Answer:
chapter 4.
in chapter 4 Spike is the new addition to the yard. Bobby warrants in Europe that he doesn't trust Spike but she tells him "there are no bad dogs, Bobby, just bad people"(4.18)
Spike and the top dog get into a vicious fight which Bobby breaks up by blasting them both with a high pressure hose. after that spike is now top dog.
Toby soon gets into a fight with Spike after the fight spike is only able to walk on three legs.
senor a Wales in Christ that they can't take her dogs but the authorities accuse her of keeping the dogs in "inhumane condition"
the authorities round up all the dogs and gas them