There are quite a few programs and policies that have been developed over the years to improve the standards of care for animals and for their well being. Proponents for animal welfare are also constantly working towards ending the abuse of animals.
There are many forms of animal abuse, but to keep it simple, we can break them up into two categories: the first is harm that comes from an act that is deliberate, and the second is the abuse that comes from negligence (the failure to take proper steps). Many times, the lines are blurred between the things that are intentional and the things that are not. After that is decided, cases are decided based on the facts from the specific case. There are felony laws in every state now against animal cruelty, but the way these cases are designated varies from state to state, as does the punishment that goes along with the crime. This can make it hard for those who are fighting against animal abuse because what is prosecuted in one state may not be prosecuted in the next.
There are many cases when abuse in the form of neglect can be just ignorance on the part of the pet owner, such as them not recognizing that veterinary treatment is needed for their pet, or in situations when a person allows a behavior to continue that harms the animals but they do not realize it is doing so.
Overt cruelty is often an abuse that animals face. There are many deliberate acts of cruelty towards animals including activities like dog fighting, beating animals, maiming them, torturing animals, or anything else that leads to severe pain or injury to the animal involved, even death. The most severe penalties are given to those who perform these deliberate acts not just for the immediate harm they impose or their shocking nature, but because of the link that is well known these days between abusing animals and performing violent behaviors towards other people.