If you are looking for a vet, Itivet is probably the best place in town. I have been using them for about 2 years and I have been to other places. It’s big, with long opening hours, It’s clean and they have an excellent reputation. They have been opened for about 30 years.
They are located near Bule Saloon, or in front of Ra Bieng Gao (a restaurant) on Yommarat road.
Inside, they sell pet food and several accessories. They price is cheaper than Klang Plaza or the Mall. (But Makro is the best!).
The place is really clean. They have young staff and they will take care of your animal. You can leave your animal there, for a small fee, if you need the animal to recover after an operation or something else.