Lactated Ringer’s

(abbreviations: LR, RL, LRS,)
*Note: similar to Hartmann’s solution, but should not be confused. Each have slightly different ionic concentrations.


No specific brand names; there are multiple manufacturers


  • Solution: 50 mL, 100 mL, 250 mL, 500 mL and 1000 mL bags.


An isotonic crystalloid volume expander that expands circulating blood volume. It approximates the fluid and electrolyte composition of blood.

Electrolytes contained in Lactated Ringer’s Solution are sodium, chloride, calcium, potassium, and lactate.
Percentages in 1 litre of solution are as follows:

  • Sodium: 130 meq.
  • Chloride: 109 meq.
  • Calcium: 3 meq.
  • Potassium: 4 meq.
  • Lactate: 28 meq.

The lactate in Lactated Ringer’s is metabolized to bicarbonate in the liver, and may be helpful in correcting metabolic acidosis.


Used in cases of:

  • hypovolemia as a result of fluid loss due to trauma
  • in cases of dehydration for rehydration and maintenance
  • as a replacement for fluid loss in chronic renal failure in small animals.

Drug Interactions or Contraindications

  • Use with caution in rats with congestive heart failure, kidney disease, or obstruction of the urinary tract, since overhydration may occur more easily.

Adverse Reactions

CV: overhydration can increase workload of the heart and precipitate congestive heart failure

Resp.: rapid breathing, pulmonary edema with overhydration

Metabolic:  fluid and electrolyte imbalances leading to muscle weakness if used inappropriately

Dosage Recommendations

Dose can be dependent on weight and severity of dehydration.

Suggested dosing per references are:

10 mL/kg to 25 mL/kg; to be given slowly over 5 min. to 10 min. bolus by IV, IO, IP,  1, 26, 34, 41, 44


50 mL to 100 mL/kg/24 hr; SQ, IV, IO  1, 26, 34


60-80 mL/kg/24 hr, dependent upon severity of dehydration; SQ, volume to be divided in two separate dosing’s given 12 hours apart. Administer by tenting the skin on the back over the area of the shoulder blades, and inserting needle into the subcutaneous tissue. Sites for administering over the area of the shoulder blades may be alternated from the center either to the left or right when choosing to administer the bolus in two smaller volumes at one time. 12


40 mL to 80 mL/kg/24 hr; IV, if animal not drinking. 10


For a 400 gm rat approximately 16 to 32 mL per day. If giving IP or SQ, it is recommended that it be in divided doses (example: 4 times/day) given during the day, and to be kept to approximately 5 mL per site to prevent skin distention and pain.  9

Locations for giving SQ fluids are the fleshy area scruff of neck (at back over shoulder blades), and the fleshy part of right or left hind quarter.

The solution should be warmed in a water bath prior to giving it by IV, SQ, IP, or IO. Note, do not overheat solution or burns can occur.


  • ALWAYS assess level of dehydration before giving!
  • Auscultate breath sounds for rales.
  • Use with caution, may result in electrolyte imbalance.
  • A one liter bag of solution has a 6-month expiration date.


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