Canine Puberty

When the male puppy starts puberty (approx. 4-9months), his testosterone level will increase to 2-3 times what it will be when he becomes physically mature. Jean Petersen of Canine Consultants (Petersen, 1995) claims this high level of testosterone stimulates the physical development of his body's secondary sexual characteristics; broader head, thicker neck, broader shoulders, and heavier lip folds that make him look definitely masculine. It also increases aggressive behavior. He will start challenging the authority of the other members of the family he lives with trying to improves his status in the hierarchy (order of authority). If he is strongly dominant genetically, this challenging process can results in serious aggressive behavior towards people and mostly other intact males. If not properly supervised, the dog may wonder away from home as if in search of a mate. Although bitches (female dogs) go into estrous twice a year, a dog can mate all year long. Other secondary sexual characteristic behavior is leg-lifting during urination and “humping” (initiating the sex act) on other organisms and inanimate objects, and attention deficits and a lack of focus. According to Ian Dunbar (Dunbar, 1996), the intersex aggression (between males) can be attributed to the scent of testosterone of each dog. Over 90% of dog fights occur between intact males. Being destructive and disobedient are other behaviors present at this stage (puberty-adolescent). In an article for clickersolutions.com (Alexander, 2008), Melissa Alexander states “A puppy’s brain is going through incredible changes. The cerebral cortex becomes a leaner, meaner thinking machine. During the period where it does all this new myelination, however, it's not a very efficient thinking machine; especially during the early adolescence period”.  The testosterone peak is from 6 - 12 months of age. It will then level off at about 3 years of age. The aggressive behavior begins to subside. The dogs focus returns, but they will leg-lift to urinate and hump female dogs. 

According to Dr Dunbar, castration in most mammals will eliminate secondary sexual characteristics, but not in dogs. The masculine characteristics of dog behavior have nothing to do with adult hormone levels. “Whether or not a male dog will lift his leg when urinating, sniff and mount female dogs and be more aggressive than female has all been preprogrammed by fetal testosterone in utero (pre-birth in the womb).

Philip K Greis