Which species are known to have holangiotic retinal vasculature?

• A. Horses
• B. Fish
• C. Dogs, cats, rodents, and ruminants
• D. Birds

Answer: (C)

Holangiotic retinal vasculature means the retinal blood vessels extend from the optic nerve head out to the peripheral edges of the retina, forming a true retinal circulation. This pattern is typical of many mammals, including dogs, cats, rodents, and ruminants, where vessels radiate across most or all of the retina to the ora serrata.

In horses, the vessels are confined to a band near the optic nerve (merangiotic), and birds and fish have different patterns of retinal blood supply that do not show the same widespread peripheral retinal vasculature.

So, the species with holangiotic retinas are dogs, cats, rodents, and ruminants.