Can hives be symptoms of dog allergies?

Yes if when with dog. Any severe allergy can cause hives in the allergic person, so yes, hives could be due to a dog. More people are allergic to cats than are allergic to dogs, by a large percentage, but some people have life- threatening dog allergies. Severe reactions can include eye swelling, throat- closing, coughing and asthma, and shock, as well as skin rashes including hives.
Yes. You can definitely get hives from exposure to a dog, if you are allergic to dogs. Particularly where they lick you.