How to Tell If Your Dog Is Sick: 15 Warning Signs & When to See a Vet

Dogs can't tell us when they're not feeling well, so recognizing the signs of illness is crucial for early intervention and treatment. While some symptoms are obvious emergencies, others are subtle changes that dog owners need to watch for. Here's your complete guide to knowing when your dog needs veterinary care.

15 Common Signs Your Dog Is Sick

1. Changes in Appetite

What to watch for:

• Loss of appetite: Skipping meals, eating less than usual, turning away from food
• Increased appetite: Suddenly eating much more (can indicate diabetes, Cushing's disease)
• Picky eating: Only eating treats, avoiding kibble

When to worry: No food for 24 hours in adults, 12 hours in puppies; sudden drastic changes; accompanied by other symptoms.

2. Vomiting

Occasional vs. concerning:

• Occasional (often okay): Single episode, dog otherwise normal, ate too fast or ate grass
• Concerning: Multiple episodes in 24 hours, projectile vomiting, blood in vomit, accompanied by lethargy or diarrhea

See detailed guide: Dog Vomiting: Causes and Treatment

3. Diarrhea

What to watch for:

• Mild: Loose stool but otherwise normal behavior
• Concerning: Bloody diarrhea, black tarry stools, accompanied by vomiting or lethargy, lasts more than 24 hours

See detailed guide: Dog Diarrhea: Causes and Treatment

4. Lethargy and Weakness

Signs:

• Sleeping more than usual
• Not interested in walks or play
• Difficulty standing or walking
• Seems "out of it" or unresponsive
• Reluctance to climb stairs or jump

When to worry: Sudden onset, severe lethargy, accompanied by other symptoms, lasts more than 24 hours.

5. Behavior Changes

Watch for:

• Hiding: Withdrawing, seeking isolation
• Aggression: Uncharacteristic snapping or biting (may indicate pain)
• Restlessness: Pacing, can't settle, whining
• Confusion or disorientation: Getting lost in familiar places, staring at walls
• Anxiety: Excessive panting, trembling, clinginess

6. Coughing or Difficulty Breathing

Types:

• Kennel cough: Dry, hacking cough (like honking goose)
• Heart-related: Cough worse at night or during rest
• Labored breathing: Rapid, shallow, or noisy breathing
• Blue gums or tongue: EMERGENCY - oxygen deprivation

When to worry: Persistent coughing, difficulty breathing, coughing up blood, won't lie down due to breathing difficulty.

7. Excessive Thirst or Urination

Normal vs. excessive:

• Normal: Increased thirst after exercise or in Mauritius heat
• Excessive: Drinking constantly, large amounts, frequent urination or accidents indoors
• May indicate: Diabetes, kidney disease, Cushing's disease, urinary tract infection

8. Weight Changes

Watch for:

• Weight loss: Especially if eating normally (can indicate diabetes, cancer, parasites)
• Weight gain: Sudden or rapid gain (may indicate thyroid issues, Cushing's disease)
• Bloating: Swollen or distended abdomen

9. Eye Problems

Signs:

• Redness or bloodshot eyes
• Discharge (clear, yellow, or green)
• Squinting or keeping eyes closed
• Cloudiness or change in eye color
• Pawing at eyes
• Swelling around eyes

When to worry: Sudden changes, painful eyes, vision loss, foreign object in eye.

10. Nose Discharge

Normal vs. concerning:

• Normal: Clear, watery discharge; slightly moist nose
• Concerning: Thick, colored (yellow/green), bloody, one-sided discharge
• May indicate: Infection, foreign object, dental disease, tumor

11. Limping or Difficulty Moving

Signs:

• Favoring one leg
• Stiffness, especially after resting
• Reluctance to jump, climb stairs, or play
• Yelping when touched or moved
• Swelling in joints or legs

When to worry: Sudden severe lameness, not weight-bearing on leg, swelling or heat in joint, doesn't improve with rest.

12. Skin and Coat Changes

Watch for:

• Excessive scratching or licking: May indicate allergies, fleas, skin infection
• Hair loss: Bald patches, thinning coat
• Redness, rash, or sores: Inflammation, hot spots
• Lumps or bumps: Any new growths should be checked by vet
• Dull, dry coat: May indicate poor nutrition or illness

In Mauritius: Year-round flea and tick problems are common - see Flea and Tick Prevention

13. Bad Breath or Dental Issues

Signs:

• Extremely foul breath (beyond normal "dog breath")
• Red, swollen, or bleeding gums
• Difficulty eating or dropping food
• Excessive drooling
• Pawing at mouth
• Visible tartar or broken teeth

14. Vocalizations

Unusual sounds:

• Excessive whining, whimpering, or crying (may indicate pain)
• Howling or barking more than normal
• Yelping when touched or moving
• Groaning or grunting

15. Seizures or Tremors

Types:

• Grand mal seizure: Loss of consciousness, paddling legs, jaw chomping
• Focal seizure: Twitching in one area, facial movements
• Tremors: Shaking, shivering not due to cold or fear

Action: Clear area, don't restrain dog, time the seizure, contact vet immediately.

When to Call the Vet

Call Immediately (Emergency)

• Difficulty breathing or choking
• Unconsciousness or unresponsiveness
• Seizures (especially first-time or lasting more than 3 minutes)
• Severe bleeding or trauma
• Bloated, hard abdomen with unsuccessful vomiting attempts (GDV emergency)
• Inability to urinate or defecate despite straining
• Suspected poisoning (antifreeze, rat poison, human medications, toxic foods)
• Heatstroke symptoms (see Heatstroke Guide)
• Pale or blue gums
• Severe pain (screaming, can't be consoled)

Call Same Day

• Multiple episodes of vomiting or diarrhea
• Blood in vomit, stool, or urine
• Not eating for 24+ hours (12+ hours in puppies)
• Sudden lethargy or weakness
• Persistent coughing
• Eye injury or sudden vision changes
• Limping severely or not bearing weight
• Distressed or seems in pain

Schedule Appointment Soon (Within 1-3 Days)

• Gradual decrease in appetite
• Mild diarrhea lasting more than 1 day
• Increased thirst and urination
• Weight loss or gain
• Skin issues (rash, excessive scratching, hair loss)
• Bad breath or dental problems
• Behavior changes that persist
• Any new lumps or bumps

What to Tell Your Vet

When calling or visiting, provide:

• Symptoms: What you're observing, when it started, how often
• Duration: Hours? Days? Weeks?
• Severity: Getting worse, staying same, or improving?
• Other symptoms: Any additional signs, even if they seem unrelated
• Diet and water: Eating? Drinking? How much?
• Bathroom habits: Normal urination and bowel movements?
• Behavior: Activity level, sleep, mood changes?
• Recent events: New foods, medications, exposure to toxins, trauma?
• Medical history: Previous illnesses, current medications, vaccination status

Home Monitoring Basics

Taking Your Dog's Temperature

• Normal temperature: 37.5-39.2°C (99.5-102.5°F)
• Method: Rectal thermometer with lubricant
• Fever: Above 39.5°C (103°F)
• Low temperature: Below 37°C (99°F) - emergency

Checking Hydration

• Skin tent test: Gently pull up skin on back of neck - should snap back immediately. Slow return = dehydrated
• Gum check: Gums should be moist and pink. Dry or sticky gums = dehydrated
• Capillary refill: Press gum, should return to pink within 2 seconds

Checking Gums

• Normal: Pink, moist
• Pale or white: Anemia, shock, blood loss
• Red: Inflammation, overheating, toxin exposure
• Blue or purple: EMERGENCY - oxygen deprivation
• Yellow: Liver disease, jaundice

Preventive Care in Mauritius

Year-Round Health Monitoring

• Parasite prevention: Monthly flea, tick, heartworm treatment (essential in tropical climate)
• Heat monitoring: Watch for heat stress signs year-round
• Hydration: Ensure adequate water intake in hot, humid climate
• Regular vet checkups: Annual exams minimum, twice yearly for seniors

Vaccinations

• Core vaccines: Rabies, distemper, parvovirus
• Keep up to date with booster schedules
• Discuss lifestyle-based vaccines with your vet

Know Your Dog's Baseline

• Normal activity level and sleep patterns
• Typical appetite and eating speed
• Regular bathroom schedule
• Usual behavior and mood
• Standard weight and body condition

Knowing what's normal for YOUR dog makes it easier to spot when something is off.

Finding a Vet in Mauritius

Establish a relationship with a vet BEFORE emergencies:

• Find veterinarians in Mauritius →
• 24/7 Emergency vets →

Save emergency vet numbers in your phone and post near your pet's supplies.

Key Takeaways

• Trust your instincts - if something seems off, call your vet
• Early detection dramatically improves treatment outcomes
• Know your dog's baseline behavior to spot changes
• Watch for multiple symptoms together (more concerning than single symptom)
• Puppies and seniors need more vigilant monitoring
• Never wait on emergency symptoms - call vet immediately
• In Mauritius heat: heatstroke is a year-round emergency risk
• No food for 24 hours (adults) or 12 hours (puppies) requires vet visit
• Vomiting + diarrhea together = more serious than either alone
• "When in doubt, check it out" - better safe than sorry