Pannus is a progressive autoimmune eye condition requiring lifelong treatment to prevent blindness in predisposed dog breeds.
Pannus causes progressive visual impairment that affects dogs' ability to navigate their environment, engage in normal activities, and maintain quality of life. The opaque, pigmented cornea that develops in uncontrolled pannus reduces light transmission and ultimately causes complete blindness. Dogs with bilateral pannus lose the ability to see clearly, navigate outdoors, and engage in play and exercise normally - profound welfare harms. The good news is that topical tacrolimus or cyclosporine, used consistently, controls pannus effectively in the vast majority of cases and maintains near-normal vision indefinitely. The welfare harm of pannus is primarily experienced by dogs whose owners are unaware of the need for lifelong, consistent treatment.