International Giant Otter Studbook Husbandry and Management

they could cause similar walking difficulties/abnormalities (Wünnemann, pers. comm. 2003).
They are also difficult for otters to use. (Climbing stairs or the other structures/surfaces
aforementioned should not be confused with other types of climbing which giant otters naturally
do in captivity and in the wild. E.g. giant otters often climb onto the top of their nestboxes,
large logs, tree stumps, etc. and this is not harmful to their health.) See Chapter 2 Section 12 for
more information on stairs etc.. Although the known number of giant otters that recovered as
aforementioned were limited, the results obviously indicate that the chance that other
individuals can make similar recoveries, if given such an opportunity, is very significant and
therefore reasonable conclusions can be drawn.
Some of the affected otters, in addition to hard surfaces as described, also did not have any
digging areas and they did not have sufficient land area (i.e. the enclosure land to water area ratio
allowed for little land area). (Two of these otters, one severely affected and one moderately
affected, recovered as aforementioned after being provided with the new living conditions
described above.) The inability to exercise the body in the natural manner done when digging
into soft loose substrates or using the land area in other normal ways may also have contributed
to the development of this physical problem. Without sufficient and comfortable land and
digging areas otters will/can not use their bodies to their full normal physical
extent/capability and they can/will not carry out the full range or extent of innate
terrestrial activities that are possible in captivity (i.e. exercising, playing, digging, and
grooming throughout the entire expanse of their land area). Hard surfaces are
uncomfortable and insufficient land area literally limits the physical space that otters have
available to freely use the land to play, exercise, dig, and groom on. This is just one reason
why appropriate land to water ratios (esp. in enclosures around or below 240m² [2,583 ft²])
and sufficient size digging areas are also crucial.
It is important to note that when walking difficulties develop gradually and progressively the
early stages of development could be easily missed if the animals are not closely monitored and
these observations are not recorded in detail so that a progression can be detected. For example,
in the early stages these animals may only display symptoms, e.g. stiffness of the hind legs, over
a very short period of time, such as only after the animal has first risen from sleeping. The
problem could then resolve shortly, e.g. within a few to several minutes or more after the animal
first moved about. Problems may also be seen to occur only on days with rain or colder
temperatures. This may occur at first, only rarely or occasionally, but it may develop to greater
problems in the following months/years if the enclosure conditions causing these problems are
not changed.
“Intervertebral disc disease is … [a] common entity reported in …otters, and other
mustelids. Exhibit space, housing, handling procedures and activity can predispose animals
to vertebral problems and should be carefully evaluated.” (Petrini 2001). “Degenerative
spinal conditions are not uncommon in older animals [mustelids]. …Spinal arthritis or
spondylosis deformans has been seen in many old mustelids, including … otter in the UK.”
(Lewis 1995). It is interesting to note that two 14.5 year old giant otters (i.e. this is very old)
housed at one institution (Brasilia Zoo), were observed to have no walking problems /
difficulties (Gatz, pers. comm. 2002). This male and female are each housed in (two
separate) 635 m 2 (6,835 ft²) enclosures with expansive land areas (85% land) nearly
entirely covered with soft loose natural substrates and an ample pool area. These otters have
dug many underground dens in the plentiful hillsides/banks that are also provided. They have
lived in these enclosures for their entire lives and the male successfully reared multiple litters
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