Premature germ cells in the ejaculate of a 4-year-old male Labrador Retriever

Abstract

A healthy, 4-year-old, Labrador Retriever was presented for routine semen collection for cryopreservation. Ejaculate had an abundance
of atypical round cells along with substantial morphologically abnormal sperm. Atypical round cells were identified as
premature germ cells, indicating testicular insult or damage of unknown etiology. After multiple visits and a period (3 months) of
rest from heavy training, premature germ cells were not observed and noticeable improvement in sperm morphology was evident.
Apparently, changes observed were induced by heat stress given the location and intensity of training, season of the year, history
and signalment of the patient, and the fact that all parameters improved following temperature management changes and rest
from training. This case illustrated the importance of recognizing an unusual cell type during a routine semen analysis and to
arrive at a possible etiology and resolution of the clinical problem.