Comprehensive Equine Medicine & Surgery Review

80 question-and-answer flashcards covering major concepts in equine internal medicine, surgery, neonatology, neurology, pharmacology, fluid therapy, preventive care, and emergency procedures. Suitable for rapid exam preparation and clinical review.

What are the normal adult horse TPR values?

Temp 99.5–101.5 °F, Pulse 20–44 bpm, Respiration 8–24 brpm

List any two clinical criteria that define SIRS in horses.

Temp < 97 °F or > 101.5 °F, HR > 52 bpm, RR > 20 brpm, WBC < 5 000 or > 12 000 cells/µL or > 10 % bands

Define sepsis in the horse.

SIRS plus suspected or confirmed infection

What is endotoxemia and name one classic mucous-membrane change?

Circulating LPS; toxic (purple) line on gingiva

Most effective preventive therapy for acute laminitis?

Continuous distal-limb cryotherapy (< 50 °F) for 72 h

Name the four ‘core’ vaccines recommended by AAEP.

Tetanus, EEE, WEE, West Nile Virus, Rabies

Dose of flunixin meglumine for analgesia in colic?

1.1 mg/kg IV q12 h

Two PE signs indicating severe colic that warrant surgery?

Refractory pain despite detomidine/opioid OR gastric reflux > 4 L yellow alkaline fluid

Net gastric reflux > 2 L suggests what problem?

Gastric outflow obstruction, proximal enteritis, or small-intestinal obstruction

Normal peritoneal fluid WBC & TP?

< 5 000 cells/µL and < 2.5 g/dL

Preferred initial imaging for pleural effusion in colic?

Thoracic ultrasonography (FLASH exam)

Top two clinical signs of esophageal obstruction (‘choke’).

Feed-tinged nasal discharge and distress with hypersalivation

One thing you should NEVER do when a horse is choked.

Give mineral oil—risk of aspiration pneumonia

Treatment of spasmodic (gas) colic?

Single dose flunixin and withhold feed

Most common abdominal site for primary peritonitis culture?

Non-degenerate neutrophils with homogeneous bacteria in peritoneal fluid

Formula to calculate donor blood volume (L) for transfusion?

((Desired PCV – patient PCV)/donor PCV) × 0.08 × patient kg

Key lab finding for uroperitoneum diagnosis in foals.

Peritoneal creatinine ≥ 2 × serum creatinine

Pathognomonic ultrasound sign for right dorsal displacement.

‘Turtle sign’—dilated colonic vessels against right body wall

Simple phenylephrine ‘eyelash test’ screens for what disease?

Equine Grass Sickness (EGS)

First-line treatment for EGUS (squamous or glandular).

Omeprazole 4 mg/kg PO q24 h × 28 d

Drug of choice for laryngeal tie-forward success rate ~60 %.

Laryngeal tie-forward surgery for DDSP

Which horses are predisposed to strangulating lipoma?

Geriatric (> 10 yr) horses—long mesenteric pedicle fat tumors

Two risk factors for epiploic foramen entrapment.

Cribbing/windsucking and > 28 d stall confinement

Most reliable radiographic sign of large-colon volvulus severity.

Marked colonic wall thickening (mural edema) on ultrasound

DPJ/enteritis vs strangulating SI obstruction—key fluid clue.

Very large volumes of gastric reflux (10–20 L q2 h) favor DPJ

Recommended antibiotic combo for Lawsonia intracellularis.

Azithromycin (10 mg/kg PO q24 h) plus rifampin 10 mg/kg PO q12 h

Two pathogens most often implicated in acute colitis of adults.

Salmonella spp. and Clostridium difficile/perfringens

Which NSAID-associated colitis localises to right dorsal colon?

Right dorsal colitis from phenylbutazone or flunixin overuse

Classic lab triad of cantharidin (blister-beetle) toxicosis.

Severe hypocalcemia, hematuria, and mucosal ulceration

Chewing lice genus most often on dorsolateral trunk?

Werneckiella (Damalina) equi

Psoroptes equi infestation typically causes pruritus where?

Ear canal—head shaking with waxy discharge

Chorioptes mange lesions localise primarily to what region?

Distal limbs (pastern/fetlock) especially in feathered drafts

Difference between urticaria and angioedema.

Urticaria = transient wheals; angioedema = larger edematous swellings in deeper tissues

Rain scald (dermatophilosis) causative organism?

Dermatophilus congolensis

Pathognomonic sign of PPID in horses.

Hypertrichosis (long, curly hair coat)

First-line medical therapy for PPID & starting dose.

Pergolide 0.002–0.004 mg/kg PO q24 h

Key dietary rule for managing EMS.

Forage < 10 % NSC at 1.5 % body weight/day; restrict pasture

Best practical management for anhidrosis.

Exercise during cooler hours and provide climate control (fans, misters)

Signalment most at risk for hepatic lipidosis.

Obese ponies, donkeys, minis in negative energy balance

Definitive test for equine asthma diagnosis.

BAL cytology—> 5 % non-degenerate neutrophils (mild) or > 25 % (severe)

First-choice treatment for Rhodococcus equi pneumonia.

Clarithromycin + rifampin PO for 6–8 weeks

Drug used pre-race to reduce EIPH severity.

Furosemide 0.5–1 mg/kg IV 4 h pre-race

Two cranial nerve deficits typical of temporohyoid osteoarthropathy.

Facial (VII) paralysis and vestibular (VIII) dysfunction

Characteristic expiratory ‘gurgling’ noise in sport horses?

Intermittent DDSP during exercise

Pathophysiology of HYPP in Quarter Horses.

Na-channel mutation → sustained depolarisation → hyperK and periodic paralysis

Emergency IV therapy for acute HYPP episode.

5 % dextrose in saline + calcium gluconate ± sodium bicarbonate

Best diagnostic to confirm PSSM-1.

Genetic test for GYS1 mutation (hair or blood)

Shaker foal syndrome is caused by what toxin?

Clostridium botulinum neurotoxin (types B/C)

Preferred prophylaxis against tetanus in a wounded horse.

Tetanus toxoid booster (and antitoxin if status unknown)

Outline the ‘1-2-3’ rule for foals.

Stand within 1 h, nurse within 2 h, pass placenta (mare) by 3 h

IgG thresholds for FPT in foals.

800 mg/dL adequate; 400–800 partial; < 400 mg/dL failure

Main treatment for neonatal isoerythrolysis.

Stop colostrum intake and give cross-matched whole-blood transfusion

Primary clinical sign of meconium impaction.

Colic and straining in the first 24 h with no meconium passed

Dummy-foal (‘PAS’) initial physical therapy technique.

Madigan squeeze for 20 min to simulate birth-canal compression

Sepsis score above what value suggests neonatal sepsis?

8–11 on modified Foal Sepsis Score

Shock fluid bolus (isotonic crystalloid) for adult horse?

20 mL/kg initially (¼ of 80 mL/kg shock dose) then reassess

Maintenance fluid rate for adult horses.

50 mL/kg/day

Maximum safe IV K⁺ supplementation rate.

0.5 mEq/kg/hour

Dose of 7.2 % hypertonic saline for hypovolemic shock.

2–4 mL/kg IV

List two AAEP core vaccines and when boosters are given.

EEE/WEE and WNV—boost in spring before mosquito season

Anthelmintic class effective against encysted small strongyle larvae.

Moxidectin or 5-day double-dose fenbendazole

Why must fluoroquinolones be avoided orally in adult horses?

Risk of fatal colitis and oral ulceration

Metronidazole is primarily used to target which organisms?

Obligate anaerobic bacteria and protozoa

Trimethoprim alone is bacteriostatic; how is it made bactericidal?

Combine with a sulfonamide (TMS) for sequential inhibition

Highest-priority critically important equine antibiotic to avoid if possible.

3rd generation cephalosporins (e.g., ceftiofur)

Cervical vertebral stenotic myelopathy Type 1 vs Type 2 difference.

Type 1 = dynamic compression in young fast-growing horses; Type 2 = static OA/narrowing in older horses

EPM diagnosis requires what CSF:serum antibody ratio?

Serum:CSF SAG2,4/3 titer ratio < 100 strongly supports EPM

Most likely nutritional cause of equine degenerative myelopathy.

Vitamin E deficiency in genetically susceptible horses

Classic clinical triad of Horner’s syndrome in horses.

Ptosis, miosis, ipsilateral facial sweating/vasodilation

Key sign of polyneuritis equi (cauda equina neuritis).

Progressive tail, anal, and bladder paralysis with perineal hypoalgesia

Main treatment for penetrating captive-bolt euthanasia.

Adjunct IV KCl or MgSO₄ after bolt to insure cardiac arrest