Kill all pit bulls. Might as well keep a cougar in the home.
Please see here for further information. It is an excerpt of the book by Semyonova:
https://www.animals24-7.org/2015/11/10/the-science-of-how-behavior-is-inherited-in-aggressive-dogs/
The heritability of abnormal aggression in certain breeds of dogs can no longer be denied. The bodies of these dogs have been selected to execute a killing bite more efficiently than other breeds. These dogs share physical conformation to the task of killing, including exaggerated jaw muscles, heavy necks and shoulders, and body mass that makes defense against an attack much more difficult. Among people who want dogs who can kill, these are the breeds of choice because they are physically more fit for it than other breeds.
Dogo Argentino
Dogo Argentino
Behavioral conformation
But breeders also selected for behavioral conformation. To perform well, a fighting dog had to attack without provocation or warning, and to continue attacking regardless of the response of the other animal. Bull and bear-baiting dogs had to be willing to attack in the absence of the species-specific signs that normally provoke aggression, responding to the mere presence of another animals, and not stopping in response to external stimuli. The Dogues du Bordeaux used to guard extended farmlands in France, the Boerbulls used similarly in South Africa, and the fugitive slave-chasing dogs of Latin America, such as the Dogo Argentino and Fila Brasiliero, all were selected to specifically for a propensity to kill.
As they selected for performance, breeders could not know exactly which physical changes they were selecting for. But research now shows that selection for aggressive performance includes consistently selecting for very specific abnormalities in the brain. These abnormalities appear in many breeds of dog as an accident or anomaly, which breeders then attempt to breed out of the dogs. In the case of the aggressive breeds, the opposite occurred. Rather than excluding abnormally aggressive dogs from their breeding stock, breeders focused on creating lineages in which all the dogs would carry the genes causing them to reliably exhibit the desired impulsive aggressive behavior.
“That aggression is not heritable is not tenable”
Now that we know exactly which brain abnormalities the breeders of fighting dogs have been selecting, the assertion that this aggression is not heritable is no longer tenable. It is also not tenable to assert that not all the dogs of these breeds will carry the genes that make them dangerous.
(excerpted)