Ruminant coccidiosis.

Coccidiosis is a protozoan disease of wild and domestic ruminant animals in every country of the world. This article provides basic information regarding the terminology, biology, epidemiology, pathology, diagnosis and control methods applicable to the causative agents and their interaction with host animals.     

Clinical coccidiosis in a boar stud.

This report describes an outbreak of coccidiosis in a boar stud. A live, untreated, adult boar with a history of diarrhea was submitted to the Iowa State University Veterinary Diagnostic Laboratory, Ames, IA. For a 3-month period, approximately 40% of the boars in this stud had developed gray to brown diarrhea that lasted 1-3 days. Affected boars did not lose condition, and antibiotic therapy did not appear to affect the clinical course ofthe disease. At necropsy, the distal ileum was palpably thickened and covered by a thick, yellow-green, fibrinous exudate. Microscopic changes in the ileum consisted of an erosive enteritis associated with the presence of numerous coccidia within mid to superficial villus enterocytes. The mucosa was covered by a fibrinous exudate admixed with numerous nonsporulated coccidian oocysts. A light growth of Salmonella enterica serovar Derby was isolated from the small intestine of this animal, but laboratory tests were negative for Lawsonia and Brachyspira spp. Individual or paired fecal samples were obtained from 6 additional boars experiencing similar clinical signs. Numerous Eimeria spinosa oocysts were identified in these samples. Neither Salmonella nor Brachyspira spp. were cultured from submitted fecal samples. Necropsy of a live boar and examination of feces from 6 additional animals confirmed that the mild, sporadic, transient diarrhea in this boar stud was due to coccidiosis.     

Atypical coccidiosis in South American camelids.

Reported clinical signs of coccidiosis in South American camelids include anorexia of a few days duration, sudden death, and diarrhea. Antemortem diagnosis of clinical coccidiosis is usually based on clinical signs and supported by detection of coccidial oocysts in feces. This report describes 2 atypical cases of coccidiosis in South American camelids that had no coccidial oocysts detected on antemortem fecal flotation, prolonged weight loss, and normal fecal consistency.     

球虫疫苗研究进展

本文对疫苗类型、疫苗的研制方法、展望三个方面进行了阐述。其中,疫苗类型有强毒活疫苗、弱毒活疫苗、灭活疫苗、基因工程苗等。疫苗的研制方法,强毒活疫苗主要通过控制球虫卵囊量,弱毒疫苗的致弱方法有鸡胚传代致弱、早熟选育致弱、物理和化学方法致弱。     

鸡球虫病的免疫防治

鸡球虫病是一种危害性较大的肠道寄生虫病，多发于3个月以内的仔鸡，尤以15～45日龄的雏鸡最易感染。其发病率高达50％～70％，死亡率为20％～30％．严重者可达80％t~。我国是养鸡大国，每年因球虫病造成的直接和间接经济损失难以估计。迄今为止，鸡球虫病的防治主要依赖药物预防，但是目前药物防治球虫病遇到了两大难题．首先是球虫极易产生耐药性．其次是药物残留，一些国家对禽肉、蛋制品中球虫药物含量有着严格的限制，我国已经加入WTO．解决禽蛋制品的药物残留已成当务之急。因此，利用免疫预防来代替药物防治控制球虫病已成为寄生虫学界的共识。近年来，球虫疫苗的应用进一步完善．为我们防治球虫病提供了一种新的途径．比较好地解决了抗药性和药物残留等问题。     

Characteristics of the labile neurotoxin associated with nervous coccidiosis.

Reported are the results of preliminary attempts to characterize the molecular weight, heat sensitivity and other features of a labile neurotoxin identified in the serum of calves exhibiting neurological signs in association with coccidial enteritis. The labile neurotoxin activity is heat labile (60 degrees C for 30 min) and is lost upon exposure to acidic pH (5.5) and cysteine (1.75 g/100 mL serum). Activity can be recovered from the precipitate of a 30% wt/vol solution of (NH4)2SO4 in serum. Ultrafiltration trials suggest that labile neurotoxin activity may be linked to a molecule of over 300,000 MW.     

鸡球虫病免疫:Ⅰ.球虫病特点和免疫原理

采用免疫方法控制球虫病已经成为一种趋势，因为它可以从根本上免除球虫抗药性和肉蛋品药残带来的一系列问题。但是随着进入市场球虫病疫苗种类的增多也带来不少问题。球虫病疫苗有毒苗和弱毒苗之分．有三价、四价、五价、七价甚至八价之分。有商品肉鸡用的，也有种鸡用的。商家宣传也各有动人之处，令人眼花缭乱．不知何以适从?如果你了解了球虫和球虫病的重要特点，了解了球虫免疫的原理就能够释疑解惑，就能够理性地选择和正确使用球虫病疫苗。本文拟就上述几个方面介绍，以飧读者。     

球虫病新理念

多年来，控制球虫病主要依靠使用抗球虫的药物。然而现在，人们已不赞同在食用动物中使用化学添加剂和抗生素，因此应该重新考虑如何控制球虫病。1 宿主特异性寄生虫球虫病由寄生性原虫所引起，它们常常寄生于禽类或其它动物的消化道中，偶尔也会感染其它一些器官，如鹅肾。对于禽类来说，主要是艾美耳型原虫属球虫，此类球虫常寄生在盲肠中。柔嫩艾美耳型属和堆型艾美尔球虫属及其它几个品系都寄生在雏鸡肠道中。有些球虫具有特异性宿主，这些球虫只寄生于雏鸡中而不会侵袭火鸡、鸭子、雉鸡等禽类。一般来说，如果宿主能幸免于难，寄生虫收…