Armando Sobrado López
National Aquarium of Cuba
Once more, blood collection
is a topic for trainers and vets.
Indeed, this procedure is vital for
the correct maintenance of our
animals in a zoological setting. As
we all know, blood samples are
maybe the most important and
most complete samples that we
can take from our animals. They
bring us the information about the
current health status of our animal,
so we should make this training of
this behavior an emphasis of our
husbandry-training program.
The knowledge of where blood
vessels lie subcutis is essential
for selection of a site for blood
collection; however, even if we
know it, most times venipuncture
must be taken ‘blind’. For that
reason, we need to know the
possible sampling sites reported
for the species in our collections.
Figure 1:
Location of some of the venipuncture sites described for eared seals.
An overview…
Figure 1 shows some
puncture sites described for sea lions. The jugular vein was reported for
the first time in a California sea lion (Zalophus californianus) in 1971 by
Palumbo, Allen, Whittow, and Perry and the first voluntary blood collection
from this site was trained in 2005 (Romagnoly & Clemons-Chevis, 2005) in
the same species. Despite being a large vessel, the jugular vein can’t be
observed easily. Besides, this site is not recommended for trainers with low
experience in phlebotomies or with very poor bonds with their animals, due
to the proximity of the mouth, thereby increasing the probability of a bite.
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Figure 2:
this zone can also be dangerous because
of the proximity to the spinal cord. Even a
little mistake during puncture may affect
motor nerves of the animal. Thus, training
requires an animal’s complete relaxation,
wide medical knowledge on the part of the
staff, and correct manipulation by the staff.
Clark et al. (2004) mentioned other
blood collection sites in fur seals and sea
lions like the cephalic vein, extradural
veins, and even a cardiac puncture for
sampling pups, but as all these locations
and techniques include physical restraint
and other risks, they are not recommended
as routine methods for blood sampling.
The brachial veins are not mentioned as
blood collection site in sea lions, although
they are very common in manatees and
most terrestrial mammals, including
humans (Bossart & Dierauf, 1990). Murie
(1874) described the vascular system in
Otariids. He mentioned the small brachial
Learning curves of blood collection behavior from brachial veins in fore flippers in
two species of eared seals: California sea lion (purple) and South American sea lion
and axillary branches in this species and
(red). Each curve represents average time of each species. Horizontal lines represent
how these vessels lose their significance,
standard error of the training time.
as compared with humans. Brachial veins
correspond to the diminished length of
the brachial region in Otaria, and they
The anterior vena cava and brachiocephalic vein have been used to
are located surrounding the short brachial
collect blood from several species (Hubbard, 1968; Clark, Holz, & Duignan, artery; moreover, they are large veins that maintain a position on the inner
2004), but in all cases anesthesia and heavy sedation of the animal is side of the median nerve.
needed. This puncture site is not recommended due to the added risks of
There are no references about the use of this vascular bundle in
anesthesia use in animals. Also, this choice isn´t useful if we don’t know the pinnipeds, at least in specialized marine mammal medicine books, although
exact weight of our animal and we can´t properly dose a drug.
brachial veins are mentioned as a recommended site for blood drawn from
Two common locations to obtain blood samples in otariid seals are seals and sea lions in the Policy on the Collection of Blood from Wildlife of
interdigital veins and tarsal plexus. These veins, located in the hind flippers, the Department of Environment and Natural Resources of Government of
are very far from the mouth of the animal making this location perfect for South Australia in 2008. The lack of references is remarkable because these
new trainers and for an animal with positive stationing. But this site also veins are large vessels that can be seen and palpated easily, and they would
has a few disadvantages. In pinnipeds, vein detection and blood drawn be an important vascular access in those species.
from the rear flippers is complicated because of the amount of hair in these
For that reason, the goal of this report is to explain how we trained
appendixes and the high sensitivity of them. Besides, as thermoregulation voluntary blood collection from brachial veins in five sea lions belonging
takes place through those flippers, the blood flow to those appendages to two species - Otaria flavescens and Zalophus californianus; and thus
varies dependent on the autonomous nervous system. Very often, the demonstrate the advantages of phlebotomies in these puncture sites.
sympathetic vasoconstriction of these veins makes it impossible for blood
collection. On the other hand, if the animal is warm, veins appear instantly Training voluntary blood collection
(which can be achieved with the application of preheated towels prior to from brachial veins…
venipuncture). Thus, vets often prefer other sites where the constriction of
Two years ago, in a previous paper (Sobrado, 2011), some steps to
the vessels is not a problem.
training voluntary blood collection from the epidural sinus in harbor seals
Alternative sites include both the caudal gluteal vein and the epidural were mentioned. In the present report, a similar methodology is assumed, so
sinus. The caudal gluteal vein (Geraci & Sweeney, 1986) is a medium-sized I will only explain a few of the steps that could be considered as ‘hot spots’
vessel which courses just lateral to the sacral vertebrae. Here we can while training.
obtain good and abundant blood samples, even though it may be considered
Five sea lions were trained: two California sea lions (both females, one
another ‘blind’ location. On the other hand, the lower back (epidural sinus) 11- and one 12-year-old) and three South American sea lions (one 18-yearsite is not recommended in the case of sea lions and fur seals; it is a old male and two females 14- and 5-years-old). Operant Conditioning
better site in phocids. The sinus may be a good option, but a puncture in Techniques and a Continuous Primary Reinforcement Schedule were applied.
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A training plan was designed with only one or two daily sessions. For the
training, we used only sterile materials: gloves, 53.3 cm (21 in) hypodermic
butterfly needles, dressings, and alcohol (70% ethanol).
Based on our methodology, the person who performs the extraction is the
trainer. It does not exclude the presence of another person if a trainer desires
nor is it our intention of understating the role of the vet. This approach took
into account not only the proper training of the trainers about these topics,
but also the relationship and confidence that should exist between trainer
and sea lion.
A behavior map was designed with eight steps, and we weighted them
with percentage values (quantitative scale) depending on the complexity
and importance of each one.
• 10%- Animal in station, out of the water, in supine position, completely
relaxed. In this position, the trainer will locate one side of the animal and
will ask the animal to unfold the nearest fore flipper. The sea lion has to
remain in that position and the trainer must have access to the ventral
face of the extended flipper. Besides, it is important to have the animal
totally relaxed to prevent manipulation mistakes or any aggression.
• 30%- Desensitizing the specific area (axillar area). In this moment,
the trainer needs to locate the veins’ furrows and begin tapping and
palpating the axillar zone. Curiously, the number of veins that we have
seen is different between the two species; in South American sea lions
we can observe two, while in California sea lions we can find three
veins.
• 40%- Application of alcohol in the specific area. The goal of this step is
to desensitize temperature changes that alcohol provokes in the skin.
• 50%- Trainer presses the area with a blunt object for a set time. At this
point the specific behavior (blood draw) differs from other behaviors that
might have the same training schedule.
• 60%- Trainer punctures the area with a sterile needle for a short time (a
few seconds) gradually increasing the time of insertion.
• 70%- The time of puncture is increased to about 30 seconds.
• 80%- Trainer punctures the area with a sterile needle and syringe for
a long time traveling deeper into the skin. This is an important step
because there are changes between manipulations with only a needle
and when we add a syringe.
• 100%- Trainer punctures in the sinus vein for about a minute and the
animal stays completely relaxed (behavior is under stimulus control).
As in other animal species, brachial veins represent a good vascular
access in sea lions and we may consider these puncture sites as noninvasive. Perhaps the proximity of the sea lion mouth has been a cause
of the lack of exploration of this blood collection site, but when we apply
proper training techniques, great achievements are possible.
Conclusions…
This is the first study of the training of blood collection from the brachial vein
voluntarily in sea lions. Blood collection from this site is possible in a relatively
short time and we can obtain abundant blood samples of a high quality.
References
Bossart, G. D., Reidarson, T., Dierauf, L. A., & Duffield, D. (1990). Clinical
pathology. In L. A. Dierauf and F. Gullard (Eds.), CRC handbook of
marine mammal medicine (2nd ed.) (pp. 383-426). CRC Press.
Clark, P., Holz, P., & Duignan, P. J. (2004). Collection and handling of blood
samples. In P. Clark (Ed.), Haematology of Australian mammals.
Collingwood, Australia: CSIRO Publishing: 17-20.
Geraci, J. R., & Sweeney, J. (1986). Clinical techniques. In M. E. Fowler (Ed.),
Zoo and wild animal medicine (2nd ed.) (pp. 771–777). Philadelphia:
W. B. Saunders.
Hubbard, R. C. (1968). Husbandry and laboratory care of pinnipeds. In
R. J. Harrison, R. C. Hubbard, R. S. Peterson, C. E. Rice and R. J.
Schusterman (Eds.) The behavior and physiology of pinnipeds. (pp.
299–358). New York: Appleton-Century-Crofts.
Murie, J. (1874). Researches upon the anatomy of the pinnipedia (Part III)
Descriptive anatomy of the sea lion (Otaria jubata). Transactions of
the Zoological Society of London. VIII (9), 501-637.
Palumbo, N. E., Allen, J., Whittow, C., & Perri, S. (1971). Blood Collection in
the Sea Lion. Journal of Wildlife Diseases 7: 290-291.
Sobrado, A. (2011). Voluntary blood collection from the epidural sinus in two
harbor seals Phoca vitulina vitulina (Carnivora: Phocidae). Soundings.
36(1), 16-17.
Editor’s note: The author can be reached for further information at
[email protected]
Our results…
Figure 1 shows the average training time for this behavior in two
species of sea lions. The behavior was under stimulus control in about
a month, in both cases and there do not appear to be differences in the
learning time between the species. In my opinion, training time is not the
most important result; it is the positive response of all animals.
Blood drawn from the brachial veins in fore flippers brings with it the
advantages of large vascular vessels and sinuses. First, there is the increased
speed of the procedure. Puncture takes place in a wide vessel with enough
blood fluid to fill the syringe quickly. Second, we don’t need anticoagulants.
An abundant blood flow is enough to prevent the activation of coagulation
chains, so the quality of blood samples is higher and probability of blood
contamination and hemolysis decrease; samples are more reliable.
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