As dog owners, we know our pups better than anyone. We know their quirks, their habits, and their routines. So when something feels off, it usually is. But dogs can’t tell us when they’re not feeling well, so it’s up to us to recognize the signs that something might be wrong.
Here’s how to tell if your dog is sick—and what to do about it.
Changes in Eating or Drinking Habits
One of the earliest and most common signs of illness in dogs is a change in appetite or water intake. If your dog suddenly refuses food, eats significantly less, or drinks excessively more or less water than usual, it could indicate an issue. Decreased appetite might signal anything from a mild upset stomach to more serious conditions like infections, kidney disease, or dental problems.
What to watch for:
- Skipping meals for more than a day
- Increased thirst and urination
- Drooling or difficulty chewing
Lethargy or Low Energy
Every dog has lazy days, especially after a long walk or a busy day at the park. But if your typically active dog is suddenly sleeping much more, seems uninterested in play, or struggles to get up, it’s worth paying attention.
Lethargy can be a sign of many illnesses, including infections, heart problems, or even pain from injuries or arthritis.
What to watch for:
- Sleeping more than usual
- Reluctance to walk or move
- Disinterest in toys or interaction
Vomiting or Diarrhea
Dogs occasionally get upset stomachs—maybe they ate something they shouldn’t have or got into the trash. But frequent vomiting or diarrhea, or any vomiting paired with other symptoms like lethargy or loss of appetite, is a red flag.
Severe or ongoing digestive issues can point to infections, parasites, food intolerance, pancreatitis, or other serious health concerns.
When to call the vet:
- Blood in vomit or stool
- Vomiting or diarrhea lasting more than 24 hours
- Signs of dehydration (dry gums, sunken eyes)
Unusual Behavior or Mood Changes
If your friendly dog suddenly becomes irritable, clingy, or withdrawn, there may be more going on beneath the surface. Changes in behavior often accompany illness or pain.
For example, a normally playful dog who becomes aggressive or isolates themselves may be trying to tell you they’re uncomfortable or hurting.
Behavioral red flags:
- Hiding or avoiding contact
- Growling when touched
- Sudden anxiety or restlessness
Changes in Coat or Skin
A healthy dog usually has a shiny, soft coat and clear skin. If you notice dull fur, excessive shedding, bald spots, flakiness, or lumps under the skin, it’s time to take a closer look.
Skin and coat issues can indicate allergies, infections, parasites like fleas or mites, or underlying conditions like hypothyroidism.
What to look for:
- Red, inflamed patches
- Constant scratching or licking
- New bumps or swelling
Coughing, Sneezing, or Breathing Trouble
Coughing or sneezing can sometimes be harmless, but persistent symptoms or labored breathing can be serious. Kennel cough, canine flu, heartworm, and even congestive heart failure can all affect the respiratory system.
Signs that need attention:
- Persistent cough or wheezing
- Difficulty breathing or rapid breathing at rest
- Pale or blue gums
Eye or Nose Discharge
Healthy dogs should have bright, clear eyes and clean noses. Discharge—especially if it’s thick, yellow, green, or bloody—could signal an infection, injury, or even an allergic reaction.
Look out for:
- Squinting or rubbing eyes
- Crusty buildup around the nose or eyes
- Foul smell from discharge
Trouble Urinating or Defecating
Changes in bathroom behavior often point to urinary tract infections, kidney issues, or gastrointestinal problems. Straining, whining, or accidents in the house might not just be behavioral—they could signal discomfort or disease.
Important signs:
- Peeing more or less than usual
- Straining or signs of pain
- Blood in urine or stool
What You Should Do
If your dog shows any of the above signs—especially in combination—don’t wait too long to act. While some symptoms might resolve on their own, many conditions worsen without treatment. Take note of your dog’s behavior, how long the symptoms last, and any changes in their environment or diet.
Call your vet and be ready to describe what you’ve noticed. They may ask for photos or videos, or suggest bringing your dog in for an exam or testing.
Final Thoughts
Your dog counts on you to be their voice and advocate. When something doesn’t seem right, trust your gut. Catching illness early can make all the difference in how quickly your dog recovers—and how serious the issue becomes.
Keeping a close eye on their normal routines, eating habits, and behavior can help you spot illness before it gets worse. And when in doubt, never hesitate to reach out to your veterinarian.
They may not be able to tell you in words, but if your dog is sick, they’re likely already trying to show you.
