Try this:
- Add a RowID column to your table.
- Create a multiple relation column that matches the shelter name with itself
- Create a Lookup column targets the RowID column via that relation. This will give you an array of RowIDs
- Use the Find Element Index column to find the index of the RowID in the array of RowIDs
- Use that in a template column to assign the ID to each dog.
Here is what that might look like:
Note that array indexes are zero based. If you want to start at 1, you could use a math column to add 1 to the index.