Large Animal Internal Medicine
Core concepts
LAIM emphasizes species-specific physiology and herd-level thinking. For equine medicine, master colic (differentiating simple obstruction, strangulating obstruction, and inflammatory disease by pain severity, reflux, and peritoneal fluid), laminitis (endocrine vs. sepsis-associated), and the approach to weight loss (dental, gastric ulcer, parasitism, inflammatory bowel disease). For bovine medicine, know the transition cow-hypocalcemia, ketosis, displaced abomasum, retained placenta, metritis-and the rumen physiology underlying ruminal acidosis and bloat. Respiratory disease (equine asthma, Rhodococcus equi in foals, bovine respiratory disease complex) and infectious disease (strangles, salmonellosis) are high-yield. Understand biosecurity and quarantine principles for herd outbreaks.
Common traps
- Treating equine colic with analgesics before a complete exam, masking surgical disease.
- Confusing left vs. right displaced abomasum and their surgical/roll-and-toggle approaches.
- Assuming all laminitis is the same-endocrine laminitis (PPID/EMS) differs in management from sepsis-related.
- Forgetting that rumen fluid pH <5.5 indicates acute acidosis and that buffer therapy has limits.
- Overlooking that foals with R. equi need thoracic ultrasound and often prolonged antimicrobials.
Worked rule of thumb
A horse with colic, nasogastric reflux >2 L, and a painful abdomen with a distended small intestine on rectal exam suggests small intestinal obstruction-refer for surgery rather than continuing medical management. A cow with a ping high on the left and ketonuria suggests LDA; a ping on the right suggests RDA.