You should be able to find canned goat's milk in the baking aisle of most any grocery store. It's usually next to the other canned milks. It is concentrated so needs to be diluted with equal parts water. Also, shake the can very well as the milk solids settle to the bottom.
Here's a link with some info about the problems with Esbilac.
LA Animal Watch: Petag's Esbilac puppy milk contains heavy metal copper