Browsing by Author "Vallee E"

Now showing 1 - 4 of 4
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    Detection of Foot-and-Mouth Disease Virus in the Absence of Clinical Disease in Cattle and Buffalo in South East Asia
    (Frontiers Media S.A., 2021-07-23) Buckle K; Bueno R; McFadden A; van Andel M; Spence R; Hamill C; Roe W; Vallee E; Castillo-Alcala F; Abila R; Verin B; Purevsuren B; Sutar A; Win HH; Thiha M; Lwin KO; Khounsy S; Phonthasy S; Souriya V; Keokhamphet C; Arzt J; Ludi A; Mioulet V; Capozzo AV
    Foot-and-mouth disease virus (FMDV) is widespread throughout much of the world, including parts of South East Asia. Surveillance is often limited in endemic areas, relying predominantly on passive outbreak reporting. As part of the World Organisation for Animal Health (OIE)'s South East Asia and China Foot-and-Mouth Disease Project (SEACFMD), field sampling was performed to help understand evidence of widespread virus exposure observed in previous studies. Serum and dry mucosal swabs were collected to evaluate the presence of FMDV RNA on the nasal, oral, and dorsal nasopharyngeal mucosal surfaces of 262 healthy cattle (n = 84 in Laos; n = 125 in Myanmar) and buffalo (n = 48 in Laos; n = 5 in Myanmar) immediately following slaughter in three slaughterhouses. Swabs and serum were tested by the OIE/FAO World Reference Laboratory for foot-and-mouth disease (WRLFMD) using pan-serotypic real-time reverse transcription-PCR (rRT-PCR) and serum was evaluated using the FMD PrioCHECK non-structural protein (NSP) ELISA. In total, 7.3% of animals had detectable FMDV RNA in one or more of the three sites including 5.3% of nasopharyngeal swabs, 2.3% of oral swabs, and 1.5% of nasal swabs. No FMDV RNA was detected in serum. Overall, 37.8% of animals were positive for NSP antibodies, indicating likely past natural exposure to FMDV. Results were comparable for Laos and Myanmar, and for both cattle and buffalo, and were not significantly different between age groups. Detectable FMDV RNA present on the oral and nasal mucosa of clinically-healthy large ruminants in Laos and Myanmar demonstrates the importance of sampling asymptomatic animals as part of surveillance, and may indicate that subclinical infection plays a role in the epidemiology of FMD in these countries.
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    Molecular characterisation and additional morphological descriptions of Eimeria spp. (Apicomplexa: Eimeriidae) from brown kiwi (Apteryx mantelli Bartlett).
    (Springer Nature, 2023-06-01) Coker SM; McInnes K; Vallee E; Biggs P; Pomroy WE; Howe L; Morgan KJ
    Brown kiwi (Apteryx mantelli Bartlett), a ratite endemic to New Zealand, is currently listed as "Vulnerable" under the IUCN classification system due to predation by introduced mammals. Operation Nest Egg (ONE) raises chicks and juveniles in predator-proof enclosures until they are large enough to defend themselves. These facilities experience an environmental accumulation of coccidial oocysts, which leads to severe morbidity and mortality of these kiwi. Four species of coccidia have been morphologically described from sporulated oocysts with additional opportunistic descriptions of endogenous stages. This research continues the morphological descriptions of these species of Eimeria with an additional novel morphotype also morphologically described. It also provides the first genetic characterisation targeting the mitochondrial cytochrome c oxidase I (COI) gene. Based on these findings, it was determined there are at least five morphotypes of Eimeria that infect brown kiwi and co-infections are common at the ONE facilities surveyed. The COI amplicon targeted for this study was sufficient to provide differentiation from other members of this genus. Sanger sequencing yielded ambiguous bases, indicating the need for more in-depth sequencing.
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    Prevalence and incidence rate of clinical lameness in three New Zealand dairy goat farms
    (Taylor and Francis Group, 2024-01-01) Jaques N; Turner S-A; Vallee E; Heuer C; Deeming L; Lopez-Villalobos N
    Clinical lameness has an impact on animal welfare and profitability in different livestock industries. The objective of this study was to estimate the prevalence and incidence rate of clinical lameness within New Zealand dairy goat farms. Up to 3246 goats on three dairy goat farms were observed 4–5 times over one year. Data on locomotion scores and animal information were collected between June 2019 and June 2020. A 5-point (0–4) locomotion scoring scale was used, where scores 3 and 4 were classified as clinical lameness. The average herd-level prevalence of clinical lameness for farms A, B, and C were 23, 12, and 10%, respectively. The annual incidence rate of clinical lameness for farms A, B, and C were 104, 56, and 55 cases per 100 goat-years, respectively. Lameness appears to be a significant welfare issue, with incidence varying between farms and between goats. Investigating both farm-level and goat-level factors is required to understand the epidemiology of lameness and design evidence-based control and prevention measures. Further investigation should be undertaken to identify variables affecting the goat's odds of becoming clinically lame. This study sets the foundation for future study of lameness in commercial dairy goat farms nationally and internationally.
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    Ultrasonographic features of the regressing yolk sac of normal captive Brown kiwi chicks (Apteryx mantelli) vary with age.
    (John Wiley and Sons, Inc., 2023-09-01) Short E; Owen M; Vallee E; Bolwell C; Morgan KJ
    Brown kiwi (Apteryx mantelli) are a culturally significant ratite species endemic to New Zealand. Chicks can develop diseases of the yolk sac which can be fatal if not promptly recognized and treated. Ultrasound examination of the yolk sac is an important component in the evaluation of chicks with suspected yolk sac disease. However, there are currently no reports of the normal ultrasonographic appearance of the regressing yolk sac in this species. The objective of this prospective reference interval study was to describe the normal ultrasonographic appearance of the yolk sac in brown kiwi chicks. Focused coelomic sonographic examinations were performed on 29 healthy chicks from >1 day of age until the yolk sac was completely absorbed or was <1 mL in volume. 41.6% (57/137) of yolks were round/ovoid in shape and 58.6% (80/137) had lobulated margins with invaginations. All yolks (137/137) were hyperechoic relative to adjacent coelomic structures. The heterogeneity of the echogenicity of the yolk was significantly associated with age (increased heterogeneity in younger birds) and was homogeneous, mildly heterogeneous, and moderately heterogeneous in 33% (46/138), 46% (63/138), and 21% (29/138) of all examinations respectively. Intrasac anechoic pockets were seen in 14% (20/139) of yolk sacs. The rate of yolk sac resorption slowed with age. In all examinations identifying a completely absorbed yolk sac or a yolk sac <1 mL in volume, chicks were less than 21 days old. The results of this study provide a reference of normal for the sonographic appearance of the yolk sac in captive brown kiwi chicks.