An allergic dog may have eaten or touched an allergen, causing a red rash on the dog. Usually it will clear up after an hour, so the owner just needs to observe what makes the dog allergic and avoid the allergen in the future. If the rash does not go away and the dog has other adverse reactions, it must be sent to the hospital as soon as possible for anti-allergy treatment. Conjunctivitis dogs will have photophobia, redness, tearing, and flushing of the conjunctiva. It is recommended that the owner place the affected dog in a shaded area with 3% boric acid drops in the affected eye.
