Your dog got a mild stomachache
Your dog may stop eating because he feels queasy or has eaten something bad. If you’re wondering, “Why is my dog not eating?” one way to tell it’s not something more serious is if your pup bounces back to his normal self pretty quickly, says Megan E. McClosky, DVM, lecturer in internal medicine at the University of Pennsylvania School of Veterinary Medicine.
Your dog has a more serious illness
Infectious diseases, like parvovirus, or conditions such as pancreatitis can be other reasons for your dog not eating, says Teller. Your pup may even have a life-threatening illness like gastric dilatation and volvulus, which cause the stomach to twist up so nothing passes—or even cancer.
When your dog is really sick, she’ll probably also be lethargic, throw up a lot, have diarrhea or even bloody stools, or cough and sneeze.
Your dog swallowed something
Eating something they shouldn’t have could be another reason your dog won’t eat. Dogs are voracious eaters, so they often scarf down things they shouldn’t—like toys, tennis balls, and even tampons.
This is especially true if your dog is young and playful (so you’ll really want to avoid these common backyard dog dangers). One clue: If your pooch vomits or poops out pieces of, say, plastic, says McClosky.
Your dog’s food has gone bad
Dogs aren’t that discriminating, but occasionally, when something has spoiled, your dog won’t eat it, Teller says. It could be a bad bag of kibble, or maybe that chicken you boiled for your pup didn’t get cooked thoroughly.
Your dog got a shot
Sometimes vaccinations can cause mild lethargy or soreness, causing your pup’s appetite to dip temporarily, Teller notes, adding that this is a pretty rare event. “This may last 24 hours. If your dog isn’t interested in the meal immediately after a vaccination, then just offer the next regular meal after that.”
Your dog is away from home
Some dogs get highly excited or stressed while traveling, and then don’t want to eat. Or they suffer from motion sickness while in the car. “This typically resolves when the travel/car ride is over,” says Teller.
Your dog is stressed
Severe separation anxiety can put a dent in your pup’s appetite. “If a dog is so panicked when the owner leaves, he often doesn’t eat. When the owner comes home, the dog often greets the owner and then rushes to the bowl to eat.
Your dog is holding out
Your dog won’t eat her favorite kibble, so you switch brands. When she stops gobbling that up, you dress it up with something yummier, like cheese or chicken. Pretty soon you’re sitting next to your pooch, coaxing her to take a bite, wondering, “Why is my dog not eating?”
