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What are some key differences b/w a neonatal and adult equine GI tract? (4)
foals have higher gastric pH and colostrum/IgG transfer to SI, colonization of ingested microbes favored in neonates, major development of hindgut takes place between 1-6 months of age
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What does normal foal feces look like?
pasty, yellow (not watery or bloody, and shouldn't stain or scald)
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What are 3 non-infectious causes of neonatal diarrhea?
"foal heat" diarrhea, perinatal asphyxia, lactose intolerance
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Describe "foal heat" diarrhea.
5-15 days, usually bright and still nursing, self-limiting
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Describe perinatal asphyxia.
necrotizing enterocolitis, may lead to intestinal ischemia, maldigestion, ileus
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What are bacterial causes of neonatal diarrhea? (5)
C. perfringens types A-E, C. difficile Types A-B, Salmonella, E. coli, Actinobacillus
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What type of C. perfringens is associated with severe hemorrhagic diarrhea?
Type C
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What are the 2 types of C. difficile and what toxin does each produce?
- Type A- enterotoxin
- Type B- cytotoxin
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Is C. diff always pathogenic?
No, some horses are asymptomatic carriers
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How do you diagnose clostridial diarrhea? (3)
culture, toxin assays, fecal smear and gram stain
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You should suspect Clostridial diarrhea in...
sick foals with hemorrhagic diarrhea.
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What is a common CBC change with Salmonella diarrhea?
neutropenia with left shift
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How do you diagnose Salmonella diarrhea in foals? (2)
5 serial fecal cultures, fecal PCR
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Diagnose Actinobacillus diarrhea by... (1)
blood culture positive.
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What are viral causes of neonatal diarrhea?
rotavirus, coronavirus, adenovirus
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In what animals does rotavirus cause symptomatic disease?
foals less than 2 months old
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Describe the features of rotavirus diarrhea. (5)
highly contagious, loss of villous epithelium--> decreased fluid absorption and lactase deficiency--> osmotic diarrhea
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How do you diagnose rotavirus diarrhea? (2)
ELISA or latex agglutination
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Describe the pathogenicity of coronavirus in foals?
isolated from healthy and sick foals in equal proportions
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What is a parasitic cause of diarrhea in neonates?
Strongyloides westeri
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How do foals become infected with Strongyloides westeri, and when does disease occur?
infected early through mare's milk; disease occurs > 10-14 days post-partum
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What is a common protozoal cause of neonatal diarrhea?
Cryptosporidium parvum
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Co-infection with ___________ and bacteria is commonly documented in neonates with diarrhea.
Cryptosporidium parvum
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Older foals are more likely to have diarrhea associated with __(3)__; foals less than 1 months old are most likely to have diarrhea associated with _________.
Salmonella, rotavirus, parasites; C. perfringens
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What fecal tests can you run on a neonate with diarrhea, and what does each one specifically test for? (4)
- fecal culture: Salmonella, Clostridium spp.
- toxin assays: C. perfringens and difficile types
- fecal float: Strongyloides, Cryptosporidium
- PCR panel: rota, corona, crypto, salmonella, rhodococcus, clostridial toxins, neorickettsia, lawsonia
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What is the treatment for neonatal diarrhea? (5)
- Supportive care
- Clostridial?--> metronidazole
- Bacteremia?--> broad spectrum antibiotics
- Rotavirus?--> provide lactase tablets
- Withhold milk, provide parenteral nutrition
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What are potential complications of neonatal diarrhea? (3)
gstric ulcers, colic, bacteremia
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If a neonate with diarrhea develops gastric ulcers (or suspected), what is your adjunctive treatment? (3)
prophylaxis with omeprazole, H-receptor antagonists, sucralfate
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Why might neonates with diarrhea develop gastric ulcers? Why is the a serious complication?
stress, NSAIDs, altered feeding; risk for gastric perforation
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If a neonate with diarrhea is colicking, how can you handle this? (5)
butorphanol, +/- NSAIDs, repeated measurement of abdomen, +/- abdominal radiographs, consider co-morbities (sepsis, HIE)
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What are infectious causes of diarrhea in older foals (> 6 months old)? (4)
Salmonella, Clostridium spp, Rhodococcus equi, Lawsonia intercellularis
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Describe the pathogenesis of Rhodococcus equi in older foals. (3)
respiratory signs most common, can cause abdominal abscesses, diarrhea
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What age foals usually have pathology associated with Rhodococcus equi?
ages 1-6 months
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How do you diagnose Rhodococcus equi in foals? (3)
ultrasound, TTW, abdominocentesis
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How do you treat Rhodococcus equi in foals? (2)
Clarithromycin and Rifampin
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In what aged foals in Lwsonia intercellularis most common?
4-7 months old
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What are the clinical signs of Lawsonia intercellularis infection? (3)
weight loss, diarrhea (proliferative enteropathy), edema
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How do you diagnose Lawsonia intercellularis in foals? (4)
severe hypoalbuminemia, ultrasound, serology, fecal PCR
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What is the treatment for Lawsonia intercellularis in foals? (2)
Oxytet, doxycycline
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What are preventative measures against foal diarrhea? (4)
good hygiene, proper biosecurity, avoid overcrowding, ensure adequate colostral transfer of immunity
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