General principles that apply to the effects of castration and spaying.
- Will generally change the frequency and intensity of typically masculine behaviors, even if it doesn't result in complete cession of the behaviors.
- If a behavior is a sexually dimorphic behavior, it is likely to be affected by castration.
Effects of castration on sexual behaviors (from Hart,Hart,& Bain 2006)
- “pronounced species differences in degree of behavior changes”
- “pronounced individual differences within a species”
- “”experience in performing the behavior appears to have no predictive value…. Will or will not engage in the behavior subsequent to castration”
From Neilson et al (1997) Effects of Castration on Problem Behaviors of Male Dogs
- Retrospective study of 57 Male Dogs between 2-7 years of age
- Greatest probability of change – roaming, urine marking, mounting
- Approx. 25% reduced aggression towards people and/or other dogs in the house
- 10-15% some reduction in aggression towards human intruders and unfamiliar dogs
- “Significant correlations were not found between the percentage of improvement and age of the dog or duration of the problem behavior at the time of castration.”
Effect of castration of cats:
- Will reduce spraying in 90% of cats regardless of age castrated or duration of problem. However, no significant data on effects of early neutering. Will also reduce roaming, and inter-male fighting.
Effects of Spaying on Dogs and Cats:
- Most likely to affect behaviors seen during estrus. Early spaying has been associated with urinary incontinence (Spain et al, 2004).
- There have been some reports on increases in aggressive behavior post spaying of female dogs.
Hart BL, Hart L, & Bain M. Canine and Feline Behavior Therapy, Blackwell Press. 2006
Hart BL & Cooper L Factors relating to urine sprayng and fighting in prepubertally gonadectomized cats. JAVMA 184: 1255-1258. (1984)
Neilson JC et al. Effects of castration on problem behaviors in make dogs with reference to age and duration of behavior. JAVMA 211: 180-182 (1997)
Spain et al. Long-term risks and benefits of early-age gonadectomy in cats. JAVMA 224: 372-379. (2004).
Spain et al. Long-term risks and benefits of early-age gonadectomy in dogs. JAVMA 224: 380-387. (2004).