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Abstract:
A major cause of male reproductive failure in a C57BL/6N mouse production colony is self-inflicted mutilation of the penis. The extent of the damage ranged from loss of the distal end to loss of the entire penis. From January 1974 to August 1976, 645 adult male mice with mutilated penis were removed from this colony--where the monthly census was 9500 mice, mated 1 male to 4 females using a continuous mating system. On necropsy, it was observed that the substance blocking the urethra in the penile stump resulted in urine retention, grossly distending the urinary bladder. Proteus mirabilis and other bacteria isolated from the urethral plugs were considered secondary invaders.
Insights
Male mice in production colonies often experience reproductive failure due to penile mutilation. This self-inflicted damage leads to urethral blockage, bladder distension, and secondary bacterial infections.
Area of Science:
- Veterinary Medicine
- Animal Reproduction
- Mouse Models
Background:
- Penile mutilation is a significant cause of male reproductive failure in C57BL/6N mouse colonies.
- Damage severity varies, from partial to complete penile loss.
Purpose of the Study:
- To investigate the causes and consequences of penile mutilation in a large mouse production colony.
- To identify factors contributing to male reproductive failure.
Main Methods:
- Observation of a mouse production colony (9500 mice monthly) over 32 months (January 1974 - August 1976).
- Removal and necropsy of 645 adult male mice exhibiting penile mutilation.
- Bacteriological analysis of urethral plugs.
Main Results:
- 645 adult male mice were removed due to penile mutilation.
- Necropsy revealed urethral blockage by a substance, causing urine retention and bladder distension.
- Proteus mirabilis and other bacteria were isolated from urethral plugs, considered secondary invaders.
Conclusions:
- Penile mutilation is a critical issue impacting male reproductive success in mouse colonies.
- Urethral blockage and subsequent urinary tract issues are direct consequences of the mutilation.
- Bacterial infections appear secondary to the primary injury.