplement will be properly balanced. Give him 20mg of EPA per pound of body weight per day. For example an 80 pound dog could take 1600mg of EPA per day.
If he isn't improving he can see his veterinarian to measure tear production.
In the meantime it is fine to use artificial tears and if he has a history of itchy skin and allergies then trying omega 3's and antihistamines too is reasonable.
Best of luck with your fellow, please let me know if you have any further questions.