A cross-sectional survey of population demographics, the prevalence of major disease conditions and reason-specific proportional mortality of domestic cattle in the Kingdom of Bhutan

A knowledge, attitudes, and practices study on ticks and tick-borne diseases in cattle among farmers in a selected area of eastern Bhutan

Livestock farming plays an important role in supporting the livelihood of resource-poor subsistence farmers in Bhutan. However, ticks and tick-borne diseases (TBDs) are one of the major constraints to livestock farming due to their negative effect on health and production. To date, no study has been conducted in Bhutan to assess farmers' knowledge, attitude, and practices (KAP) about ticks and TBDs in cattle, although such information is essential in ensuring the development and adoption of effective prevention and control measures. Therefore, a KAP survey was conducted among 246 cattle owners in the Samkhar sub-district of eastern Bhutan in June 2019, using a structured questionnaire. Based on our scoring criteria, 52% [95%CI: 45.5-58.4] had adequate knowledge about ticks as potential vectors of diseases. Logistic regression analysis showed that the individuals who practiced a stall-feeding system of cattle rearing were 2.8 times [OR = 2.8 (95%CI: 1.66-4.78)] more likely to have adequate knowledge than others. Sixty-eight percent [95%CI: 62.5-74.4] had a favorable attitude toward tick prevention and control programs. Men were 1.95 times [OR = 1.95 (95%CI: 1.09-3.55)] more likely to have a favorable attitude than women, and the individuals who practiced a stall-feeding system were 2.59 times [OR = 2.59 95%CI: 1.45-4.78)] more likely to have a favorable attitude than others, after adjusting for the effect of other variables in the model. Overall, only 38% [95%CI 32.5-45] of the respondents reported tick infestation as one of the most important animal health problems, but 100% reported using acaricides to control ticks in cattle. Despite a high level of acaricide usage, the level of knowledge was low among the farmers interviewed. Findings from this study underline the importance of considering identified knowledge gaps and initiating education efforts to improve the adoption of effective tick prevention and control measures among farmers.

Identification, Distribution, and Habitat Suitability Models of Ixodid Tick Species in Cattle in Eastern Bhutan

Tick infestation is the most reported parasitological problem in cattle in Bhutan. In May and June 2019, we collected ticks from 240 cattle in two districts of Eastern Bhutan. Tick presence, diversity, and infestation prevalence were examined by morphological identification of 3600 live adult ticks. The relationships between cattle, geographic factors, and infestation prevalence were assessed using logistic regression analyses. Habitat suitability for the tick species identified was determined using MaxEnt. Four genera and six species of ticks were found. These were Rhipicephalus microplus (Canestrini) (70.2% (95% confidence interval (CI): 68.7-71.7)), Rhipicephalus haemaphysaloides Supino (18.8% (95% CI: 17.5-20.1)), Haemaphysalis bispinosa Neumann (8.2% (95% CI: 7.3-9.1)), Haemaphysalis spinigera Neumann (2.5% (95% CI: 2-3)), Amblyomma testudinarium Koch (0.19% (95% CI: 0.07-0.4)), and a single unidentified Ixodes sp. Logistic regression indicated that the variables associated with infestation were: longitude and cattle age for R. microplus; latitude for R. haemaphysaloides; and altitude and cattle breed for H. bispinosa and H. spinigera. MaxEnt models showed land cover to be an important predictor for the occurrence of all tick species examined. These findings provide information that can be used to initiate and plan enhanced tick surveillance and subsequent prevention and control programs for ticks and tick-borne diseases in cattle in Bhutan.

Revisiting an old disease? Risk factors for bovine enzootic haematuria in the Kingdom of Bhutan

Bovine enzootic haematuria (BEH) is a debilitating disease of cattle caused by chronic ingestion of bracken fern. Control of BEH is difficult when bracken fern is abundant and fodder resources are limited. To fill a significant knowledge gap on modifiable risk factors for BEH, we conducted a case-control study to identify cattle management practices associated with BEH in the Bhutanese cattle population. A case-control study involving 16 of the 20 districts of Bhutan was carried out between March 2012 and June 2014. In Bhutan sodium acid phosphate and hexamine (SAP&H) is used to treat BEH-affected cattle. All cattle greater than three years of age and treated with SAP&H in 2011 were identified from treatment records held by animal health offices. Households with at least one SAP&H-treated cattle were defined as probable cases. Probable case households were visited and re-classified as confirmed case households if the BEH status of cattle was confirmed following clinical examination and urinalysis. Two control households were selected from the same village as the case household. Households were eligible to be controls if: (1) householders reported that none of their cattle had shown red urine during the previous five years, and (2) haematuria was absent in a randomly selected animal from the herd following clinical examination. Details of cattle management practices were elicited from case and control householders using a questionnaire. A conditional logistic regression model was used to quantify the association between exposures of interest and household BEH status. A total of 183 cases and 345 controls were eligible for analysis. After adjusting for known confounders, the odds of free-grazing for two and three months in the spring were 3.81 (95% CI 1.27-11.7) and 2.28 (95% CI 1.15-4.53) times greater, respectively, in case households compared to controls. The odds of using fresh fern and dry fern as bedding in the warmer months were 2.05 (95% CI 1.03-4.10) and 2.08 (95% CI 0.88-4.90) times greater, respectively, in cases compared to controls. This study identified two husbandry practices that could be modified to reduce the risk of BEH in Bhutanese cattle. Avoiding the use of bracken fern as bedding is desirable, however, if fern is the only available material, it should be harvested during the colder months of the year. Improving access to alternative fodder crops will reduce the need for householders to rely on free-grazing as the main source of metabolisable energy for cattle during the spring.