TL;DR: Green vomit in dogs is often bile or grass, but requires veterinary care if accompanied by lethargy or an inability to keep water down. Capturing a photo of the vomit can help your vet provide a faster diagnosis.
What causes my dog to vomit green fluid?
When your dog vomits green fluid, it is most often bile. Bile is a digestive fluid produced by the liver and stored in the gallbladder that helps break down fats. If a dog vomits on an empty stomach, or if the vomiting is frequent enough to empty the stomach of food, the yellow or green bile is what remains. In some cases, green vomit can also be caused by the ingestion of grass or other green plants, or more rarely, toxic substances like certain rodenticides.
Is my dog's green vomiting a veterinary emergency?
- Urgency Level: Generally categorized as Medium.
- Monitor at Home: If your dog vomits once but continues to act normally, eat, and drink, it may be a temporary stomach upset or 'Bilious Vomiting Syndrome.'
- Contact a Vet (12-24 Hours): Seek professional advice if vomiting is accompanied by lethargy, abdominal pain, diarrhea, or a refusal to eat.
- Immediate Emergency: Seek care right away if your dog is unable to keep water down or appears extremely distressed.
Why should I take a photo of my dog's vomit for the triage team?
- Accurate Assessment: A photo helps the vet determine the consistency and the exact shade of green.
- Identify Contaminants: Visuals help detect traces of blood, mucus, or foreign objects like grass and plastic.
- Precision Diagnosis: Visual evidence provides much more accurate information than a verbal description, allowing for a faster diagnosis during your appointment.
Clinical Context (Merck Veterinary Manual)
Vomiting of green fluid in dogs may indicate the presence of bile in the vomitus, often associated with sudden-onset vomiting. Potential causes include dietary indiscretion or intolerance (ingestion of novel, spoiled, or contaminated foods, or foreign material), drug or toxin ingestion (antibiotics, NSAIDs, corticosteroids, plants, chemicals), systemic illness (pancreatitis, uremic gastropathy, hypoadrenocorticism), endoparasitism (Physaloptera sp.), or bacterial (Helicobacter-associated disease) or viral (canine parvovirus gastroenteritis) infection. If vomiting persists despite symptomatic treatment, or if hematemesis or melena are present, further diagnostics are warranted. Abdominal palpation and radiographs should be performed to assess for foreign bodies or intestinal obstruction. Diagnostic testing, including a CBC, serum biochemical profile, and urinalysis may be indicated, and followed by more specific testing.
Chapter: Gastroenterology, Toxicology, Infectious Disease
Source: The Merck Veterinary Manual, 11th Edition (Page 387)