APPENDIX V: VETERINARY SECTION - CETACEANS
PLEASE MAKE THE
ATTENDING VET AWARE THAT YOU ARE CARRYING THIS INFORMATION, SO HE / SHE CAN REFER TO IT, AS WELL AS TO THE INFORMATION IN THE MAIN TEXT OF
Please note that this section is
intended for the use of vets. The exceptions to this are the section on fluid therapy, for the use of those with experience in
stomach tubing, and the information on euthanasia by shooting, for the use of licensed firearms users, which is
included in the triage.
Clinical Triage for Stranded Cetaceans
The following triage is designed as a guide for
vets called upon to assess and treat stranded cetaceans. We would also suggest that those inexperienced in
the management of stranded cetaceans should contact one of the following vets for further advice.
Barnett, British Divers Marine Life Rescue
07703 855399 (mobile)
Jepson, Institute of Zoology, London
(Strandings Programme, England and Wales)
Robinson, R.S.P.C.A. Norfolk Wildlife Hospital
Patterson, SAC Veterinary Services, Inverness
(Strandings Programme, Scotland)
To determine if alive, look for
opening and closing of blowhole. N.B. big whales may hold breath for ± 20 mins. In these
animals, checking for a corneal reflex and assessing other reflexes (see below) will help.
includes twitching, muscle
tremors, pronounced and sustained lateral or ventral flexion, listing, lack of
responsiveness ± movement. Such behaviour may take several hours to correct.
may be present in neonates. Dependent calves of harbour porpoises strand more frequently
than calves of other species: born mainly June/July, suckle for seven to ten months, and
are 90 95 cm in length when weaned. Very occasionally, mother may still be
condition assessed by examination of shape of lumbar muscles below dorsal fin. Reasonable
if flat to convex in profile. If concave ± visible neck, not suitable for refloat.
Interpretation complicated by number of factors: blubber thickness often seasonally and
age dependent and may be maintained despite atrophy of underlying muscles, shape of animal
may be distorted when beached and animals in good body condition may suffer from acute
(often occurs on stranding)
generally not clinically significant, despite often heavy bleeding. Deeper wounds,
penetrating muscle layer, extensive abscesses or haematomas affect prognosis, as do
fractures and dislocations, although may be difficult to detect. N.B. stress and trauma of
stranding can cause significant muscle damage, which may not be clinically apparent.
|Skin condition deteriorates out of
water; exacerbated by
wind and high temps.; skin wrinkles, peels, cracks and blisters. Excessive skin loss leads
to fluid loss and increased risk of secondary infection. This is associated with a poor
|Can assess jaw and
tongue tone, blowhole, flipper and palpebral reflexes. Poor reflexes and muscle tone may
be associated with shock and a decreased level of consciousness, and are a poor prognostic
|Supportive treatment (oral fluids,
i/v steroids, etc.) and
moving the animal into the water may well be required to improve reflexes and muscle tone,
i.e. reverse the onset of shock. If no reflexes or evidence of jaw and tongue tone are
seen over the course of an hour, the prognosis is likely to be poor.
|Deep bleeding from anus, blowhole
and mouth is a poor
|Signs of respiratory
disease include shallow respirations, strong smelling exhalations, mucopurulent blowhole
discharge, occasionally coughing and sneezing, and adventitious lung sounds (N.B. latter
only detectable in animals < 3 metres).
|Breathing rates for small cetaceans, e.g. common dolphin:
2-5 breaths/min. - normal
over 6 breaths/min. - mild stress or respiratory compromise
over 10 breaths/min. - severe stress or over 10 breaths/min. - severe stress or
Normal rate for pilot whale : 1 breath/min.
Normal rate for sperm whale : as low as 1 breath/20 mins.
respiratory rate is due to stress, then removal of stressors should bring the rate down in
a few minutes. If due to hyperthermia, rate should come down quickly after extensive
expiration-inspiration gap (> 4 secs.) may be seen with respiratory disease, or with
onset of shock. Capillary refill time normally <= 2 secs.
|Supportive treatment (oral fluids,
i/v steroids, etc.)
and moving the animal into the water may well be required to reduce the gap between
expiration and inspiration, i.e. reverse the onset of shock. If a response is not seen
over the course of an hour, the prognosis is likely to be poor.
|Temperatures taken with standard
digital thermometer in
animals < 50kg. In larger animals, thermistor probe should be inserted min. 20cm into
rectum, although sealed digital thermometer securely attached to length of stomach tubing
may suffice. Positive response to cooling in hyperthermic animals is good prognostic sign.
|Sample small cetaceans from central
tail veins, running near
midline of ventral and dorsal surfaces of each tail fluke. In larger animals, alternative
site is central arteriovenous complex in midline of dorsal fin. Apart from harbour
porpoise, no reference ranges available. Results (particularly from in
practice analysers) should be interpreted with caution; only muscle enzyme (CK,
AST) levels much higher than expected should influence prognosis. Serial bleeding during
prolonged refloat may give useful information about stability of condition. As speed of
response important, delaying refloat for results is not advisable.
|A decrease in the muscle enzyme
levels is unlikely to occur
until the cetacean is moved into the water and refloating is initiated (see below). This
decrease may take several hours to occur.
|Carry into waist deep water or, if
too heavy, refloat on tide,
in a pontoon (N.B. refloatation of very large cetaceans is not usually feasible). Support
with blowhole above water, until control of breathing is regained; rock gently to
alleviate muscle stiffness or circulatory impairment, and to help restore.
|See notes above re. behaviour in
water. Also : inability to
lift head to breathe, no closure of blowhole on immersion, no co-ordinated, forceful
efforts to swim. Some signs not necessarily associated with poor prognosis, as may take
several hours to correct.
|When appears able to
support itself, and making an effort to swim, move into deeper water to see if muscle
stiffness abated sufficiently to allow swimming unaided. If so, guide seawards, or take
further out for release with boats ± pontoons. N.B. successful refloat may take several
hours to complete.
|As animal may
restrand, it is essential that some post release monitoring is carried out. At very least,
dorsal fin should be photographed, and watch maintained on coastline for min. 48 hours.
Biodegradable ribbon tied loosely around tail stock will also help identification.
Repeated restranding after optimal care on beach is indicative of poor prognosis.
is performed by intramuscular injection of Large Animal Immobilon. Intravenous
barbiturates are preferred for animals under 2 metres and, depending on size of animal and
length of needles available, intraperitoneal barbiturates can be used in larger animals if
LA Immobilon is not available. Animals under 3 metres can be shot from close range through
blowhole with rifle (greater than .22 calibre), aiming towards line midway between
pectoral flippers. Very large cetaceans are best left to die naturally.
|Until improved, long
term monitoring of refloated animals is implemented, success can only be assumed.
Satellite tracking may well be implemented in the future, but present concerns include
logistics, cost and the welfare of the tagged animal.
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Where practically possible, rehydration through stomach tubing is advisable, as
most stranded cetaceans are dehydrated. Cetacean stomachs are relatively small and,
therefore, volumes of rehydration fluid need to be kept low (1% v/w, e.g. 1 litre for an
adult common dolphin). The procedure is also stressful and should not be carried out more
than 4 times in a 24 hour period. Oral fluids that have been administered to stranded
cetaceans include Lectade Plus, and Ringers, Hartmanns and glucose-saline solutions.
Stomach tubing can be carried out
in the water, with adequate support, or out of the water, on an air mattress or moistened foam. Most small cetaceans will open their mouths relatively easily
when introducing a stomach tube. Larger or intractable animals may require additional
measures, such as working towels into the mouth, which then can be used to pull the jaws
apart gently. After negotiating the centrally located, dorsally pointing larynx, an
appropriately sized lubricated equine stomach tube is passed to a point between the
pectoral and dorsal fins, to enter the stomach. Before fluids are passed, the animal is
allowed to take a breath to ensure the larynx has not been dislodged.
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|Cross section of dolphin head showing larynx.
Antibiotics may be administered to animals to be refloated, to reduce the
risk of secondary infection of any wounds sustained by the animal on stranding.
Antibiotics administered to live strandings in the U.K. to date include depot amoxycillin
(15 mg/kg, Clamoxyl LA), potentiated amoxycillin (8.75 mg/kg, Synulox), depot
oxytetracycline (20 mg/kg, Engemycin 10%) and
enrofloxacin (5 mg/kg,
Baytril), all by intramuscular injection. Depot preparations may be useful prior to an
early refloat, while short acting preparations can be administered daily to animals
requiring two or more days treatment before refloatation.
Intramuscular flunixin (1.0 mg/kg) has been used in cetaceans for its analgesic
and anti-inflammatory properties. If used, decisions regarding prognosis should not be
made within eight hours of administration, due to the potential masking of clinical signs.
Steroids may be beneficial in the treatment of shock but, again, any decisions regarding
prognosis should be delayed until after their effects have worn off; their value in
animals considered fit enough for an early refloat is questionable.Multivitamin injections may
be beneficial, but
anthelminthics are contraindicated, as the die off of any lungworm present may
precipitate a severe inflammatory response in species, such as harbour porpoises, known to
carry a heavy burden. Diazepam (0.15 mg/kg)
has been used to
sedate cetaceans prior to transport, but cannot be recommended for animals that are to be
refloated immediately afterwards. Generally, tranquillisers are contraindicated, due to
their adverse effects on respiration and thermoregulation.
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Injection sites and needle sizes
In small cetaceans, intravenous injections can be given into the paired
central tail veins, running along the midline of the ventral and dorsal surfaces of each
tail fluke (see diagram under
In larger animals, where tail restraint is difficult, a more suitable site is the
large central arteriovenous complex in the midline of the dorsal fin, which has small
vessels running parallel to it. Sites in the pectoral fins and caudal peduncle have been
used, but there is a greater risk of extensive necrosis following thrombovasculitis if
these sites are used. 1 - 3.5 inch, 18 - 21 gauge needles will be required, depending on
the size of the animal.
Intramuscular injections are given into the lumbar muscles lateral and caudal to the dorsal fin.
Needles should bridge the blubber layer and sizes needed to achieve this will be
1.5 - 10 inch, 14 - 21 gauge, depending on the size of the animal. Certainly, a minimum
3.5 inch (9 cm) spinal needle should be used in an adult common or striped dolphin or larger animals.
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and wound care
|James Barnett administering drugs to a stranded orca
The eyes of stranded cetaceans are vulnerable to desiccation, irritation and
trauma. Flushing with saline and application of ocular lubricant and antibiotic
preparations may be beneficial. Superficial wounds can be cleaned and flushed, but topical
preparations usually wash off on immersion, except possibly Orabase (ConvaTec). Suturing
of wounds is not advisable,
as dehiscence is likely.
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See triage for information. Needle sizes are as for intravenous injections (see
above). The diagram below illustrates the commonly used sampling sites. In addition to the
central tail veins and central arteriovenous complex in the dorsal fin, sites in the
pectoral fins and caudal peduncle have been used, but there is likely to be a greater risk
of thrombovasculitis if these sites are repeatedly sampled.
|Blood sampling sites in cetaceans
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|Dave Coombs bleeding a juvenile striped dolphin
See triage for information. More details on drug-induced euthanasia are given
Large Animal Immobilon:
Dolphins and porpoises: 0.5 mls per 1.5 metres
Whales: 4.0 mls per 1.5 metres
Route of administration: injections ideally should be made through the
blubber layer into the lumbar muscles, lateral and caudal to the dorsal fin. Needle sizes
are given above - large cetaceans may require needles up to 10 inches (25 cm) in length.
However, if no suitable sized needles are available, then injections with shorter needles
will still produce results, as the blubber layer contains an effective capillary network.
Care must be taken when injecting into the blubber layer, as its fibrous nature makes
injection of large volumes difficult and there is a risk of needle separation from the
syringe due to the resultant pressure. It may prove necessary to inject small volumes at several different sites.
After LA Immobilon administration, it may take several minutes for an animal to
die, particularly if the injection was given into the blubber layer. There also may be an
excitatory phase prior to death, which can be distressing for onlookers.
Dose rates: Give to effect. Rates required may significantly exceed those for terrestrial mammals.
Route of administration: in small cetaceans, the intravenous route is
recommended, via the central tail veins (see blood sampling). The
intraperitoneal route can also be used in larger animals if LA Immobilon is not available
and adequately sized needles
are to hand.
N.B. Carcasses of cetaceans euthanased with drugs should be disposed
of safely, to avoid poisoning scavengers.