VGO 511: Veterinary Andrology and Reproductive Techniques (1+1)

MISCELLANEOUS CAUSES FOR LOSS OF LIBIDO OR INABILITY TO COPULATE

• Hernias
• Premature erection
• Loss of sensory innervation of the glans penis
• Urinary calculi
• Other causes

Hernias

• Umbilical and ventral hernias as well as deep pendulous abdomen may interfere or prevent normal copulation by affecting the entry of the glans penis into the vagina at a natural mating.
• Umbilical and small ventral hernias may respond to surgery but since umbilical hernia may be hereditary the affected male should not be used as a sire.

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Premature erection

• Premature erection may occur in the dog, stallion and certain bulls and interfere with normal intromission.
• Premature erection in the dog as an obstacle to coitus and a cause of impotency. Artificial insemination as the quickest and easiest solution for this problem.
• Stallions the glans penis occasionally becomes too large to readily enter the vulva of a small mare or a mare whose vulva has been sutured to prevent pneumovagina.
• This cause of inability to copulate can usually be overcome by helping to direct the penis into the vulva before it fully erect, by lubricating the vulva or by incising the sutured vulvar lips dorsally.
• The mare may be artificially inseminated or may be bred to a stallion of suitable size.
• Bulls with a strong sex drive and with a narrow penis develop corkscrewing or coiling of the free end of the penis at premature full erection that prevents intromission.

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Loss of sensory innervation of the glans penis

• Prevents natural intromission and the “thrust” reflex necessary for ejaculation and leads to pronounced decline in sex drive.
• Lack of sensation of the glans penis may be caused by injury to the dorsal nerve of the penis secondary to rupture and hemorrhage of the cavernosum penis.
• By the improper technique of the injecting local anaesthesia on the dorsal nerve at the sigmoid flexure of the penis.
• Rarely by an operation to correct the spiraling of the bovine penis or by a rubber band from an artificial vagina or other source that is placed around the penis and not removed for several days.
• Lack of sensation of the glans penis may also be due to severe necrosis of the mucosa of the glans penis due to severe balanitis of an infectious etiology or due to trauma resulting in severe scarring.
• Amputation of the glans penis due to rubber band or following extensive surgery for tumor produces the same effect.

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Urinary Calculi

• Urinary calculi lodging in the urethra may occasionally be a acute pain, obstruction and rupture of the urethra in male domestic animals and cause reluctance to copulate and inability to copulate.
• In the ram calculi may lodge in the sigmoid flexure area as in bulls but are more commonly found in the urethral process.
• Calculi are common in the male cat and uncommon in the dog.
• In order to preserve the breeding potential of these animals conservative therapy such as massage and flushing in the removal of the urethral calculi and aftercare is indicated, surgery should be used only as a last resort.

Other causes

• Pain caused by infection of the genital organs or peritoneum. It may be a cause of impotency or refusal to copulate.
• Bulls with acute semino-vesiculitis were slow or refused mount.
• Boars with brucellar orchitis refused to copulate.
• Acute prostatitis in dogs might similarly affect the copulation.
• Severe congenital or acquired cardiac diseases often result in dyspnea and inability to perform coitus by male animals.

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