Holistic veterinarians do exist within the United States. From my readings there is not a different training until after their degree is obtained. There are many courses that offer a different aspect of holistic treatment for animals.
These veterinarians in their treatment use an integrative or holistic approach. Perhaps like me, an integrative MD , their might use fewer conventional medicines, and even look at your pet’s dietary lifestyle
Alternative treatments as acupuncture, laser and even massage can be used to manage your pets pain. I have even used bee stings or bee venom therapy for a dog’s arthritis
Seek out a integrative veterinarian