My dog is straining, not pooping, and vomited. Is he blocked?

Hi and thanks for using Petco Pet Education Center, formerly Petcoach! Sorry to hear that Roko is having problems. I always tell clients that if signs persist, worsen, or other signs develop after
12-24 or even 36 hours (depending on their severity), I advise a check up at their veterinarian. If the pet is acting sick then the waiting time goes down to zero, they should be seen immediately. So if Roko doesn't act sick or isn't uncomfortable, you could probably wait this out and see what happens. If he is constantly straining to have a bowel movement then of course he should be seen immediately. Vomiting and diarrhea can have many causes such as intestinal parasites, dietary indiscretion (eating things dogs are not supposed to eat), overgrooming with resultant hair ingestion, toxin ingestion, foreign body ingestion, other problems with the gastrointestinal tract, problems with organs outside of the gastrointestinal tract, among many others. Your vet can get a detailed history and do a thorough exam. Once those are done, a diagnostic plan and treatment plan can be discussed and implemented. Possible tests include fecal/blood/urine tests and xrays as a starting point, called a minimum data base. If Roko isn't acting sick and straining a lot you could try some canned pumpkin with his food which is high in fiber. 1-2 teaspoons with each meal (canned pumpkin, NOT pumpkin pie filling). This will increase fiber to the gut and hopefully get the gut back on track. Good luck with Roko.