The authors present the characteristics of equine testicular teratomas. An
abnormal cryptorchid testicle was removed from the abdominal cavity of a 3
year old Hungarian Half-bred stallion. One of the testicles had removed 7 m
onth before, but excessive masculine and agressive behaviour still remained
. Rectal examination was not helpful in locating the position of the testes
. With the stallion under general anesthesia, it was placed in dorsal recum
bency for cryptorchidectomy. Exploratory surgery via the right inguinal app
roach was undertaken.
The abnormal testicle measured 18 cm by 12 cm and 1.6 kg. Incision of the t
esticle revealed cysts filled with fluid and hair. Histologically, the cyst
walls were completed from keratinizing epithelium and mucous epithelium. C
ollagenous connective tissue comprised most of the cyst walls. Cartilage-,
bone-, central nervous- and collagenous connective tissues filled the space
among the cysts. By histologic examination of the testicle the alteration
was classified as a matured teratoma.
3 month later excessive masculine and agressive behaviour of the horse disa
ppered. 9 month after the operation with clinical examination signs of post
operative complication and metastasis were not found. Nowadays the horse is
used for show jumping.