Gastrointestinal System e.g. colic, weight loss, diarrhoea
Ultrasound
With the appropriate probes, ultrasound can be a valuable tool in evaluating the abdominal structures of a horse. Ultrasound can be used to evaluate the thickness of the intestines, the size and motility of the intestines, and the structure and size of other abdominal structures such as the liver, kidneys and spleen. The causes of colic and weight loss in the horse are vast, abdominal ultrasound is a valuable tool when investigating this and other gastrointestinal related problems.
X-rays
In general adult horses are too large for obtaining useful X-rays of their abdomen. However, this tool is very useful in foals and some small ponies. Even in foals, powerful X-ray machines, such as we have here at Massey University, are needed in order to obtain good images of the abdomen.
We can also perform “contrast” studies to study gastrointestinal function in foals and small ponies. A radio opaque contrast agent (shows up as “white” on an X-ray) can be introduced into the intestinal tract (usually by feeding) and followed using X-rays to look for narrowing or obstruction within the gastrointestinal tract.
Fluoroscopy
Fluoroscopy is a technique for obtaining "live" X-ray images of a living patient using a fluoroscope. With the dynamic nature of this modality we can evaluate the gastrointestinal and respiratory systems in “real time”. This can prove very useful when there is some sort of obstruction or narrowing in the region or interest. As with X-rays, contrast agents can be used, with the advantage of being able to view their passage as they move through the gastrointestinal system.
Similar to X-rays, the size of an adult horse limits is usefulness for abdominal evaluation. However, this method is excellent for use in foals and small ponies, as well as the upper respiratory tract or oesophagus of any sized horse or pony.
Abdominocentesis
Abdominocentesis is the procedure of collecting the fluid that lines the abdominal cavity using a needle or catheter. This is generally performed at the underside of the abdomen because this is where the fluid accumulates in the standing horse. The abdominal fluid is evaluated by various parameters such as protein content and cell count. Changes in the fluid can be suggestive of compromise to the intestine, inflammation, infection, or even tumours.
Biopsy
With the availability of ultrasound we may detect an abnormality within the abdominal cavity. Blood tests could also point to a problem with kidney or liver function. We are able to take biopsy samples (small samples of tissue) of structures within the abdominal cavity using the ultrasound to guide us. A biopsy sample can give more specific information about why a certain organ is not functioning appropriately or indicate what kind of abnormality is present.
In a horse with chronic weight loss and/or diarrhoea a biopsy of the rectal mucosa may provide an indication of what is causing the problem.
Each of these techniques can be performed by our clinicians and are analysed by our laboratories.
Gastroscopy
Endoscopy is a procedure where a thin flexible gastroscope is used to view the lining of your horse’s stomach/bowel. The image produced via the video processor is displayed on a television screen that allows an excellent view for us to see. We are able to determine if a horse has ulceration of the stomach and may be able to detect abnormal growths if they are present. Special instruments can be passed down the gastroscope to obtain a biopsy (a tiny tissue sample).
