Various terms define the same disease: IBD (Inflammatory Bowel Disease), chronic inflammatory enteropathy.
The wall of the intestine is made up of different layers. An outer layer of muscles mixes and moves food through the digestive tract. An inner layer in contact with food is where nutrients are absorbed. In the case of inflammatory bowel disease, cells involved in inflammation and immune response build up abnormally within these layers. This disrupts the mixing and advancement of food as well as its absorption.
All areas of the digestive tract can be affected by this disease.
Several types of inflammatory cells can infiltrate the wall of the intestine, but the most common are lymphocytes and plasma cells. This is called lymphoplasmacytic enteritis. In some cases, the thickening of the digestive wall prevents the absorption of proteins; a decrease in the level of proteins is then observed in the blood.
The most common hypothesis to explain this disease is that the digestive tract develops an inappropriate and excessive immune reaction in response to food, microbial or genetic aggressors.
Certain breeds are more frequently affected, such as the German Shepherd, Sharpei, terriers and the Siamese cat. Symptoms most often appear in adulthood with an average age of 6 years.
It is not abnormal for a dog or cat to have episodes of vomiting or diarrhea from time to time, as long as this remains occasional. Indeed, when cats groom they swallow large quantities of hair which form balls which must be evacuated and dogs have the annoying tendency to eat things which they are not supposed to ingest like leftovers in putrefaction from compost or garbage cans, other animal droppings, pieces of wood, pebbles or toys.
However, if vomiting and/or diarrhea become persistent or seem too frequent, a veterinarian should be consulted. In cases of inflammatory bowel disease, owners generally report chronic diarrhea and/or vomiting which may be associated with weight loss and variable appetite.
Many diseases can cause the above-listed symptoms. It is therefore essential to have a systematic approach and to neglect nothing. At first, one starts with eliminating other potential diseases that are not of digestive origin but which cause similar symptoms (for example hypoadrenocorticism, chronic renal insufficiency or exocrine pancreatic insufficiency).
Next, when it has been established that the problem comes from the digestive tract, one proceeds by excluding other intestinal diseases which can also cause inflammation and infiltration of the intestines such as parasitism, tumors, injury by a foreign body, bacterial or viral superinfection, etc. This is why a stool analysis and an abdominal ultrasound are essential. The diagnosis of inflammatory bowel disease is usually a diagnosis of exclusion, which means that one must first eliminate other hypotheses to arrive at this diagnosis.
Abdominal ultrasound often shows a thickening of the intestine wall. However, in order to determine the type of cells involved in the infiltration (cancer cells or inflammatory cells: lymphocytes and plasma cells, eosinophils or neutrophils), biopsies of the intestinal wall must be taken. These biopsies are performed by endoscopy or by surgery.
Depending on the response to treatment, 3 types of inflammatory bowel disease are defined.
Therapeutic trials are generally carried out in this order if the animal is sufficiently stable. The combination of these 3 treatments may also be necessary.
The implementation of these various therapeutic trials takes several weeks. Therefore, if the animal is not sufficiently stable, it is envisaged to set up an immunomodulatory treatment more quickly.
The prognosis is highly variable depending on the severity of the disease. For patients who require immunomodulatory therapy, it is common for them to need this treatment long term.
Dr Emilie Vangrinsven
Diplomate from European college of veterinary internal medicine | PhD U-Liège
Assistant at the Liege University in the university clinic for PETs | Author and co-author of numerous scientific publications