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and symptomatic management (Hoole and Goddard, 2007). Although the effects of
D. typus
envenomation in dogs and humans appear very similar, there are differences
in management of envenomated dogs compared with that of humans, as discussed by
Leisewitz et al. (2004). Pet owners living within the range of
D. typus
or
Thelotornis
spp. should be aware of the possible threat posed by these snakes, and should take
appropriate precautions to protect their pets from envenomation.
4.3.1.4 Conclusion and Assessment of
D. typus
and
Thelotornis
spp.
As with the vast majority of bites from snakes in the artificial colubrid assemblage,
the most publicized bites are inflicted by these snakes while being handled by her-
petologists and amateur snake collectors. However, in some parts of Africa (e.g., the
Kenyan coast), local agricultural workers are occasionally bitten by
D. typus
. Many
documented bites from
D. typus
and
Thelotornis
spp. have produced life-threatening
clinical effects and fatalities typified by consumptive coagulopathy/DIC and hem-
orrhagic diathesis. The morphological adaptations outlined earlier combined with
high venom toxicity for humans endow these snakes with notable lethal potential.
Aside from a single documented case of moderate local effects from a
T. flavigula-
ris
bite, the clinical importance of other Dispholidini (
Rhamnophis
and
Thrasops
)
is unknown. Partial characterization of the transcriptome of
T. jacksoni
suggests an
array of toxins similar to those of
D. typus
. Therefore, other members of this tribe
should be approached with caution. Any bites from these snakes should be assessed
by a physician, and serial blood coagulation assays should be included in the assess-
ment of a patient bitten by any of these species.
Assessment of
D. typus
,
T. capensis
, and
T. kirtlandii
based on available evi-
dence: Hazard Level 1
(see
Table 4.3
).
4.3.2
Rhabdophis subminiatus
and
Rhabdophis tigrinus:
Background
and General Features of Documented Bites
The Asian natricid genus,
Rhabdophis
(the Asian keel-backs), consists of 18 spe-
cies. Of these, only
R. subminiatus
and
R. tigrinus
(Plates 4.45A-C and 4.46A and
B, respectively) have caused medically significant bites. These include several thor-
oughly documented fatal and life-threatening envenomations consisting of consump-
tive coagulopathy, DIC, hemorrhagic diathesis, anemia, AKI, and severe ecchymoses
(see Plate 4.46C;
Table 4.1
). For example, a 25-year-old Thai man was bitten five
times while feeding his pet
R. subminiatus helleri
in Ranong. He went to the local
hospital with bleeding gums and was inappropriately given 10 ampoules of Malayan
pit viper antivenom together with 6 units of fresh frozen plasma (FFP). On the sec-
ond day, his hand was swollen and, after 5 days, he was referred to Chulalongkorn
Hospital in Bangkok with incoagulable blood (PT
100, PTT
100 s). He was
treated with a further 14 units of FFP, 13 units of packed red blood cells (PRBCs),
10 units of cryoprecipitate, and, again inappropriately, with 24 ampoules of green
pit viper (
Cryptelytrops albolabris
) antivenom. After a further 5 days, the bleeding
stopped (Kijjirak et al., 1998). This was the first reported case of
R. subminiatus
