Diseases of intestine Cecal dilatation and volvulus

Medicine 4^th stage Lec 6 Dr. Ali Rabee

Diseases of intestine

• 
  Cecal dilatation and volvulus
  

Cecal dilatation occurs primarily in dairy cattle in the first few months of lactation; the cecum may be dilated with gas or distended with ingesta, and volvulus may occur.

Etiology

The etiology is uncertain, but may be due to

1. 
   A rise in the concentration of volatile fatty acids in the cecum can result in cecal atony.
   
2. 
   Dietary carbohydrates not completely fermented in the rumen are fermented in the cecum, resulting in an increase in the concentration of volatile fatty acids, a drop in pH and cecal atony.
   
3. 
   Butyric acid has the greatest depressant effect on cecal motility while acetic has the least.
   
4. 
   Inhibition of cecal motility may lead to accumulation of ingesta and gas in the organ and consequently dilatation, displacement and possible volvulus.
   

Clinical findings

1. 
   In cecal dilatation without volvulus: There are varying degrees of anorexia, mild abdominal discomfort, a decline of milk production over a period of a few days and a decreased amount of feces.
   
2. 
   In some cases there are no clinical signs and the dilated cecum is found coincidentally on rectal examination.
   
3. 
   In simple dilatation, the temperature, heart rate and respirations are usually within normal ranges.
   
4. 
   A distinct ping is detectable on percussion and simultaneous auscultation in the right paralumbar fossa.
   
5. 
   In cecal volvulus, anorexia, ruminal stasis, reduced amount or complete absence of feces, distension of the right flank, dehydration and tachycardia are evident, depending on the severity of the volvulus, and the viscus is usually distended with ingesta and feels enlarged and tense on rectal palpation.
   
6. 
   There may be some evidence of mild abdominal pain characterized by treading of the pelvic limbs and kicking at the abdomen.
   
7. 
   The ping is centered over the right paralumbar fossa and may extend to the 10th and 12th intercostal spaces; fluid-splashing sounds are usually audible on ballottement and auscultation of the right flank.
   

Treatment

The method of treatment depends on the severity of the case and whether there is uncomplicated dilatation and displacement caudally or if volvulus is present.

1- Medical therapy

Mild cases of uncomplicated gaseous dilatation may be treated conservatively by feeding good-quality hay and recovery can occur in 2-4 days. The use of parasympathomimetic drugs such as neostigmine given subcutaneously every hour for 2-3 days has been recommended Bethanechol at 0.07 mg/kg BW and neostigmine at 0.02 mg/kg BW increased the frequency of cecocolic spike activity, the duration of cecocolic spike activity and the number of cecocolic propagated spike sequences every 10 minutes.

2- Surgical correction for torsion and volvulus with the accumulation of ingesta and the possibility of necrosis of the cecum, the treatment of choice is surgical correction and the prognosis is usually good.

• 
  Intestinal obstruction
  

Intestinal obstructions in cattle include volvulus, intussusception and strangulation.

Etiology

The commonest causes are the intestinal volvulus, intussusception and strangulation - in which there is physical occlusion of the intestinal lumen.

There are three common groups of causes:

1. 
   Physical obstruction of the intestinal lumen along with infarction of the affected section of intestine - intestinal accidents.
   
2. 
   Physical obstruction of the intestinal lumen - luminal blockages.
   
3. 
   Functional obstructions with no passage of intestinal contents but with the lumen still patent - paralytic ileus.
   

Clinical findings

1. 
   There is an initial attack of acute abdominal pain in which the animal kicks at its abdomen, treads uneasily with the hindlegs, depresses the back and may groan or bellow from pain.
   
2. 
   The pain occurs spasmodically and at short, regular intervals and may occasionally be accompanied by rolling.
   
3. 
   There is anorexia and little or no feces are passed.
   
4. 
   The temperature and respiratory rates are relatively unaffected and the heart rate may be normal or elevated, depending on whether or not blood vessels are occluded.
   
5. 
   If there is infarction of a section of intestine there will be signs of endotoxic shock, including low blood pressure, very rapid heart rate, and muscle weakness and recumbency.
   
6. 
   The abdomen is slightly distended in all cases.
   
7. 
   Splashing sounds can be elicited only on the right side, just behind the costal arch.
   
8. 
   When there is intussusception or volvulus of the small intestine, the affected segment is usually felt in the lower right abdomen but the site varies with the nature of the obstruction.
   

Treatment

1- Slaughter for salvage may be the most economical option for the disposition of animals which are of commercial value. If the diagnosis of intestinal obstruction requiring surgery can be made early in the course of the disease, the animal will usually pass premortem and postmortem inspection at a slaughter house.

2- Surgical correction

Surgical correction of physical obstructions of the intestine is the only method of treatment for animals in which survival and recovery are desirable.

• 
  Fluid therapy
  

Fluid and electrolyte therapy given intravenously may be necessary preoperatively and always postoperatively.

• 
  Antimicrobials
  

Antimicrobials pre- and postoperatively are recommended for the control of peritonitis.

• 
  Non-steroidal anti-inflammatory drugs
  

NSAIDs have also been used for their anti -inflammatory and anti-endotoxic effects.

• 
  Hemorrhagic bowel syndromes (jejunal hemorrhage syndrome)
  

Hemorrhagic bowel syndrome, also known as jejunal hemorrhage syndrome, is a recently recognized disease of cattle characterized clinically by a syndrome similar to obstruction of the small intestine causing abdominal distension, dehydration and shock due to necrohemorrhagic enteritis affecting primarily the small intestine.

Etiology

The etiology is unknown. C. perfringens type A has been isolated from the intestines of naturally occurring cases but its significance is uncertain. Because C. perfringens type A can be found in the intestinal tracts of healthy cattle and is able to proliferate quickly after death, the role of the organism in the pathogenesis of hemorrhagic jejunitis is uncertain.

Clinical findings

1. 
   Common historical findings include sudden anorexia and depression, marked reduction in milk production, abdominal distension, and weakness progressing to recumbency.
   
2. 
   Bloody to dark-red feces or dry scant feces, dehydration and abdominal pain, including bruxism, vocalization, treading and kicking at the abdomen.
   
3. 
   Sudden death without prior clinical findings has been reported.
   
4. 
   On clinical examination there is depression, dehydration, the body temperature may be normal to slightly elevated, the heart rate is increased to 90-120 beats/min, the mucous membranes are pale and the respiratory rate is increased.
   
5. 
   The abdomen is usually distended moderately over the right side. The rumen is usually atonic. Fluid splashing sounds are commonly audible by succussion over the right abdomen.
   
6. 
   On rectal examination, the feces are black-red, jelly-like and sticky, and smell like digested blood.
   

Treatment

No specific treatment is available. For valuable animals, intensive fluid and electrolyte therapy is indicated. Because of the possibility of clostridial infection, penicillin is indicated if treatment is attempted. Laparotomy and resection of the affected segment of the intestine and anastomosis is indicated but has been unsuccessful to date.

Equine colic

Gastrointestinal disease causing signs of abdominal pain in horses is commonly referred to as colic. Colic is a frequent and important cause of death and is considered the most important disease of horses encountered by practicing veterinarians.

Etiology

Several classification systems of equine colic have been described including a disease-based system classifying the cause of colic as:

1. 
   Obstructive.
   
2. 
   Obstructive and strangulating.
   
3. 
   Nonstrangulating infarctive.
   
4. 
   Inflammatory (peritonitis, enteritis).
   

Clinical findings

1- Behavior

• 
  Pain is manifested by pawing, stamping or kicking at the belly or by restlessness evident as pacing in small circles and repeatedly getting up and lying down, often with exaggerated care, other signs are looking or nipping at the flank, rolling, and lying on the back.
  
• 
  Often the penis is protruded without urinating or with frequent urination of small volumes.
  
• 
  Continuous playing with water without actually drinking (sham drinking) is common.
  
• 
  The posture is often abnormal, with the horse standing stretched out with the forefeet more cranial and the hindfeet more caudal than normal - the so- called 'saw-horse' stance. Some horses lie down on their backs with their legs in the air suggesting a need to relieve tension on the mesentery.
  
• 
  Distension of the abdomen is an uncommon but important diagnostic sign, symmetrical, severe distension is usually caused by distension of the colon, sometimes including the cecum, secondary to colon torsion, or impaction of the large or small colon and subsequent fluid and gas accumulation.
  
• 
  Projectile vomiting or regurgitation of intestinal contents through the nose is very unusual in the horse and is a serious sign suggesting severe gastric distension and impending rupture.
  
• 
  Defecation patterns can be misleading. It is often mistakenly assumed that there is no complete obstruction because feces are still being passed. But in the very early stages of acute intestinal obstruction there may be normal feces in the rectum, and the animal may defecate several times before the more usual sign of an empty rectum with a sticky mucosa is observed.
  

2- Physical examination

a- Heart and respiratory rates

- The heart rate is a useful indicator of the severity of the disease and its progression but has little diagnostic usefulness, horses with heart rates less than 40/min usually have mild disease whereas horses with heart rates above 120/min are usually in the terminal stages of severe disease.

- The respiratory rate is variable and may be as high as SO/min during periods of severe pain.

b- Mucous membranes and extremities

- Mucous membranes of normal horses and of horses without significantly impaired cardiovascular function are pink, moist and regain their normal color within 2 seconds after firm digital pressure is removed. Dehydrated horses have dry mucous membranes, although the capillary refill time and color are normal.

- Cool extremities may be indicative of compromised cardiovascular function but should be interpreted with caution and only in the context of the rest of the clinical examination.

- Sweating is common in horses with severe abdominal pain and, when present in a horse with cool extremities and signs of cardiovascular collapse, is indicative of a poor prognosis.

3- Auscultation and percussion

Auscultation of the abdomen can provide useful diagnostic and prognostic information and should be performed thoroughly and without haste. All four quadrants (dorsal and ventral, left and right sides) of the abdomen should be examined for at least 1 minute at each site. Attention should be paid to the intensity, frequency and characteristics of the spontaneous gut sounds (borborygmi), repeated observations are often necessary to detect intermittent or rapid changes in the character of the borborygmi.
4- Rectal examination

A careful rectal examination is probably the most important part of the clinical examination in colic and should not be neglected; the examiner must note the presence of the following things:

• 
  Small intestinal distension.
  
• 
  Colonic distension, impaction and displacement.
  
• 
  Distension of the small colon.
  
• 
  Displacement of the large colon.
  

Clinical pathology

1- Hematology and serum biochemistry

Measurement of hematocrit and plasma total protein concentration is useful in assessing hydration status, hematocrit increases as a consequence of splenic contraction or dehydration, making the use of this variable as a sole indicator of hydration status unreliable.

2- Measures of serum electrolyte concentration are important in providing an assessment of the horse's electrolyte status and in tailoring fluid therapy.

3- Acid-base status

Most horses with severe colic have metabolic acidosis.

Treatment

Medical treatment

The specific treatment of each case of colic varies and depends on the nature of the lesion and the severity of the disease. However several principles are common to the treatment of most colic:

• 
  Provision of analgesia as NSAlDs, sedating analgesics and spasmolytics.
  
• 
  Correction of fluid, electrolyte and acid-base abnormalities.
  
• 
  Gastrointestinal lubrication or administration of fecal softeners.
  
• 
  Treatment of underlying disease.
  

2- Surgery

The only definitive treatment for many causes of equine colic is surgical correction or removal of the lesion.