| General Description |
Hookworm
infections in other species may cause anaemia, haemorrhagic diarrhoea and
impaired absorption from the intestines; this may also occur in bears. As
with other species, it is likely that the most severe effects may be seen
in newborn cubs. (J345.3.w3)Clinical
signs
- Blood in faeces;
- Anorexia;
- Weight loss; severe infection may result in poor body condition.
(B16.9.w9,
B64.26.w5, B407.w18)
- Infection in young cubs can cause severe clinical signs. (B64.26.w5)
- In juveniles, hookworms may cause diarrhoea, anaemia and
debilitation, and can be fatal. (B22.32.w15)
Transmission
- Transmitted in the milk and can cause peracute disease. (B22.32.w15)
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| Further Information |
Occurrence
- "Occurs with some frequency in all ursids." (B64.26.w5)
- Hookworm Ancyclostoma malayanum was found in a Cinnamon bear
(Ursus americanus - American black bear).
(J4.155.w3)
- Dochmoides yukonensis was first described having been found
in the small intestine of Ursus americanus - American black bear
in the Yukon (J30.34.w1)
- In black bears (Ursus americanus - American black bear)
and grizzly bears (Ursus arctos - Brown bear)
from Alaska, two different hookworms were described in the small intestines, named as
Uncinaria yukonensis and Uncinaria rauschi, a new species.
(J30.46.w1)
- Dochmoides yukonensis were found in the small intestines of 10/21 bears
during a survey of grizzly bears (Ursus arctos - Brown bear)
from northern Canada, 1965-1967, with one to 475 hookworms per bear. (J30.47.w1)
- Uncinaria yukonensis were found in 6% of Ursus americanus - American black
bears during a study in Quebec, Canada, June 1971-November 1972.
(J1.13.w11)
- Uncinaria sp. were found in 17.3% (12/69) of bears during a
study of grizzly bears (Ursus arctos - Brown bear)
from Montana and Wyoming. Average intensity of infection was 128.8
worms per bear (range 1-900), which "suggests that it may
constitute a significant drain on the northern Montana grizzly
populations.".[1976](J345.3.w3)
- Uncinaria sp. hookworms were found in the small intestines of
1/30 bears (3.3%) during a study of Ursus americanus - American black
bears from Montana and Wyoming. In the one host there were 23
worms. [1976](J345.3.w3)
- Found at necropsy in in the small intestines of Ursus americanus - American black bear
in Chicago Zoological Park. (P1.1968.w4)
- Ancylostoma malayanum was described from Ursus torquatus, the Himalayan
bear (Ursus thibetanus - Asiatic black bear)
from India and Ceylon; it was noted that it had also been described previously from the Malay bear,
Helarctos malayanus - Sun bear.
(J92.4.w1).
- Ancylostoma caninum was found in 64% of small intestines during a survey of 22 Florida black bear
Ursus americanus floridanus
(Ursus americanus - American black bear)
cubs (up to 12 months old) between 1998 and 2003. (J11.90.w1)
- Ancyclostoma tubaeforme was found in 14% of small intestines during a survey of 22 Florida black bear Ursus americanus floridanus
(Ursus americanus - American black bear) cubs (up to 12 months old) between 1998 and 2003. This was a new host record for the
parasite. (J11.90.w1)
- Numerous hookworms, thought to be probably Uncinaria yukonensis,
were found in the small intestine of a female wild Ursus americanus - American black bear
during a study at Big Creek. (D274)
Treatment
- Treatment of choice:
- Ivermectin, 0.3 mg/kg subcutaneously (can also be used orally)
once, repeated at eight-week intervals. (B22.32.w15)
- Levamisole, 11 mg/kg subcutaneously (can also be used orally),
repeated as required. (B10.48.w45);
10 mg/kg orally or subcutaneously. Note: doubling the dose
reaches toxic levels. (B22.32.w15)
- Other drugs which are effective:
- Disophenol, 7.5 mg/kg by subcutaneous injection, repeated after
three weeks. Use with care in animals over 50 kg. (B10.48.w45)
- Dichlorvos (an organophosphate), 25 - 35 mg/kg orally, divided
into two doses, with half the dose given on each of two
consecutive days. (B10.48.w45);
15 mg/kg orally, repeated the following day. (B22.32.w15)
33-48 mg/kg orally in two or three divided daily doses. (B64.26.w5)
- Mebendazole, 15 mg/kg daily for two days. N.B. this is not
approved for use in carnivores. (B10.48.w45)
- Pyrantel emboate 25 - 60 mg/kg once orally. (B22.32.w15)
- Mebendazole, 5-15 mg/kg orally daily for three days. (B22.32.w15)
- Fenbendazole or febantel orally 50 mg/kg daily for three days or
20 mg/kg daily for five days. (B22.32.w15,
B407.w18)
- 10 mg/kg daily for two consecutive days effectively reduced
faecal egg counts to zero in Ursus arctos - Brown bear
and egg counts were still negative 30 days post treatment. (P1.1980.w4)
Prevention
- Prophylactic treatment with anthelmintics every four to eight weeks,
as for ascarid infections. (B22.32.w15)
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