-Diyala University
-Internal medicine
-College of Vet. Medicine
- Lecture (7)
-Dep. Of Internal and Preventive Medicine
Dr. Khalid M. Hammadi
DIARRHEA
Diarrhea is the increased frequency of defecation accompanied by feces that
contain an increased concentration of water and decrease in dry matter content.
The consistency of the feces varies from soft to liquid.
Common causes of diarrhea are:
1- Enteritis, including secretory enteropathy
2-Malabsorption, e.g. due to villous atrophy and in hypocuprosis (due to
molybdenum excess)
3- Neurogenic diarrhea as in excitement
4- Local structural lesions of the stomach or intestine, including:
- ulcer, e.g. of the abomasum or stomach
- tumor, e.g. intestinal adenocarcinoma
5-Indigestible diet, e.g. lactose intolerance in foals
6- Carbohydrate engorgement in cattle
7- In some cases of ileal hypertrophy, ileitis, diverticulitis and adenomatosis
8- Terminal stages of congestive heart failure (visceral edema)
9- Endotoxic mastitis in cattle.
10- Chronic and acute undifferentiated diarrhea in horses.
11- Vagus indigestion in cows causes pasty feces but bulk is reduced.
CONSTIPAT ION
Constipation is the decreased frequency of defecation accompanied by feces
that contain a decreased concentration of water. The feces vary in consistency
from being hard to dry and of small bulk. True constipation as it occurs in
humans is usually characterized by failure to defecate and impaction of the
rectum with feces. When the motility of the intestine is reduced, the alimentary
transit time is prolonged and constipation or scant feces occurs. Because of the
increased time afforded for fluid absorption, the feces are dry, hard and of small
bulk and are passed at infrequent intervals. Constipation may also occur when
defecation is painful, as in cattle with acute traumatic reticuloperitonitis.
SCANT FECES
Scant feces are small quantities of feces, which may be dry or soft. Scant feces
occur most commonly in cattle with abnormalities of the forestomach or
abomasum resulting in the movement of only small quantities of ingesta into the
small and large intestines (an outflow abnormality).
Common causes of constipation or scant feces are:
1-Diseases of the forestomach and abomasum causing failure of outflow
2-Impaction of the large intestine in the horse and the sow
3- Severe debility, as in old age
4- Deficient dietary bulk, usually fiber
5-Chronic dehydration
6- Pa rtial obstruction of large intestine
7-Painful conditions of the anus
8- Paralytic ileus
9- Grass sickness in horses
10- Chronic zinc poisoning in cattle
11-Terminal stages of pregnancy in cows.
ILEUS (A DYNAMIC AND DYNAMIC ILEUS)
Ileus is a state of functional obstruction of the intestines or failure of peristalsis.
It is also known as paralytic ileus or adynamic ileus. Dynamic or mechanical
ileus is a state of physical obstruction. In paralytic ileus there is loss of intestinal
tone and motility as a result of reflex inhibition. This can occur in acute
peritonitis, excessive handling of viscera during surgery, and prolonged and
severe distension of the intestines as in intestinal obstruction or enteritis. ileus
can also be caused by acid-base imbalance, dehydration, electrolyte imbalances
such as hypocalcemia and hypokalemia, and toxemia. ileus can affect the
stomach, causing delayed gastric emptying and subsequent dilatation with fluid
and gas. The effect of ileus on the intestines is to cause failure of movement of
fluid, gas and ingesta and accumulation of these substances, which results in
intestinal distension and varying degrees of abdominal pain, dehydration and a
marked reduction in the amount of feces.
Postoperative ileus of the large intestine is a common complication of
surgical treatment for colic in the horse.
The etiology and pathogenesis of ileus in farm animals are not well understood.
The treatment of ileus depends on the original cause. Physical obstruction of
the intestines and torsion of the stomach must be corrected surgically.
Postoperative ileus in the horse is difficult to manage and the case fatality rate is
high. Fluid therapy and gastric reflux decompression using a nasogastric tube
are standard recommendations. Nonsteroidal anti-inflammatory drugs (NSAlDs)
are used to control abdominal pain. Xylazine is contra-indicated because of its
depressant effect on gastric and intestinal motility.
ALIMENTARY TRACT HEMORRHAGE
Hemorrhage into the stomach or intestine is a common occurrence in farm
animals. The main causes are:
1- Gastric or abomasal (rarely duodenal) ulcers
2- Severe hemorrhagic enteritis
3-Structural lesions of the intestinal wall, e.g. adenomatosis, neoplasia
4- Infestation with blood-sucking nematodes, e.g. bunostomiasis
5-Local vascular engorgement or obstruction as in intussusception and
verminous thrombosis.
Hemorrhage into the stomach results in the formation of acid hematin, which
makes vomitus a dark brown color like coffee grounds, and feces have a black
or very dark brown, tarry appearance (melena) . The change in appearance of
the feces caused by hemorrhage into the intestine varies with the level at which
the hemorrhage occurs. If the blood originates in the small intestine, the feces
may be brown-black, but if it originates in the colon or cecum, the blood is
unchanged and gives the feces an even red color. Hemorrhage into the lower
colon and rectum may cause the voiding of feces containing or consisting
entirely of clots of whole blood. Hemorrhage into the pharynx is unusual, but
when it occurs the blood may be swallowed and appear in the feces or vomitus.
TENESMUS
Tenesmus, or persistent straining. is common in many diseases of the organs of
the pelvic cavity; therefore it is not necessarily a diagnostic sign of disease in the
lower alimentary tract. It is sometimes associated with frequent defecation
caused by neurological stimulation of peristalsis.
Common causes of tenesmus are listed by species below.
Cattle:
• Lower alimentary tract disease, e.g. colitis and proctitis caused by coccidiosis
• Genital tract disease, e.g. severe vaginitis, retained placenta
• Estrogen toxicity in steers, e.g. estrogen implantation,
• Lower spinal cord lesions – spinal cord abscess, rabies
• Idiopathic.
Horses
" Tenesmus does not usually occur
except during parturition.
Special examination
1-NASOGASTRIC INTUBATION
Examination of the rumen contents is often essential to assist in determination
of the state of the rumen environment and digesta. Passage of a stomach tube
into the rumen will determine the patency of the esophagus and if there is
increased intraruminal pressure associated with a frothy or free-gas bloat.
2-MEDICAL IMAGING
a-RADIOGRAPHY
Because of their large size, and the presence of substantial amounts of gas in
the large intestine, abdominal radiography has not been used routinely as a
diagnostic aid in mature horses with abdominal pain. Similarly, in mature
cattle the sheer size of the abdomen and the gas in the rumen has not favored
abdominal radiography except for identifying the presence of metal objects
in the reticulum. Esophageal radiography is, however, useful for the diagnosis of
disorders of swallowing in horses. Foals, calves and small horses are too small
to be palpated per rectum, and abdominal radiography, with and without
contrast media, has been used diagnostically in colic of foals.
b-ABDOMINAL ULTRASONOGRAPHY
Abdominal ultrasonography has been used to identify small intestine intussusceptions, large colon displacements, abdominal viscera and neoplasms. The
technique may require only several minutes in the hands of an experienced
clinician.
3-ENDOSCOPY
a-GASTROENTEROSCOPy
Fiberoptic gastroduodenoscopy is a practicable procedure in a sedated horse
that has had no feed for 12-24 hours. A 275 x 13.5 cm fiberoptic instrument is
passed via a nostril to the stomach, which is then distended with air.
b-LAPAROSCOPy.
In this procedure a laparoscope is passed through an incision in the abdominal
wall of either the left or right paralumbar fossa. Feed must be withheld for
36 hours, analgesia is provided during the procedure, and abdominal insufflation
with carbon dioxide is required in order to separate the viscera for viewing.
4-EXPLORATORY LAPAROTOMY (CELIOTOMY)
An exploratory laparotomy is useful for palpating and inspecting the abdominal
viscera as a diagnostic aid in cattle, sheep and horses of all ages. Cost and time
are important factors but if abdominal disease is suspected and other diagnostic.
5-ABDOMINOCENTESIS FOR PERITONEAL FLUID
Peritoneal fluid reflects the pathophysiological state of the parietal and visceral
mesothelial surfaces of the peritoneum. Collection of a sample of peritoneal
fluid is a useful aid in the diagnosis of diseases of the peritoneum and the
abdominal segment of the alimentary tract. It is of vital importance in horses in
the differential diagnosis and prognosis of colic and in cattle in the diagnosis of
peritonitis.
6-INTESTINAL AND LIVER BIOPSY
An intestinal biopsy may be obtained from an exploratory laparotomy but is
costly and time-consuming. Rectal biopsy is easily done and of low cost. It is a
valuable diagnostic aid for evaluating certain intestinal diseases of the horse.