In the United States, the specific agency that needs to be called when a dead cat, or any other deceased animal, is found varies slightly from state to state. However, almost all states have a government organization that can be called when this happens.
In the majority of states, there is a subdivision of the health or sanitation department that deals specifically with the pickup of dead animals. Often, this division operates at the city or county level. The employees are trained to dispose of dead animals in a sanitary and safe way. Almost all cities and counties have an address or phone number that can be contacted to request a dead animal pickup free of charge.