The practice has treated small animals and horses since 1896, and will now join 14 other Scottish veterinary practices to be part of VetPartners.
Practice owners Harvey Carruthers and Jamie Gartside will remain at the practice as clinical directors, along with their team of vets and veterinary nurses.
It was also the first practice in Scotland to achieve Gold Standard cat-friendly clinic status through the International Society of Feline Medicine.
In addition, it is renowned for its care of rabbits after receiving accreditation as a rabbit-friendly clinic from the Rabbit Welfare Association and Fund.
Jamie Gartside said: “Tay Valley Vets has been providing a top-class service to the animal owners of Perth for many years and we are delighted to be joining VetPartners.
“Although there will be no major changes to the service we provide, we feel the values and ambitions of VetPartners align perfectly with how we want to see our practice develop over the next few years.”
He added: “We see this as a positive move for ourselves and our valued clients, who will still be able to see familiar faces at the practice when they bring your pet or horse.
“For the equine side, it is very exciting as it means we are joining a group that includes Clyde Vet Group in Scotland and prestigious UK equine hospitals like Liphook and Rainbow in England.”
VetPartners CEO Jo Malone said: “We are delighted to welcome Tay Valley Vets and Equine Centre to our family of practices as they are a highly respected practice.
“Their decision to join VetPartners shows we are committed to attracting some of the best veterinary businesses across all species, both in the UK and Europe.”
She added: “We are committed to growing our mixed, farm and equine groups, which will bring benefits of scale, local support for our teams and access to a wide range of excellent specialist services.”