What are the symptoms of conjunctivitis in dogs?

Redness of the conjunctiva (the white of the eye, the third eyelid), ocular discharge (from watery and clear to mucopurulent yellow or green), swollen eyelids, blepharospasm (squinting), frequent pawing at the eye, and photophobia (avoiding light).

Can I use human eye drops for my dog?

Not without veterinary prescription. Human eye drops may contain active ingredients that are harmful to dogs — some (such as concentrated chlorhexidine or certain anti-inflammatories) can cause corneal damage. If your vet specifically prescribes a human product, it may be appropriate, but never do so on your own initiative.

Does conjunctivitis in dogs heal on its own?

Mild irritation from dust or wind may resolve with gentle cleaning. Most cases require treatment: antibiotic drops for bacterial conjunctivitis, antihistamines or steroids for allergic, and foreign-body removal if needed. Without treatment it can progress to corneal ulceration.

Is dog conjunctivitis contagious to other dogs?

Viral and bacterial conjunctivitis can spread between dogs, especially in groups (kennels, dog parks). Allergic or irritant conjunctivitis is not contagious. If you have multiple dogs, use separate items and wash your hands after handling the affected dog.

Conjunctivitis in Dogs: Symptoms, Types and Treatment

What Is Conjunctivitis?

The conjunctiva is the mucous membrane lining the inner surface of the eyelids and the front of the eyeball (sclera). Dogs also have a third eyelid (nictitating membrane) in the inner corner of the eye — when it protrudes or becomes red, it is a visible sign of inflammation. Conjunctivitis means inflammation of this membrane.

Types of Canine Conjunctivitis

Bacterial Conjunctivitis

The most common form. Caused by Staphylococci, Streptococci or Pseudomonas. Typically presents with purulent, yellowish-green discharge and crusting of the lids in the morning. Treatment: topical antibiotic drops or ointment (e.g. gentamicin, chloramphenicol) after a swab culture.

Viral Conjunctivitis

Usually bilateral, often accompanied by sneezing and nasal discharge. Can be a sign of canine distemper (Carré disease) or adenovirus. Distemper is a veterinary emergency — vaccination is the only protection.

Allergic Conjunctivitis

Bilateral, watery discharge, often seasonal (pollen) or year-round (dust mites, mould). Frequently combined with atopic dermatitis. Treatment: antihistamines, topical corticosteroids as prescribed by a vet.

Keratoconjunctivitis Sicca (KCS) — Dry Eye

Insufficient tear production leads to chronic inflammation, thick mucoid discharge and a dull corneal surface. Common in Cavalier King Charles Spaniels, West Highland White Terriers and Bulldogs. Diagnosed with the Schirmer Tear Test (normal >15 mm/min). Treatment: cyclosporin or tacrolimus drops, usually lifelong.

Brachycephalic Breeds

Pugs, Bulldogs, French Bulldogs — their prominent eyes are more prone to irritation, corneal ulcers and entropion (inward-rolling eyelids that rub the conjunctiva). Regular ophthalmological checks are strongly recommended for these breeds.

Diagnosis

Slit-lamp examination: assesses conjunctiva, cornea, lids and third eyelid.
Schirmer Tear Test: measures tear production (suspected KCS).
Fluorescein staining: reveals corneal ulcers (blue glow under UV light).
Conjunctival swab: for recurrent or treatment-resistant cases.

When Is It an Emergency?

Sudden intense pain, eye held tightly shut (possible corneal ulcer).
Cloudy or bluish-white cornea.
Suspected foreign body in the eye.
Signs of distemper (fever, cough, nasal discharge).
No improvement after 48 hours of treatment.

Home Eye Care

Gently remove discharge with sterile saline and a soft cloth — always wipe from inside to outside, never use the same cloth on both eyes. Do not force off dried crusts. Use a cone collar if the dog is pawing at the eye. Always complete the full course of prescribed drops.

Log your dog's eye health in Purzi — record symptoms, vet visits and ongoing treatment so you have all the information to hand at every appointment.