Lecture 5: Approach to Medical Diseases of the Equine Small Intestine Flashcards
What is anterior enteritis
Inflammatory/infectious disease of the duodenum and proximal jejunum
What infections is anterior enteritis associated with
Clostridia spp, salmonella spp, or idiopathic
What is anterior enteritis characterized by
Voluminous SI secretions, functional ileus, copious gastric reflux
What is the pathophysiology of AE
- C-diff spores ingested in stomach
- Spores then pass through pylorus to the duodenum
- Proximal SI is rich in bile acids secreted the major duodenal papilla
- Spores interact with the bile and germinate into vegetative cells
- These cells then multiply, colonize, and produce toxins cause the epithelial damage and inflammation that ultimately leads to ileus and colic signs
What are the clinical characteristics of horses with Anterior enteritis
- Increase HR- due to pain from gastric distention
- Increase reflux
- Fever
What is the other primary differential when considering anterior enteritis
Strangulating SI lesion
What are some complications of anterior enteritis
Laminitis (endotoxins), arrhythmias (increase HR), ascending hepatic/pancreatic disease, peritonitis
What are the therapeutic goals for Anterior Enteritis
- Remove excess GI secretions
- Restore normal GI motility
- Maintain hydration and volume status
- Maintain electrolyte balance
- Maintain colloid osmotic pressure (20 mm Hg)
- Maintain a positive energy balance
- Prevent laminitis
- Address inflammation and endotoxemia
What is a likely cause of equine proliferation enteropathy
Law Sonia intracellularis
What age group primarily gets equine proliferative enteropathy
Weaklings (4-6 months)
What does a horse with equine proliferative enteropathy present with/like
Weight loss, unthriftiness, edema, depression, fever
How can you diagnose equine proliferative enteropathy
Clinical signs, serology, fecal PCR
What is the most common change on blood work in horses with equine proliferative enteropathy
Hypoproteinemia
What is the treatment for equine proliferative enteropathy
Long term antibiotics
What are some common comorbidities of equine proliferative enteropathy
Parasites, gastric ulcers, other infections
What are the therapeutic goals for equine proliferative enteropathy
- Eliminate organism
- Restore protein levels to normal range
- Restore volume and hydration
- Restore patient to a proper plane of nutrition
- Treat co-morbidities
- Initiate biosecurity measures
What age group does IBD occur
Any age
How do horses with IBD present
Weight loss +/- colic +/- diarrhea
What is the treatment for IBD
Corticosteroids, surgical excision, parasite control, diet
What is the prognosis for longterm survival in horses with IBD
Poor to moderate due to repeated colics and long term use of corticosteroids
What is Eosinophilic enterocolitis
Infiltration of eosinophils and lymphocytes into the mucosa of the SI and large colon
What is idiopathic focal Eosinophilic enteritis
Intramural masses or bands within the SI, possibly representing an acute, focal exacerbation of diffuse infiltrate
What is multisystemic Eosinophilic epitheliotropic disease
Infiltration of eosinophils into other tissues such as skin, lungs, and liver in addition to GIT
What is granulomatous enteritis
Infiltration of lymphocytes and macrophages most severely in ileum. Horses with granulomatous enteritis occasionally have granulomatous in other organs such as lungs and liver
What is lymphocytic-plasma cystic enterocolitis
Infiltration of lymphocytes and plasma cells without the presence of macrophages
Case example: horse presents with colic, pawing, attempting to lay down and roll. What is first thing you do
Take a heart rate- good indicator of pain
Case example: horse that presents with colic has HR-68, why?
Pain, hypovolemia, excitement, fever, metabolic/electrolyte derangements, primary heart disease
Case example: after you take a heart rate , what do you do next
Pass a nasogastric tube, may need to sedate first
Case example: pass NG tube and reflux 8L of reddish foul-smelling fluid
T=102.7, P=52, R=20
MM- bright red and tacky
CRT-3 seconds
GI sounds decreased in 4 quadrants
Rectal exam: loops of distended fluid filled small intestine
What are you two top differentials
- Anterior enteritis
- Small intestinal strangulation/ obstruction
Case example: after you establish differentials of AE and SI strangulation, what do you do next
Referral
Give Banamine
Leave NG tube in
CBC results for AE case: increase HCT, platelets, and increase fibrinogen. What does this tell you
HCT: increase RBC-dehydrated
Platelets decrease: dehydrated, inflammation
Fibrinogen: acute systemic inflammation
Chemistry results for AE: total protein increases, GGT increase, increased total bilirubin, increase indirect bilirubin, increase creatinine, decrease Na+, K+. And Cl-
Increase lactate
Total protein, GGT, and total bilirubin increased: dehydration
Increased indirect bilirubin: anorexia
Increased creatinine- dehydrated
Decrease Na, K, Cl-: fluid loss to intestines
Increased lactate: hypovolemia/hypoperfusion
What is wrong in these two photos
Left: dilated SI loops
Right: enlarged stomach
Abdominocentesis for AE horse reveals protein of 2.4mmol/L wht does that mean
Inflammation- losing protein to abdomen
Case example: what are some signs that lead to diagnosis of AE vs SI strangulation
AE:
1. Decrease HR after reflux
2. Fever present
3. Pain controlled early on with low dose analgesics
What is the treatment plan for AE
- NG tube
- IV fluids: maintenance and loss: 2-3mL/kg/hr
- Potassium added to fluids (20 to 40mE/L)
- Add calcium gluconate 23% (125mL/5L fluids)
- Colloids- plasma hetastarch- for protein loss- will decrease more with hydration
- Antibiotics
- Pro kinetics- lidocaine CRI
- NSAIDS/anti-endotoxin: banamine, polymixin B
- Laminitis prevention- cryotherapy
- Parental nutrition
Calculate the maintenance fluids for 450kg horse
3mL(450kg)-1.3L.hr=32.L/ day
Do not exceed ___ potassium when adding to fluids
0.5mEq/kg/hr
Case example: 9 month old filly is unthrifty, quiet, BCS 3/9, T=102.1, P-50, R-36, ventral pitting edema, pot-bellied
What are you top differentials
- Parasitism
- Equine proliferative enteropathy
- IBD
Case example with unthrifty 9 month old filly. After physical, what do you do next
- Abdominal ultrasound
- Blood sample
- Fecal screen- FEC, PCR for L. Intracellularis, culture
Case example with unthrifty 9 month old filly test results:
1. CBC- mild leukocytosis
2. Fecal float: strongly and ascarid eggs
3. FEC 500 peg
4. PCR + for L. Intracellularis
5. Fecal culture negative for Salmonella and clostridia
How does this help determine differentials
equine proliferative enteropathy- positive L. Intracellularis
Case 9 month old filly: after Bloodwork, physical, what do you do next for treatment
- Antibiotics- macrolide+rifampin, chloramphenicol, tetracycline
- Plasma
- Anthelmintics
- Repeat FEC in 2 weeks
Case 9 month old unthrifty filly. What if tests for L. Intracellularis were negative what other tests would you do
- Rectal, intestinal biopsy
- D-xylose absoprtion test
Looking for IBD, lymphoma
A 10 year old paint are presents with colic, a heart rate of 64pm, respiratory rate 25bpm, and temperature of 103.2. What is most appropriate first step in working up case
Pass NG tube
Treating a 475kg thoroughbred mare for anterior enteritis. What parameters will you monitor to ensure that fluid plan is working
- Protein levels
- Electrolytes
- PCV/TP
- MM, skin tent, distal pulse
- Urine output
- Heart rate
- Lactate
What three things would be supportive of a diagnosis of anterior enteritis rather than strangulating lesion
- Fever
- Improvement with low dose analgesia
- Decrease HR after reflux
