The Association of the Bar of the City of New York provides documents in English and Spanish on how to identify animal cruelty, and why and how to report it:

A Guide to Reporting Suspected Animal Cruelty or Neglect in New York State [PDF]

Reportando Sospechas de Crueldad y Descuidode Animal en el Estado de Nueva York [PDF]

To report animal cruelty in progress, please call 911 immediately, and also report it to the closest NYPD precinct. Each precinct is usually assigned an ASPCA Liaison Officer that handles abuse and neglect complaints. If you call and they say that they do not have one, ask for the Neighborhood Coordination Officer/Community Affairs Officer, and tell them that you want to file a complaint about animal abuse. It is helpful to contact them when the cruelty is happening so that they can address it while it is happening. If you send a complaint online, or by email, please note the time(s) that you witnessed the abuse or neglect happening.

To report ongoing animal abuse or neglect, please call 311 or file a NYPD Crime Stoppers report online, or by calling 1-800-577-TIPS (1-800-577-8477).

You also can file a complaint for ongoing animal abuse or neglect online (non-emergency response) through the City of New York’s NYC 311 website.