Farm-level factors associated with above-average production on pig farms in Evia, Greece

The aim of this study was to identify farm-level factors associated with above-average production of pig farms in Evia, Greece. Cross-sectional data on pig farm characteristics and management, farmer characteristics, worming practices, anthelmintics used, and the parasite loads of 10 randomly selected boars, sows, weaners, and fatteners were collected from 28 pig enterprises in the Evian region of Greece (74% of the total number of pig enterprises in this region). Above-average productivity was defined as weaning 18 or more piglets per sow per year. A multivariate logistic regression model found that employing immigrant workers reduced the odds of a farm being an above-average producer (OR 0.016, 95% CI 0.001–0.27), while having a veterinarian select the anthelmintic strategy significantly increased the odds of a farm being an above-average producer (OR 10.24, 95% CI 0.78–135.13). None of the gastrointestinal parasites under investigation were significantly associated with above-average productivity. It is concluded that despite the fact that endoparasite load was not significantly associated with above-average production, a quantification of the impact of intestinal worms on pig productivity is needed to know how much control can be envisaged for gastrointestinal worms before reaching the threshold at which it is no longer physically or financially reasonable to continue pursuing control.     

Bronchoalveolar lavage cytology from captive badgers

Background: Bronchoalveolar lavage (BAL) fluid is evaluated for the diagnosis and study of lung disease and airway inflammation. Cytologic profiles for BAL fluid have not been reported for badgers and may be useful in understanding the pathogenesis of pulmonary diseases such as Mycobacterium bovis. Objective: The aim of this study was to evaluate cytologic and microbial findings in BAL fluid from captive European badgers (Meles meles) and identify correlates with the results of concurrently collected blood and fecal samples. Methods: BAL fluid (by a nonbronchoscopic method) and jugular venous blood samples (for routine CBC) were obtained from 23 captive tuberculosis‐free anesthetized badgers on 2 occasions 4 weeks apart. Fecal samples were collected for routine parasitology. Morphologic evaluation and 100‐cell differentials were done on cytocentrifuged BAL specimens. Pellets from centrifuged BAL were aerobically cultured for bacteria. Results: With the 2 BAL samples from each of the 23 badgers combined, the median (range) cell percentages were 73.0% (5–95%) neutrophils, 7.5% (2–16%) macrophages, 8.0% (0–27%) lymphocytes, and 9.5% (0–92%) eosinophils. Macrophages frequently contained silica‐like crystals. Other findings included ciliated epithelial cells, goblet cells, mucus, and Aelurostrongylus sp. larvae. A light growth of Streptococcus, Pasteurella, or Escherichia coli was cultured in 6 badgers. Trypanosoma pestanai were identified in blood from 10 badgers and fecal parasites (mainly coccidia) were found in 20 badgers. No correlation was found between BAL and CBC results and the presence of parasites. Conclusions: The predominance of neutrophils in BAL fluid from badgers differs from the predominance of macrophages found in BAL from other species. This difference may reflect the burrowing lifestyle or the unique immune response of badgers.     

Towards the implementation of the "basket of options" approach to helminth parasite control of livestock: emphasis on the tropics/subtropics

The virtual reliance on anthelmintic drugs alone to control internal parasites of livestock is inappropriate and ultimately unsustainable. In the tropics and subtropics, widespread and high levels of anthelmintic resistance, particularly in nematode parasites of small ruminants, is rife. But more to the point, many farmers in these regions of the world are resource poor and cannot afford, or are reluctant to purchase drugs that may also be of dubious quality. As it is with any intervention, the benefits must outweigh the costs. This is not only in terms of conventional parameters such as reduced mortality and increasing productivity (meat, milk, fibre and traction power) of livestock, but also within the broad framework of helminths of veterinary/human importance, the aim should be a positive impact on reducing the threat of helminth zoonoses. However, understanding the issues involved and education of the end-users (farmers) is of fundamental importance, before any internal parasite control program should be promoted. Within the above context, we provide examples of how the "basket of options" approach could be adopted for the control of three quite disparate helminth problems in the tropics and subtropics, viz.: strongyle nematode infections of donkeys, the Taenia solium cysticercosis/taeniosis problem of pig and man and Haemonchus contortus infections in small ruminants. The "best practice" approaches can be defined as those "basket of options" that are practical, affordable, available and appropriate, whether to the commercial producer, or to the resource-poor farmer. Constraints that may restrict applying such options are accessibility to, and affordability of, suitable remedies and above all, the availability of information needed to make informed decisions in this regard.     

Common and Emerging Diseases in Commercially-Cultured Summer Flounder,Paralichthys dentatus

Abstract

Infectious diseases are one of the most common causes of losses in commercial aquaculture for all life stages of fish production. Parasitic infestations such as Trichodinasp., Cryptocaryonsp., Amy-loodiniumsp., Trypanoplasmasp., and monogenic trematodes may have detrimental health consequences when present in high numbers within a cultured population. Bacterial agents such as Vibriosp., Edwardsiellasp., Flexibactersp., and Mycobacteriumsp. may be dormant in some populations but then result in high morbidity or mortality when the fish become stressed by environmental or nutritional factors. Viral diseases are more difficult to diagnose but there are reports of lymphocystis and other viral diseases occurring in flounder species. Many of these diseases result in similar clinical signs of disease. For accurate disease diagnosis, appropriate methods must be implemented to identify and prevent the introduction or dissemination of disease in an aquaculture facility.     

Preliminary success using hydrogen peroxide to treat Atlantic salmon,Salmo salar L., affected with experimentally induced amoebic gill disease (AGD)

Currently, the only effective and commercially used treatment for amoebic gill disease (AGD) in farmed Tasmanian Atlantic salmon is freshwater bathing. Hydrogen peroxide (H₂O₂), commonly used throughout the aquaculture industry for a range of topical skin and gill infections, was trialled in vitro and in vivo to ascertain its potential as an alternative treatment against AGD. Under in vitro conditions, trophozoites of Neoparamoeba perurans were exposed to three concentrations of H₂O₂ in sea water (500, 1000 and 1500 mg L^?1) over four durations (10, 20, 30 and 60 min) each at two temperatures (12 and 18 °C). Trophozoite viability was assessed immediately post‐exposure and after 24 h. A concentration/duration combination of 1000 mg L^?1 for >10 min demonstrated potent amoebicidal activity. Subsequently, Atlantic salmon mildly affected with experimentally induced AGD were treated with H₂O₂ at 12 and 18 °C for 15 min at 1250 mg L^?1 and their re‐infection rate was compared to freshwater‐treated fish over 21 days. Significant differences in the percentage of filaments affected with hyperplastic lesions (in association with amoebae) and plasma osmolality were noted between treatment groups immediately post‐bath. However, the results were largely equivocal in terms of disease resolution over a 3‐week period following treatment. These data suggest that H₂O₂ treatment in sea water successfully ameliorated a clinically light case of AGD under laboratory conditions.     

野生动物园动物肠道寄生虫感染情况调查

为了解四川某野生动物园动物肠道寄生虫感染情况,本试验采用离心沉淀法、卢戈氏碘液染色法、饱和蔗糖溶液漂浮法对40种野生动物及混居水禽共计180份粪便样本进行调查。寄生虫总感染率为74.4%,共发现8种寄生虫,其中球虫、阿米巴原虫、蛔虫、鞭虫、毛细线虫、圆线虫、绦虫和吸虫感染率分别为31.1%、19.4%、15.6%、10.6%、17.2%、20.6%、4.4%和1.7%。结果表明,某野生动物肠寄生虫感染较为普遍,应采取有效的综合防治措施,以保证野生动物的健康。     

An evidence‐based approach to equine parasite control: It ain't the 60s anymore

Most veterinarians continue to recommend anthelmintic treatment programmes for horses that derive from knowledge and concepts more than 40 years old. However, much has changed since these recommendations were first introduced and current approaches routinely fail to provide optimal or even adequate levels of parasite control. There are many reasons for this. Recent studies demonstrate that anthelmintic resistance in equine parasites is highly prevalent and multiple‐drug resistance is common in some countries, but few veterinarians take this into account when making treatment decisions or when recommending rotation of anthelmintics. Furthermore, the current approach of treating all horses at frequent intervals was designed specifically to control the highly pathogenic large strongyle, Strongylus vulgaris. But this parasite is now quite uncommon in managed horses in most of the world. Presently, the cyathostomins (small strongyles) are the principal parasitic pathogens of mature horses. The biology and pathogenesis of cyathostomins and S. vulgaris are very different and therefore require an entirely different approach. Furthermore, it is known that parasites are highly over‐dispersed in hosts, such that a small percentage of hosts harbour most of the parasites. The common practices of recommending the same treatment programme for all horses despite great differences in parasite burdens, recommending prophylactic treatment of all horses without indication of parasitic disease or knowing what species of parasites are infecting the horses, recommending use of drugs without knowledge of their efficacy and failing to perform diagnostic (faecal egg count) surveillance for estimating parasite burdens and determining treatment efficacy, are all incompatible with current standards of veterinary practice. Consequently, it is necessary that attitudes and approaches to parasite control in horses undergo a complete overhaul. This is best achieved by following an evidence‐based approach that takes into account all of these issues and is based on science, not tradition.     

青海省畜禽寄生虫虫种资源与分布

本文简要介绍青海省畜禽寄生虫虫种资源与分布,并对绵羊主要线虫虫卵和幼虫在天然草场的生活力进行了观察。迄今从该省牛、羊、马、猪、鸡、免等畜禽检出寄生虫301种,隶属于6门,9纲,22目,58科,97属。     

Polyculture of western white shrimp,Litopenaeus vannamei Boone, 1931 with Grey mullet,Mugil cephalus Linnaeus, 1758 controls external parasites of western white shrimp

The main aim of this study was to examine the effects of a polyculture system on the control of the external parasites of western white shrimp, Litopenaeus vannamei. To this end, the western white shrimp postlarvae (PLs) were stocked in nine earthen ponds (600 m²) at a density of 20 PLs m^?2 and reared for 4 months. After 40 days of shrimp stocking, Mullets, Mugil cephalus, were stocked at various densities including: control (0 fish/100 m² pond), treatment 1 (T₁: 2 fish/100 m² pond) and treatment 2 (T₂: 4 fish/100 m² pond). Over the course of the experiment, the external parasites of shrimps were investigated by the preparation of a wet mount from the gill tissue. Based on the obtained results, totally two genera of protozoan parasites, i.e. Zoothamnium sp. and Epistylis sp., were identified over the course of the experiment. In all experimental groups, the incidence and abundance of Zoothamnium sp. was significantly higher than Epistylis sp. (P < 0.05). Also, mean incidence per cent and mean abundance of Zoothamnium sp. and Epistylis sp. were significantly lower in the polyculture treatments (T₁ and T₂) compared to the monoculture group (control) (P < 0.05). Throughout this experiment, the total organic matter (TOM %) content of the bottom sediments and biological oxygen demand (BOD₅ mg L^?1) of water samples in the polyculture ponds were significantly lower than the monoculture group (P < 0.05). In contrast, the polyculture ponds had a higher concentration of water dissolved oxygen (O₂ mg L^?1) compared to the monoculture (P < 0.05). In conclusion, our results show that mullet as a secondary farmed species can reduce indirectly the parasitic pollution of western white shrimp probably through reducing the total organic matters in water and sediments and improving the water quality parameters.     

Impacts of parasites on marine survival of Atlantic salmon: a meta‐analysis

Parasites can, in theory, have large impacts on the survival of fish populations. One method to evaluate such impacts on anadromous species is to apply manipulative field experiments in which parallel groups of antiparasitically treated and non‐treated fish are simultaneously released and then subsequently recaptured as returning adults. A systematic review and meta‐analysis on all such Norwegian studies on Salmo salar provided a data set for the time period 1996 to 2011 on 118 release groups comprising 657 624 fish released and 3989 recaptured. The overall risk ratio (RR) was estimated to be 1.18 (95% CI: 1.07–1.30). The effect varied strongly between groups, (Higgins I² = 40.1%). Over 70% of this heterogeneity could be explained by the release location, time period and baseline survival. The most important predictor variable was baseline survival. In groups with low recapture in the control group (low baseline survival), the effect of treatment was high (RR = 1.7), while in groups with high recapture in the control group (high baseline survival), there was no effect of treatment (RR ~ 1.00). The most prevalent parasite in the region affected by the drugs administered was Lepeophtheirus salmonis. Hence, the meta‐analysis supports the hypothesis that L. salmonis contributes to the mortality of S. salar during outward migration. However, the effect of treatment was not consistent, but was evidently strongly modulated by other risk factors. The results suggest that the population‐level effects of parasites cannot be estimated independently of other factors affecting the marine survival of S. salar.