International Giant Otter Studbook Husbandry and Management

provided as recommended, so that otters can not only relieve their stress, but they can also avoid
damaging their feet. Digging is a strong natural behavior that behaviorally healthy giant otters,
such as these animals, typically carry out frequently throughout the day and throughout their
entire enclosure. They will likely, with an extraordinarily high/excessive degree, dig throughout
their entire enclosure during stressful or unusual events to relieve and/or counteract stress. See
Part B below.) Because these otters' enclosures had appropriate land to water ratios and soft
substrates the otters would have been able to recover from this unhealthy foot condition within
the same enclosure. The animals were young when they were separated from their parents and
they were almost 2 years old when they were observed with off-white/light pink pads in 1998.
The aforementioned mates were separated multiple times during their lives and they were old
when first observed in 1998. Detailed information about these events are not known. The otters
with healthy normal (i.e. brown pads etc.) were not known to be separated as aforementioned.
The otters observed at the other five zoos were also young to very late in age and observations
did not include cubs 1 . This included ten otters that were observed closely enough to determine
foot condition, between the years 1996-2004. At these zoos, every otter throughout the majority
or all of its lifetime, except for one, was either kept on all (in at least one zoo), mostly, or at
least “some” hard surfaces. (I.e. “Some” means, the greater portion of the total enclosure land
and floor area at these zoos are/were covered with soft substrates. Two of these zoos, in
addition to their outdoor exhibits with soft substrates, had indoor housing with no or very little
soft substrates on their concrete floors.) As well, some of these enclosures had insufficient land
area because of inappropriate land to water ratios. All of the otters in these five zoos, except for
the one just aforementioned, were observed to have pink toe/foot pads of varying severity or
worse foot conditions. The more hard surfaces that the otter was exposed to, the worse the foot
condition appeared. In the cases where the otters were also exposed to coarse, entirely
damp/wet surfaces, or/and a lack of sufficient land area because of improper land to water
ratios, foot condition appeared significantly worse. (These foot conditions were comparable to
those listed in the general description pages above.) During this study four of these individuals
recovered from having unhealthy feet, which they had for a long time. After recovery they had
off-white/light pink color toe and foot pads and the remaining parts of their feet appeared
healthy (i.e. brown etc.). These otters achieved this significant degree of recovery only after
they were housed in enclosures where the land and floor areas were nearly entirely covered with
mulch and/or soft sand as recommended and land to water ratios were appropriate. Their
recovery took place at Dortmund Zoo. The enclosure conditions that these recovered animals
were housed in during recovery, are aforementioned in the paragraph that introduced this
comparison study. It is important to note that previously before these enclosures were modified,
they had inappropriate substrates/surfaces as described in the beginning of this paragraph and
one enclosure also had insufficient land area because of improper land to water ratios (see
below). These four otters as well were originally housed in one or more of the other four
institutions described in this paragraph, in addition to being housed at Dortmund. 1 “Cub” refers
to a giant otter that is between approx. one day to six months old.
Groenendijk, on a visit to Dortmund Zoo, pointed out, after viewing five giant otters held in
three different enclosures at this institution, that one of the otters had foot and toe pad,
webbing, and skin condition comparable to that of a wild giant otter. This particular otter’s
entire feet (top and bottom) were/are brown in color and very healthy and natural in appearance.
This otter was the individual that was housed throughout its lifetime in enclosures nearly
entirely covered with soft substrates. (I.e. she was held in Dortmund's modified/appropriate
enclosures and at Brasilia Zoo.) In regards to the foot condition of the other four otters
Groenendijk observed at that time, their foot and toe pads were off-white/light pink in color.
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