Urgent — same day vet contact Immediate vet if blood, repeated unproductive retching, or unresponsiveness

Dog vomiting — when to worry

Withhold food for 4–6 hours, offer small sips of water, and phone the vet if vomiting repeats, contains blood, or the dog seems unwell.

Dog

Recognise the signs

Bringing up partly digested food (true vomiting) versus undigested food immediately after eating (regurgitation — different cause)
Yellow or green bile, often on an empty stomach
White foam
Blood — fresh red flecks or 'coffee ground' dark material
Repeated retching with nothing produced (red flag for bloat)
Lethargy, refusing water, painful belly

First aid steps

Remove access to food for 4–6 hours.
Offer small amounts of water every 30 minutes — a tablespoon at a time for small dogs, half a cup for larger.
If the dog keeps water down for 2 hours, offer a small bland meal (boiled chicken and white rice, or boiled white fish).
Continue small bland meals every 3–4 hours for 24 hours, then transition back to normal food.

Do NOT

Do not give human anti-sickness medication (e.g. metoclopramide tablets from a person's prescription, or anti-nausea wristbands).
Do not give milk to settle the stomach — most dogs are mildly lactose-intolerant.
Do not give a fatty meal (mince, sausage, scrambled egg with butter) as a 'treat' to coax appetite.
Do not assume grass-eating means it's mild — grass-eating with repeated vomiting is still worth a vet check.

When to phone the vet immediately

Vomiting more than 3 times in 12 hours
Any blood in vomit (red flecks or dark coffee-ground material)
Repeated unproductive retching (suspected bloat — see dog-bloat-gdv)
Vomiting alongside diarrhoea, especially with blood
Lethargy, collapse, or pale gums
Suspected toxin or foreign body ingestion
Puppy under 6 months — far less reserve, dehydrate fast
Diabetic or unwell senior dog

Signs that can usually wait for a routine appointment

A single vomit in an otherwise bright, alert dog who quickly settles, drinks water normally and is hungry within a few hours can usually be monitored at home for 24 hours.

Common causes

Dietary indiscretion — bins, leftovers, fatty food
Sudden diet change
Mild gastritis from grass eating
Worms or other parasites
Toxin or foreign body ingestion
Pancreatitis (often after fatty food)
More serious illness: kidney disease, liver disease, Addison's, pyometra

What the vet will need to know

How many times the dog has vomited and over what period
Appearance of vomit — colour, blood, food, foreign material
Any recent diet change, scavenging or known ingestion
Other symptoms — diarrhoea, lethargy, drinking more or less
Current medications and recent vaccinations
Photos of the vomit (genuinely useful)

Aftercare

Bland diet for 2–3 days then gradual return to normal food.
Probiotic paste from the vet can shorten recovery.
Watch stools for the next week — gut upset can swing to diarrhoea after vomiting settles.
If the cause was scavenging, secure bins and worktops.

Prevention

Bin-proof your kitchen — most home vomiting cases trace to scavenging.
Avoid sudden food changes; transition over 5–7 days.
Keep fatty food, takeaway leftovers, and rich human food out of reach — pancreatitis often follows.
Stay current on worming.
Pick up known scavenged items on walks: dropped chicken bones, mouldy food, dead wildlife.

Breed-specific notes

Pancreatitis particularly common in Miniature Schnauzers, Cocker Spaniels, Yorkshire Terriers, Cavaliers.
Brachycephalic breeds prone to regurgitation that can be confused with vomiting.

Frequently asked questions

What's the difference between vomiting and regurgitation?

Vomiting involves abdominal heaving and partly digested food; regurgitation is a passive bringing-up of undigested food, usually shortly after eating, with no retching. Regurgitation points to oesophageal problems and needs a different vet investigation.

Can I give my dog Pepto-Bismol or Imodium?

No — Pepto-Bismol contains salicylates that can be toxic to dogs and dangerous to cats. Imodium can mask serious problems and is not safe in some breeds (Collies and related breeds carry MDR1 gene mutation risk). Always ask your vet.

My dog vomited once and then ate the cat's food — is that bad?

If the dog seems otherwise bright and the vomit was unremarkable (food, bile, foam), a single vomit followed by normal appetite is rarely concerning. Monitor for further episodes over 24 hours and contact the vet if more vomiting, lethargy or diarrhoea develops.