I would not shop there again. I would be sure to tell as many people as possible how the owner of that store is dealing with this situation. I would post on YELP... FB.. and all method you can think of. The loss of business will change his mind.
If pets were not allowed why were you not told before? He may have been wrong for not telling you before ... for example in Florida pets are not allowed in any store that sells food. If a person walks in with a pet and are not asked to leave the implied message is the pet is allowed. If the pet is allowed he has responsibility for your and your pet's safety.. at least I think so.
Also I have had situations of cat fights. I had a neighbor's cat go onto my property and get in a fight with my cats and I had a very large vet bill. I called animal control and was told cats are "ruled differently" than dogs. Owners are not liable for cats roaming. It would be very hard to prove liabilities.
BUT.... this was a place of business... and it was implied your pet was allowed. So.. if your dog was on a leash I would think the store owner would have some liability.
ha... I watch too much law and order
