Currently there are no federal laws protecting animals from abuse and situations such as dog fighting. Nearly all of the cases end with the offender being sentenced with a fine and an obscure minimal jail sentence. Many offenders do not even get jail time, they have to complete anger management classes or community service (many times involving animals).
There should be minimum sentences in the cases of animal cruelty and death of two years. For multiple cases of abuse with extreme circumstances, up to five years.