Colic in horses: what is it and why do they occur? WikiPet.ru
Gastrointestinal tract disease in horses is one of the most dangerous conditions. Not only can they be extremely painful, but sometimes they cause the death of the animal. What colic in horses and why they occur?
What is colic in horses?
About 70% of diseases of the digestive system are accompanied by a complex of symptoms called colic.
The name "colic" itself comes from the word colon (the name of the gut), that is, in fact, indicates pain in the colon. However, pains reminiscent of colic occur with many other diseases of the stomach, intestines (any department), kidneys, liver, and bladder. Therefore, at the moment, the name "colic" has become very arbitrary. And in the clinical sense, this means acute pain in the organs of the abdominal cavity, sometimes manifested as a seizure - a consequence of convulsive contractions of the internal organs, as well as compression of the nerve endings.
Features of the digestive system in horses
Horses are herbivores with a single chamber stomach. Their digestion is perfectly adapted to the assimilation of various plant foods. Horses eat slowly, chew food thoroughly and swallow it in small portions.
Horses are “armed” with strong teeth and strong masticatory muscles, therefore, with profuse salivation, they chew dry solid foods and moisten them with saliva abundantly. Saliva plays an important role in digestion, creating an alkaline environment in the stomach - this is necessary for the action of enzymes that are produced by microflora and are contained in plant food. Also, saliva regulates the acid-base balance and neutralizes the acid of the stomach. It contains substances that have a bactericidal effect (lysozyme and inhibit), it is involved in the thermoregulation of the horse organism.
The food stays in the mouth for a short time, after which it passes into the stomach through the esophagus in a crushed, moist form. The esophagus enters the stomach at an angle, and from the side of the inner surface of the stomach, the fold covers the entry point, which makes it impossible for the gases to escape through the esophagus and vomit in the horse.
The volume of the stomach, depending on the size of the horse, can range from 6 to 16 liters.
It is important to remember that the secretion of digestive glands in a horse proceeds continuously, and a huge amount of gastric juice (up to 30 liters) can be released per day.
The feed entering the stomach is layered and stays there for several hours. Then the contents of the stomach move into the small intestine (duodenum, jejunum and ileum). Here, the food masses are “processed” by pancreatic juice, bile and intestinal juice. The nature of the diet affects the composition of pancreatic enzymes. The mucous membrane of the small intestine is covered with a large number of microvilli (total surface is about 12 sq. M), due to which the cleavage products are absorbed.
From the small intestine, the food mass enters the large intestine, in particular, into the cecum. For digestion in the large intestine, bacteria that break down fiber are important (in horses, the process takes place in the cecum, which plays the role of a “second stomach,” where food lingers for a long time). The large intestine contains a large number of bacteria that cause rotting of proteins and fermentation of carbohydrates. In this case, toxic compounds are formed, which are absorbed into the bloodstream and neutralized by the liver.
The rectum through the anus with the sphincter comes out. Defecation is carried out from 5 to 12 times a day.
Why do horses colic happen?
First of all, it is the need to carefully chew food. Any violations of the chewing process (dental diseases, changes in the masticatory muscles, damage to the joints of the jaw, disease of the mucous membrane of the mouth, excessively hard food or greedy eating of food) create the prerequisites for the development of gastrointestinal diseases accompanied by colic.
The state of the autonomic nervous system is also important. Clinically distinguish:
- Vagotonia is an increase in the tone of the parasympathetic system, manifested in narrowing of the pupils, slowing and lability of the pulse, nervous arrhythmia, excessive sweating at the beginning of work, rapid eating of food and insufficient chewing, increased salivation, tendency to diarrhea.
- Sympathicotonia is an increase in the tone of the sympathetic nervous system. Such horses are characterized by dilated pupils, tachycardia, dry skin and oral mucosa, and slow feed intake.
- Normotonia is the normal tone of the autonomic nervous system.
If a horse has vagotonia, it, due to the abundant release of saliva, swallows food (especially grain) very quickly, without crushing it sufficiently. These horses often have increased secretion of the glands of the stomach, increase its motor functions and are prone to catarrh of the stomach and spastic colic.
If the horse has sympathicotonia, it carefully chews the food (since saliva is not secreted enough), but is prone to a significant expansion of the stomach, atony and stagnation of the contents of the intestine.
Both of these can lead to colic in the horse. "