Digestive problems, such as diarrhoea, constipation, flatulence or anal gland inflammation should not be dismissed by pet owners as temporary issues, but be seen as serious warning signs. As a rule, such symptoms indicate that something is wrong in the animal’s body.

Even if the complaints mentioned are often only related to temporary imbalances, viral diseases, infections and feeding or age-related disorders, which pet owners can treat themselves, a vet should always be consulted. In some cases, digestive problems can also indicate more serious causes, such as an organ disease.

Digestive problems in focus: Diarrhoea

Digestive problems can be caused by the following:

  • Feed intolerances
  • Inflammation
  • Allergies
  • Viral diseases / infections
  • Parasites
  • Cancer
  • Ulcers
  • Foreign bodies
  • Toxins
  • Other diseases (kidneys, pancreas, etc.)

Feeding-related diarrhoea is the easiest to resolve. The wrong choice of food or incorrect composition with a high carbohydrate content can lead to the carbohydrate digestion capacity of the small intestine being exceeded, which causes diarrhoea. Before being given to your pet, carbohydrates such as potatoes, rice or millet must be boiled until very soft to break down the starch and make them digestible.

A basic distinction is made between diarrhoea in the small intestine and in the large intestine, which also have different effects on the animal organism:

A graph showing the differences between small and large intestine diarrhoea and their symptoms.
In the case of diarrhoea, a distinction is made between small and large intestine diarrhoea.

Too high concentrations of easily fermentable carbohydrates (pectin, lactose, lactulose, etc.), which are often given in self-prepared rations, can be responsible for digestive problems. Environmental factors such as too high temperatures or incorrect storage of conventional food (canned or dry food) as well as incorrect thawing of home-made rations can also result in symptoms such as diarrhoea or flatulence. It is always important to ensure that dry food bags are sealed well and stored in a cool place. Canned food must not show any external damage such as dents or a slightly open closure. Pet owners should thaw frozen rations they have made themselves in the refrigerator to avoid contamination with microorganisms.

Avoiding digestive problems: Be careful when changing your pet’s diet

An important point for pet owners who want to switch to a different type of feeding or just change the food is to do the changeover slowly. The intestinal flora must adapt to the new conditions. This cannot be done from one day to the next. As a rule, you should expect a conversion period of five to seven days, with old animals this acclimatization phase can take longer.

The exact composition of the feed should also be taken into account. Soy products, feedstuffs rich in connective tissue (gullet, tripe, etc.) but also animal by-products, which can contain almost anything, can throw the digestive system off balance. It is advisable to take a close look at the manufacturer’s exact composition and to contact them if you have any questions. In the case of self-prepared rations, animal owners should reconsider the components of the composition or discuss them with experts.

How should dog or cat owners react to acute diarrhoea?

First of all, the animal should be put on a fasting diet (zero diet with water). For dogs that should be 24 to 48 hours, for cats a maximum of twelve hours. Cats are more sensitive to a zero diet. Overweight cats in particular should never fast for longer, as it can cause hepatic lipidosis. This also applies to young animals, where fasting is contraindicated.

Drinking plenty of water is also essential to avoid dehydration. Pet owners can easily check for dehydration with the neck fold test.

Why is fasting so important?

Fasting can prevent the subsequent development of a feed allergy.

Inflammation of the intestines, also known as enteritis, loosens the cell connections between the intestinal cells. This allows proteins to migrate through the intestinal barrier and come into contact with the immune cells. The proteins are then classified as a danger (so-called allergens) and the organism produces antibodies against them. If pet owners remain consistent in the withdrawal of food, the intestinal mucosa regenerates within 24 to 48 hours. The organism then produces new intestinal cells to strengthen the intestinal barrier. So the barrier does not become or stay permeable.

The second important reason for fasting is that the pulverised nutrient building blocks (carbohydrates and protein) can have an osmotic effect and increase diarrhoea.

After the fasting period, the animal can be given bland food for two days and then returned to its normal feed ration. Home-made, low-fat and easily digestible rations that are given in several stages throughout the day are suitable for this. A large meal should be avoided. One possible combination would be well-cooked rice, lean poultry meat and cottage cheese. Although that composition is well suited for a light diet, it should not be used as the only food over a long period. Without vitaminised mineral feed supplementation, this would lead to a nutrient deficiency.

Soup as a feeding option for diarrhoea

Moro’s carrot soup is an excellent home remedy for diarrhoea. It can also be used alongside treatment as a feeding option for pets with intestinal infections. However, pet owners should not consider it a replacement to treatment by a vet, but as a supplementary measure.

Recipe: Moro’s carrot soup

  • Peel carrots and cover with water.
  • Add 5g (1 tsp) salt/kg carrots and cook for at least an hour (soft-boil).
  • Puree the mixture.


  • Very small dogs: 0.1 litres
  • Small dogs: 0.25 litres
  • Medium Dogs: 0.5 litres
  • (Very) large dogs: correspondingly more

Dogs should be given the soup about half an hour before each main meal. Ideally, Moro soup covers every part of the small intestine with oligosaccharides. Boiling carrots forms the smallest sugar molecules (acidic oligogalacturonides), which resemble the receptors of the intestinal epithelium and attach to pathogenic intestinal germs. These pathogens are then no longer attached to the intestinal epithelium, but to the sugar molecules and are excreted.