Diarrhoea in dogs: the 24-hour plan, and the three signs that end it early

It is the most common reason a dog sees a vet, and the most common reason a dog did not need to. Something from a bin, a new bag of food, a stolen sausage, a stressful day at the kennels, and the next morning you are scrubbing the hallway. In an adult dog who is otherwise bright, this is usually a 24 to 48 hour problem that the body sorts out itself.

Usually. The skill is knowing which kind you are looking at, and that is decided less by what is on the floor than by how the dog is.

The three signs that end the plan early#

If any of these is true, do not start a home plan. Ring the vet.

1. Blood, or black. A streak of fresh red on a formed stool is common and rarely serious. A stool that is mostly blood, looks like raspberry jam, or is black and tarry is different: the first can be acute haemorrhagic diarrhoea, which dehydrates a dog frighteningly fast, and the second is digested blood from higher up the gut.

2. Vomiting as well. Diarrhoea alone lets a dog keep drinking. Diarrhoea with repeated vomiting means fluid is leaving from both ends and none is staying in, and a dog that cannot keep water down needs a drip, not rice. (Our guide to vomiting: what can wait and what can't covers that side.)

3. A dog who is not themselves. Flat, quiet, not interested in a walk or in you, a hunched back, a tight or swollen belly, shivering, pale or tacky gums. A dog with an ordinary upset stomach is embarrassed and still wants the ball. A dog who has stopped being a dog is ill.

And four kinds of dog for whom the waiting period is much shorter, a few hours rather than a day:

• Puppies, especially under six months or not fully vaccinated. Parvovirus starts exactly like this and kills quickly.
• Very small dogs, who have no reserves to lose.
• Old dogs, and dogs with a condition such as diabetes, kidney or heart disease, Addison's, or anything treated with steroids or anti-inflammatories.
• Any dog who may have eaten something: a toy, a corn cob, a sock, bones, human medicines, chocolate, grapes or raisins, xylitol, rat bait. That is a poisoning or a blockage until proved otherwise.

The 24-hour plan#

For the bright, adult, otherwise healthy dog.

Water, always. Diarrhoea is a fluid problem before it is anything else. Keep fresh water down at all times and notice whether it is going. If the dog is not drinking much, offer ice cubes or water with a spoon of the cooking liquid from plain boiled chicken.

Do not starve them. The old advice was a 24-hour fast. It has gone: the cells lining the gut feed directly from what passes through it, and they recover faster with food than without. Skip at most one meal if the dog clearly does not want it.

Small, bland, often. Four to six small meals through the day, rather than two large ones. Plain boiled chicken breast or white fish with well-cooked white rice, roughly one part meat to two parts rice, no skin, no oil, no salt, no stock cubes (onion and garlic are toxic to dogs). Plain cooked pumpkin or sweet potato is a good addition. A veterinary gastro-intestinal tin does the same job with less cooking.

Nothing else. No treats, chews, dental sticks, table scraps, milk or bones. One contributor, one rule, for everyone in the house, or you will never know what worked.

A probiotic if you have one. The pastes and powders made for dogs have modest but real evidence behind them and do no harm. Human yoghurt does very little.

Rest, and short lead walks to the nearest grass. Pick up promptly and keep the dog away from other dogs for a few days, since some causes are catching.

Write it down. Time, what it looked like, any blood, how the dog seemed. A quick note on the dog's profile in mypet care is enough. If you do end up at the vet, "six times since 7 am, watery, no blood, last ate normally on Tuesday" is worth more than any description from memory, and a photo is worth more still.

What not to give#

• Human anti-diarrhoea tablets. Loperamide (Imodium) can be dangerous in collies, shepherds and related breeds that carry a common gene mutation, and in any dog it can hide a problem that needs treating.
• Human painkillers. Ibuprofen, diclofenac and naproxen cause stomach ulcers and kidney failure in dogs at small doses.
• Left-over antibiotics. For years dogs were sent home with metronidazole for simple diarrhoea. The current European guidance is not to: in trials it does not shorten an ordinary bout, and it disrupts the gut bacteria for weeks afterwards. If your vet does not prescribe one, that is good medicine, not a brush-off.

When the plan has run its course#

Go to the vet if:

• it has not clearly improved in 24 hours, or has not stopped in 48;
• it is very frequent (more than about six times in a day) or pure water;
• any of the three signs above appears at any point;
• the dog is straining and producing nothing, or crying when trying;
• it clears up and comes back, again and again, over a few weeks. That is chronic diarrhoea and has a different list of causes: parasites such as giardia, food intolerance, pancreatic problems, inflammatory bowel disease.

Take a fresh sample in a sealed pot or bag. It is the single most useful thing you can bring, and nobody at the clinic will think it odd.

Going back to normal#

When the stools have been formed for a full day, move back to the usual food over three to four days: a quarter normal food mixed into the bland diet, then half, then three quarters. Going straight back is the most common reason for a relapse on day three.

Making it rarer#

Most repeat offenders have the same few causes, and they are all preventable:

• Change foods slowly, over a week, every time.
• Secure the bin, and watch what is picked up on walks.
• Keep treats under a tenth of the day's food, and keep the rich ones (pig's ears, fatty scraps) rare. We wrote about the diet you don't count.
• Worm regularly and keep vaccinations current; a reminder on the dog's profile does the remembering for you.
• Notice patterns. If it follows every kennel stay, it is stress. If it follows one particular chew, stop buying the chew.

An upset stomach is part of owning an animal that considers a dead pigeon a snack. One day of chicken and rice, a watchful eye, and a clear idea of the three signs is all most of them ever need.