DIGESTIVE ENDOSCOPY OR GASTROSCOPY
Also called "gastroscopy", the digestive endoscopic exam allows to visualise the proximal part of the digestive tract, namely the oesophagus, the stomach and the first portion of the intestine: the duodenum. This examination is helpful to diagnose lesions of the digestive tract, such as gastric ulcers for instance, or to check the integrity of the mucosa following an oesophageal obstruction.
Because of their diet and lifestyle, working horses are particularly at risk to develop gastric ulcers. Scientific studies led in horses of various populations have shown that the prevalence of ulcers ranges between 50 and 99%!
When is a gastroscopy indicated?
The digestive endoscopy is recommended in cases of
Loss of appetite
Weight loss
Dull or recurrent colic
Poor performances
Horses with ulcers may also grind their teeth or yawn frequently. Because ulcers can be painful during work, some horses show reluctance to exercise.
How is a gastroscopy performed?
To allow a complete observation of the whole stomach, the horse must be fasted prior to the examination, namely:
- at least 12 hours for food
- 6 hours for water
The examination is generally programmed in the morning: the horse receives his last meal on the evening before the examination. To avoid that the horse eats, it is recommended to put a basket or to place him on shavings.
INTESTINAL BIOPSY
In case of a suspicion of intestinal abnormality (infiltration, infection, inflammation, tumour..), a biopsy can be done and after analysis at the laboratory, can help establish a precise diagnosis.
How is this exam performed?
The intestine can be biopsied at two sites on a sedated, standing horse:
Biopsy of the small intestine, during a gastroscopy.
Biopsy of the rectum, by rectal approach.
In both situations, a special clamp is used and allows taking a sample of mucosa. No suture is necessary.
ABDOMINAL ULTRASONOGRAPHY
Abdominal ultrasonography in horse allows us to explore a large portion of the intestine, liver, spleen, kidneys and stomach. It is particularly useful to explore organs that we are unable to palpate by transrectal exam.
How is this exam performed?
Abdominal ultrasonography is performed on a standing horse. Sedation is seldom necessary. Hair is clipped if needed and warm water and coupling gel or alcohol is applied on the skin to allow a good contact with the probe.
ABSORPTION TEST
In case of chronic weight loss, it is useful to determine if the horse is able to assimilate (absorb) the food that he eats. For this, we administer a known quantity of sugar diluted in water and we evaluate intestinal assimilation by measuring sugar level in blood.
How is this exam performed?
The horse is fasted for 12 h (one night). A blood sample is taken and initial
blood glucose is measured (glycaemia). A nasogastric tube is then introduced in the horse’s stomach and a known quantity of dextrose diluted in water is administered. Glycaemia is measured every 30 minutes for 4 hours and analysis of the values determines in absorption function is normal or diminished/slowed.
ABDOMINAL PARACENTESIS
Abdominal organs are bathed in a lubricating fluid called abdominal fluid. In case of a problem in a an abdominal organ (infection, abscess, neoplasia..), this liquid can be modified. Sampling and laboratory analysis of this fluid can thus bring precious information about abdominal organs in horses.
How is this exam performed?
The horse is sedated and a square of 15x15 cm square of skin under the belly is clipped and disinfected. A thin needle or a cannula is inserted inside the abdomen. A few drops are needed for analysis. The needle is then retrieved and a disinfecting spray is applied.
