This study investigated differences in behavior and cognition between rescue dogs and non-rescue dogs using a series of cognitive tests. These tests were simple enough that they could be performed by owners in their own homes. Therefore, citizen science was used to collect behavioral data on rescue dogs (n = 30) and non-rescue dogs (n = 20). Owners of the dogs also completed questionnaires to assess the dog-owner relationship and personality of the dog. Results revealed that rescue dogs maintained eye contact for a significantly shorter duration compared to non-rescue dogs (U = 162.5, P = 0.029). However, they performed significantly better than non-rescue dogs in a simple memory test (chi(2)(1, N = 40) = 4.40, P = 0.036). Rescue dogs were significantly more fearful than non-rescue dogs (P < 0.05), but the groups did not differ in their dog-owner relationship questionnaire scores. Hence, there may be some differences between rescue and non-rescue dogs, and citizen science could be a viable method to collect behavioral data on rescue dogs after they are rehomed.