In New York, physical therapy of any kind (including massage and chiropractic) can only be performed on humans, by the State's definition of those health care professions.
Animal treatments of any kind must be performed by licensed veterinary professionals, and the laws/regulations/guidelines that govern veterinary practice can be accessed through this webpage: http://www.op.nysed.gov/prof/vetmed/vetlaw.htm https://www.op.nysed.gov/title8/education-law/article-135.
Some New York veterinary professionals are certified/trained to perform things like acupuncture, hydrotherapy, electrostimulation, ultrasound and laser therapy, and they offer those services at their veterinary practices.