1- AHMAD N., NOAKES D.E., MIDDLETON D.J., Use of ultrasound to diagnose testicular degeneration in a goat, Vet. Rec., 1993, 132, 436-439

2- BRUERE A.N., Some clinical aspects of hypoorchidism (small testes) in the ram, N. Z. Vet. J., 1970, 18, 189-198

3- FRASER A.F., PENMAN J.H., A clinical study of ram infertilities in Scotland, Vet. Rec., 1971, 89, 154-158

4- GALLOWAY D.B., WRIGHT P.J., De KRETSER D., CLARKE I.J., An outbreak of gonadal hypoplasia in a sheep flock: clinical, pathological and endocrinological features, and aetiological studies, Vet. Rec., 1992, 131, 506-512

5- MEMON M.A., Male infertility, Vet. Clin. North Am. Large Anim. Pract., 1983, 5, 619-635

6- MOBINI S., HEATH A.M., PUGH D.G., Theriogenology of sheep and goats, In: PUGH D.G., Sheep and goat medicine, Philadelphia: WB saunders, 2001, 129-186

7- OTT R.S., HEATH E.H., BANE A., Abnormal spermatozoa, testicular degeneration, and varicocele in a ram, Am. J. Vet. Res., 1982, 42, 241-246

8- PARKINSON T.J., Fertility and infertility in male animals, In: NOAKES D.E., PARKINSON T.J., ENGLAND G.C.W., Veterinary Reproduction and Obstetrics. 8th edn., W. B. Saunders Co. Ltd., London, England, 2001, 695-750

9- SPONENBERG D.P., SMITH M.C., JOHNSON R.J., Unilateral testicular hypoplasia in a goat, Vet. Pathol., 1983, 20, 503-506

10- TARIGAN S., LADDS P.W., FOSTER R.A., Genital pathology of feral male goats, Aust. Vet. J., 1990, 67, 286-291

11- WATT D.A., Testicular pathology of merino rams, Aust. Vet. J., 1978, 54, 473-478