2. Give crystalloid fluids as the first-line treatment.9-14

- Normosol-R® or Plasmalyte-A® are optimal for dogs; however, saline or LRS are acceptable in emergent cases.
- Crystalloid fluid challenges, as needed based on response to therapy, are better than large volume fluid administration.11-13 Be prepared to administer up to 90 mL/kg of crystalloids in the first hour (1 blood volume for the dog). Aggressive, but careful, fluid delivery, with frequent reassessment of the patient‘s status, is critical. Most MWDs can be resuscitated with much less than this calculated maximum volume.
- For quick reference, ADD a ZERO to the dog’s body weight (in pounds) to approximate a safe but effective bolus volume. For example, a 45# dog would need about a 450 mL bolus, and a 75# dog would need about 750 mL as a bolus.

3. Use synthetic colloids and hypertonic saline (HTS) in dogs with refractory shock. Very limited data in dogs suggest increased risks,15-18 but dogs do not seem as sensitive to the adverse effects of these fluids as are people. Two recent studies in dogs showed no adverse side effects, specifically acute kidney injury, with tetrastarch use.19,20 The benefits outweigh the risks, so be aggressive with synthetic colloid and HTS.15-17

- Give hydroxyethyl starch (HES) as an IV or IO bolus of 10-20 mL/kg total over 5-10 minutes if clinical signs of shock do not abate after the first 30 minutes or the first 2 bolus crystalloid challenges), or response to crystalloid challenges is not sustained.11-13,15,20,21 Repeat this bolus if no response to therapy.
- Use HTS IV boluses, if 7.0 - 7.5% HTS is available, for MWDs that fail to respond to 2 or 3 boluses of crystalloids and/or 1 or 2 boluses of HES. Give 4 mL/kg over 5 minutes.11-13,20 Do not administer HTS by the IO route.

4. Human serum albumin (HSA) use. Do not give HSA or other synthetic colloids (e.g., dextrans) to MWDs, because severe allergic reactions are possible (HSA) and coagulopathies are common (dextrans). Some data suggest benefit in a very limited subset of patients with severe hypoalbuminemia,22,23 but risks far outweigh potential benefit in dogs with shock.

5. Blood product use. Canine blood products are not available for immediate HCP use.2 Dogs cannot be transfused with human blood products. HCPs will have to manage hemorrhagic shock with crystalloid and colloid therapy.

6. Tranexamic acid (TXA) and ɛ-aminocaproic acid (EACA) use. There is limited, but promising, data to guide use of TXA24-27 and EACA28 in dogs with hemorrhage. Dogs appear to be hyperfibrinolytic compared to humans, suggesting higher doses of TXA may be needed in dogs. Consider TXA or EACA if the dog is anticipated to need significant blood transfusion, such as severe hemorrhagic shock, limb amputation, penetrating torso trauma with severe non-compressible bleeding, because canine blood products are not available. Administer these drugs as soon as possible after trauma, but NO LATER THAN 3 HOURS post injury.

- TXA: 10 mg/kg in 100 mL NS or LRS, IV over 15 min.
- EACA: 150 mg/kg in 100 mL NS or LRS, IV over 15 min.
- If bleeding continues, a CRI of additional TXA at 10 mg/kg/hour for 3 hours can be administered.

7. Targeted shock resuscitation end points that are practical for HCPs include systolic and mean arterial pressures, level of consciousness and mentation, mucous membrane color and capillary refill time, HR, RR, and pulse quality.

- Target a MAP >65 mmHg or a Sys >90 mmHg. Note that neonatal or pediatric blood pressure cuffs must be used (See CPG 2).
- Target normal level of consciousness (LOC) and an alert mentation.
- Target light pink-to-salmon pink MM and a CRT <2 seconds.
- Target a HR that is 60-90 beats per minute at rest with a strong, synchronous pulse quality.
- Target a respiratory rate at rest of 12-40 breaths per minute with normal effort.
- Once shock has abated, continue IV crystalloid fluids at 3-5 mL/kg/hour for 12-24 hours to maintain adequate intravascular volume.

8. Provide supplemental oxygen therapy. Oxygen supplementation is critical. Every shock patient should receive supplemental oxygen therapy until stable (See CPG 3).

9. Identify and treat the cause of shock. The cause of shock must be corrected, if possible.

- Patients with massive intra-abdominal or intrathoracic bleeding need surgery to find the site of bleeding and surgically correct the loss of blood, with the caveats in mind as discussed previously.
- CPG 4 addresses emergent resuscitative thoracotomy. CPG 7 addresses emergent abdominal laparotomy.
- Euthanasia should be considered to prevent undue suffering for a MWD for which emergent surgery is deemed necessary but cannot be performed or has proven unsuccessful (See CPG 21).