Oh dear-it sounds like Rocko has a upper respiratory infection! Possible causes may be bordetella infection (kennel cough), canine influenza, or canine distemper virus. I would highly recommend Rocko be taken to his nearest veterinarian today or tomorrow for an exam and antibiotics at the very least. Rocko may be IV fluids and other supportive medications as needed.
I hope you are able to get him in soon-thank you for using Petco Pet Education Center, formerly Petcoach!