Dental "hooks" - the front half of each first upper cheek tooth is much too long and must be floated (filed down) so that the horse can chew with normal motion, and so the lower jaw can slide forward without catching on the hooks, as is required when a horse lowers its head to do collection work.
Squamous Cell Carcinoma - a common tumor of the third eyelid (the pink tissue in the corner of the eye). The third eyelid appeared lumpy and somewhat protruding from the corner of the eye. A biopsy confirmed the diagnosis and the tumor was surgically removed.
Radiograph of a Fractured Mandible. This horse had caught her lower incisor teeth on a door latch, panicked and tossed her head up resulting in a complete fracture across the jaw just behind the front teeth. She had surgery to wire and pin the jaw back into normal alignment and later made a full recovery.
A louse - this picture was taken with an iPhone camera looking down a microscope lens. Lice are not commonly found on horses, but are occasionally seen in this area. The horse had a several month history of extreme itchiness. It took many skin scrapings to find this louse and confirm a diagnosis. Lice are tiny - the black lines in the photo are horse hairs.