Corneal Disease in Dogs: Welfare and Treatment
Common Canine Corneal Conditions
Dogs are prone to a range of corneal conditions: corneal ulceration (most common; from trauma, entropion, distichiasis, or exposure); pigmentary keratitis (chronic corneal pigmentation, particularly in brachycephalics); chronic superficial keratitis (CSK/'pannus' — immune-mediated condition in German Shepherd Dogs and Greyhounds); interstitial keratitis (deep stromal inflammation); corneal dystrophy (inherited lipid deposits); and sequestrum (rare in dogs). Each requires different management.
Corneal Ulceration Welfare Impact
Corneal ulceration causes acute pain: blepharospasm, epiphora, photophobia, and conjunctival hyperaemia are reliable indicators. Superficial ulcers can progress to deep ulcers and descemetoceles (rupture risk) within 24-48 hours if infected or self-traumatised. Brachycephalic breeds are at elevated risk due to exposure keratopathy (prominent globes, reduced blink rate). Early treatment with broad-spectrum topical antibiotics, atropine (for ciliary spasm pain), and Elizabethan collar to prevent self-trauma is essential.
Indolent Ulcers
Indolent (refractory) corneal ulcers are superficial ulcers in older dogs that fail to heal despite weeks of standard treatment due to poor adhesion of epithelium to the underlying stroma. They cause persistent, frustrating low-grade pain and require specific treatment: grid keratotomy, diamond burr debridement, or superficial keratectomy to debride abnormal epithelium and stimulate healing. Boxers, Corgis, and Retrievers have breed predispositions.
Brachycephalic Ocular Welfare
Brachycephalic breeds (Pugs, French Bulldogs, Shih Tzus, Pekinese, Boston Terriers) have prominent globes, reduced blink rate, reduced blink completeness, shallow orbits, and often eyelid conformation abnormalities. These anatomical features cause chronic exposure, desiccation, and pigmentary keratitis. Regular application of ocular lubricants, surgical correction of eyelid abnormalities (medial canthoplasty, correction of entropion/ectropion), and in severe cases partial tarsorrhaphy (lid shortening) protect corneal welfare.
Chronic Superficial Keratitis
CSK (pannus) is an immune-mediated condition causing vascular, pigmented ingrowth from the lateral limbus that progressively covers the cornea and reduces vision in German Shepherd Dogs and Greyhounds. It is managed (not cured) with topical ciclosporin (alone or combined with corticosteroids). Lifelong treatment is required; UV light exposure accelerates progression, so protection from bright sunlight is recommended. Regular monitoring allows dose adjustment. Well-controlled CSK dogs maintain good vision and welfare.