Dog vomiting but acting normal: what is urgent and what a blood test adds

Why a bright dog still needs the list above

The most common reason owners search for vomiting but acting normal is to be reassured, and for one vomit in an otherwise well adult dog that reassurance is often reasonable. The problem is that the two conditions with the tightest clock, a twisted stomach and an obstruction, both begin in dogs that still look alert. A dog with a ball in its intestine can be bright for hours. A deep chested dog with a twisting stomach is restless and retching long before it looks collapsed. Demeanour is the last thing to go, not the first, so it is the wrong thing to wait for.

The practical rule: demeanour tells you how far along you are, it does not tell you what is happening. Use the pattern instead. How many times, over what period, what came up, is water staying down, what else has changed, and what could the dog have reached.

What to record before you ring or go

• The number of episodes and the times. Write them down, because it is easy to lose count.
• What came up: food, bile, foam, water, blood, coffee ground material, something recognisable.
• Whether it was vomiting, which is active heaving from the abdomen, or regurgitation, which is food coming back up with no effort. Vets treat these as two different problems.
• Whether water is staying down.
• Faeces: normal, loose, absent, black, bloody.
• Access: bins, compost, the garden, slug pellets, a child's toy, a visitor's handbag, any human medicine in the house.
• Medicines, recent food changes, recent worming or vaccination.
• Weight, if you have a recent figure, and whether it has moved.

What the blood panel contributes

Blood work does not see a blockage. What it does is tell the vet how the organs behind vomiting are behaving, and how much the vomiting has already cost the dog.

Reading notes on each group:

• Creatinine and urea rising together in a dog that has been sick for a day often reflect dehydration rather than the kidney itself, which is why hydration on the day of the sample matters and why a urine sample taken before any fluids is worth so much. Urea rising alone can also follow bleeding in the gut.
• ALT comes from liver cells and alkaline phosphatase from the bile ducts, so the pair read together points somewhere more precise than either alone. Alkaline phosphatase on its own is the most frequently flagged and least specific line on a canine panel.
• Lipase has to be the right kind. A general catalytic lipase is not specific to the pancreas, while the pancreas oriented assays, the DGGR method or a canine pancreatic lipase test, are the ones used to answer that question. Ask which was run.
• Potassium and chloride are the lines that show what has been lost. Prolonged vomiting typically strips chloride and potassium, and a low potassium makes a dog weak in a way that looks like deterioration from the original problem. A potassium that is high alongside a low sodium is one of the patterns that makes a vet think of Addison's disease, an under recognised cause of recurrent vomiting in dogs.
• Glucose is read both ways round. A low glucose in a small dog or a puppy is an urgent finding in itself, and a high one in a very sick vomiting dog raises questions a vet pursues quickly.

Expect imaging to be proposed alongside, because an X ray or an ultrasound scan answers the structural question a blood panel cannot. A normal panel does not mean nothing is wrong, and compare every value only with the range printed on your own report.

Questions to ask your vet

1. Given what I have seen, is this something to watch or something to image today?
2. Do creatinine and urea reflect dehydration, or the kidney itself, and was urine taken before any fluids?
3. Which lipase method was used, and does the result support the pancreas?
4. Have potassium, sodium and chloride been measured, and what do the losses look like?
5. Is there a pattern here that makes Addison's disease worth excluding?
6. Do we need an X ray or an ultrasound scan before this panel can be interpreted?
7. What exactly should make me ring you back, and at what point do I go to the out of hours service?

When should I see a vet for a vomiting dog?

Ring immediately for any of the signs in the alert panel above, and in particular for retching that produces nothing, a hard or swollen abdomen, blood, marked dullness, a puppy, or any suspicion of a swallowed object or a poison. Ring the same day for vomiting that has happened more than twice in a few hours, for vomiting with diarrhoea, for a dog that cannot keep water down, or for any vomiting in a dog with a known condition or on medication. A single vomit in a bright adult dog that then eats, drinks and behaves normally is the one situation that can reasonably wait for advice by phone.

My dog is vomiting bile in the morning. Does that need a blood test?

Yellow or green vomit first thing, in a dog that is otherwise well and eats normally afterwards, is the classic description of an empty stomach overnight. It is common and often settles once the gap between the last meal and the first one is shortened, which is a change to discuss with your vet rather than to decide at home. It earns a blood test when it becomes frequent, when weight starts to move, when the dog is off colour, or when it is new in an older dog.

What does blood work show in a vomiting dog?

Four groups. The kidney, through creatinine and urea, because reduced filtration makes dogs sick and because vomiting itself dehydrates and pushes those values up. The liver and bile ducts, through ALT and alkaline phosphatase. The pancreas, through a lipase measured with a pancreas oriented method. And the salts and sugar, through potassium, sodium, chloride and glucose, which tell you how much the vomiting itself has cost. What blood work cannot show is structure: a swallowed toy, a twist or an obstruction needs imaging.

My dog is vomiting white foam. What does that mean?

White foam is saliva and air rather than stomach contents, so it mostly tells you the stomach is empty, not what is wrong. It matters far more whether the dog is managing to bring anything up at all. Repeated unproductive retching with a swelling abdomen, above all in a large or deep chested dog, is an emergency and should never be watched at home. Foam in a bright dog that then drinks and settles is a different matter, though still worth reporting.

My dog is vomiting and has diarrhoea. Is that more serious?

It raises the stakes, mainly because the two together lose fluid and salts much faster than either alone, and a dog can become dehydrated within a day. Ring the same day, and sooner if there is blood in either, if the dog is dull or if it is a puppy, where an infectious cause needs ruling out urgently. Take a note of the number of episodes and roughly how much, because that is what the vet will use to judge fluid losses.