Breeding Soundness Exams & Diagnostic Tools
Any mare that is being considered for breeding should undergo a breeding soundness exam to ensure the mare is a suitable candidate to carry a foal to term. Many of these exams will also be useful in diagnosis of any reproductive diseases.
• Case History – • Physical exam – • Perianal conformation - • Speculum – • Rectal exam (Physical/Ultrasound/Endoscope) – • Histology Exams - • Cytological Exams (swab) –
Reproductive Diseases of the Mare
Ovarian Cysts
Ovarian cysts are not well recognized in mares. They are considered to be idiopathic but may be related to a genetic predisposition as familial trends have been reported. . Deficiencies in follicle stimulating hormone (FSH) and luteinizing hormone (LH) from the pituitary gland cause a failure in the maturation process of the ovarian follicle and the release of the ovum from the follicle. Instead the follicle continues to enlarge attached to the ovary causing enlargement of the ovary and disruption of the normal cycle. It has also been reported that cysts may form from secondary follicles that fail to regress into the state known as the corpus leutum. Instead these follicles become filled and may explain the development of multiple cysts in a single ovary or the development of bilateral ovarian cysts though there is only a single primary follicle per ovulation. In horses most ovarian cysts are formed from Ovarian cysts are seen in mares older than two years as these individuals are sexually mature. It is reported that ovarian cysts are more common in mares that are under stress such as competition or racing. The clinical presentation of ovarian cysts includes erratic or frequent esterous behaviour, stallion- like behaviour, development of male secondary sex characteristics such as exaggeration of the crest and alteration in voice, poor performance, back pain, pain on palpation of the lumbar, inguinal or flank areas, hind limb lameness and asymmetric muscular atrophy of the hindquarters. Rectal palpation may reveal enlargement or abnormal shape of one or both ovaries.
358
Made with FlippingBook Publishing Software