Vomiting and diarrhoea in dogs and cats: the warning signs

A soiled carpet at dawn, a litter tray that smells stronger than usual: every owner knows these episodes. Most pass within 24 hours. A few hide an obstruction, a poisoning or a gastric torsion that plays out in hours. Here is how to tell them apart, what to do at home and when to call the on-call vet.

Vomiting, regurgitation, diarrhoea: what are we talking about?

Vomiting is active: abdominal contractions, nausea, drooling, then expulsion of partly digested contents. Regurgitation is passive: the animal brings up undigested food, often sausage-shaped, without effort. The distinction matters, because regurgitation points to the oesophagus and vomiting to the stomach, the intestine or a general illness (kidneys, liver, pancreas, toxin).

As for diarrhoea, one or two soft stools in a pet that is eating and playing have nothing in common with a liquid jet every hour or black, sticky stools.

The common, often harmless causes

• Sudden change of food, table scraps, unusual treats.
• Dietary indiscretion: the bin, carrion on a walk, large amounts of grass.
• Hairballs in cats, especially long-haired ones.
• Intestinal parasites, in particular worms and Giardia in young animals; our guide on how often to deworm sets out the schedule.

In an alert adult that is drinking and has vomited only once or twice, this usually settles at home.

When it is an emergency

Some signs call for an immediate phone call to the vet, day or night:

Gastric dilatation-volvulus mainly affects large breeds (Great Dane, German Shepherd, setters, Standard Poodle, Saint Bernard), often after a large meal followed by exercise. The dog is restless, tries to vomit without success, its belly tightens: every hour counts, and 25 to 30% of affected dogs do not survive despite surgery.

For toxic substances, the Belgian Poison Centre also answers for animals on 070 245 245 (weekdays 8 am to 4 pm, weekends 10 am to 4 pm). Never make your pet vomit yourself. See also our articles on toxic plants and the dangers of chocolate.

Spotting dehydration in two steps

Dehydration is the most frequent complication, and the most insidious in small animals. Two tests:

1. The skin fold: gently pinch the skin between the shoulder blades and let go. In a hydrated animal it springs back in under a second. If the fold stays up, the animal is short of water.
2. The gums: lift the lip. Pink, moist, shiny gums are normal. Dry gums that stick to your finger, pale or greyish, signal a problem.

A dehydrated kitten or puppy cannot be rehydrated at home: it needs a drip.

What to do at home when the signs are reassuring

For a lively adult, with no blood or pain, after one or two episodes:

• Short fast: withhold food for 12 to 24 hours in an adult dog, and never more than 12 hours in a cat, whose liver copes poorly with fasting. No fasting for puppies, kittens, elderly or diabetic animals.
• Water always available, in small repeated amounts rather than a large bowl gulped down in one go, which would trigger another vomit. If water does not stay down, see the vet.
• Gradual return to food: well-cooked rice with chicken breast or lean fish, or a veterinary gastrointestinal diet, in 4 to 6 small meals a day for 2 to 3 days, then a progressive return to the usual ration.
• No human medicines. Paracetamol, ibuprofen and loperamide can kill a cat or a small dog. Use only what your vet has prescribed.
• Note the time and appearance of each episode: it speeds up the diagnosis.

If nothing improves after 24 hours, or if a single warning sign appears in the meantime, call. At night or on a Sunday, our guide explains how the on-call vet works.

Prevention: food transitions and weight tracking

The digestive tract likes routine. Any change of brand, range or type of food (kibble to wet food, for example) is made over 7 to 10 days, increasing the share of the new food by quarters. The same transition principles apply to herbivores, as our article on feeding rabbits explains.

Weight is your best long-term indicator. A 5% loss in a month, together with recurring digestive episodes, warrants a check-up even if each episode seemed trivial. Vets also use the 9-point body condition score: the ribs should be felt under a thin layer of fat, without being seen.

In Zoolinko, your pet's free health record keeps the weight curve, the foods and the treatments; if you have to rush to an on-call vet, the 72-hour emergency access gives them the whole history in a single scan.