Dogs are incredibly loyal companions, but they can’t tell us when something is wrong. As responsible pet owners, it’s important to watch for subtle signs of illness that may indicate your dog needs medical attention. Early detection often leads to better outcomes and faster recovery.

In this blog, we’ll walk you through 10 common signs that your dog might be sick, what they could mean, and what steps to take. Whether you’re a first-time dog owner or a seasoned pet parent, this guide will help you stay proactive about your dog’s health.

1. Loss of Appetite in Dogs

A sudden disinterest in food is one of the most obvious signs something’s wrong. While dogs can skip a meal occasionally, going more than 24 hours without eating could signal issues like:

• Dental pain
• Gastrointestinal problems
• Infections
• Organ dysfunction

What to do:
Monitor your dog’s eating habits closely. If your dog refuses food for over a day or shows other signs like vomiting or lethargy, contact your vet.

2. Vomiting or Diarrhea in Dogs

An upset stomach can result from minor dietary indiscretions, but frequent vomiting or diarrhea is a red flag.

Possible causes include:

• Ingesting toxins or foreign objects
• Parasites
• Food allergies
• Pancreatitis

What to do:
If symptoms persist for more than 24 hours, or if there’s blood in the vomit/stool, seek veterinary care immediately.

3. Lethargy or Fatigue in Dogs

Every dog has lazy days, but if your typically energetic pup is suddenly tired, something could be wrong.

Causes might include:

• Infections (like canine flu or Lyme disease)
• Heart issues
• Pain from injuries or arthritis
• Anemia

What to do:
Note how long the fatigue lasts. Persistent lethargy (over 24 hours) requires a vet visit, especially if it’s paired with other symptoms.

4. Coughing or Difficulty Breathing in Dogs

Respiratory problems in dogs can be serious. Look out for:

• Persistent coughing
• Labored breathing
• Wheezing or nasal discharge

These may signal conditions like kennel cough, heart disease, or pneumonia.

What to do:
Coughing that lasts more than a few days, or any difficulty breathing, should be evaluated by a vet right away.

5. Changes in Urination or Defecation Habits in Dogs

If your dog suddenly starts having accidents indoors, struggles to urinate, or goes more (or less) than usual, pay attention.

Potential causes:

• Urinary tract infections (UTIs)
• Kidney disease
• Diabetes
• Bladder stones

What to do:
Keep track of frequency and appearance. Take your dog to the vet for urinalysis and bloodwork to rule out underlying conditions.

6. Sudden Weight Loss or Gain in Dogs

A noticeable change in weight without any diet or exercise changes can be a symptom of:

• Thyroid disorders
• Metabolic diseases
• Parasites
• Cancer

What to do:
Weigh your dog monthly and consult your vet if you notice unexpected fluctuations.

7. Excessive Thirst or Urination in Dogs

Drinking more water than usual? Frequent urination can accompany this. Conditions that may cause this include:

• Diabetes
• Kidney issues
• Cushing’s disease

What to do:
If your dog is emptying their water bowl faster than usual or asking to go outside more, don’t ignore it—see your vet.

8. Skin and Coat Changes in Dogs

Healthy dogs typically have shiny, smooth coats. If you notice:

• Bald patches
• Excessive itching or scratching
• Scabs or sores
• Dry, flaky skin

These could indicate:

• Allergies
• Skin infections
• Mange or fleas

What to do:
Use flea preventatives regularly and check for parasites. Persistent skin issues may require a vet-prescribed medicated shampoo or treatment.

9. Bad Breath or Dental Issues in Dogs

Foul-smelling breath isn’t just unpleasant—it can signal dental disease or other health concerns like kidney disease or diabetes.

Also look for:

• Swollen gums
• Yellow or brown teeth
• Difficulty chewing

What to do:
Regular brushing and dental cleanings are essential. Schedule a dental checkup if symptoms persist.

10. Behavioral Changes in Dogs

Sudden aggression, hiding, whining, or restlessness may indicate discomfort, stress, or illness.

Behavioral changes could stem from:

• Pain
• Neurological issues
• Anxiety
• Sensory decline (vision/hearing loss)

What to do:
Don’t chalk it up to “just getting older.” Monitor your dog’s behavior and discuss any changes with your veterinarian.

When to See the Vet

You should always trust your instincts. If your dog seems “off” for more than 24 hours, or displays multiple symptoms from the list above, contact your vet. Catching problems early can make a huge difference in treatment and recovery.

Tips to Keep Your Dog Healthy Year-Round

• Schedule regular vet checkups (at least once a year)
• Maintain a balanced diet and proper exercise
• Stay on top of parasite prevention (fleas, ticks, heartworms)
• Brush your dog’s teeth regularly
• Provide mental stimulation and social interaction

FAQs About Sick Dogs

Q1: Can I give my dog over-the-counter medicine?

A: No—many human medications can be toxic to dogs. Always consult your vet before giving any meds.

Q2: My dog vomited once but seems fine. Should I worry?

A: If it’s a one-time event and your dog is otherwise acting normal, monitor them. If vomiting continues or other symptoms appear, call your vet.

Q3: How do I know if it’s an emergency?

A: Difficulty breathing, continuous vomiting or diarrhea, seizures, or collapse are medical emergencies—seek immediate care.

Q4: Should I be concerned if my senior dog sleeps more?

A: Older dogs do tend to sleep more, but excessive fatigue or other changes could indicate health issues.

Q5: What should I bring to the vet if my dog is sick?

A: Bring a list of symptoms, pictures or videos if possible, and a sample of vomit/stool if relevant.