Sick cria management: the Tennessee method (Proceedings)
Nov 1, 2010
By: Jerry Roberson, DVM
CVC IN SAN DIEGO PROCEEDINGS
|
 |
Dealing with a sick cria and an anxious client can be quite daunting at times.
This task becomes less daunting when one understands the main problems and how
to manage them. Neonatal crias are typically admitted to the UT College of
veterinary medicine due to prematurity/weakness/inability to stand, suspected or
real failure of passive transfer (FPT), and septicemia. The condition of these
crias, upon admittance, various from bright and alert to comatose.
The Normal Cria/overly concerned owner :
Crias that are bright and alert should be evaluated for congenital defects (e.g.
cleft palate, heart murmurs, choanal atresia, etc) and signs of systemic
disease. Crias will normally be standing by 1 hour of birth and will nurse by
2-4 hours. Each suckling episode may last no longer than 30 seconds and may
occur up to 4 times per hour. Suckling times much longer than 30 seconds and
constant attempts to suckle suggest that the dam may have insufficient milk.
Blood should be obtained for a total protein (TP), sodium sulfite precipitation
test (SSPT) and pack cell volume (PCV). The TP and SSPT are not as specific as
IgG levels but are quick and practical means of assessing FPT. If the TP is >
5.0 (some use 6 mg/dl; I personally like 5.5) or the SPT is positive
(precipitation) and the PCV is not > 40, the cria is probably in good shape.
However to be absolutely sure about the success or failure of passive transfer,
we may also submit a serum sample for IgG levels by radial immunodiffusion
(RID), which takes 24 hour for test results. The dam should be evaluated for
milk production and if milk is available the cria is probably good to go. Alpaca
and llama dams do not tend to have large udders and sometimes the first
parturition females are slow to come into their milk. Domperidone has been
recommended but there are no known scientific studies documenting the efficacy
of this product. There are anecdotal reports of this product being effective but
the effect may just be coincidental with naturally occurring postpartum milk
production. We do use domperidone at 4 times the equine dose and anecdotally
some believe it works well. If there is still question as to whether the cria is
nursing successfully, it and its dam may be kept overnight for observation. It
is important to accurately weigh the cria on the day of admittance and then
reweigh the cria the following day to ensure weight gain. Healthy neonatal crias
tend to gain around 0.5-1 lb per/day. Crias may lose weight the first day (up to
0.5 lb)....weight loss greater than this would be concerning especially in the
hospital setting but maybe not the farm setting. Fowler notes that the neonate
is not likely to gain weight during the first 3 days of life and may lose up to
1 lb (Fowler, 1998).
The FPT
Cria :
Colostrum may still be absorbed systemically if the cria is less than 24 hours
old. However, the closer to the 24 hour period, the less likely that colostrum
will be absorbed adequately. Thus, plasma transfusion should be considered for
those cases. The success of colostrum ingestion can be evaluated 18-24 hours
after the first feeding. However, Weaver and coworkers concluded that the best
time to evaluate passive transfer status by IgG levels is at 36 hours post-birth
(2000). If camelid colostrum is not available and insufficient colostrum is
available from the dam, then goat or cow colostrum is preferred. The cria should
receive ~10-20% of its body weight in colostrum divided into 4-8 oz amounts with
the majority ingested by 12 hours of birth. The colostrum should be administered
via suckling from a bottle if possible. If the cria won't suckle, a nasogastric
tube should be passed to the level of the distal esophagus to facilitate passage
of the colostrum to the 3rd compartment (C3). If the cria does have a
low TP, then a plasma transfusion is highly recommended. Although at greater
risk, healthy appearing crias with FPT can survive and do fine (Weaver et al.,
2000). Commercial llama plasma is available in 300 ml units (Triple J Farms). A
jugular catheter is recommended for the transfusion. Jugular catheters are easy
to place in crias because their skin is still quite thin as opposed to the
adults in which because of the thickness of the skin it is sometimes difficult
to see the jugular rise. However, sometimes catheter placement in crias can be
challenging because of their thin and tortuous neck and because camelids in
general they seem to have more prominent jugular valves. Hereby, we often place
over-the wire catheter when we know they are going to need an IV access for days
(we do place a short term IV catheter when they come just for plasma
administration). The plasma should be administered at 15-25 ml/kg slowly IV over
the first 10-15 minutes to ensure no adverse reactions and then can be
administered more rapidly over the next 2-3 hours. Reactions are quite rare. We
like to keep the dam and cria overnight and recheck the TP/PCV and IgG levels
the next day. Usually 1 unit of plasma is sufficient and providing that the cria
is gaining weight and nursing, it can be discharged. However, we find that crias
have a very variable IgG increase after plasma administration. We prefer an IgG
level > 1000 mg/dl; this is not always obtained and thus may utilize another
unit of plasma. In a recent unpublished UT study, IgG levels were measured
before plasma administration, after 1 unit and after 2 units. As might be
expected, 2 units of plasma provided a greater percentage of satisfactory IgG
levels (>800-1000 mg/dl) but even 2 units resulted in IgG levels < 800 mg/dl
indicating the substantial variability seen when plasma is administered. Based
on these results, we recommend 2 units ($150/unit). For the most accurate
interpretation of weight gain or loss, it should take place at the same time
every day. As a precaution (maybe without really being necessary), we will often
place the cria on a systemic antibiotic (usually ceftiofur HCl) and IV
Omeprazole (1mg/kg). I don't believe we've seen a neonatal cria with gastric
ulceration problems but ulcers are occasionally seen at necropsy. FPT crias can
certainly become septic.
The Premature Cria:
Premature crias may be able to rise but are often weak and tend to lie in
lateral recumbency rather than sternal. Their ears are usually flipped over at
the tips. Their incisors may not be erupted. Many are described as having a soft
and silky hair coat. They may or may not have good suckle reflexes but are
almost always FPT. Colostrum may not be absorbed well in the premature cria even
though it nurses or is tubed with normally adequate amounts of colostrum within
the first 12 hours of life. Premature llama crias usually have birth weights <
15 lbs (average birth weight in the 20s; normal range 18-35 lbs). The premature
alpaca cria usually weights < 8-12 lbs (average birth weight ~ 15-16 lbs; normal
range 12-20 lbs). As long as they are not septic, the prognosis is still good
but it may be 2 weeks before the cria is able to be discharged. The premature
cria has some difficulty maintaining normal body temperature (100-102°F). A
properly positioned heat lamp will greater facilitate temperature control but
any form of heating or cooling management should be followed with rectal
temperature monitoring of the neonate. The premature cria is almost always
hypoglycemic and an initial glucose bolus (20 mg/kg) may be administered IV.
Because premature crias also tend to have premature lungs, some are placed on
oxygen (100% @ 5 l/min) for the first few days. We recently lost a premature
cria that had been improving over the course of 2 days but then developed acute
respiratory distress. Necropsy revealed extensive areas of atelectic lungs.
Anecdotal evidence (Whitehead, 2009) suggests that administration of
aminophylline at 2 mg/kg subcutaneously every 4 hours for 24 hours, then every 6
hours for the next 24 hours, then every 8 hours for the next 24 hours helps
prevent the severe respiratory dyspnea that may occur with premature cria lungs.
It is important to keep the dam with the cria (often separated by a see through
panel). Many of these premature crias will not suckle adequate amounts of milk
and must be tube fed. We usually suture a rubber catheter feeding tube (8 French
110 cm) via the nose to allow easy feeding. The nasogastric tube should extend
from the external nare to just inside the thoracic inlet. It is thought that
feeding in this area will help facilitate transport of the milk/colostrum to C3
instead of C1. The tube should be measured and marked prior to placement. An
orogastric tube may be inserted at each feeding but a properly place and sutured
nasogastric tube eliminates the need to conduct this procedure with every 2 hour
feeding. When passing either tube, it is important that the head and neck not be
extended which increases the chance of the tube entering the trachea instead of
the esophagus. Rather, the head and neck should be a more normal position. The
tube should be seen or felt on the left side of the neck during passage. A few
milliliters of water should be passed in the tube initially if there is any
question as to its correct placement. We usually try to feed 10% (ranges from
5-15%) of the body weight daily via the feeding tube (feeding every 2 hours over
the first few days then increasing the amount and decreasing the number of
feedings) but attempt bottle feeding as the cria gets stronger. Eight to 10% of
body weight is thought to be the requirement for maintenance with an additional
5-8% required for growth. All tube feeding should be by gravity flow to decrease
the chance of regurgitation which could result in aspiration pneumonia. We
usually start with 5 % of the cria body weight, and then we slowly increase the
percentage by 2% per day. When the dam's milk is not available, we use goat milk
replacer and use 1 part replacer to 6 parts water. The glucose is monitored
during this time as hyperglycemia has occasionally been a problem. Camelids
easily develop hyperglycemia which is believed to be due to insulin resistance.
In crias, one of the biggest concerns is their risk of developing hyperosmolar
syndrome (discussed below). When this happens, we back off of the feedings a bit
and if this doesn't lower the glucose we may consider insulin. As time goes on
and the cria begins to suckle the bottle well, we allow the cria to attempt to
suckle the dam. The suckling instinct must be very strong as all that have
survived eventually maintain themselves via nursing the dam and some have gone
for > 2 weeks without nursing. We do our best to milk the dams and cessation of
milk production in the dams has not yet been a problem. We monitor the weight
(any weight gain is considered positive and helps us determine when the cria is
nursing enough off the dam so that hand feeding can be discontinued) and glucose
of the crias at least once daily.
The
Septic Cria :
Major blood work is not really required for the uncomplicated FPT cases or
normal cria unless some abnormalities have developed. But for the septic cria
both a CBC and chemistry panel are easily justifiable. Many things can and do go
wrong with the neonatal camelids. Initial management includes placement of an
over the wire IV catheter. Fluid therapy can begin with normal saline until
electrolyte abnormalities are known. It is relatively easy to overhydrate a cria
and create life-threatening pulmonary edema so exercise caution with fluid
rates. We start with 40 ml/kg/24hr. Glucose should be administered depending on
glucose levels and insulin may be needed as well. The action point for glucose
varies from one source to the next but if > 300 or < 70 action is needed
(unfortunately the urinary glucose threshold has not been investigated).
Bactericidal antibiotics are preferred. We typically use potassium penicillin
(44,000 IU/kg QID IV) and ceftiofur HCl (4.4 mg/kg) or amikacin (21 mg/kg IV;
extrapolated from neonatal foal dose).
Miscellaneous Conditions:
Meconium impaction:
Meconium is normally passed within 18-20 hours of birth. It is certainly
possible that the passage of meconium could be missed but as long as the cria is
acting normally, this should not be reason for alarm. The actual incidence of
this condition is not known but it is a differential for straining in the
neonate. A couple of warm water soapy enemas usually do the trick. Occasionally
an owner will over-do-it on the enemas and this in itself creates the straining.
Thus, if the cria is passing manure, repeat enemas are not necessary.
Hyperosmolar syndrome (HOS):
The history may include dystocia, sepsis, or any condition that might result in
decreased milk intake. Signs suggestive of HOS include lethargy, anorexia,
hyperthermia, tremors, seizures and if standing a wide-based stance. Although
numerous biochemical abnormalities may be identified, the syndrome primarily
centers around hypernatremia and hyperglycemia. The hyperglycemia may be the
initiating factor and is thought due to endogenous release of glucocorticoids
released during stressful events. The hypernatremia is thought to occur due to
glucosuria which results in an osmotic diuresis resulting in sodium retention
and body water loss. The excess sodium is thought to affect the cerebrum
resulting in the neurologic signs. While the hypernatremia may be corrected by
treatment with Na dilute fluids, the hyperglycemia may need to be corrected
first and usually requires insulin treatment (Buchheit et al., 2010). As they
are hyperglycemic (have seen up to 1000 mg/dl), they develop glucosuria,
accompanied by water; consequently, the cria gets dehydrated. With the
dehydration, they become hypernatremic, which overall increases the osmolarity
of the blood. Clinical signs include lethargy, tremors, and neurologic signs.
For this reason, in hyperglycemia and/or hypernatremic crias, we perform regular
blood work (with the I-stat machine) to measure their sodium, potassium, glucose
and BUN in order to calculate the osmolarity. The normal osmolarity if 300-310
mOsm; clinical signs of hyperosmolar syndrome can start to be seen when the
blood osmolarity reaches 350 or 360 mOsm. When hyperosmolar syndrome is a
concern, we dilute the IV fluids: usually we start with ¾ regular fluids (plasmalyte,
Norm-R) mixed with ¼ sterile water; sometimes we use a 0.5:0.5 ratio. We monitor
the blood osmolarity (every 6 or 12 h) and observe for neurological signs.
References
1.
Buchheit TM, Sommardahl CS, Frank N, Roberson JR. Use of a constant rate
infusion of insulin for the treatment of hyperglycemic, hypernatremic,
hyperosmolar syndrome in an alpaca cria. J Am Vet Med Assoc 2010,
236:562-566.
2. Fowler
ME. Neonatology. In 2nd Edition Medicine and Surgery of South
American Camelids, editor ME Fowler, Iowa State Press, 1998, pg. 452-467.
3. Triple
J Farms Llama Plasma, 777 Jorgensen Place, Bellingham, WA 98226.
4. Weaver
DM, Tyler JW, Scott MA, et al. Passive transfer of colostral immunoglobulin G in
neonatal llamas and alpacas. Am J Vet Res 2000, 61:738-741
5.
Whitehead C. Management of neonatal llamas and alpacas. Vet Clin North Am:
Food Animal 2009, 25:353-366.
|