F145
Dehydration in Animals

Clinical Signs: Sunken eyes, skin remains tented, dry nose, weakness, pale, dry gums, and a capillary refill time longer than 2 seconds are some of the more common signs of dehydration. See page C100 and C115 for additional information on dehydration and skin tent. Not every animal will experience all of these symptoms.

Additional Diagnostics: One of the best ways of evaluating the extent of dehydration in an animal and determining if hydration efforts have been successful is by drawing blood and running a complete blood count (CBC). See page D125 for additional details on this procedure.

Hints: 1 gallon = 3.7 liters and 1 kg = 2.2 lbs.

This fluid can be given orally (PO), subcutaneously (SQ), or intravenously (IV). Only sterile fluid (0.9% saline solution or sodium chloride) should be administered SQ or IV. It is essential that any dehydrated animal, particularly newborns with diarrhea, have oral, SQ, or IV fluid supplementation.

1. Calculate the animal’s fluid requirements using the previous example. Give no more than 250 mLs at one time to small newborns or 3-5 liters to adults.
2. If electrolytes are going to be fed, reconstitute them exactly according to the manufacturer’s instructions.
3. The best way for a newborn to obtain oral fluids is by suckling a nipple bottle. This allows the fluid to enter the abomasum through the esophageal groove. If the newborn is too weak to suckle, fluids can be administered with an esophageal or tube feeder. This method, however, causes the fluid to enter the rumen directly and not the abomasum. See page C854 for instructions on using these feeders.
4. Do not be reluctant to administer milk or milk replacers in addition to electrolytes to newborns. Electrolytes do not contain adequate nutrition for the lamb/kid; therefore, milk is necessary. It is true that some milk replacers can increase the amount of diarrhea that is produced, yet this is a necessary trade off for the extra nutrition the animal requires. All electrolytes and milk replacers should be fed at least 30 minutes apart and never mix the two fluids. Milk digestion is slowed when combined with oral electrolytes.
5. Dehydrated adult animals may require oral administration of fluid through a stomach tube. See page C854 for details on how to administer the fluid.
6. The frequency of fluid administration can be variable and depends on the severity of the fluid loss and management issues. In general, animals that are only slightly dehydrated may require only two oral doses, while animals that are around 5% dehydrated may require oral fluid every 2 hours.
   
   
   

1. If the animal is greater than 8% dehydrated, IV fluids should be given.
2. Warm the fluids to body temperature before administration.
3. Use only sterile isotonic fluids (0.9% saline solution).
4. The loose skin areas of the neck, shoulder, and behind the elbow are good areas to administer SQ fluid. The injection area should be cleaned and sterilized before inserting the needle.
5. The fluid can be given as one large bolus or can be given over a period of time. Do not give over 60 mLs in one location and over 300 mLs total to one newborn at one time. Adult animals can tolerate larger volumes. It usually takes about 4-6 hours for the fluid to completely absorb.
6. Oral and SQ fluids can be given at the same time and are often a great method of restoring proper hydration.
   
   
   

1. Only administer sterile fluids (Lactated Ringers, 0.9% saline solution, etc.).
2. Calculate the animal’s fluid needs by utilizing the table and example at the front of this discussion.
3. Many animals with diarrhea are acidotic (meaning that they have a low blood pH). Because of this, bicarbonate may need to be added to the first 1-3 liters of fluid. If 0.9% sterile saline solution or sodium chloride is used, approximately 13 grams of sodium bicarbonate or 150-175 mLs of 8.4% sodium bicarbonate solution should be added to each liter of fluid to make a 1.3% solution. To make a 5% sodium bicarbonate solution for acidosis, 50 grams of sodium bicarbonate should be added to each liter of fluid.
4. Supplemental glucose is often necessary. Adding 30 mLs of 50% dextrose solution to 1 liter of IV fluids makes a 1.5% dextrose solution; adding 100 mLs of 50% dextrose to 1 liter makes approximately a 5% dextrose solution.
5. In general, once the amount of fluid the animal requires is calculated, two-thirds of that amount can be given in the first hour. For example, if the animal requires 750 mLs of fluid, 500 mLs can be given in the first hour. After the first hour, the rest of the fluids (250 mLs) can be given evenly over a 2-3 hour period.
6. After the initial calculated fluid dose is administered, additional fluids can be given at a rate of 5 mLs for every 2.2 lbs. of body weight, every hour. This means that a 20 lb. (9 kg) lamb that is 9% dehydrated should initially receive a total of 0.81 liter of fluid. Approximately 0.5 liter should be given in the first hour, and the final 0.3 liter given over a 2-3 hour period. Once the 0.81 liter is given, a dose of 45 mLs of fluid should be given every hour until the animal is fully rehydrated and back to normal.
7. In addition to the 5 mLs/2.2 lbs/hour, additional fluid may be required to keep up with continued losses because of diarrhea, etc.