Retinal dysplasia in other animals
Cats - Retinal dysplasia occurs in utero or in newborns infected with feline leukemia virus or feline panleukopenia, which cause necrosis and disorganization of the retina. It appears as folds and rosettes. Cattle - Retinal dysplasia occurs in utero through infection with bovine viral diarrhea. It is also inherited in Shorthorns and Herefords. Both forms often cause retinal detachment. Sheep - Retinal dysplasia occurs by in utero infection with bluetongue disease. Horses - Retinal dysplasia is bilateral, not inherited, and appears as multifocal or geographic disease. It is usually accompanied by other eye problems. Chickens

See also
Progressive retinal atrophy


== References ==
Cyclopia (named after the Greek mythology character cyclopes) is the most extreme form of holoprosencephaly and is a congenital disorder (birth defect) characterized by the failure of the embryonic prosencephalon to properly divide the orbits of the eye into two cavities. Its incidence is 1 in 16,000 in born animals and 1 in 200 in miscarried fetuses. Signs and symptoms
Typically, the nose is either missing or not functional. This deformity (called proboscis) forms above the center eye and is characteristic of a form of cyclopia called rhinencephaly or rhinocephaly. Most such embryos are either naturally aborted or are stillborn upon delivery. Although cyclopia is rare, several cyclopic human babies are preserved in medical museums (e.g. The Vrolik Museum, Amsterdam, Trivandrum Medical College).Some extreme cases of cyclopia have been documented in farm animals (horses, sheep, pigs, and sometimes chickens). In such cases, the nose and mouth fail to form, or the nose grows from the roof of the mouth, obstructing airflow and resulting in suffocation shortly after birth. Causes
Genetic defects or toxins can misdirect the embryonic forebrain-dividing process. One highly teratogenic alkaloid toxin that can cause cyclopia is cyclopamine or 2-deoxyjervine, found in the plant Veratrum californicum (also known as corn lily or false hellebore). Grazing animals are most likely to ingest this plant and induce cyclopia in offspring.