Q. Hasn't pooped since Sat....no appetite
A. For severe constipation, your pet should be seen by a vet. Hard stool building up in the colon stretches it out of shape, and it also causes stretching of the muscles around the anus, causing perianal hernias that trap the collected feces, effectively making a plug. Your pet may need more than one enema and even manual extraction of the feces in order to relieve this episode.
To help avoid this in the future, you can add Miralax to the food. Miralax is a very gentle, easy to give treatment for constipation, available over the counter at any pharmacy. The dose of Miralax is 1 tsp per 50 lbs mixed in with food once a day. You can also add a tablespoon of vegetable or olive oil to his food once daily, or add a couple of teaspoons of canned pumpkin (not pie filling) to his food daily.