International Giant Otter Studbook Husbandry and Management

times over 10 years) then disappear without medical treatment. (At least one time they were
treated, although it is unclear whether they faded away naturally or the treatment was
successful.) They did/do not seem to bother the otters and their cause/identification is unknown
(scrapings of the lesions have been analyzed but they revealed nothing conclusive) (Osmann,
pers. comm.). (See Chapter 1 Section 2 under inbreeding and thyroid malfunctions causing the
death of the cubs at Dortmund Zoo. These were the cubs that were observed to have lesions at
Dortmund. The parents of these cubs also had lesions and the parents themselves resulted from
two generations of inbreeding.) Flügger (pers. comm. 2003) commented that these lesions
might occur when the otters’ immune system is compromised. It is also interesting to note that
a picture of a very young orphaned wild giant otter cub that had been taken to a wildlife
rehabilitation center had similar looking lesions as aforementioned (the photo was taken by
Lazzarini). This cub died the day it was brought in from a blocked urethra. Note: these lesions
are different than and not related to those described under poor foot condition because of
exposure to inappropriate enclosure conditions. See below under “Miscellaneous”.
Low Heat Tolerance: Captive giant otters have been observed to have a low heat tolerance
(Carter & Rosas 1997; Sykes-Gatz & Gatz pers. comm.).
Mental/Behavioral Health Problems and Abnormalities: It is not uncommon that giant otters
carry out some essential behaviors in an unhealthy and abnormal way and that these otters are
also mistakenly thought to be exhibiting healthy and normal behavior. These problems are
caused by inappropriate enclosure conditions and such conditions result because of general
misconceptions about otter behavior. Inappropriate enclosure conditions can negatively affect
the otters’ ability to successfully rear cubs, adjust to new/unusual situations, and maintain
mental/behavioral (as well as physical) health. See a discussion of these problems in Chapter 2
Section 3.
Miscellaneous: The necropsy of a 4 1/2 month old captive born male cub did not reveal the
cause of death. Although, before its death it was noted to have a “grayish circular spot –
about 1.5 cm [0.59”] in diameter” on its tail. This cub was also smaller and less developed
than its only sibling, its sister, who survived to independence. “Some days after birth, this
specimen showed very little signs of progress, compared with its sister and depended always on
its mother’s help for feeding until its death.” (Autuori & Deutsch 1977)
In captivity, giant otters have been reported to take up large mouth fulls of sand and it
appears that they also purposely (i.e. not by accident) swallowed sand as well. (A few
institutions have reported these occurrences.) Giant otters also have been reported to bite off
pieces of bark from large logs and it appears that these pieces were chewed up and
swallowed as well. On the rare occasion they also have been observed to chew on mulch (i.e.
tree bark) pieces and might have swallowed the rare piece as well. On other occasions they
have been seen to chew on and bite off pieces of wood on the corners of their wooden nestboxes
or the edges of other structures made of wood. No harm or health problems were reported to
have been caused by any of these actions. The otters do not seem to be able to bite on wood
structures that have no edges or no corners and there are no known reports that otters have done
such. It has not been proven necessary to line the inside of wooden transport crates with
fence/lattice when transporting giant otters and this is not advisable E.g. Giant otters have been
transported successfuly and without problems from distances as far as South America to Europe
when wooden transport boxes were not lined with fence/lattice. Exposure to fence/lattice on the
inside of crates could likely cause damage to the otters’ delicate sensitive foot pads, webbing
and/or skin.
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