International Giant Otter Studbook Husbandry and Management

unpublished report 1997). His hind legs also appeared very stiff. He almost appeared as if he
was paralyzed in the hind end/lower back and legs, although otherwise he did not appear or act
sick. He progressively and dramatically improved within two hours and by the end of the day
he was able to walk fairly normally. During the day he progressively became less stiff in his
hind legs when he was walking. Throughout the day (after his dramatic recovery in the 2 hours
noted) he was active, playing, and appeared otherwise normal and ate well. On the next
morning he was a little stiff in the hind legs, but he was eating well and active and then he
appeared totally normal. No medical treatment or medications were administered for this
problem. This acute severe problem was reported to never occur again (this report was
concluded in June 2004).
Note: On three separate occasions, one occurring in March 1997, April 1997, and August 1997,
Banjo was observed with hind leg stiffness and was found shuffling his hind legs/feet on the
floor rather than lifting them normally off of the floor when he was walking. In March 1997
and April 1997, his brother named Rio, was found occasionally during these months also
exhibiting the same behaviors as just described in the last sentence. Since the last occurrences
noted, both of these otters exhibited the same problems as just aforementioned on rare occasions
in the summers and the winters that followed until at least June 1999 (when this report was
concluded). (Note: these animals did not display the aforementioned problems continually
throughout the day on which they were noted to occur. They only occurred over a short period
of time, usually this was after the animal first had risen from sleeping. This problem resolved
shortly, i.e. within a few to several minutes or more after the animal first moved about. This
problem had to be closely monitored or it could have been easily missed. E.g. it may or may not
have occurred before March 1997.) No medical care was given for these problems. The
physical problems that were reported to occur with both animals since the beginning of March
1997 were mild in their appearance compared to those that Banjo displayed on Feb. 1, 1997
which were severe in appearance. It seems reasonable to assume that these two types of
problems (i.e. those reported in the paragraph above vs. those in this paragraph) were not related
as they (comparatively) appeared very different in severity and one type was reoccurring and the
other occurred only once. It seems that the problem that occurred occasionally may be related
to the significant exposure that the animals had to hard surfaces or the significant amount that
the otters had to climb, or to both problems (see below). This might possibly have been the
early developmental stages of the on-going and progressive walking difficulties seen in some
giant otters that have been continually exposed to hard surfaces for long periods, i.e. three or
more years (although the giant otters with this ongoing health problem were not exposed to
situations where they had to climb).
In response to the Philadelphia Zoo’s inquiry about what factors may have caused the acute
severe problem seen displayed by Banjo on Feb. 1, 1997, the following was communicated.
Wünnemann (pers. comm. March 26, 1997) commented that he regards the hind legs as the
weak point of giant otters. He commented, in captivity they move much more on land than in
the wild and especially when they are moving on hard surfaces or climbing a lot there may be an
overload on the hind legs or the last part of the spine. [See in Chapter 2 Section 3A how
exposure to hard surfaces caused on-going walking difficulties among some giant otters and soft
surfaces were needed to resolve and prevent these problems.] In order to deal with
[avoid/reduce/resolve] problems involving the hind legs and lower back, Wünnemann advised
the following. Avoid that the animals become overweight, modify the enclosure so that the
otters do not have to regularly (daily) climb to access areas (they climb enough voluntarily
while playing), and give them a lot of area where they can exercise and move about on soft
surfaces. He also states that giant otters are very curious. If there is something that is of interest
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