Originally Posted by Analise

If you're doing this at rush hour, it could be tight. You will indeed have to go through security at LGA even if Delta checks you in all the way. If you want to know, call Delta to verify the check in. I would think you would HAVE to check in at LGA because you've got your dogs to check in. Delta isn't going to transport your dogs to LGA for you. So waiting for your dogs at JFK could take a while.

Immigration line could be long especially if you're not one of the first off the plane. At rush hour, the traffic to LGA could be bad, the taxi line could be long, and the check in and security lines at LGA both could be long.