50 Common Dog Symptoms Explained by Vets (2026 Guide)
Quick Answer
Vet-reviewed reference for the 50 most common dog symptoms. What each symptom usually means, the red flags that need an emergency vet, and what to track at home. Reviewed by Dr. Ashim Sarkar, DVM.
Key Takeaways
- A single symptom is a data point. Two symptoms appearing together is a clinical pattern.
- Most dog symptoms fall into 4 urgency tiers: home monitor, same-day vet, see today, or emergency.
- Behavioral changes (hiding, lethargy) often precede the visible symptoms by days.
- Tracking what you observe creates the timeline your vet uses to diagnose.
Photo: Roberto Nickson / Unsplash
Reviewed by Dr. Ashim Sarkar, BVSc & AH, veterinarian with 2.5 years of hands-on experience in small animal practice. This content is for informational purposes only and does not constitute veterinary advice. Always consult a licensed veterinarian for your pet's health concerns.
The single-page reference for what your dog's symptoms actually mean
Dogs hide pain. That's not a quirk, it's an evolutionary survival instinct. By the time most owners notice a symptom, the underlying problem has often been brewing for days or weeks. This guide is the vet-reviewed reference for the 50 most common symptoms you might see, what each one usually means, the red flags that demand an emergency vet visit, and what to track at home so your next vet appointment is actually useful.
For any acute or worsening symptom, use [Omelo's free symptom checker](https://www.beomelo.com/pet-symptom-checker) to triage in 30 seconds.
Digestive symptoms
- Vomiting once, Usually self-limiting (ate too fast, mild stomach upset). Watch for: more than 2-3 episodes, blood, lethargy, distended belly.
- Vomiting repeatedly, Same-day vet. Could be pancreatitis, foreign body, toxin exposure.
- Vomiting with blood, Emergency. Could be ulcer, severe gastritis, foreign body.
- Diarrhea (single episode), Usually dietary. Bland diet for 24h.
- Diarrhea with blood, Same-day vet. Could be parvovirus (young dogs especially), HGE, colitis.
- Black or tarry stool, Vet today. Indicates upper GI bleeding.
- Not eating for >24 hours, Vet visit. In small breeds, hypoglycemia risk.
- Drinking excessive water, Polydipsia. Vet workup needed. Common in diabetes, kidney disease, Cushing's.
- Bloated abdomen, Possible GDV (bloat), emergency in deep-chested breeds (Great Dane, Standard Poodle, GSD).
- Constipation, Vet if >48h. Common in seniors.
Respiratory symptoms
- Coughing (kennel cough sound), Honking, dry. Usually Bordetella. Vet for confirmation and treatment.
- Coughing at rest, Vet visit. Heart disease consideration in small breeds.
- Reverse sneezing, Episodic snorting, common in small breeds. Usually benign.
- Wheezing, Vet visit. Could be allergic bronchitis, laryngeal paralysis.
- Open-mouth breathing at rest, Emergency in brachycephalic breeds (Pug, Bulldog, Boxer).
- Blue or pale gums, Emergency. Indicates oxygen problem or shock.
Movement and mobility
- Limping (mild, single limb), Rest 24-48h. Vet if persistent or worsening.
- Won't bear weight, Vet today. Could be fracture, cruciate tear.
- Stiffness after rest, Common in seniors. Osteoarthritis workup.
- Dragging back legs, Emergency. Spinal cord issue (especially in dachshunds).
- Sudden weakness or collapse, Emergency. Cardiac, neurological, or metabolic.
Skin and coat
- Excessive itching, Allergies most common. Flea check first.
- Hot spots, Acute moist dermatitis. Vet visit; antibiotics often needed.
- Hair loss in patches, Vet visit. Could be infection, mange, allergy.
- Lumps under skin, All lumps deserve a vet check. FNA (fine needle aspirate) is cheap and informative.
- Cracked paw pads, Mostly cosmetic. Vet if bleeding or limping.
Neurological
- Seizure, Time it. <2 min and recovers normally: vet within 24h. >5 min or repeated: emergency.
- Head tilt, Vet visit. Vestibular disease common in seniors.
- Disorientation, Vet visit. Could be cognitive decline, toxin, neurological event.
- Tremors, Vet visit. Many causes, some emergencies.
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Eyes and ears
- Red, irritated eye, Vet visit. Could be conjunctivitis, scratch, glaucoma.
- Squinting one eye, Often corneal ulcer. Vet today.
- Cloudy eye, Vet visit. Cataracts vs nuclear sclerosis.
- Head shaking / ear scratching, Ear infection likely. Vet visit.
- Foul ear odor, Yeast or bacterial infection. Vet visit.
Behavior changes
- Suddenly aggressive, Pain until proven otherwise. Vet workup.
- Hiding, In normally social dogs, sign of pain. Vet visit.
- Pacing, Could be anxiety, pain, or cognitive decline.
- Compulsive licking, Often anxiety or itch. Vet workup.
- Personality change, Vet visit. Can be early sign of many conditions.
Urinary and reproductive
- Straining to urinate, Same-day vet (UTI, stones, in males possible blockage = emergency).
- Blood in urine, Vet visit. UTI or stones most common.
- Increased urination + drinking, Workup needed. Diabetes, kidney, Cushing's.
- Genital licking (excessive), Vet visit. UTI, anal gland, allergy.
Weight and appetite
- Weight loss without trying, Vet workup, especially in seniors.
- Weight gain despite normal eating, Hypothyroidism workup.
- Picky eating, Sometimes behavioral. Vet check if persistent.
- Ravenous hunger, Diabetes, Cushing's, or worms in puppies.
Other
- Bad breath (sudden change), Often dental, sometimes kidney or diabetes.
- Excessive panting at rest, Vet visit. Pain, heart, respiratory, or endocrine.
The thing all 50 symptoms have in common
A single symptom is a data point. Two symptoms at the same time is a clinical pattern. The single hardest thing for pet parents to do, alone, is notice the *combination*. That's what Omelo's clinical reasoning is built to do, log each symptom in 5 seconds and let the app surface the pattern.
Related reading
- [Pet First Aid Guide: 12 emergencies and what to do](https://www.beomelo.com/pet-first-aid)
- [Foods Toxic to Dogs (vet-reviewed list)](https://www.beomelo.com/foods-toxic-to-dogs)
- [Dog Vaccination Schedule 2026](https://www.beomelo.com/dog-vaccination-schedule)
- [Free pet symptom checker](https://www.beomelo.com/pet-symptom-checker)
References
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Dr. Ashim Sarkar, BVSc & AH
Veterinarian · Medical Reviewer
Reviews all clinical and triage content on Omelo. Hands-on small-animal practice experience across vomiting, dermatology, vaccinations, and emergency triage. All Omelo recommendations pass through Dr. Sarkar before publication.
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