Testing, Researching, and Expanding Alternative Treatments Act or the TREAT Act This bill addresses Department of Veterans Affairs (VA) pilot programs related to complementary and integrative health services. Specifically, the bill requires the VA to expand the pilot program on using complementary and integrative health services (e.g., meditation) to complement pain management and mental health treatment for veterans. The bill also requires the VA to implement a three-year pilot program to provide complementary and integrative health services (e.g., animal therapy) to eligible veterans for the treatment of post-traumatic stress disorder, depression, or anxiety. Eligible veterans are those who are enrolled in the VA health care system and have received care from the VA or rehabilitation or counseling services from a Vet Center within the last two years. The VA must enter agreements with academic researchers to study the effectiveness of the treatments in the pilot program.