International Giant Otter Studbook Husbandry and Management

Killed rabies vaccinations are given at 4 months of age and must be repeated annually (Petrini et
al 2001). Killed parvovirus and distemper vaccinations are given at 8, 12, and 16 weeks of age
and boosters are given annually thereafter (Petrini et al 2001).] The compiler/author of this
manual has found no scientific research on the safety, efficacy, and duration of immunity of any
vaccines used on giant otters specifically, although this is true with many vaccinated exotic
species. As well, only a few zoos have reported vaccinating their giant otters, so experience is
not widespread [see below].
Controversy continues over whether to vaccinate otters with killed or modified live distemper
vaccines. To avoid the possibility of vaccine-induced disease, killed virus distemper vaccines
are preferable over modified live virus distemper vaccines (Merck 1986; Wünnemann 1995;
Lewis 1995; Read & Meier 1996; Moore 1997). Modified live distemper vaccines have caused
vaccine-induced distemper in a “variety of mustelids” (Petrini et al 2001; Hinshaw et al 1996;
Lewis 1995). Killed distemper vaccines will not cause vaccine-induced distemper, although
they may not “stimulate a strong protective immune response”, “have not provided long-lived
protection”, and are not available in many countries. “There is marked variation between
species and individuals in their reaction to MLV [modified live virus] vaccines.” (Merck 1986).
There are some commercial varieties and strains of MLV distemper vaccines that should be
entirely avoided and a few that are considered/found more safe for some otter species (Lewis
1995; Petrini et al 2001; see Hagenbecks Tierpark below for giant otters specifically). For
example, “Live vaccines of canine or mink cell culture origin should be avoided as these are
capable of producing clinical disease in vaccinated mustelids. Non-Onderstepoort strain MLVs
of chicken embryo tissue culture origin should also be avoided for the same reason.” (Lewis
1995). “Ferret-virulent-MLV vaccines are poorly attenuated and therefore contraindicated for
use in any nondomestic carnivores.” (Merck 1986). In addition to the usual great cautions
needed when vaccinating exotic, previously unvaccinated, and young animals, “…caution is
advised in vaccinating wild-caught animals because of the possibility that they may have been
exposed to the virus and be incubating the disease.” (Merck 1986). This can be especially
critical for handreared orphaned wild giant otter cubs. A veterinarian must carefully evaluate
the risk of vaccine-induced distemper versus the actual chances of contracting distemper. The
compiler/author has found no reports of captive or orphaned handreared wild giant otters with
distemper.
Of 10 zoos / institutions surveyed (Sykes 1997-99) who hold / held giant otters in South
America, only one reported giving vaccinations of any kind (distemper vaccination - not
specified whether live or killed - given to one 18 month old otter held in Trinidad). In early
2000 although, reports indicated that at least one or more giant otters might have been
vaccinated for leptospirosis at Brasilia Zoo (Pimentel pers. comm.). Only two [Hagenbeck
Tierpark and Dortmund Zoo] of the five zoos outside of South America who hold / held giant
otters reported giving any vaccinations (see below). No killed distemper vaccine was available
within South America and at least two institutions there reported they did not vaccinate with
modified live distemper for fear of vaccine-induced distemper. Philadelphia Zoo (U.S.)
reported they did not vaccinate their adult giant otters (that were acquired from and previously
vaccinated at Hagenbecks Tierpark) because a killed distemper vaccine was unavailable in the
U.S.. The surveyor found one zoo that vaccinated with modified live distemper vaccine,
although this was on limited occasions and only after otters were vaccinated with initial killed
distemper vaccines (i.e. only after at least the initial 3 killed distemper vaccinations were
completed). (See Hagenbecks Tierpark Vaccination Schedule.) Vaccinations have been
administered by small blowpipe darts when the otter is confined in a den or by hand syringe
while the otter (a cub) is physically restrained (Dortmund Zoo, Osmann, pers. comm.).
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