Introduction

• Poor libido and failure to copulate.
• An occasional problem in dogs, mostly due to psychological causes.

Pathogenesis

Etiology

• Distractions, slippery floor and inexperience.
• Male shows no interest: organic abnormalities:
  • Poor libido due to testicular malfunction (rare).
  • Persistent penile frenulum which may cause discomfort during erection.
  • Fractured os penis (due to trauma).
  • Phimosis due to preputial constriction.
• Bitches raised with the male often establish dominance over him. Male is aware of this and will not attempt to mount as a consequence.
• When a bitch has been raised in the absence of other dogs she may only identify with humans and will not allow dogs near her. When bitch shows aggression, the male loses interest. Also, when dogs are raised in the absence of other animals they may not recognize bitches as 'self'.
• Female may not be in proper standing estrus and a show of aggression may intimidate the male.
• When the male mounts then dismounts almost immediately and shows no or little further interest, the female should be examined for evidence of vaginal obstructions such as constricting circumferential bands in the region of the urethral orifice and dorsoventral vaginal bands that are remnants of the Mullerian system.
• Orthopedic problems in back +/- legs may → discomfort on mounting → memory of previous pain → poor libido.

Predisposing factors

• Bitch raised with male is often dominant over him; dog is aware of female dominance.
• May also have problems when dog or bitch has been raised only with humans since puppyhood; may not recognize the other as 'self'.
• Male may also be easily intimidated by a bitch that is not yet in good standing estrus.

• Various vaginal abnormalities that cause discomfort for the male when copulation is attempted (dyspareunia).

• Testicular malfunction due to general debility.
• Specific diseases such as diabetes mellitus Diabetes mellitus and hypothyroidism Hypothyroidism.
• Chromosomal abnormalities and hypothalamic-pituitary-gonadal axis malfunction due to unknown causes.

Pathophysiology

• Male shows no interest: organic abnormality possible but less likely than psychological problems.
• Bitch aggressive towards male: usually the bitch has been raised with the male from puppyhood or has been raised in the absence of other dogs.
• Male mounts but dismounts almost immediately and shows no further interest: female has obstruction in the vagina/abnormal vagina Vestibulovaginal stenosis.

Timecourse

• Dominance of bitch or failure of bitch to recognise male as 'self' (or vice versa) usually permanent.
• Bitches not in proper standing estrus may intimidate some males permanently; short-term problem.
• Various organic problems as mentioned previously may be corrected over time.

Diagnosis

Treatment

Prevention

Outcomes