Fluid Calculation Practice Problems
1. Calculate the IV fluid rate in mls/hr and gtt/sec for the following healthy
surgical patients:
35 lb dog; 15 gtt/ml
79.5 ml/hr
0.33 gt/sec  x 3 = 1 gt/3 sec
9.5 # cat; 60 gtt/ml
13 ml/hr
0.22 gt/sec  x 5 = 1gt/5 sec
3 pound dog; 60 gtt/ml
6.8 ml/hr
0.11 gt/sec  x 9 = 1 gt/9 sec
2. Calculate the IV fluid rate in mls/hr and gtt/sec for the following dehydrated
patients:
26# dog, 6% dehydrated, urinated 21 mls in the last hour. Correct over 4
hours using a 15 gtt/ml set.
Urine amount is normal
11.82 x 0.06 x 1000 = 709 ml total over 4 hours = 177.25 ml/hr
(177.25 ml/hr x 15 gtt/ml ) / 3600 sec/hr = 0.74 gt/sec x 4 = 3 gtt/4 sec
8.3 lb cat, 5% dehydrated, vomited 18 mls in the last 30 mins. Correct
over 3 hours using a 60 gtt/ml set.
(3.77 kg x 0.05 x 1000 ml) + 36 ml = 224.6 ml total over 3 hrs = 74.88 ml/hr
(74.88 ml/hr x 60 gtt/ml) / 3600 sec/hr = 1.25 gtt/sec x 4 = 5 gtt/4 sec
3. How many gtt/sec would you set your rate to if you need to maintain a 13 kg
dog on IV LRS for the next 8 hours, using a 15 gtt/ml set? Using a 60 gtt/ml set?
780 ml/24 hours = 32.5 ml/hr
15 gtt/ml: 0.14 gt/sec  x7 = 1 gt/7 secs
60 gtt/ml: 0.5 gt/sec  x2 = 1 gt every other second
*Make sure you understand why these two answers “make sense” and deliver
the same amount of fluid
Fluid Calculation Practice Problems
4. Your anesthetized, 17.4 kg canine patient is going into hypovolemic shock.
How many mls of Hetastarch will you bolus your patient with?
Colloid shock dose
Your answer should be between 43.5 ml and 87 mls
If you used 15 ml/kg: 261 ml / 4 = 65.3 ml bolus
5. Your 33 pound Boxer is estimated to be 6% dehydrated and has been having
diarrhea (~28 mls worth) since admitted. Dr. Dev wants this corrected over the
next 5 hours, and for maintenance fluids to be included. You do not have a fluid
pump- how many gtt/sec must you set your infusion set to? Use 15 gtt/ml set.
Rehydration: 900 ml + 56 ml = 956 ml
Maintenance: 900 ml/24 hr = 37.5 ml/hour x 5 hours = 187.5 ml
*You can also get both parts into ml/hr and add them together, more than one way to solve
Total: 956 ml + 187.5 ml = 1,143.5 ml over 5 hours = 228.7 ml/hour
(228.7 ml/hr x 15 gtt/ml) / 3600 sec/hr = 0.95 gt/sec or ~1gt/sec
6. A 50 lb dog needs a morphine CRI. The hourly dose rate for morphine is
0.2mg/kg/hr. You have a 1-liter bag of fluids. The hourly fluid rate for this
patient is 50 mL/hr. The concentration of morphine is 15mg/mL. How many mLs
of morphine need to be added to the 1-liter bag of fluids?
1000ml / 50 ml/hr = 20 hours
22.73 kg x 20 hrs x 0.2 mg/kg/hr = 90.92 mg
90.92 mg / 15 mg/ml = 6.06 ml of morphine