Molecular survey of selected viral pathogens in wild leopard cats (Prionailurus bengalensis) in Taiwan with an emphasis on the spatial and temporal dynamics of carnivore protoparvovirus 1.

The leopard cat (Prionailurus bengalensis) was listed as an endangered species under the Wildlife Conservation Act in Taiwan in 2009. However, no study has evaluated the possible direct or indirect effects of pathogens on the Taiwanese leopard cat population. Here, we targeted viral pathogens, including carnivore protoparvovirus 1 (genus Protoparvovirus), feline leukemia virus (FeLV), feline immunodeficiency virus (FIV), coronaviruses (CoVs), and canine distemper virus (CDV), through molecular screening. The spatial and temporal dynamics of the target pathogens were evaluated. Through sequencing and phylogenetic analysis, we clarified the phylogenetic relationship of viral pathogens isolated from leopard cats and domestic carnivores. Samples from 23 live-trapped leopard cats and 29 that were found dead were collected from 2015 to 2019 in Miaoli County in northwestern Taiwan. Protoparvoviruses and CoVs were detected in leopard cats, and their prevalence (95% confidence interval) was 63.5% (50.4%-76.6%) and 8.8% (0%-18.4%), respectively. Most of the protoparvovirus sequences amplified from Taiwanese leopard cats and domestic carnivores were identical. All of the CoV sequences amplified from leopard cats were identified as feline CoV. No spatial or temporal aggregation of protoparvovirus infection in leopard cats was found in the sampling area, indicating a wide distribution of protoparvoviruses in the leopard cat habitat. We consider sympatric domestic carnivores to be the probable primary reservoir for the identified pathogens. We strongly recommend management of protoparvoviruses and feline CoV in the leopard cat habitat, particularly vaccination programs and population control measures for free-roaming dogs and cats.

Association of Human Q Fever with Animal Husbandry, Taiwan, 2004-2012.

In Taiwan, Q fever cases in humans began increasing in 2004 and peaked in 2007 but dramatically declined in 2008 and 2011. Cases were significantly correlated with the number of goats. The decline might be associated with the collateral effects of measures to control goat pox in 2008 and 2010.

Albumin and other metabolic parameters as potential indicators of purulent vaginal discharge in dairy cows during the transition period.

The aims of this study were to evaluate metabolic profiles obtained at -14, 14, and 28 days in milk (DIM), and to identify potential predictive biomarkers of Holstein dairy cows with purulent vaginal discharge (PVD) at 28 DIM. The body condition score (BCS) and hematocrit (Hct) were evaluated, and a metabolic profile test (MPT) was performed at -14, 14, and 28 DIM using serum samples. Cows at 28 DIM were classified using a vaginoscopy and divided into groups of healthy cows (n=89) and cows with PVD (n=31). Albumin (Alb), total cholesterol (TCho), calcium (Ca) and, magnesium (Mg) levels were lower in cows with PVD than in healthy cows at 14 DIM. At 28 DIM, levels of Alb, TCho, Ca, blood urea nitrogen (BUN), Mg, and Hct were lower in cows with PVD. A multivariate stepwise logistic regression analysis showed that higher non-esterified fatty acids (NEFA; odds ratios; OR=4.47; P<0.01), lower Alb (OR=0.07; P<0.01) and lower TCho (OR=0.99; P=0.08) at 14 DIM, and lower Hct (OR=0.83; P=0.05), lower Alb (OR=0.12; P<0.01), and lower BUN (OR=0.74; P=0.02) at 28 DIM were significantly associated with PVD. In conclusion, serum Alb levels was a potential indicator associated with PVD, reflecting dietary protein deficiency preceding disease. Our findings suggest that MPT should be considered to monitor health status during the postpartum period for early diagnosis of PVD.

The First Nationwide Surveillance of Severe Fever with Thrombocytopenia Syndrome in Ruminants and Wildlife in Taiwan.

Since the first discovery of severe fever with thrombocytopenia syndrome virus (SFTSV) in China in 2009, SFTSV has rapidly spread through other Asian countries, including Japan, Korea, Vietnam and Pakistan, in chronological order. Taiwan reported its first discovery of SFTSV in sheep and humans in 2020. However, the prevalence of SFTSV in domestic and wildlife animals and the geographic distribution of the virus within the island remain unknown. A total of 1324 animal samples, including 803 domestic ruminants, 521 wildlife animals and 47 tick pools, were collected from March 2021 to December 2022 from 12 counties and one terrestrial island. The viral RNA was detected by a one-step real-time reverse transcription polymerase chain reaction (RT-PCR). Overall, 29.9% (240/803) of ruminants showed positive SFTSV RNA. Sheep had the highest viral RNA prevalence of 60% (30/50), followed by beef cattle at 28.4% (44/155), goats at 28.3% (47/166), and dairy cows at 27.5% (119/432). The bovine as a total of dairy cow and beef cattle was 27.8% (163/587). The viral RNA prevalence in ticks (predominantly Rhipicephalus microplus) was similar to those of ruminants at 27.7% (13/47), but wild animals exhibited a much lower prevalence at 1.3% (7/521). Geographically the distribution of positivity was quite even, being 33%, 29.1%, 27.5% and 37.5% for northern, central, southern and eastern Taiwan, respectively. Statistically, the positive rate of beef cattle in the central region (55.6%) and dairy cattle in the eastern region (40.6%) were significantly higher than the other regions; and the prevalence in Autumn (September-November) was significantly higher than in the other seasons (p < 0.001). The nationwide study herein revealed for the first time the wide distribution and high prevalence of SFTSV in both domestic animals and ticks in Taiwan. Considering the high mortality rate in humans, surveillance of other animal species, particularly those in close contact with humans, and instigation of protective measures for farmers, veterinarians, and especially older populations visiting or living near farms or rural areas should be prioritized.

An in vitro comparison of antimicrobial efficacy and cytotoxicity between povidone-iodine and chlorhexidine for treating clinical endometritis in dairy cows.

This study aimed to assess the in vitro antimicrobial effects of chlorhexidine (CHX) and povidone-iodine (PI) on clinical isolates of Escherichia coli (E. coli) and Trueperella pyogenes (T. pyogenes) from the vaginal discharge of dairy cows, as well as to compare the cytotoxicity effects of CHX and PI on bovine endometrial epithelial cells (BEnEpC). In Experiment 1, 12 E. coli and 10 T. pyogenes were isolated from the vaginal discharge of cows with a uterine infection. The MIC and MBC against CHX and PI were analyzed in vitro. In Experiment 2, the cytotoxicity effects of CHX and PI on BEnEpC were analyzed using a Viability/Cytotoxicity Kit, wound scratch healing assay, and the expression of pro-inflammatory cytokine genes (IL-6, IL-8, and TNF-α). In Experiment 1, the MIC and MBC values of CHX against E. coli were 0.0002% and 0.0002 to 0.00025%, respectively. The MIC and MBC values of PI were 1.25 to 2.5% and 1.25 to 5%, respectively. For T. pyogenes, the MIC and MBC values of CHX were 0.00002%. The MIC and MBC values of PI were 1.25%. In Experiment 2, the cell viability significantly decreased, and wound closures were significantly inhibited after treatment with ≥ 0.002% CHX and ≥ 0.025% PI. The expression of IL-6, IL-8, and TNF-α significantly increased after treatment with PI. Only IL-6 showed a significant increase after cells were treated with 0.00002% and 0.0002% CHX. The results suggested that both CHX and PI had high antibacterial effects. However, veterinarians and farmers should be aware of their cytotoxicity, which decrease viability of endometrial epithelial cells and inhibit wound healing in vitro.

Prevalence of respiratory bacterial pathogens and associated management factors in dairy calves in Taiwan.

This study aimed to investigate the prevalence at both farm-level and calf-level and to identify the risk factors of respiratory bacterial pathogens in dairy calves in Taiwan. The status of bovine respiratory disease (BRD) was evaluated by using the Wisconsin scoring system from a total of 400 pre-weaned calves from 32 different farms in Taiwan, then the nasopharyngeal swabs were collected. The prevalence of respiratory pathogens was 84.37% at farm-level and 45.50% at calf-level, and Pasteurella multocida (P. multocida) was the most prevalent pathogen. The presence of Mycoplasma bovis (M. bovis), P. multocida, Mannheimia haemolytica (M. haemolytica) and Histophilus somni (H. somni) were all higher in BRD positive calves than BRD negative calves, but only in H. somni was significant (P<0.001). Then nine farm management risk factors were analyzed by using multivariate logistic regression models to determine the risk factors of respiratory bacterial pathogens (farm and calf-level). In the result at farm-level, only unheated colostrum was significantly associated with pathogen positive farms (Odds Ratio (OR)=11.43). At calf-level, the predominant risk factor for each pathogen, M. bovis, P. multocida, M. haemolytica and H. somni, was late first colostrum feeding (OR=272.82), unheated colostrum (OR=3.41), waste milk feeding (OR=6.59) and high pneumonia treatment cost (OR=2.52), respectively. For effective preventive measures, farmer education on milk and colostrum feeding are urgently warranted.

Cryptosporidium parvum infection and management-based risk factors of dairy calves in Taiwan.

Cryptosporidiosis is one of the major causes of diarrhea in calves. Cryptosporidium parvum is considered the most important calf diarrhea pathogen in the Cryptosporidium species. Not only could infected calves spread C. parvum, but infected adult cattle could also shed oocysts. The objectives of this study were (1) to investigate the prevalence of C. parvum in dairy herds in Taiwan, including calves, the dams in delivery enclosure, the floor, and the drinking water; (2) to clarify the relationship of diarrhea, management, and C. parvum infection. Twenty dairy herds in Taiwan were selected by random sampling, including 226 calves and 198 dams, and other environmental samples were collected. A questionnaire was filled out by the farm owners to collect information regarding the management of calves and the delivery enclosure. Hierarchical logistic regression was used to analyze the risk factors for C. parvum infection. The prevalence of C. parvum infection in calves was 26.5% (60/226), while in dams, it was 19.7% (39/198). The C. parvum infection in calves increased with environmental contamination of C. parvum and clinical signs of diarrhea, while it decreased with a yard provided in the delivery enclosure. In conclusion, the management of the delivery enclosure appears to be more important for preventing cryptosporidiosis in calves in Taiwan.

Epidemiological survey of Toxoplasma gondii and Neospora caninum infections in dairy goats in Central-Southern Taiwan.

Toxoplasma gondii and Neospora caninum are intracellular protozoan parasites that cause reproductive disorders in ruminants and humans. Information on the risk factors of T. gondii and N. caninum infections in goats is very limited in Taiwan. The aim of the study was to investigate the epidemiology and identify the risk factors of these two infections in goats. A total of 630 caprine sera were collected from 42 dairy goat farms and the owners were interviewed by a structured questionnaire. The apparent seroprevalences of T. gondii in farm- and individual- levels were respectively 88.1% and 32.22%, while those of N. caninum were 19.05% and 2.54%, respectively. Toxoplasma gondii B1 gene was identified in 7 feed samples and 8 from the water samples whereas N. caninum was not found. Wooden flooring was the main risk factor for T. gondii infection while the frequency of visits by staff to other farms and the breed of goat were risk factors for N. caninum. The improvement of flooring materials or thorough cleaning, periodic disinfection and maintenance of dryness on the floor are highly recommended for the prevention of T. gondii infection in farmed goats. In addition, unnecessary visits to other farms should be limited to prevent the spread of N. caninum. These factors should be highlighted for the prevention of T. gondii and N. caninum in goats, particularly when raised in intensive housing system with flooring on height.

Evidence that the dominant follicle of the first wave is more active than that of the second wave in terms of its growth rate, blood flow supply and steroidogenic capacity in cows.

To clarify the different characteristics of the dominant follicle (DF), the DF in first ovarian follicular wave (DF-1) after spontaneous ovulation and DF in second follicular wave (DF-2) and after induced ovulation of the first-wave DF by GnRH were examined in non-lactating Holstein cows. Follicular maturation of DF-1 and DF-2 were induced by PGF2α and GnRH treatment on Day 6 and 8 (Day 0=Day of follicular wave emergence), respectively. Follicular growth and blood flow (BF) in the follicular wall of DF-1 and DF-2 were examined. To analyze sex steroids in follicular fluid (FF) and amount of mRNA in granulosa cells, DF-1 and DF-2 were aspirated on Day 8 or 9 in different estrous cycle. Diameter in DF-1 was larger than DF-2 on Day 8 and 9. From Day 8 to 9, BF area (BFA) and percentage of the follicular wall with BF, which represents the degree of distribution of BF, increased in DF-1 but not in DF-2. BFA per length of follicle circumference with BF, which represents the thickness of BF, was not different between DF-1 and DF-2. Concentrations of 17ß-estradiol (E2) in plasma, E2 and androstendione in FF and amounts of LH receptor mRNA were greater in the DF-1 on Day 8. Gene expression for steroidogenesis, prostaglandin synthesis and angiogenesis did not differ between DF-1 and DF-2. These results indicated that DF-1 were more active than DF-2 in growth, BF supply and steroidogenesis. The greater BFA observed in the DF-1 may be derived from as a result of the greater vascularity in the follicular wall.

Slow recovery of blood glucose in the insulin tolerance test during the prepartum transition period negatively impacts the nutritional status and reproductive performance postpartum of dairy cows.

In peripartum dairy cows, insulin resistance (IR) increases to adjust the direction of energy to lactation after calving. To investigate the effect of prepartum IR on postpartum reproductive performance, the insulin tolerance test (ITT) was applied to 15 cows at 3 weeks (Pre21) and 10 days (Pre10) before the predicted calving date. Blood glucose area under the curve (AUC(glu)) within 120 min after administration of 0.05 IU/kg-BW insulin was calculated. The occurrence of first ovulation, days to first artificial insemination (AI) and first AI conception rate were recorded. Nutritional status postpartum was evaluated by blood chemical analysis. Based on AUC(glu) changes from Pre21 to Pre10, cows were classified into either the AUC-up group (AUC(glu) increase, n=5) or the AUC-down group (AUC(glu) decrease, n=10). There was no difference in the decrease in blood glucose at 30 min after insulin injection between groups, although glucose recovery from 30 to 60 min during the ITT was slow at Pre10 in the AUC-up group. The AUC-up group had a higher number of days to first AI and high glucose, total protein, globulin, γ-glutamyltransferase, triacylglycerol levels and a low albumin-globulin ratio at the 14th day postpartum. The present study infers that prepartum slow glucose recovery rather than insulin sensitivity might increase the potential for subclinical health problems postpartum and thus suppress reproductive performance. During the prepartum transition period, glucose dynamics in the ITT can be considered as a new indicator for the postpartum metabolic status and reproductive performance of dairy cows.