Animal Rehabilitation and Therapy is the application of physical therapy techniques to animals for a rehabilitative purpose.  This includes treatments such as massage, stretching, exercise (active, passive, resistance), hydrotherapy, application of heat or cold, physical, chemical and other properties of heat, light, water, electricity, sound, and stimulation, among others.
The rehabilitative purpose is essential, as it triggers Veterinary Medical Board (VMB) oversight of the practice.  In California, the overall procedure of animal physical rehabilitation is considered the practice of veterinary medicine. (Bus. & Prof. Code § 4826(c).) The practice of veterinary medicine may only be performed by a California licensed veterinarian. (Bus. & Prof. Code § 4825.)  The “purpose” becomes significant as some physical therapy techniques do not differ greatly from a general massage or even exercise that the animal owner might be giving him or herself, solely for the general welfare of the animal.  For example, prescribing a particular type of physical therapy technique to address a problem in the animal is the practice of medicine.  Furthermore, delivering that technique to the animal is also the practice of medicine, and requires at least veterinarian supervision and oversight of the individual delivering it (i.e. animal owner, registered veterinary technician (RVT), or unregistered assistant).  (Bus. & Prof. Code § 4826(c).)
A similar situation arises for musculoskeletal manipulation (MSM) and chiropractic practice.  MSM when performed upon animals constitutes the practice of veterinary medicine. (16 CCR § 2038(a).)  Although MSM performed upon animals constitutes the practice of veterinary medicine, it may be performed by a veterinarian or a chiropractor under specific conditions. Again, for the chiropractor to perform MSM, there must be a supervising veterinarian working in consultation with the chiropractor and on the premises or in the general vicinity of the treatment. (16 CCR § 2038(b)(2)(A-C).)
Changes may be afoot.  The California Veterinary Medical Association held a task force in 2011-12 to address the overlap of the practice of Veterinary Medicine and Physical Therapy for animals.  The CVMA Animal Rehabilitation Task Force proposed language specifically addressing this cross-over.  It has since been taken under consideration by the VMB Multidisciplinary Committee (MDC) in 2012.  The MDC may recommend to the VMB that it adopt regulations establishing specific tasks associated with Animal Rehabilitation and Therapy that may be performed by an unregistered assistant, an RVT, or a licensed veterinarian. Alternatively, the VMB may adopt regulations that establish the degree of supervision required for a veterinarian over a non-veterinarian for any of tasks specified. (Bus. & Prof. Code § 4836(b).)  A review of California Physical Therapy Law and Regulations and a sample of a potential regulation was purportedly considered by the MDC in its November 2012.  So, we will keep an eye open on this developing area of professional licensing and health care law.