How do dogs act when they get sick?

You might’ve noticed your usually energetic pup suddenly curling up on the couch all day, or turning their nose up at their favorite kibble—and wondered if something’s wrong. Dogs can’t tell us when they feel under the weather, so knowing how they act when sick is key to catching issues early. Small changes in behavior, like skipping playtime or hiding more than usual, are often their way of saying they’re not feeling right.

From a behavior science perspective, dogs tend to revert to “survival mode” when ill. In the wild, showing weakness makes them vulnerable, so even domestic dogs might act more withdrawn or quiet when sick. You might also see physical signs tied to this: excessive panting, shivering, or frequent licking of a specific body part—like a paw or belly—which could mean they’re in pain or discomfort. For example, if your dog normally greets you at the door but now stays in their bed, and also licks their hind leg nonstop, it’s a sign they need your attention.

When you spot these signs, start with simple, practical checks before rushing to the vet. First, take their temperature (a dog’s normal temp is 101–102.5°F; use a rectal thermometer gently). Next, check their food and water intake—if they haven’t drunk anything in 12 hours or eaten in 24, that’s a red flag. Also, keep an eye on their bathroom habits: diarrhea, constipation, or blood in their stool/urine are clear indicators something’s off. Jot down these details (when the symptoms started, how often they happen) to share with your vet—it’ll help them diagnose faster.

Don’t forget to tie these checks to legal and community responsibilities. If your dog is sick, skip trips to the dog park or communal green spaces—this prevents spreading illnesses to other pups, which is both a courtesy and a rule in many neighborhoods. Also, make sure their vaccines are up-to-date; some sick behaviors (like lethargy or fever) could be signs they’re missing a crucial shot, which is required by law in most areas to keep public spaces safe. Never try to “tough it out” with home remedies if symptoms last more than a day—neglecting care could lead to worse health issues, and in some places, it’s considered a violation of animal welfare laws.

Learning how dogs act when sick turns you into your pup’s best advocate. By noticing small behavior shifts, using simple at-home checks, and staying on top of legal and community guidelines, you can get them the care they need fast. Remember, your dog relies on you to understand their unspoken cues—so trusting your gut when something feels “off” will help keep them happy and healthy for years to come.