“My cat had diarrhea, the vet treated it, and there’s no poop in the litter box.”
“We treated my dog’s diarrhea, and she hasn’t pooped in 3 days. When do I worry?”
These are common questions that I get asked a lot. What’s going on?
First of all, don’t panic. It is actually quite common for a dog or cat to not produce feces for a few days after having significant diarrhea. The first couple days you might not notice – you’re just relieved to not be cleaning it up any more! Once you’ve recovered, you realize you haven’t seen much of anything in the fecal department in a day or two. This can be expected, and for a couple reasons.
When a dog or cat has diarrhea, the feces are moving through the intestinal tract very quickly. This causes them to be, well, empty. Normally the intestinal tract contains various stages of ingesta – digested food that is being transformed in feces as it moves through. With diarrhea, the ingesta blazes through, causing it to come out more watery, and emptying out the digestive tract.
Then when we treat the diarrhea, what do we do? Sometimes we’ll give a medication to slow down the digestive tract, giving the intestines a break, and making things travel at a more normal speed.
We also tend to feed a special diet, either home cooked or a prescription diet from your veterinarian. These diets are easy on the tummy, and give the digestive tract a rest. Another feature of these diets is they are often low residue, meaning they are meant to be digested efficiently and produce only minimal feces.
So we have an emptied-out dog or cat, possibly given meds to slow down the pooping, and being fed a diet meant to minimize poop production. It’s easy to understand how a dog or cat can go from diarrhea to not pooping for a few days.
Most animals tend to poop within 2-3 days. If more days go on and you’re not seeing any feces (and your pet is eating!), talk to your vet. Constipation after diarrhea is possible, but is very uncommon. The few cases I have seen were caused by the owner continuing medications like immodium for more doses than the veterinarian prescribed (that poor digestive tract was NOT budging!) Most cases, it just takes the intestines time to re-calibrate. Just enjoy the break from poop while it lasts!