Monitoring & Treatment of Concurrent or Developing Problems

Shock is common in MWDs with heat stroke and should be managed as indicated (see K9 Shock Management CPG). Monitor blood pressure, lactate clearance, clinical assessment of perfusion, and assessment of volume status until the MWD is evacuated.

Glucose, acid-base, and electrolyte abnormalities are common. If able, monitor blood glucose and venous blood gas analyses every 6-12 hours. Dextrose should be administered to hypoglycemic dogs (blood glucose < 60 mg/dL) as a single slow bolus (1 mL/kg IV of 50% dextrose diluted 1:2-1:4 in a sterile fluid). If hypoglycemia persists, administer a 2.5–5% dextrose CRI, with close monitoring to maintain glucose between 60-150 mg/dL.20 Monitor arterial blood gas analysis (or surrogates such as pulse oximetry and capnography). If hypokalemia develops (< 3.5 mEq/L), supplement IV fluids with KCl as indicated in Table 2 to maintain normokalemia.21 Do not bolus IV fluids that contain added potassium!

Hypercoagulable and consumptive coagulopathic states (e.g., thrombocytopenia, disseminated intravascular coagulopathy) are common.8,19 Gastrointestinal hemorrhage is common during recovery, and may be present on admission. Canine fresh frozen plasma (20 mL/kg), freeze dried plasma, or canine serum albumin may be necessary; however, these may not be available to providers. Providers must NOT give human fresh frozen plasma or human blood to dogs and should only administer human serum albumin in rare cases to select patients with guidance from a veterinary clinical specialist (AOC 64F Veterinary Clinical Medicine Officer). See the Transfusion for the Military Working Dog CPG for further guidance.22 Coagulation testing for MWDs may not be readily available and is not reliable on analyzers used for human blood. Providers should monitor the MWD and CBCs (if available) for evidence of thrombocytopenia (petechiae, ecchymoses, low platelet count) or signs of clotting abnormalities (e.g., hematoma formation, intracavitary bleeding, epistaxis, hematuria). URGENT evacuation to veterinary facilities is critical to survival of MWDs that develop bleeding disorders, as veterinary personnel can facilitate canine blood product collection and administration.

Cardiac arrhythmias, especially ventricular arrhythmias, are common. Perform continuous or intermittent ECG monitoring. Treat ventricular arrhythmias only if ventricular tachycardia is sustained (> 160 bpm for 30 seconds or longer) or if the ventricular arrhythmia is causing hemodynamic compromise (hypotension or other evidence of poor perfusion), using lidocaine (2 mg/kg IV bolus, then 50-75 mcg/kg/min CRI).

Vomiting and diarrhea are typical. Diarrhea is often hemorrhagic. Start pantoprazole therapy (1 mg/kg IV q12h) for any MWD with heat stroke. Treat nausea and vomiting with ondansetron (1 mg/kg, IV q12h) and, if available, maropitant citrate (1 mg/kg IV or SQ q24h). Add sucralfate (1 gram PO q8h) for any MWD with a history of hematemesis, after vomiting has stopped. Allow food and water once vomiting has resolved. Hygiene is critical, and bedding should be changed as needed; shave long tail hair to minimize soiling.

Acute kidney injury resulting in renal insufficiency is possible. Maintain urine production at 1-2 mL/kg/hour and monitor for pigmenturia. Monitor for subcutaneous edema, body weight gain (weigh every 6 to 12 hours), and nasal discharge as evidence of fluid overload.23 Monitoring urine output in males will be difficult without canine-specific urethral catheters and urinary catheter placement in female dogs is difficult. Use estimates of voiding or weigh absorbent pads or blankets to estimate urine output. Alternatively, in male dogs, adapt a 10- or 12-Fr suction catheter (ubiquitous in trauma bays) by removing the control valve end, aseptically inserting the remaining catheter into the urethra to the level of the urinary bladder, and connecting the distal end to a sterile empty IV bag or closed collection system by way of an adapter. If available, monitor renal values through blood chemistry every 24 hours.

Treat seizures with a benzodiazepine (diazepam 0.3 mg/kg; IV, IN, rectally or midazolam, 0.3 mg/kg; IV, IM or IN) as needed, up to 3 doses over 2 hours or as a 0.25 – 0.4 mg/kg/hour IV CRI for recurrent seizures. If seizures continue, give levetiracetam at a 60 mg/kg IV loading dose once, followed by 20 mg/kg IV every 8 hours. Treat any MWD with stupor or coma with mannitol on admission (0.5-1 grams/kg, IV, over 20 minutes) and repeat every 4-6 hours (for up to 2 additional doses). Alternatively, hypertonic saline can be administered (4 mL/kg bolus over 15 minutes). Rule out hypoglycemia. CNS abnormalities typically resolve with mild or moderate cases of heat stroke. Cortical blindness is common and usually resolves over a period of several days.

Initiate consultation to the overseeing veterinary clinical specialist (AOC 64F) as soon as possible and coordinate referral to a higher level of care as soon as possible. If a 64F cannot be reached, can contact the ADVISOR line at 1-833-238-7756 or DSN 312-429-9089 to reach additional veterinary subject matter experts.

Table 1. MWD Heat Injury Protocol
Table 2. Guideline for Potassium Supplementation