Pigmentary Keratitis In Pugs

Pugs are becoming increasingly popular as a breed due to their fun-loving nature and small size. It is common for them to have large and prominent eyes and as a result suffer from a pre-disposition to pigmentary keratitis that can significantly reduce vision – often starting in young dogs.

Most Pugs will have some pigment on the medial cornea, but they vary in severity from being nearly unaffected to having severe thick black pigment covering a large part of the cornea.

This 2 year old Pug already has mild to moderate pigmentary keratitis of both eyes.

The cause is thought to be multi-factorial, with entropion/trichasis believed to be a significant contributor due to chronic irritation/inflammation of the ventromedial cornea. Further factors include macropalpebral fissure, prominent eyes and lagophthalmos, causing exposure and drying of the central cornea.
Central and complicated deep ulceration with neovascularisation, fibrosis and pigmentation is a further significant contributor and finally keratoconjunctivitis sicca (KCS) and/or qualitative tear-film disorders. In short any contributor to inflammation will contribute to cause pigmentary keratitis in the Pug.

Another Pug with medial entropion/trichiasis, early KCS and dense medial pigment already obscuring a large part of the pupil.

Management is most successful if the pigmentary keratitis is treated and managed from the early stages of onset. It is important to eliminate as many inciting factors as possible and underlying KCS should be identified and managed. Additionally many Pugs will benefit from surgery to reduce exposure and eliminate entropion. MEDIAL PERMANENT CANTHOPLASTY combined with ENTROPION surgery is the treatment of choice. It also reduces the medial eyelid opening and therefore also the exposure of the cornea, as well as improving the spreading of the tear film which helps to protect the eyes.

Pug post bilateral medial canthoplasty and corneoconjunctival transposition graft in the left eye for treatment of a deep central corneal ulcer.

Other brachycephalic breeds such as the Shih Tzu, The Boston Terrier, The Bulldog, The French Bulldog, The Japanese Spitz, can also suffer from similar problems and benefit from the same treatment, but the pigmentary keratitis is rarely as severe as in the Pug.