Pathogenesis of blue fox parvovirus on blue fox kits and pregnant vixens

To study the pathogenicity of a newly isolated parvovirus of blue fox (Alopex lagopus), pregnant vixens and 43 kits of different ages were experimentally infected with the agent. The kits had no clinical signs of disease, even though most of them excreted virus in their feces, and they responded immunologically to viral exposure. Infection during pregnancy appeared to affect the fetuses. A group of 15 blue fox vixens inoculated with the virus produced a statistically smaller number of kits (78) than did 15 untreated controls (131). Vaccination with a homologous inactivated virus preparation appeared to afford protection against reproductive losses. After infection, 15 vaccinated vixens gave birth to 97 kits, compared with 54 kits born to a similar, non-vaccinated experimental group.     

Liquoid-induced disseminated intravascular coagulation in the blue fox

The present experiments were performed to study the effects of a single high intravenous dose of Liquoid (10 mg/kg body weight) upon platelets, coagulation activities and hematocrit in blue foxes, and their correlation with the survival time. Both “short-living” (< 9 h) and “long-living” (24 h or more) blue foxes showed a marked consumption of coagulation factors, initial fall in fibrinogen, positive ethanol gel test and a gradual decrease in platelet counts. In addition “short-living” animals developed a marked rise in hematocrit, reflecting a considerable increase in vascular permeability. We conclude that activation of plasma proteases has as one of its effects increased permeability in microvasculatory vessels and that this may play a central role for the course and outcome of Liquoid-induced disseminated intravascular coagulation.     

Ultrastructural studies of blue fox spermatozoa

The fine structure of epididymal and ejaculated spermatozoa from blue fox is analyzed by electron microscopy. The result of this investigation seems to indicate that the blue fox spermatozoon is of the same type as that of the dog. The apical body appears, however, to have a rather characteristic shape and to be more well-developed than found in sperm cells from the usual domestic animals.The other structures studied in the different parts of the blue fox spermatozoon including the head, neck and flagellum displayed the same principal characteristics as those in the sperm cells of other domestic species.In a few cases double development of the middle piece could be observed.     

蓝狐自咬症的诊治

蓝狐的自咬症是一种特殊的疾病，这种疾病具有一定的传染性。一般情况下病狐咬伤四肢(常常是后肢)上端和尾根的表面，在急性发作期不自觉的发生自咬现象，将自己的后肢和尾巴咬得鲜血淋漓，甚至将胯部软组织全部咬掉裸露出白骨，尾巴仅残存根部的白骨，自咬程度剧烈往往继发感染而死亡。     

Brain and spinal cord lesions in encephalitozoonosis in the blue fox

The central nervous system lesions in encephalitozoonosis were studied in 11 naturally infected blue foxes. Immunohistochemical staining was employed in the demonstration of the parasites and identification of host cells. Consistent findings in acute to subacute stages included granulomatous meningoencephalomyelitis and vasculitis, with arterial lesions similar to polyarteritis nodosa. Chronic stages were dominated by arteriosclerosis, perivascular mononuclear infiltrations and gliosis, with less prominent granulomatous reaction. Parasites were almost constantly observed in association with active lesions both in vessels and nervous tissue. Parasitophorous vacuoles (PV) occurred in endothelial cells and in the medial layer of arteries. Neurons, including even their processes, were widely parasitized, a fact that may account for the brain being an important target organ. PV also occurred in ependymal cells of the choroid plexus and occasionally in macrophages. A great number of parasites was demonstrated in phagolysosomes of macrophages, a fact that probably reflects a relative resistance to digestion, and may consequently contribute to the development of the prominent granulomatous reaction. It was concluded that the brain lesions, except in chronic stages of mild infections, seem to be pathognomonic for encephalitozoonosis in the blue fox.     

Variation between ranch blue fox populations in cranial form

The aim of this study was to describe the differences in cranial size and shape that occur between different farmed blue fox populations within and between countries. The skulls were obtained at the pelting time from three Finnish, one Estonian, one Norwegian and seven Canadian farms. The material was subjected to a principal component (PC) analysis for each sex. The first PC-factor explained about 50% of variation. It was identified as the size factor; it discriminated Finnish blue foxes at one end and Nova Scotia foxes at the other end of the scale. The second PC-factor explained about 10% of variation in skull morphology but failed to discriminate the populations. The third factor, which was dominated by interorbital width, discriminated Nova Scotia foxes from the other populations. PC-factor 4 received its highest loading from the length of upper tooth row. This factor differentiated, although poorly, the Newfoundland fox populations, whether local or crosses between the local and the imported Finnish stock, from the others. The sexes were significantly different on most single parameters and the skulls of all farm populations were larger than those of wild Arctic foxes. However, there were also large differences in skull morphology between farms within one country. This shows that farmed blue foxes in different countries have not yet diverged into anatomically distinct populations.     

蓝狐丹毒病的诊断与治疗

丹毒病是由猪丹毒杆菌（Ergsipechrix rhusiopathiae）所引起的败血性传染病。蓝狐发生此病的并不多见。现将本次发病、诊断、治疗的情况报告如下。     

Validation of a direct radioimmunoassay of melatonin in the blue fox

A direct radioimmunoassay procedure for the determination of melatonin in the blood of blue fox has been validated and applied.The assay required 50 μl of sample and standard, 100 ul of antiserum and 100 μl of (³H)melatonin. After overnight incubation at 4°C the antibody bound melatonin was separated from the free hormone with dextran-coated charcoal. Following centrifugation the antibody bound (³H)melatonin was determined in a beta scintillation counter.The antiserum bound 30–35 % of the (³H)melatonin at a final dilution of 1:36000. The non specific binding represented less than 5% of the total radioactivity in all assays. The lowest detectable amount of melatonin was 2.6 fmol/tube, corresponding to 52.5 pmol/1. The inter-assay coefficient of variation at 178 and 510 pmol/1 was 15.6 and 8.8%, respectively. The precision profile, calculated from a 10-replicate standard curve, showed that the coefficient of variation decreased from 43% at 84 pmol/1 to 15% at 336 pmol/1, and remainded at or below 10% for concentrations exceeding 670 pmol/1.Plasma was collected from 2 male blue foxes at about hourly intervals during a 24 h period in September and assayed for melatonin. Maximum (421 pmol/1) and minimum (97 pmol/1) concentrations of the hormone were inversely related to light intensity.     

辽西沿海地区养殖蓝狐寄生虫感染情况调查

随机抽检辽西沿海地区人工养殖蓝狐240只,采集血清样本120个、粪便和血液涂片样本各75个,采用寄生虫学完全剖检法进行检查。结果发现,蓝狐感染体内外寄生虫16种,分别隶属于8纲15科16属,确定优势虫种为狐疥螨(Sarcoptes scabiei var lupi)、犬弓首蛔虫(Toxocara canis)、犬钩虫(Ancylostoma caninum)、狐毛尾线虫(Trichuris vulpis)、狐等孢属球虫(Isospora lupi)和华支睾吸虫(Clonorchis sinensis)。本研究为辽西沿海地区养殖蓝狐寄生虫病防治工作提供了依据。     

New fertility traits in breeding value evaluation of Finnish blue fox

Abstract

Fertility traits have been included in the Finnish blue fox breeding goal for several generations. However, genetic trend in reproductive performance has been undesired due to unfavorable correlations to other important traits such as animal size (AS). The aim of this study was to estimate genetic parameters for pregnancy rate (PREG) and felicity (FEL), and their genetic correlations to litter size (LS) and AS. The estimated heritabilities were low for PREG (0.028) and FEL (0.049). The genetic correlations between LS and PREG (0.63), and LS and FEL (0.75) were clearly positive. Thus, on an average females having genetically larger LS have higher PREG and FEL. The genetic correlation between AS and PREG was close to zero (?0.05), but correlation between AS and FEL was moderate (?0.27) indicating that larger animals are more likely barren or to lose their pups during pregnancy or right after birth.     

蓝狐和水貂被毛真菌菌群的调查

为了解蓝狐和水貂被毛携带真菌的情况,采集动物体表7个点上的被毛,接种于沙保劳氏培养基26℃培养2周,对菌落进行宏观和微观鉴定。结果表明,山东昌邑地区健康蓝狐的被毛致病性真菌,检出率占总数的33%,且链格孢霉为优势菌群,皮肤丝状真菌(犬小孢子菌)的带菌率为3.33%(1/33);健康水貂的被毛致病性真菌检出率为26.67%,其中优势真菌为念珠菌,未检出皮肤丝状真菌;对疑似癣病蓝狐的被毛做真菌培养,致病真菌检出率为46%,包括4株犬小孢子菌、3株须毛癣菌。本次调查为临床诊断和治疗提供依据,并具有重要的公共卫生意义。     

Risk aversion affects economic values of blue fox breeding scheme

The profit and production of an average Finnish blue fox farm was simulated using a deterministic bio‐economic farm model. Risk was included using Arrow‐Prat absolute risk aversion coefficient and profit variance. Risk‐rated economic values were calculated for pregnancy rate, litter loss, litter size, pelt size, pelt quality, pelt colour clarity, feed efficiency and eye infection. With high absolute risk aversion, economic values were lower than with low absolute risk aversion. Economic values were highest for litter loss (18.16 and 26.42 EUR), litter size (13.27 and 19.40 EUR), pregnancy (11.99 and 18.39 EUR) and eye infection (12.39 and 13.81 EUR). Sensitivity analysis showed that selection pressure for improved eye health depended strongly on proportion of culled animals among infected animals and much less on the proportion of infected animals. The economic value of feed efficiency was lower than expected (6.06 and 8.03 EUR). However, it was almost the same magnitude as pelt quality (7.30 and 7.30 EUR) and higher than the economic value of pelt size (3.37 and 5.26 EUR). Risk factors should be considered in blue fox breeding scheme because they change the relative importance of traits.     

Comparison between microscopic and automated differential leukocyte counts in the silver fox (Vulpes vulpes) and the blue fox (Alopex lagopus)

Differential leukocyte (WBC) counts in blood from clinically healthy silver foxes (n=32) and blue foxes (n=37) obtained from an automated hematology analyzer (Technicon H*1 Hematology System) with canine software were compared with microscopic differential WBC counts (M-diff). There was good agreement between the automated differential cell count (A-diff) and the M-diff for neutrophil and lymphocyte percentages. The correlation was lower for monocyte percentages and variable for eosinophil percentages. There was no significant difference between the A-diff and M-diff in either fox species. The A-diff counts were very precise, and may be a good alternative to the traditional M-diff for screening populations of clinically healthy foxes or for studies on stress and animal welfare. Intercept values, however, indicated a constant bias that must be taken into account before interpreting results based on different methods of analysis     

Effect of evening primrose oil as food supplement on reproduction in the blue fox.

Addition of evening primrose oil (EPO) to a blue fox diet in the reproduction period was evaluated in an experiment with 2 groups, each of 12 male and 25 female blue foxes, regarding the effects on reproductive performance. The experiment was carried out as a field trial and the experimental period lasted from March 10 until the end of the mating season (males) or early July (females). During this period the control group was fed the standard diet of the farm and the experimental group was fed the same diet supplemented with 4.5 g EPO and 2.5 mg zinc sulphate per animal and day. An addition of 10 mg vitamin E per 500 mg EPO was made. The results were evaluated regarding male and female treatment effects. There was an increased rate of abortions in the EPO-group, but simultaneously a non-significant decrease in the frequency of barren females, resulting in a similar level of females without litters in both groups. A tendency for increased litter size in the EPO group was found, mainly as an effect of male treatment, which might indicate an effect on semen quality.