Lecture: Specific diseases of foals

Question 1

Proliferative Enteropathy

(Lawsonia intracellularis)

CS

Answer 1

• 3-4 months (weanlings)
• Lose tons of protein
  
  • Edema
• Lethargy
• Variable fecal consistency
• Weight loss/ ill thrift
• Colic

Question 2

Lawsonia intracellularis

Diagnosis

Answer 2

• Panhypoproteinemia
• Inc SI wall thickness
• Fecal PCR
• Serum antibody

Question 3

Lawsonia intracellularis

TX/ Prognosis

Answer 3

• Macrolides
• Chloramphenicol
• Tetracyclines
• Treatment for a couple weeks
• Plasma not necessary
• • Prognosis good

Question 4

Colic in neonates

Answer 4

• Decisions similar to adults
• Therapy
  
  • medical/surgical
• Lesion location
  
  • small/large other
• Response to pain medication

Question 5

Colic in neonates

Diff in DX approach

Answer 5

• Foals dramatic
• Abominal distension can be measured
• Rectal exam done digitally
• difficult to obtain NG reflux
• U/S
  
  • gastric size

Question 6

Ultrasound evaluates

Answer 6

• Umbilical structures
• Intestine
  
  • wall thickness
  • distention
  • echogenicity (fluid vs gas)
• Peritoneal fluid - character
• specific lesions
  
  • intussusception
  • bladder distention

Question 7

Meconium retention

Answer 7

• First 48 hours
• Clinical signs
  
  • straining
  • colic
  • dark/tarry feces in rectum
• Diagnosis
  
  • digital rectal
  • U/S

Question 8

Meconium retention

TX

Answer 8

• Enemas
  
  • soapy water
  • Retention - acetylcysteine => mucolytic
• IV fluids
• Pain management
• Intestinal lubricants

Question 9

Neonatal noninfectious diarrhea

Answer 9

• Foal heat diarrhea
• nutritional
• asphyxia related gut injury
• other

Question 10

Foal - heat diarrhea

Answer 10

• most common non-infectious cause of diarrhea
• non-fetid low volume, soft to watery
  
  • non-debilitating
• Timing occurs with mare’s foal heat
  
  • 5-15 days of age
• TX usually not required

Question 11

Nutritional causes

Foal diarrhea

Answer 11

• typically milk replacers
  
  • improper preparation
  • change in brand
• bovine
  
  • greater fat content
• Goat milk
  
  • better

Question 12

Lactose intolerance

Primary

Secondary

Treatment

Answer 12

• Primary
  
  • congenital lactase deficiency rare
• Secondary
  
  • infectious diarrhea
    
    • rotavirurs
    • clostridium
• results in osmotic diarrhea in large colon
• Treatment
  
  • withdrawal of milk
  • lactase supplementation

Question 13

Asphyxia-related gut injury

Answer 13

• intolerant to feeding
• severely ill foals
• may colic

Question 14

Sand

Answer 14

Some foals preferentially eat sand

Question 15

Infectious diarrhea

Answer 15

• sepsis
• bacterial
• viral
• parasites

Question 16

Sepsis

Answer 16

• 50% of foals with diarrhea are bacteremic
• diarrhea common presenting complaint for foals
• Assume any sick foal < 2 weeks old with diarrhea is septic
  
  • in foals antimicrobial therapy IS warranted

Question 17

Salmonella

Answer 17

• Mare is usual source
• CS
  
  • fever
  • diarrhea
  • dehydration
  • colic
• any age

Question 18

Salmonella

Sequelae

Answer 18

• High risk for synovial infections
• Osteomyelitis
• Infectious synovitis
• Uveitis
• Pneumonia
• Meningitis

Question 19

Clostridium perfringens

Answer 19

• bloody diarrhea within first 48 hours of life
• healthy vigorous foals prior to onset

Question 20

Clostridium perfringens

Type A

Answer 20

• Alpha toxin, enterotoxin
• Transient bloody stool
• Colic
• Fever
• Lower mortality (<30%)

Question 21

Clostridium perfringens

Type C

Answer 21

• alpha, beta toxin
• hemorrhagic diarrhea
• colic
• abdominal distention
• shock
• high mortality (>75%)

Question 22

Clostridium difficile

Answer 22

• More age variability
  
  • enteritis +/- hemorrhagic diarrhea
• Similar to disease in adults

Question 23

Clostridium

Prevention

Answer 23

• Vaccinate pregnant mare
  
  • type C and D toxoid
• Management
  
  • reduce grain for mare periparturent period
  • clean environment
• Medication
  
  • anti-toxin

Question 24

Rotavirus

Answer 24

• Most common infectious cause of diarrhea in foals
• Group A (NAVLE)
• 5-35 days of age (up to 60 days)
• Highly contagious
• Short incubation period
• Fecal oral transmission

Question 25

Rotavirus

Pathophysiology

Answer 25

• Affects small intestine
• Villous tip blunting
• Results in brush border enzyme (lactase) deficiency
  
  • inadequate digestion
  • leads to osmotic diarrhea in colon

Question 26

Rotavirus

Diagnosis

Answer 26

• Farm history
• Numbers affected
• Physical exam findings
• Fecal antigen tests (cheap and easy and quick)
  
  • sensitive
  • rapid dx

Question 27

Clostridium

Treatment/Management

Answer 27

• Supportive care - IV/oral fluids
• +/- antibiotics < 2 weeks old
• Maternal vaccine - modest protection
• isolation
  
  • typically shed ~ 10 days
  • phenol based disinfection
• Biosecurity

Question 28

Uncommon infectious diarrhea causes in foals

Answer 28

• coronavirus
• cryptosporidium parvum
• giardia
• strongyloides westeri