Baled silage-associated uveitis in cows

Listeria infections of the eye

The bacterium Listeria monocytogenes resides originally in the environment. Infections of the eye have been induced experimentally; for example, in rabbits and guinea pigs. Natural ocular infections occur in various animals; in most instances, they are induced exogenously; for example, by contaminated silage affecting primarily the conjunctiva, cornea, or the anterior chamber. Sporadic infections as well as outbreaks have been described. In humans, besides exogenous infections, endogenous infections also occur, inducing mainly endophthalmitis. Since an exact diagnosis of the causative agent is often delayed, specific therapy starts too late, so that the outcome is often poor. The antibiotics of primary choice would be ampicillin or a quinolone such as moxifloxacin or levofloxacin. The role of fosfomycin for therapy of ocular infections is discussed.

Examination techniques and therapeutic regimens for the ruminant and camelid eye

A step-wise procedure and necessary equipment for examination of the ruminant and camelid eye are detailed. Restraint techniques and usage of local anesthetics to facilitate examination are described. Common examination findings and their significance are discussed. Finally, therapeutic options for keratoconjunctivitis and uveitis are explored. A complete ocular examination of ruminants is often not performed in the field because of lack of time, lack of appropriate facilities, and/or lack of equipment. Although individual ophthalmic examinations are not frequently performed as part of a herd health program, they can be of value in select cases. Ocular manifestations of systemic diseases may assist the clinician in establishing a diagnosis on the farm and for little additional cost. For patients with a specific ocular complaint, a complete ophthalmic examination is critical. After completion of the examination and arrival at a diagnosis, one must also be cognizant of the therapeutic regimens that are appropriate for use in ruminants, particularly animals that may be used for meat or milk.

Brainstem and cranial nerve abnormalities: listeriosis, otitis media/interna, and pituitary abscess syndrome

This article reviews three disorders associated with multiple asymmetric cranial nerve deficits in ruminants: encephalitic listeriosis,otitis media/interna, and pituitary abscess syndrome. Emphasis is placed on encephalitic listeriosis, an infectious disease of the brainstem and cranial nerves caused by Listeria monocytogenes. The epidemiology, pathophysiology, clinical manifestations, diagnosis,and treatment of encephalitic listeriosis are reviewed, and differences between cattle and small ruminants are noted. Physical and neurologic examination findings that distinguish otitis media/interna and pituitary abscess syndrome from encephalitic listeriosis are highlighted.