Why Is My Dog Losing Weight
This page is educational reference material for preparing questions. A licensed veterinarian examines the animal, makes the diagnosis, and sets the treatment.
Unexplained weight loss in dogs: cancer, diabetes, kidney disease, parasites, and dental problems. When to get blood work.
Understanding This Symptom
As a dog owner, noticing changes in your pet's behavior or health is the first step to getting them the help they need. This page covers the most common causes, warning signs that indicate an emergency, and what you can expect at the veterinarian.
When to Seek Emergency Care
Drive to an emergency clinic immediately for: sudden laboured breathing, a distended and painful belly, collapse, uncontrolled bleeding, seizures, or suspected toxin ingestion. These scenarios do not wait well.
Common Causes
Less Serious Causes
More Serious Causes
- Poisoning or toxic exposure
What to Watch For
A clear grasp of the fundamentals is what turns later decisions from anxious guessing into informed choices
- Lethargy or reluctance to move or play
- Vomiting, diarrhea, or changes in stool
Home Care and First Steps
Veterinary Diagnosis
Your veterinarian will typically:
- Perform a thorough physical examination
Treatment Options
Prevention
Long-Term Management
When to Get a Second Opinion
Related Symptom Guides
- Why Is My Dog Not Eating?
- Why Is My Dog Shaking?
- Why Is My Dog Limping?
- Why Is My Dog Vomiting?
- Why Is My Dog Coughing?
Should I go to the emergency vet?
Go sooner if the weight loss comes with black stool, repeated vomiting, or a dog that is too weak to walk. Steady loss over weeks in a dog that is still active should be seen this week with the food log. A puppy that is thin and has bloody diarrhea should be seen the same day.
How much will treatment cost?
Weight loss with a normal or increased appetite needs an exam, a body-condition check, and usually bloodwork and a fecal test. Intestinal disease and endocrine disease are sorted with those results. Ultrasound is the later step. Get the first-visit estimate before blood is drawn.
Can I treat this at home?
Weigh the dog on the same scale every week and write the number down. Bring the food brand and the amount you actually pour. Do not add a new supplement stack while you wait. A dog that is also vomiting or has black stool should be seen this week.