传染性法氏囊病病毒主要结构蛋白VP2、VP1和VP2-VP1串联基因的原核表达及其初步应用

为获得传染性法氏囊病病毒(IBDV)特异性抗体检测用抗原VP2、VP1及VP2-VP1蛋白,分别设计引物扩增IBDV野毒株NN1172的VP2和VP1基因,并扩增VP2和VP1基因中抗原性和亲水性较好的重要区域,通过PCR扩增基因串联方法对截短的VP2和截短的VP1基因进行串联,首次获得VP2-VP1串联基因,并对VP2、VP1和VP2-VP1串联基因进行了原核表达和鉴定。结果成功构建了原核表达载体pET-VP2、pET-VP1和pET-VP2-VP1;诱导表达条件显示,3个重组质粒分别转入BL21菌株后经0.05 mmol/L IPTG诱导表达,分别得到分子量为69、114和63 kDa的VP2、VP1和VP2-VP1重组蛋白,且均以包涵体形式表达,3个重组蛋白分别于诱导后5、3和6 h时表达量最多。Western blot结果显示,表达的VP2、VP1和VP2-VP1蛋白与鸡抗IBDV阳性血清均具有良好的反应原性。以纯化的VP2、VP1和VP2-VP1蛋白作为包被抗原对传染性支气管炎病毒(IBV)、呼肠孤病毒(ReoV)、禽白血病病毒(ALV)和新城疫病毒(NDV)4种阳性血清检测均为阴性,表明所获得的纯化蛋白具有高度的特异性;对免疫了IBD灭活疫苗,IBD基因工程疫苗和IBD弱毒疫苗的商业鸡群进行抗体检测,结果均能显示疫苗免疫后机体抗体水平的变化趋势。本研究表明利用该原核表达系统所表达的3个蛋白均具有良好的免疫反应活性,为IBDV特异性抗体的检测和新型亚单位疫苗的研发奠定基础。     

表达鸡IL2和IL15重组新城疫病毒的免疫增强作用研究

为提高新城疫病毒(NDV)弱毒疫苗的免疫保护效果,本研究选取鸡IL2(chIL2)和chIL 15两个细胞因子作为分子佐剂,通过反向遗传操作技术分别将这两个基因克隆于NDV Clone30株中,构建表达chIL2和chIL15的重组病毒rClone30-chIL2和rClone30-chIL15.ELISA法检测结果表明两种细胞因子在重组病毒中均能够稳定表达.将重组病毒免疫雏鸡,以NDV强毒BJ株进行攻毒试验,测定其抗体产生情况和保护效果.结果表明,两种重组病毒均可以诱导雏鸡产生较高水平抗体;而且两种重组病毒保护率可达100％,具有较好的保护效果.本研究为进一步提高NDV重组基因工程疫苗的效果提供了新思路.     

表达双基因的重组新城疫病毒载体的构建

为了构建表达双外源基因的重组新城疫病毒载体,试验采用分子生物学方法对重组新城疫病毒进行了研究。通过反向遗传学操作构建并拯救表达双基因的重组新城疫病毒[r Clone30-EGFP(NP/P)-RFP (P/M)];用重组新城疫病毒感染鸡胚成纤维细胞并绘制生长曲线;通过免疫荧光试验检测重组新城疫病毒感染HepG2细胞后荧光蛋白的表达情况。结果表明:试验成功构建并拯救了表达双基因的重组新城疫病毒;重组新城疫病毒的生长动力学与亲本病毒相似,差异不显著(P0. 05);重组新城疫病毒能够在HepG2细胞中稳定表达增强型绿色荧光蛋白(EGFP)和红色荧光蛋白(RFP)。说明重组新城疫病毒感染HepG2细胞后可稳定表达双外源基因。     

共表达新城疫病毒F基因、传染性法氏囊病病毒VP0基因的重组鸡痘病毒的抗原性和免疫原性

以鸡痘病毒(FPV)282E4株TK基因为侧翼,将2个相同的复合启动子ATI@p7.5×20以反向方式连接,分别调控新城疫病毒(NDV)F基因和传染性法氏囊病病毒(IBDV)VP0基因,得到重组转移质粒pVP0-2ATI@p7.5×20F.然后将该重组转移质粒用脂质体转染预先感染FPV 282E4株的鸡胚成纤维细胞(CEF),在经BrdU(5-溴-脱氧尿嘧啶)加压处理后的CEF上传代,用间接免疫荧光试验、Western blot检测,有2株鸡痘病毒能同时表达NDV F蛋白和IBDV VP0蛋白.用这2株重组鸡痘病毒刺种商品Leghorn雏鸡,于刺种前及刺种后1、2、3周对抗NDV特异性抗体水平和淋巴细胞转化能力检测,结果发现,重组鸡痘病毒能激发机体产生良好的免疫反应.结果表明,重组鸡痘病毒可以作为疫苗备选株进行研究与开发.     

表达禽腺病毒4型中国流行株Fiber2蛋白重组新城疫病毒的构建与鉴定

利用NDV LaSota弱毒疫苗株反向遗传操作系统,将禽腺病毒4型(FAdV-4)中国流行株的全长Fiber2基因插入到NDV基因组的P和M基因之间,构建并拯救出重组病毒rLaSota-Fiber2。利用RT-PCR和序列测定,以及Western blot对重组病毒进行了鉴定。结果显示,Fiber2基因插入位置和方向正确,Fiber2蛋白得到正确表达,表达形式为可溶的游离形式而非嵌入到NDV颗粒中。第10代重组病毒的鸡胚致病性试验和在鸡胚中的生长特性研究结果显示,重组病毒的半数鸡胚感染量(EID_(50))最高可达10~(8.5)/100μL,鸡胚平均致死时间(MDT)为120 h, 1日龄雏鸡脑内接种指数(ICPI)和6周龄鸡静脉接种致病指数(IVPI)均为0,重组病毒保持了LaSota弱毒疫苗亲本毒株的低致病特性和对鸡胚良好的高滴度生长适应性。重组病毒与亲本LaSota株生长滴度在相近时间达到峰值,生长动力学特性与亲本株无明显差异。本试验构建的表达FAdV-4中国流行株Fiber2基因的重组病毒rLaSota-Fiber2有望为同时防控NDV和FAdV-4的感染提供安全、廉价和高效的辅助工具。     

表达鸡传染性支气管炎病毒S基因的重组新城疫病毒构建

为构建以新城疫病毒(NDV)为活毒载体表达鸡传染性支气管炎病毒(IBV)S基因的重组病毒,本研究利用RT-PCR技术,以IBV的Massachusetts41株RNA为模板,通过RT-PCR扩增得到IBV S基因(3534bp),将其插入到NDV感染性克隆pBRN-FL中,构建了含有IBV S基因的重组NDV cDNA克隆pBRN-FL-IBVS。利用磷酸钙转染法,在辅助质粒pBS-NP、pBS-P和pBS-L的共同作用下,将pBRN-FL-IBVS转染表达T7聚合酶重组痘病毒感染的BSR细胞,救获重组NDV(rL-IBVS)。采用RT-PCR检测接种重组病毒的鸡胚尿囊液,结果表明rL-IBVS中含有相应外源基因。IFA试验表明,rL-IBVS可与鸡抗IBV的高免血清发生特异性反应,证明S蛋白在感染的BSR细胞中得到表达。其鸡胚平均致死时间、脑内致病指数和静脉内致病指数等指标显示rL-IBVS保持了亲本疫苗株高滴度的鸡胚生长特性和低致病力特性。本研究采用反向遗传操作技术构建了表达IBV S蛋白的重组NDV,为进一步研制IBV和NDV的重组基因工程活载体疫苗奠定了基础。     

猪O型口蹄疫病毒样颗粒的构建及鉴定

为开发猪O型口蹄疫病毒(FMDV)病毒样颗粒(VLPs)基因工程亚单位疫苗,试验参考GenBank中登录的FMDV毒株基因序列(登录号:JN998085),设计针对VP1、VP2、VP3和VP4 4个基因片段的特异性引物,以O型FMDV O/MYA98/XJ/2010毒株的cDNA序列为模板,对目的基因进行PCR扩增;将获得的VP3、VP1和VP4、VP2基因片段分别插入2个杆状病毒供体质粒(pFastBacDual)的p10和pH双元启动子中,构建pFBD-VP3-VP1和pFBD-VP4-VP2 2个重组转座质粒;将验证正确的2个重组转座质粒分别转化含有穿梭载体(Bacmid)的大肠杆菌DH10Bac感受态细胞,获得2个重组杆粒rBacmid-VP3-VP1和rBacmid-VP4-VP2,经验证正确后,对其进行扩增和提取,将其分别转染Sf9贴壁昆虫细胞,构建2个重组杆状病毒rvAc-VP3-VP1和rvAc-VP4-VP2;2个重组杆状病毒共同感染悬浮培养的Sf9昆虫细胞,利用杆状病毒表达系统在昆虫细胞内对4个基因进行表达,目的蛋白通过间接免疫荧光试验(IFA)、SDS-PAGE、Western blotting及透射电镜(EM)进行检测。结果显示,本研究成功构建2株分别表达FMDV VP1、VP2、VP3和VP4 4个结构蛋白的重组杆状病毒;特异性抗体检测发现,4个蛋白VP1～VP4均成功表达,且具有良好的特异性反应;4个蛋白在Sf9昆虫细胞内能够完成自我组装,形成与天然病毒结构相似的VLPs,直径大小在25～30 nm。本研究利用共感染表达方式在Sf9昆虫细胞内成功制备出FMDV病毒颗粒,为开发高效安全的FMDV基因工程亚单位疫苗开辟了一条新思路。     

鹅细小病毒VP3基因与鹅γ干扰素基因在重组禽痘病毒中的共表达

为了构建共表达鹅细小病毒(GPV)VP3基因与鹅IFNγ基因的重组禽痘病毒,本研究将GPV-VP3基因和鹅IFNγ基因克隆到禽痘病毒转移载体中,构建串联基因的禽痘病毒转移载体pSY-GoIFNγ-VP3,采用脂质体法将其转染禽痘病毒感染的鸡胚成纤维细胞(CEF),经蓝斑法筛选重组病毒,并进行8轮蚀斑纯化,以及PCR鉴定和间接免疫荧光(IFA)分析。结果表明,所获得的重组病毒rFPV-GoIFNγ-VP3能稳定表达外源基因。本研究为进一步开展GPV重组禽痘病毒疫苗的研制奠定了基础。     

鸡传染性法氏囊病病毒超强株VP2基因重组新城疫病毒胚胎免疫安全性及效力试验

为研制能够同时预防传染性法氏囊病(IBD)和新城疫(ND)的疫苗,本研究选用表达IBD病毒(IBDV)超强毒株(vvIBDV)VP2基因的重组ND病毒(NDV)LaSota疫苗株(rL-VP2),测定其半数鸡胚感染量、平均鸡胚致死时间、脑内接种指数和静脉内致病指数等指标,按不同剂量接种18胚龄SPF鸡胚,分别于出雏后第9d、第14d和第21d采血,用微量凝集法和ELISA方法测定血清中抗NDV抗体和抗IBDV抗体水平,并于出雏后28d用NDV强毒(F48E9株)和vvIBDVGx株攻毒,评估重组疫苗的胚胎免疫效果。结果显示:按104EID50/枚剂量进行免疫不会影响SPF鸡胚出雏率和出雏后21d存活率,并且该免疫组雏鸡能够对NDV强毒和vvIBDV攻毒提供安全的免疫保护。     

鞭毛蛋白及鸡GM-CSF重组新城疫病毒对鸡的免疫增强作用

为评价鼠伤寒沙门氏菌鞭毛蛋白(FliC)以及鸡GM-CSF(chGM-CSF)对新城疫病毒(NDV)弱毒疫苗的免疫增强效果,本实验通过PCR扩增fliC,并合成chGM-CSF编码基因,分别构建重组质粒pBrClone30-fliC和pBrClone30-GM-CSF,拯救获得重组病毒rClone30-fliC和rClone30-GM-CSF。RT-PCR和ELISA检测结果表明:fliC和chGM-CSF基因正确插入重组病毒,并获得稳定表达;重组病毒免疫7 d后重组NDV HI抗体效价检测显示,实验组平均HI效价分别达到4.5 log2和4.8 log2,而r Clone30组和空白组HI效价仅为3 log2和1 log2;免疫7 d后攻毒,空白组SPF鸡均死亡,rClone30组有两例发病,实验组SPF鸡全部存活并且无任何临床症状。本研究结果表明,FliC和chGM-CSF作为佐剂能够有效提高弱毒疫苗的免疫效果。     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

A brief history of the prevention of infectious diseases by immunisations

Infectious diseases have always been a terrible scourge for humans. The appearance of these plagues, as they were called without distinction, was generally connected to various conditions: asters, climatic changes or religious reasons. The concept of contagious, and then infectious, diseases came slowly. Variolation, i.e. transmission of ‘virulent’ matter to induce a natural disease and the immunity against it, was brought from Constantinople to England by Lady Montague, in 1721. This ‘variolation’ technique was also often performed in veterinary medicine against diseases like sheep-pox or pleuropneumonia. As ‘vaccination’ is the term generally accepted for ‘immunisation’, variolation can be the word designating such a technique. The second period of the history of immunisation began, in 1880, with the studies of Pasteur and his collaborators. A great number of bacterial vaccines were developed: dead, live but attenuated or only parts of pathogens. The viruses were produced in animals, then in eggs and at last, in tissue cultures. Second generation vaccines appeared with genetic engineering: recombinant vaccines, vector vaccines, nucleic acids vaccines, and markers vaccines, among others. These novel technologies can permit the development of new ones and improve the quality of the vaccines already existing.     

Micronutrient Content of Certain Tropical Conventional and Unconventional Feed Resources of Southern India

The ash, silica and certain important micronutrients were estimated in conventional and unconventional feed and fodder resources available in Southern India. Commonly used dry roughages, such as paddy straw, ragi straw, maize kadbi/stalk, jowar kadbi/stalk, bajra stalk and wheat straw, were high in ash (9.9% +/- 0.77%) and silica (6.4% +/- 0.65%) and low in most of the other micronutrients, except iron, with paddy straw containing most silica (>9%). Cultivated non-leguminous (maize, jowar) and improved green crops (hybrid napier, guinea, green panic, NB-21, CO-1) were also high in ash (10.5% +/- 0.60% and 12.5% +/- 0.51%) but were moderate sources of P, Mg and Cu and good sources of Zn (98 +/- 13.8 ppm and 55 +/- 6.7 ppm). Leguminous green fodders (stylosanthus, lucerne, cow pea, soyabean) were excellent sources of Ca (1.9% +/- 0.16%), Mg (0.40% +/- 0.05%), Cu (30 +/- 5.2 ppm), Zn (121 +/- 14.7 ppm) and Fe (1234 +/- 166 ppm) and moderate sources of P. Mixed local grasses and weeds were high in silica (6.9% +/- 1.00%) but were good sources of Cu, Zn and Fe. Cereal grains (maize, wheat, rice, ragi) were low in ash (2.9% +/- 0.33%) and were relatively poor sources of Ca (0.22% +/- 0.03%), Mg (0.19% +/- 0.03%) and Cu (13 +/- 3.1 ppm). Pulses were low to medium sources of most minerals and good sources of Fe (1230 +/- 293 ppm). Oil seed cake/extractions (groundnut cake, cotton seed cake, soyabean meal, sunflower cake, safflower cake) and cereal by-products (rice polish, rice bran, wheat bran) were excellent sources of P (1.1% +/- 0.47% and 2.3% +/- 0.19%) and good sources of Zn (65 +/- 3.9 ppm and 66 +/- 10.7 ppm) and Fe (938 +/- 130 ppm and 662 +/- 126 ppm). Among the unconventional feeds screened, orange peel, sunflower heads, meat meal, rubber seed cake, spirulina algae and sea weeds contained plentiful Ca, Zn and Fe: tree leaves/top feeds (mulberry, erythrina, glyricidia, banana, subabul, groundnut haulms) were excellent sources of Ca (1.5% +/- 0.13%), Zn (120 +/- 22.9 ppm) and Fe (1033 +/- 133 ppm) but relatively poor sources of P. Soyabean husk, cocoa seed husk, rubber seed cake and meat meal were moderate to good sources of P (1.0% and 0.33%). The high Zn and Fe values of most feeds/fodders were probably due to soil contamination. This account of the micronutrient content of feed/fodder resources should help in strategic supplementation intended to alleviate local deficiencies.     

Bovine Mastitis in Selected Areas of Southern Ethiopia

A study on bovine mastitis, designed to determine the causal agents, prevalence of infection and impact of risk factors in three cattle breeds, was conducted in selected areas of southern Ethiopia. A total of 307 lactating and non-lactating cows, of which 162 were indigenous Zebu, 85 Jersey and 60 Holstein-Friesian, were examined by clinical examination and the California mastitis (CMT) test. Of these, 40.4% were positive by CMT and bacteriology for clinical or subclinical mastitis, with prevalence rates of 37.1% and 62.9%, respectively. Out of 1133 quarters examined, 212 (18.7%) were found to be infected, 83 (39.2%) clinically and 129 (60.8%) subclinically. The prevalence of mastitis was significantly higher in Holstein-Friesian than in indigenous Zebu, in non-lactating cows than in lactating cows, in the early lactation stage than in the mid-lactation stage, in cows with lesions and/or tick infestation on skin of udder and/or teats than in cows without this factor, and in the wet season than in the dry season. Mastitis increased with parity number (R = 0.9). Of 248 CMT and clinically positive udder quarter samples analysed microbiologically, 212 were culturally positive for known mastitis pathogens and 36 were negative. Of the 199 positive samples, Staphylococcus accounted for 39.2%, Streptococcus for 23.6%, coliforms for 14.1%, Micrococcus and Bacillus species for 8.0% each and Actinomyces or Arcanobacterium (Corynebacterium) for 7.0%. It was concluded that there was a high prevalence of clinical and subclinical mastitis, mainly caused by Staphylococcus aureus, Streptococcus agalactiae and Escherichia coli, in this study area.     

不同日粮氮水平对山羊氮代谢和微生物蛋白质合成的影响

本试验旨在探讨不同日粮氮水平对内蒙古白绒山羊氮代谢和微生物蛋白质合成(MCP)的影响,以达到提高氮利用率,减少环境污染和饲料资源的浪费。试验选用9只体况良好、体重为(43.83±2.95)kg,装有瘤胃瘘管的内蒙古白绒山羊,按体重随机分为3组,每组3只。日粮分为低氮7.5%、中氮10.5%、高氮13.5%3个氮水平。试验使用常规试验方法分析测定粪尿血液等生化指标,通过全收尿法和尿嘌呤衍生物法估测MCP。结果表明:随着氮水平增加,氨氮(NH3-N)浓度、氮摄入量、尿氮排出、尿中尿素氮(UUN)和MCP显著增加(P0.05),干物质采食量(DMI)显著降低(P0.01);沉积氮占总摄入氮的比例在中氮组最高,MCP在高氮组最高。综上所述,适当降低日粮氮水平可减少粪尿氮排放,提高反刍动物氮利用率。     

Microsporidial keratopathy in two dogs

A microsporidial keratopathy is described in two dogs. Both dogs presented with a unilateral stromal keratopathy characterized by multifocal coalescing opacities, and the diagnosis was made on histopathologic examination of keratectomy specimens. Transmission electron microscopy (TEM) on formalin‐fixed, paraffin‐embedded corneal tissue was performed in one dog, and the morphologic features were consistent with Nosema species infection. Both dogs were initially diagnosed and treated by superficial keratectomy. One dog received additional antifungal medication and underwent a penetrating keratoplasty following local recurrence two years later. No other systemic lesions attributable to the microsporidial infection were identified clinically. The clinical and diagnostic pathology findings, treatment, and follow‐up are discussed.