Distribution and Hosts of the Ruminant Parasite Teladorsagia davtiani Andreeva and Satubaldin, 1954 (Nematoda: Trichostrongylidae) in the United States

Becklund, Willard W.

doi:10.2307/3275219

Cited by 5 publications

(5 citation statements)

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“…Clinical signs would be expected to parallel those described for hookworm disease and anemia typical of other ruminants but are unlikely to be observed due to the low numbers of parasites usually present in parasitized hosts (Prestwood and Pursglove 1981). Becklund (1964) and Rickard and Bishop (1991). bMinor morphotypes for polymorphic species of ostertagiines are not listed.…”

Section: Monodontus Louisianensismentioning

confidence: 98%

“…Contrary to Worley and Sharman (1966), nematodes depicted in photomicrographs of tissue sections were mature adults rather than parasitic stages of larvae. This ostertagiine is known from cattle in Wyoming, Montana, and Colorado (Becklund 1964;Lichtenfels and Pilitt 1991).…”

Section: Ostertagia Bisonismentioning

confidence: 99%

“…This is primarily a parasite of the abomasum in A. americana from western North America and is seldom observed in O. hemionus and O. canadensis. There have been subsequent records from domestic sheep in this region, but none from cattle (Becklund 1964). It has been suggested that the occurrence of this nematode in domestic stock is dependent on the presence of pronghorn (Lucker and Dikmans 1945).…”

Section: Monodontus Louisianensismentioning

confidence: 99%

“…Additionally a concern is its potential for crosstransmission from cervids and its association with ostertagiosis in cattle in the United Kingdom and New Zealand (Borgsteede 1982;Hoberg et al 1993b). Ostertagia mossi and the associated minor morphotype, O. dikmansi, have a distribution restricted to eastern North America and have only been reported from white-tailed deer (Dikmans 1931;Becklund andWalker 1967b, 1968;Pursglove 1981, Forrester 1992;Hoberg et al 1993b); it appears to be absent in the southeastern United States. Morphologically, this species is difficult to distinguish from O. leptospicularis, but can be identified based on the structure of the genital cone and terminal processes of the spicules in males (Hoberg et al 1993b).…”

Section: Ostertagia Bisonismentioning

confidence: 99%

See 3 more Smart Citations

Gastrointestinal Strongyles in Wild Ruminants

Hoberg¹,

Kocan²,

Rickard³

2001

Parasitic Diseases of Wild Mammals

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Section: Monodontus Louisianensismentioning

confidence: 98%

Section: Ostertagia Bisonismentioning

confidence: 99%

Section: Monodontus Louisianensismentioning

confidence: 99%

Section: Ostertagia Bisonismentioning

confidence: 99%

See 2 more Smart Citations

Gastrointestinal Strongyles in Wild Ruminants

Hoberg¹,

Kocan²,

Rickard³

2001

Parasitic Diseases of Wild Mammals

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“…Within the male nematode population, three morphotypes exist; the predominant T. circumcincta morph and the minor morphs T. davtiani and T. trifurcata. This study examined the frequency of the minor male morphs and their association with the host and nematode infra-population, which is more detailed than most surveys that tend not to differentiate between the minor morphs (Becklund, 1962; Lichtenfels & Hoberg, 1993; Drozdz, 1995). Considering the fact that intensity of Teladorsagia varies with host age, it is interesting to note that the three morphotypes always occurred in more or less fixed proportions.…”

Section: Discussionmentioning

confidence: 99%

Sex ratio and morphological polymorphism in an isolated, endemicTeladorsagia circumcinctapopulation

2009

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Teladorsagia circumcincta is a polygamous nematode that exhibits morphological polymorphism. Sex ratio is typically female biased and the male nematodes occur in association with the genetically similar, minor morphotypes Teladorsagia davtiani and Teladorsagia trifurcata. In experimental infections, sex ratio (proportion male) and the proportion of minor male morphs observed have been shown to be influenced by both host and nematode-related factors. As similar investigations from natural systems are rare, this study examined whether sex ratio and minor male morph frequency were associated with host age and sex and nematode infra-population size in the isolated Soay sheep population on St Kilda. Count data for Teladorsagia were analysed for sheep of all age classes and both sexes from the winters of three consecutive population crashes (1999, 2002 and 2005). Generally, the intensity of Teladorsagia nematodes increased with host age until the age of 2 years before decreasing. In 2005, abundance of nematodes was generally higher than in the previous crashes, nematode sex ratio was negatively associated with host age and tended to be negatively associated with nematode intensity. Within the male nematode subpopulation, T. circumcincta always predominated, followed by T. davtiani and then T. trifurcata, with little variation in the relative proportions between hosts. The presence of each minor morph was primarily associated with the intensity of male T. circumcincta and, in those hosts where all three male morphs were detected, intensity of each minor morph was most associated with intensity of Teladorsagia females. Therefore, in a year when the nematode was generally more abundant, sex ratio appeared to be influenced by both host and nematode-related factors, whereas in all years examined, the frequency of morphological polymorphism was primarily density dependent.

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