Which describes the normal horse fundus?

• A. Oval, ping optic nerve head in ventral location
• B. Paurangiotic with 30-60 small blood vessels that extend a short distance from the disk edge
• C. Variable color/presence of tapetum
• D. Stars of Winslow seen in choroid as end on capillaries within the tapetum

Answer: (B)

The normal horse fundus is characterized by a paurangiotic retinal pattern, meaning the retinal vessels are relatively sparse and originate from the optic disc, extending only a short distance from the edge of the disk. In horses, you typically see about 30–60 small vessels near the disc, and they do not spread far into the peripheral retina. This reflects how the retinal blood supply relies more on the underlying choroid and tapetum for nourishment, with the superficial vessels confined to a narrow annulus around the optic nerve.

A prominent tapetum lucidum is a hallmark of the equine fundus, providing bright reflectivity that helps with night vision. Within the tapetum you may observe the Stars of Winslow—small, end-on capillaries in the choroid that can appear as bright points. The color or presence of the tapetum can vary among horses and breeds, but the defining normal feature is the limited, central retinal vasculature rather than a wide peripheral network.