Evaluation of the safety of fenbendazole in cats

OBJECTIVE: To evaluate the safety of fenbendazole in domestic cats. ANIMALS: 28 six- to seven-month old domestic short-hair cats. PROCEDURE: Cats were randomly assigned to 1 of 3 treatment groups or a control group (n = 7/group). Cats in the treatment groups were given fenbendazole at a dosage of 50, 150, or 250 mg/kg, PO, every 24 hours for 9 days; control cats were given a placebo. A fecal examination, coagulation tests, serum biochemical analyses, CBC, and urinalyses were performed before and 5, 9, and 21 days after initiation of treatment; cats were closely monitored for adverse reactions. After the last dose of fenbendazole was given, 4 control cats and 4 cats given fenbendazole at the highest dosage were euthanatized, and necropsies were performed. RESULTS: None of the cats developed any adverse reactions. For cats in the control and all treated groups, laboratory test results were within reference limits, and there were no significant differences in results of laboratory tests among groups. No gross or histologic lesions were identified in the control or treated cats that were euthanatized. CONCLUSIONS AND CLINICAL RELEVANCE: Fenbendazole administered to healthy cats at a dosage 5 times the dosage and 3 times the duration approved for use in dogs and wild felids did not cause any acute or subacute adverse reactions or pathologic changes. Results suggest that cats may be safely treated with fenbendazole.     

Rates of molecular evolution are linked to life history in flowering plants

Variable rates of molecular evolution have been documented across the tree of life, but the cause of this observed variation within and among clades remains uncertain. In plants, it has been suggested that life history traits are correlated with the rate of molecular evolution, but previous studies have yielded conflicting results. Exceptionally large phylogenies of five major angiosperm clades demonstrate that rates of molecular evolution are consistently low in trees and shrubs, with relatively long generation times, as compared with related herbaceous plants, which generally have shorter generation times. Herbs show much higher rates of molecular change but also much higher variance in rates. Correlates of life history attributes have long been of interest to biologists, and our results demonstrate how changes in the rate of molecular evolution that are linked to life history traits can affect measurements of the tempo of evolution as well as our ability to identify and conserve biodiversity.     

Determination of sarafloxacin residues in fortified and incurred eggs using on-line microdialysis and HPLC/programmable fluorescence detection

Isolation of sarafloxacin (SAR) from fortified and incurred chicken eggs was done by a combination of liquid-liquid extraction and aqueous on-line microdialysis performed on an automated trace enrichment of dialysates (ASTED) system. The ASTED system coupled a sample cleanup procedure with HPLC and programmable fluorescence detection. Overall recoveries of 87-102% for SAR were obtained from samples fortified over a range of 1-100 ng/g. The relative standard deviation values ranged from 22 to 26% for samples fortified between 1 and 5 ng/g and from 2 to 12% for samples fortified between 10 and 100 ng/g. The limits of detection and quantitation were 0.2 and 1 ng/g, respectively. Eggs containing incurred SAR, which were collected over a 3-day dosing period and for 5 consecutive days thereafter, also were analyzed by using this technique. Because the method is automated, 35 samples can be processed within a 24-h period, which enables large data sets to be acquired over a short time period.     

A survey of helminth parasites in backyard flocks in Michigan by litter examination

The prevalence of parasitic infections in backyard flocks was surveyed using litter samples from 74 pens located on 12 farms in central lower Michigan. Eight species of birds were represented. Two methods of litter examination (a sucrose flotation technique and a multiple washing/ZnCl2 flotation) were compared; the sucrose flotation technique was found to be more useful and was used in the survey. The following parasites eggs/oocysts were observed; ascarid-type eggs (in 34 pens from nine farms), Capillaria eggs (in 30 pens from nine farms), Strongyloides eggs (in nine pens from five farms), Syngamus eggs (in five pens from four farms), and coccidial oocysts (in 40 pens from 10 farms). Contamination of litter with ascarid-type eggs, Capillaria eggs, and coccidial oocysts was commonly found, irrespective of bird species. The contamination level in pens with more than one bird species was lower than in pens with a single species. The relatively high contamination rate may be an indication of the risk of parasitic disease in birds that are not raised under controlled conditions in confinement.     

天然饲料补充正辛酸减少商品肉鸡空肠弯曲菌的寄居

空肠弯曲菌能引起人类的食物性传染疾病,且流行病学研究也表明家禽及其产品是人类感染该疾病的重要来源。减少家禽肠道中的空肠弯曲菌会减少其对家禽产品的污染。正辛酸是中链脂肪酸,据报道其可有效杀死包括空肠弯曲菌在内的各种细菌性病原体,但对于已经寄居在商品肉鸡肠道中空肠弯曲菌的治疗效果还未见报道。试验旨在研究正辛酸对42日龄鸡盲肠中空肠弯曲菌的治疗效果。试验共设4个试验组。前两个试验组,     

Ejaculation does not contribute to the stress response to electroejaculation in sheep

Electroejaculation procedures (EEPs) provoke stress; nevertheless, ejaculation produces physiological changes similar as those usually used to measure stress responses. The application of EEP to animals that cannot ejaculate—as ewes—may be useful to discriminate the responses induced by ejaculation from those provoked by EEP. The aim was to determine the stress response to EEP in rams and ewes. The EEPs were applied to 10 rams and 10 ewes during the non‐breeding season, and the number of vocalizations, the heart rate, rectal temperature, serum cortisol concentration, biochemical and haematological parameters were measured. Overall, EEP provoked increases in cortisol concentration, glycaemia, rectal temperature and concentration of creatine kinase (all them: p < .0001) as well as relative concentration of granulocytes (p = .003) and absolute granulocyte concentration (p = .0002) in both, rams and ewes. Heart rate, relative concentration of lymphocytes (p = .001), haematocrit (p = .02) and haemoglobin (p = .045) decreased in animals from both genders after EEP. Besides, cortisol (p < .0001), rectal temperature (p = .002) and glycaemia (p = .001) were greater in ewes than rams, and creatine kinase also tended to be greater in ewes than rams (p = .054). On the other hand, the number of animals that vocalized (p = .006), white blood cells (p = .02) and absolute lymphocytes (p = .02) were greater in rams than ewes. The general trends show a similar pattern of stress responses in animals from both genders. Therefore, we concluded that ejaculation does not contribute to the stress response provoked by the EEP. This procedure also provokes muscular damage and probably pain.     

Comparison of methods for handling censored records in beef fertility data: field data

The purpose of this study was to compare methods for handling censored days to calving records in beef cattle data, and verify results of an earlier simulation study. Data were records from natural service matings of 33,176 first-calf females in Australian Angus herds. Three methods for handling censored records were evaluated. Censored records (records on noncalving females) were assigned penalty values on a within-contemporary group basis under the first method (DCPEN). Under the second method (DCSIM), censored records were drawn from their respective predictive truncated normal distributions, whereas censored records were deleted under the third method (DCMISS). Data were analyzed using a mixed linear model that included the fixed effects of contemporary group and sex of calf, linear and quadratic covariates for age at mating, and random effects of animal and residual error. A Bayesian approach via Gibbs sampling was used to estimate variance components and predict breeding values. Posterior means (PM) (SD) of additive genetic variance for DCPEN, DCSIM, and DCMISS were 22.6d2 (4.2d2), 26.1d2 (3.6d2), and 13.5d2 (2.9d2), respectively. The PM (SD) of residual variance for DCPEN, DCSIM, and DCMISS were 431.4d2 (5.0d2), 371.4d2 (4.5d2), and 262.2d2 (3.4d2), respectively. The PM (SD) of heritability for DCPEN, DCSIM, and DCMISS were 0.05 (0.01), 0.07 (0.01), and 0.05 (0.01), respectively. Simulating trait records for noncalving females resulted in similar heritability to the penalty method but lower residual variance. Pearson correlations between posterior means of animal effects for sires with more than 20 daughters with records were 0.99 between DCPEN and DCSIM, 0.77 between DCPEN and DCMISS, and 0.81 between DCSIM and DCMISS. Of the 424 sires ranked in the top 10% and bottom 10% of sires in DCPEN, 91% and 89%, respectively, were also ranked in the top 10% and bottom 10% in DCSIM. Little difference was observed between DCPEN and DCSIM for correlations between posterior means of animal effects for sires, indicating that no major reranking of sires would be expected. This finding suggests little difference between these two censored data handling techniques for use in genetic evaluation of days to calving.     

Threshold-linear analysis of measures of fertility in artificial insemination data and days to calving in beef cattle

Mating and calving records for 47,533 first-calf heifers in Australian Angus herds were used to examine the relationship between days to calving (DC) and two measures of fertility in AI data: 1) calving to first insemination (CFI) and 2) calving success (CS). Calving to first insemination and calving success were defined as binary traits. A threshold-linear Bayesian model was employed for both analyses: 1) DC and CFI and 2) DC and CS. Posterior means (SD) of additive covariance and corresponding genetic correlation between the DC and CFI were -0.62 d (0.19 d) and -0.66 (0.12), respectively. The corresponding point estimates between the DC and CS were -0.70 d (0.14 d) and -0.73 (0.06), respectively. These genetic correlations indicate a strong, negative relationship between DC and both measures of fertility in AI data. Selecting for animals with shorter DC intervals genetically will lead to correlated increases in both CS and CFI. Posterior means (SD) for additive and residual variance and heritability for DC for the DC-CFI analysis were 23.5 d2 (4.1 d2), 363.2 d2 (4.8 d2), and 0.06 (0.01), respectively. The corresponding parameter estimates for the DC-CS analysis were very similar. Posterior means (SD) for additive, herd-year and service sire variance and heritability for CFI were 0.04 (0.01), 0.06 (0.06), 0.14 (0.16), and 0.03 (0.01), respectively. Posterior means (SD) for additive, herd-year, and service sire variance and heritability for CS were 0.04 (0.01), 0.07 (0.07), 0.14 (0.16), and 0.03 (0.01), respectively. The similarity of the parameter estimates for CFI and CS suggest that either trait could be used as a measure of fertility in AI data. However, the definition of CFI allows the identification of animals that not only record a calving event, but calve to their first insemination, and the value of this trait would be even greater in a more complete dataset than that used in this study. The magnitude of the correlations between DC and CS-CFI suggest that it may be possible to use a multitrait approach in the evaluation of AI and natural service data, and to report one genetic value that could be used for selection purposes.