large animal surgery evaluation of colic in foals rectal tears/ rectal prolapse
TRANSCRIPT
Large Animal Surgery
Evaluation of colic in foals
Rectal Tears/ Rectal Prolapse
What important factors in the history can help to diagnose colic in foals
• Breed• Sex• Birth circumstances (immune status, weak down
foals)• Deworming• Vaccination • Other illnesses• Pregnancy problems• Health of other mares and foals
What is the normal temp for a foal
• 99-101.5 degrees
What is the normal HR for a foal
• 70-100 bpm
What do you need to evaluate in a foal with colic
• Pain
• CV status
• GI tract
How do you evaluate for possible sepsis
• Look for hypoglycemia
• Depressed immune function
• Decreased intake
How to you evaluate the GI tract of foals
• Observe for distention and feces
• Auscultation
• NG reflux
• Abdominal palpation
• Ancillary procedures
What types of ancillary procedures might be done in a foal with colic
• US
• Rads
• Contrast rads
• Abdominocentesis
• CBC
What is the TP in foals compared to adults
• Lower in foals
What are the main differentials in a foal with colic in the neonatal period
• Meconium impaction
• Enteritis
• Ulcers
• Hernia w ruptured tunic
What are the main differentials in a foal w colic from 2-5 days of age
• Ruptured bladder
• Atresia coli
• Enteritis
• Ulcers
What are the main differentials in older foals w colic
• Ulcers
• Enteritis
• Gastric outflow obstruction
• Small intestinal volvulus
• Intussusception
• Hernias
What are the general principles when treating colic in foals
• Evaluate immunity and correct w IV plasma
• Minimal use of analgesics
• Rehydrate
• Resume feeding ASAP or use TPN
• Preventative therapy for ulcers
Meconium impaction commonly occurs in foals of what age
• <36 hours
Which foals have an increased risk for meconium impaction
• Males
• FPT foals
• Weak foals
What are the CS of meconium impaction
• Straining
• Absence of feces
• Abdominal distention
What is the main ddx for meconium impaction
• Atresia
How do you rule out atresia
• Digital palpation
• Rads
• Barium enema
How is meconium impaction treated
• Acetylcysteine enema
What are some causes of enteritis in foals
• C perfringens
• C difficile
• E coli
• Rotavirus
How do you diagnose enteritis in foals
• Fever, leukopenia
• Diarrhea
• Response to fasting
How do you treat enteritis in foals
• Check for systemic illness and give ATBS if necessary
• Decrease or discontinue milk if bloat
• NPO w TPN for a few days
How do you diagnose ulcers in foals
• Bruxism
• Colic after nursing
• Excessive salivation in older foals
How do you treat ulcers in foals
• Ensure hydration
• Address other problems
• Sucralfate
• If d/t NSAIDS give H2 blockers or omeprazole
What are the CS of ruptured bladder
• Depression, decreased nursing
• Progresive abdominal distention
What lab data is associated w a ruptured bladder
• Hyponatremia, hypochloremia, hyperkalemia
How do you diagnose a ruptured baldder
• US, rads, contrast rads
Is a ruptured bladder a surgical emergency
• No but it is a medical emergency
How do you treat a ruptured bladder
• Decrease serum potassium
• Abdominal drainage
• Sx when stabilized
What is the prognosis for uroabdomen
• Good-excellent for urachal or bladder tear
• Guarded for ureteral tear
What are the CS of atresia coli
• Initial signs of meconium impaction
• Progressive abdominal distention
• No feces
How do you dx atresia coli
• Confirm w barium enema
What is the cause of gastric outflow obstruction
• Duodenal ulcers
What are the CS of gastric outflow obstruction
• May be no hx of illness
• Bruxism
• Spontaneous reflux
• Colic after nursing
What is the tx for gastric outflow obstruction
• Gastrojejunostomy (w or wo jejunojejunostomy)
What are the CS of small intestinal obstruction
• Pain
• Abdominal distention
• reflux
What types of small intestinal obstruction occur
• Congenital or acquired hernia
• Intussusception
• Volvulus
• Meckels diverticulum
Which Cs should make you suspect intussusception or volvulus
• Pain following onset of diarrhea
What is your diagnosis
• Meckels diverticulum
What is a meckels diverticulum
• Embryologic remnant of the omphalomesenteric duct– Band that connects antimesenteric surface of
the ileum to the umbilicus
What is your diagnosis
• Umbilical hernia
What is your diagnosis
• Intestinal adhesions
What is the prognosis for foals <14 days old w SI obstruction
• 10% survival
What is the prognosis for foals 15-150 days old w SI obstruction
• 46% survival
Why is the prognosis so bad for SI obstructions
• Increased risk of adhesions
• Delayed indentification
• Sepsis
What are some examples of LC and SC obstructions
• Fecalith, bedding ingestion, hairball
What is the main cause of rectal tears
• Iatrogenic d/t rectal palpation
How will you first know that there is a rectal tear
• Blood on the rectal sleeve
• Feel rectum suddenly relax
Where are most rectal tears
• Dorsally between 10 and 2 oclock
What is a grade 1 rectal tear
• Mucosa and submucosa
What is a grade 2 rectal tear
• Disruption of the muscular layer (mucosa and serosa still intact)
What is a grade 3 rectal tear
• Disruption of the mucosa, submucosa and muscularis
What is the difference between a 3a and 3b tear
• 3a the serosa remains intact
• 3b is extension into the mesocolon
What is a grade 4 rectal tear
• Disruption of all layers of the rectal wall
What is your dx
• Grade 4 rectal tear
What is your dx
• Grade 1 rectal tear
What is your dx
• Grade 2 rectal tear
What is your dx
• Grade 3a rectal tear
Which grades of rectal tear should be referred
• Grade 3 or 4
What should be done prior to referring a grade 3 or 4 rectal tear
• Pack rectum cranial to tear
• Banamine
• ATBs
• Atropine (to slow intestinal motility)
What is the tx for grade 1 or 2 rectal tear
• No palpation for a few weeks
• Banamine
• ATBs
• Diet that will cause soft feces
What are the options for surgical repair of a grade 3 or 4 rectal tear
• Rectal liner
• Colostomy
What surgical approach is needed to place a rectal liner
• Caudal ventral midline incision
What is the principle behind placing a rectal liner
• Liner is placed using a PVC pipe and long plastic bag so that feces will pass through the bag and not interrupt the rectal tear
• The tear heals by second intention
How is the rectal liner removed
• Chromic gut is used to suture it in place…breaks down in 2 weeks and the PVC pipe and plastic bag are passed in feces
What is a complication of placing a rectal liner
• Retraction of the liner into the rectum when the horse lies down
What can be done to prevent retraction of the liner into the rectum
• Patient should be kept standing until the ring has been passed
What is a colostomy
• Fecal diversion to the left paralumbar fossa
How long are colostomys left in place
• 6-7 weeks
What is the prognosis for for a grade 1 or 2 tear
• Good
What is the prognosis for for a grade 3 or 4 tear
• Fair-poor
What is the etiology of rectal prolapse
• Straining to defecate
• Chronic pneumonia
• Short tail
What is the tx for rectal prolapse
• Epidural anesthesia
• Manual reduction or sx resection
• Topical agents/astringents
• +/- purse string
What can be done to create inflammation and adhesions around the
rectum in ruminants• Inject iodine perirectally
What can be done to create inflammation and adhesions around the
rectum in foals or mares• Nothing you cant inject iodine in equines
What is your diagnosis
• Grade 4 rectal prolapse; full thickness tear w omentum coming out
What is your diagnosis
• Rectal and vaginal prolapse
How would you treat the previous case
• Amputate the devitalized tissue
What is the prognosis with a grade 1 or 2 rectal prolapse with reduction
• Good
What is the prognosis with a grade 1 or 2 rectal prolapse with resection
• Guarded
What is the prognosis with a grade 3 or 4 rectal prolapse
• Guarded-poor