Managing a Colic in a Captive Giraffe
A 12-year-old female reticulated giraffe at an AZA-accredited zoo presents with a 24-hour history of anorexia, decreased fecal output, and mild abdominal distension. She is 4.5 m tall and weighs approximately 800 kg. The animal is housed in a mixed-species exhibit with greater kudu and ostrich. Physical exam reveals tacky mucous membranes, heart rate 80 bpm, respiratory rate 20 bpm, and rumen motility of 1 contraction per 2 minutes. The zoo has a hydraulic chute and a padded restraint room. Bloodwork shows PCV 42% (ref 30-40%), total protein 8.5 g/dL (ref 6.5-8.0), and a mild hypochloremic metabolic alkalosis. The keeper reports the giraffe consumed a large amount of alfalfa hay and a foreign object was seen in the enclosure (a piece of shade cloth).
1. What are the immediate priorities for stabilization and diagnostic evaluation, and how do you balance the risks of chemical restraint versus physical restraint in this tall, high-risk species?
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Immediate priorities: 1) Assess hydration and cardiovascular status; tacky mucous membranes and hemoconcentration (PCV 42%) suggest dehydration. 2) Relieve distension and prevent ruminal tympany; passing a stomach tube may be possible standing, but in giraffes, esophageal access is long and requires a long tube (≥3 m). 3) Provide analgesia (flunixin meglumine 1.1 mg/kg IV or IM) and fluid therapy (balanced isotonic crystalloids, 20-40 L IV or PO if tolerated). 4) Perform abdominal ultrasound and radiography if available, but the height complicates imaging. 5) Monitor for signs of obstruction or peritonitis (fever, worsening pain).
Balancing restraint: Physical restraint in a hydraulic chute is preferred for minor procedures (injections, IV catheter placement) because chemical restraint carries high risk of regurgitation, aspiration, and fatal tympany in giraffes. If chemical restraint is necessary, use a combination of an alpha-2 agonist (e.g., detomidine 0.02-0.04 mg/kg) and an opioid (butorphanol 0.05-0.1 mg/kg) to allow standing sedation, avoiding intubation. Always have reversal agents (atipamezole) and a plan for emergency tracheostomy. The chute must be padded and sized appropriately. For this case, standing sedation in the chute for IV catheter and gastric tube placement is ideal. Surgical exploration is a last resort and carries a grave prognosis.
2. Interpret the bloodwork and explain the pathophysiologic mechanism for the hypochloremic metabolic alkalosis. How does this influence your treatment plan?
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The PCV of 42% and total protein of 8.5 g/dL indicate hemoconcentration due to dehydration. The hypochloremic metabolic alkalosis is likely due to sequestration of chloride-rich gastric secretions (abomasal reflux or proximal obstruction) and possibly due to excessive bicarbonate production from salivary loss (giraffe saliva is bicarbonate-rich). In ruminants, abomasal displacement or outflow obstruction can cause hypochloremia and alkalosis. Additionally, the foreign object (shade cloth) may be causing a partial obstruction, leading to rumen stasis and sequestration.
Treatment: Administer 0.9% NaCl or a balanced polyionic solution with added KCl (20-40 mEq/L) to correct hypochloremia and alkalosis. Avoid lactate-containing fluids (e.g., LRS) because they may worsen alkalosis. Monitor electrolytes closely. If the animal is not drinking, provide oral fluids via stomach tube (electrolyte solution) and consider partial parenteral nutrition. The alkalosis may also be exacerbated by pain and stress, so provide analgesia. Surgical intervention is indicated if obstruction is confirmed and not resolving with medical management.