International Giant Otter Studbook Husbandry and Management

to them and happening in an area where they must stand upright on their hind legs to see it, they
may have to stand upright for long periods to satisfy their curiosity because there is no other
possibility for the otters to look at something interesting without standing. He advised to
monitor such situations. [Wünnemann also reported (pers. comm. 2003) stairs or any
structure/surface that otters must climb every day in a significant manner to access or utilize it
should not be used in enclosures. Note: climbing stairs or the other surfaces/structures as
aforementioned is not the same as other forms of climbing. Captive giant otters often climb
onto and lay on the top of their nestboxes and large diameter logs, tree stumps etc. This
behavior is natural (they climb and lay on large fallen trees in the wild), they enjoy it, and it is
not harmful to their health.] Dr. Osmann (pers. comm., April 6, 1997), of the Dortmund Zoo in
Germany, also communicated: A relationship between vitamin E deficiency and hind leg
paralysis is something else that should be considered for this acute problem. [Note: a vitamin
B1 (thiamine) deficiency may also cause similar problems and should be considered.] See
under “Dietary Related Problems” above for more information on vitamin deficiencies.
At Philadelphia, the majority of the entire land area (including that within the indoor and
outdoor enclosures) that the otters were exposed to daily was hard. No changes were made to
the indoor or outdoor enclosure surfaces from April 29, 1996 (when they arrived at
Philadelphia) until at least June 1999 when this report was concluded. Also, the outdoor land
area was very limited/very small in size as the land to water ratio offered a significantly smaller
land proportion than what is recommended. (Update: In late 2002 or early 2003 and based upon
the recommendations made in the giant otter studbook husbandry guidelines, within the indoor
enclosure, mulch was added to completely cover over the concrete floors, a deep digging area
made of mulch was also provided, and an additional den area was added to help increase the
amount of land area.) The giant otters were also exposed to various areas within their indoor
enclosure, which they had access to every day, that they had to regularly climb to access and
use. One enclosure modification was made (in approx. 4/1997) to reduce the amount of
climbing, although this change did not significantly limit climbing and it had to be removed (see
below) and other changes to do such could not be made. The otters therefore still climbed a
significant amount on a daily basis from 4/1996 until at least 6/1999. For example, the otters
had to climb vertically a height of 92 cm (3 ft.) to enter their small indoor above ground swimtank
which they used frequently. They sometimes used the single step provided to access the
tank. Though a wooden ramp was installed to reduce climbing, the otters rarely used it and
instead they chose to access the tank as before. The ramp was removed later. As well, to access
all of their dens in the indoor enclosure the otters regularly (i.e. frequently) had to climb up and
down concrete rockwork, which was a nearly vertical incline of approx. 130 cm ( 4.3 ft) in
height, that separated the dens. The rockwork formed an uneven surface creating various
artificial rocks that could be climbed on. This area could not be modified, so the otters
continued climbing there. A very large tub (with a single access step), that extended 61 cm (2
ft.) above the den floor, was also climbed into frequently and it was not removed.
At Philadelphia, fresh-water fish formed the main part of the giant otters’ diet, although saltwater
fish were fed for variety. In 2/1997, Toddes modified the diet offered in consideration of
the possibility of vitamin deficiencies. Although the otters were not overweight, the amount of
fish offered was reduced in Feb.-March/1997 (as a significant amount of fish that was offered
was normally left in the enclosure uneaten). (See their body weights listed in Table 7.) The
amount of vitamin B1 and E previously offered in their diet were increased as follows.
Previously given were one 50 mg vitamin B 1 tablet per otter daily and one 400 IU vitamin E
geltab and one tablet of K-dec (multiple vitamin & mineral for adult humans) per otter 3
times/week. In February 1997 this was changed and the following was given: one 100 mg
50