Assessing Hydration Status:
* It is essential that any animal, particularly calves with diarrhea, have
oral, subcutaneous (SQ), or intravenous (IV) fluid supplementation.
Use the following guidelines to determine the hydration status of an animal:
% Dehydrated
|
Eyeball Position
|
*Skin Remains
Tented (sec)
|
Mucous Membranes
|
Normal
|
Normal
|
<1
|
Moist
|
1-5
|
Normal
|
1-4
|
Moist
|
6-8
|
Slightly sunken
|
5-10
|
Tacky
|
9-10
|
Gap between eyeball and surrounding tissue
|
11-15
|
Tacky to dry
|
11-12
|
Large gap and very sunken
|
16-45
|
Dry
|
*See page B115 for additional
information on skin tent.
Fluid Replacement:
Once the level of dehydration in the calf has been determined, a simple
calculation can be done to identify how much fluid is required.
- Take the % dehydrated and multiply by the calf’s body weight in kg.
- For example, an 80 lb. (36 kg) calf is determined to be 9% dehydrated.
.09 X 36 kg = 3.24 – This means that 3.24 liters of fluid (oral
electrolytes, SQ, or IV fluid) are required to replace what has been lost.
- After the initial calculated fluid dose is administered, additional fluids
can be given at a rate of 5 mL for every 2.2 lbs., every hour. In addition
to the 5 mL/2.2 lbs/hour, an additional 1-4 liters each day may be required
to keep up with continued fluid losses because of diarrhea, etc.
Hints:
1 gallon = 3.7 liters and 1 kg = 2.2 lbs.
In this example the calf weighs 36 kg (80 lbs. divided by 2.2 = 36 kg)
This fluid can be given orally (PO), SQ, or IV (V is much better in an
animal that is down and lethargic). Only sterile fluid (0.9% saline solution or
sodium chloride) should be administered SQ or IV. See page F755
for
additional suggestions.
Oral Fluid Administration: Oral fluids should only be used in calves that
are 1-5% dehydrated. If the calf is more dehydrated than this, oral
fluids alone do not meet the calf’s needs. The most common problems with oral
fluid administration is that the method and frequency of administration is not
ideal and the quantity administered is often insufficient. To overcome these
problems, the following suggestions are a must:
- Reconstitute the oral electrolyte exactly according to the manufacturer’s
instructions.
- Calculate the calf’s fluid requirements using the previous example.
Administer no more than 2 liters at one time.
- The best way for a calf to obtain oral fluids is by suckling a nipple
bottle. This allows the fluid to enter the abomasum through the esophageal
groove. If the calf is too weak to suckle, fluids can be administered with
an esophageal feeder. See page B850 for instructions on using an esophageal
feeder. This method, however, causes the fluid to enter the rumen directly
and not the abomasum. Frequent feedings with an esophageal feeder can cause
decreased gastrointestinal (rumen/intestines) function and other
complications.
- Do not be reluctant to administer milk replacers in addition to
electrolytes. Electrolytes do not contain adequate nutrition for the calf
and therefore milk replacers are necessary. It is true that some milk
replacers can increase the amount of diarrhea that is seen. This is a
necessary trade off for the extra nutrition the calf 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.
- The frequency of feedings can be variable and depend on the severity of
the fluid loss and management issues. In general, calves that are only
slightly dehydrated may require only two oral feedings, while calves that
are around 5% dehydrated may require feeding every 2 hours.
Subcutaneous (SQ) Fluid
Administration: This method of fluid
administration should be used in those calves that are 6-8% dehydrated. If SQ
fluids are given, remember the following:
- If the calf is greater than 8% dehydrated, IV fluids should be given.
- Warm the fluids to body temperature before administration.
- Use only sterile isotonic fluids (0.9% saline solution).
- Because of potential infections, do not add glucose to any fluid given SQ.
- The loose skin areas of the neck, shoulder, and behind the elbow are great
areas to administer SQ fluid. The injection area should be cleaned and
sterilized before inserting the needle.
- The fluid can be given as one large bolus or can be given over a period of
time. Do not give over 500 mL in one location and over 2 liters total to one
calf at one time. It usually takes about 4-6 hours for the fluid to
completely absorb.
* Oral and SQ fluids can be given at the same time and are often a
great method of restoring proper hydration.
Intravenous (IV) Fluid Administration: IV fluid administration requires
that a sterile catheter be placed in the animal. This requires professional help
and