Gonadectomy in immature dogs: Effects on skeletal, physical and behavioral 
development (continued)

Comments related to orthopedics:

"To our knowledge, there are no reports of musculoskeletal abnormalities 
associated with lack of gonadal hormones during development."

"Dogs neutered prior to skeletal maturity might be more susceptible to 
sustaining traumatic Salter fractures for a longer period of time, compared 
to sexually intact dogs." 

Implications of this study (to me):
When breeders look at neutered animals as an indication of the production of 
sire and dam, they should keep in mind that boys neutered prior to sexual 
maturity are likely to be about 9% leggier than they would have been if left 
intact and ES/N bitches are likely to be 11% leggier than their intact 
sisters, but those spayed at 7 months aren't significantly impacted.

There is no indication of prepubertal neutering impacting hip and elbow 
development, however, there are no long term studies specifically evaluating 
this to the best of my knowledge.

The growth plates of males neutered pre-pubertally and bitches spayed early 
(ie: 7 weeks) may be susceptible to damage for a longer period of time than 
animals kept intact longer.  Since the longest avg timeframe for closure in 
this study of smaller dogs was 60 weeks, I'd  go easy on BMD joints for the 
first 18 months or so.  

Non-skeletal findings:

"The rate of weight gain (slope) was not affected by gonectomy, but males 
gained weight more rapidly than females.  Although it is generally believed 
that neutering predisposes dogs to obesity, there is little scientific 
documentation of the predisposition."

"All of the neutered dogs (ed. gender neutral) scored higher for "general 
activity" and Group 1 males scored higher for "excitability"; therefore, 
gonadectomy did not result in lethargy or inactivity during the evaluation 
period.  More sophisticated behavioral studies have shown that castrating 
pups shortly after birth does not alter social interactions between dogs, nor 
does it totally eliminate masculine sexual behavior (ie:, mounting and 
thrusting) or urine marking.  In addition, neutering 40 day old male pups did 
not affect aggressive/competitive behavior when early castrates and their 
sexually intact littermates competed for bones or estrous bitches."

***I found the following EXCEPTIONALLY interesting...especially if you're 
looking for a puppy/breeder***

"Behavioral problems were encountered in one litter.  Fear biting, excessive 
aggression with other dogs, and shying away from strangers were exhibited by 
most of the dogs in litter 2.  From a total of 3 females and 4 males in this 
litter, 2 males (Group 1 and Group 3) and 2 females (Group 2 and Group 3) 
were euthanized at the end of the study because of their untrustworthy 
behavior.  One female (Group 1) and two males (Group 1 and 2) were adopted by 
families, but all 3 dogs ran away within 4 weeks of placement.  The reason 
for the maladjusted social behavior may have been genetic or environmental."

"The most striking differences in the development of secondary sexual 
characteristics were the immaturity of the prepuce, penis, and os penis in 
the Group 1 males."

"The vulvas of both the Group 1 and Group 2 females were small and infantile, 
compared with sexually intact females, but no clinical problems were 
evident..."
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-Sherri Venditti
continued

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