Red eyes – conjunctivitis in dogs and cats
Source: Merck Veterinary Manual

When a dog comes in for a “check eye” visit my mind immediately worries about a corneal ulcer / scratch. That is the FIRST rule out and the BEST reason to have any eye condition checked when noticed.

But quite often if BOTH eyes are pink or red, it’s conjuncitivitis which has a bunch of possible causes.

  • Allergies
  • Atopy
  • Chemical / environmental irritation
  • Bilateral corneal damage
  • Infections
  • Low tear production

MOST cases are caused by atopic / allergic causes.

When bacteria are involved there’s often more “redness” instead of pinkness and very often there’s discharge (often yellowish) from the eye.

By fortunate happenstance most eye ointments I would prescribe for atopic / inflammatory responses ALSO contains antibiotic activity. Usually Neomycin, Polymyxin, Bacitracin, -or- Terramycin, Tobramycin. And even more recently, a quinolone antibiotic.

“Pink eye” isn’t usually a dog “thing” because they have their OWN version of pink eye which isn’t contagious to you. Caused by Moraxella ‘bovis’ which is principally a cow germ –  not a dog germ but sometimes crosses over and becomes a dog germ. People have their own contagious Moraxella species I forget what it’s called. But it’s not the dog version so don’t worry about getting ‘pinkeye’ from your dog. Nor should you worry about giving you dog pinkeye.

Under most circumstances I prescribe PBN-Dex or similar but on occasion, SIMILASAN is enough. I also “stain” the eye with Flourescein to make sure there’s no CORNEAL ULCER.

So that’s what you ought to know about conjunctivitis.

Doc Johnson





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