Blood clearance of radiolabeled gold colloid by the turkey mononuclear phagocytic system

Radiolabeled gold colloid (198Au), which has been used to assess particle clearance in mammalian species, was used to assess blood-borne particle clearance in turkeys. When turkeys 16 weeks of age were injected intravenously with these particles, there was greater than a 98% decrease in blood gamma emission from 1 minute to 6 minutes postinjection. Uptake of particles was predominantly hepatic with minor uptake by the spleen and bone marrow. Negligible uptake was observed in lung, kidney, and skeletal muscle. Autoradiography demonstrated particles within Kupffer cells of the liver, periarteriolar macrophages of the spleen, and bone-marrow macrophages. Particles could not be demonstrated within the lung or kidney. The mononuclear phagocyte system responsible for blood particle clearance in turkeys is therefore located predominantly within the liver, spleen, and bone marrow and is similar to that of rats, mice, rabbits, and dogs. Pulmonary intravascular macrophages, which have recently been described in ruminants and pigs, are not apparent in this species.     

Pathogenic and immunosuppressive effects of avian pneumovirus in turkeys

Avian pneumovirus (APV) causes a respiratory disease in turkeys. The virus has been associated with morbidity and mortality due to secondary infections. Our objective was to determine if APV caused immunosuppression in the T-cell or B-cell compartments and to study the pathogenesis of the disease in APV maternal antibody-lacking 2-wk-old commercial turkeys. APV was administered by the eyedrop/intranasal route. Observations were made for gross lesions, viral genome, and T-cell mitogenesis and cytokine secretion at 3, 5, 7, 14, and 21 days postinoculation (DPI). During the acute phase of the disease that lasted for about 1 wk, the turkeys exposed to APV showed clinical signs characterized by nasal discharge and sinus swelling. Virus genome was detected by in situ hybridization in cells of turbinates and trachea at 3 and 5 DPI. At 3 and 5 DPI, spleen cells of the birds infected with APV markedly decreased proliferative response to concanavalin A (Con A). Con A and lipopolysaccharide stimulation of spleen cells from virus-exposed turkeys resulted in accumulation of nitric oxide-inducing factors (NOIF) in the culture fluid. NOIF were not detected in culture fluids of Con A-stimulated spleen cells of virus-free turkeys. APV did not compromise the antibody-producing ability of turkeys against several extraneous antigens such as Brucella abortus and tetanus toxoid.     

Propagation of virulent and avirulent turkey hemorrhagic enteritis virus in cell culture

Virulent and apathogenic isolates of turkey hemorrhagic enteritis virus (HEV) were successfully propagated in lymphoblastoid cell lines of turkey origin, whereas spleen and kidney cell cultures from HEV-infected turkeys failed to replicate the virus. The lymphoblastoid cell lines used were MDTC-RP16 and MDTC-RP19, which were previously established from tumors induced by Marek's disease virus in turkeys. Virus replication followed co-cultivation of lymphoblastoid cells with spleen cells from HEV-infected turkeys. Virus replication was demonstrated by immunofluorescence, by agar-gel-precipitin tests, and by electron microscopy. Supernatant fluid of cultures infected with virulent HEV caused death and specific lesions in turkey poults. Poults vaccinated with apathogenic HEV were protected against death and lesions after challenge with pathogenic HEV, which was recovered from infected cultures. The MDTC-RP19 cell line appeared far more susceptible than the MDTC-RP16 cell line to infection with HEV.     

Pathology of spontaneous colibacillosis in a broiler flock

Forty-eight of 134 chickens collected from a flock on a broiler farm were diagnosed pathologically and microbiologically to have colibacillosis. Both acute septicemia (seven birds, 1 to 36 days old) and subacute serositis (41 birds, 5 to 57 days old) were found. The former consisted of necrosis with fibrinous exudates in the ellipsoids and lymphoid follicles of the spleen, and fibrinous thrombi in sinusoids of the liver with occasional necrosis of hepatic cells. The latter had fibrinopurulent inflammation with granulomatous changes in the serosal tissues--including the epicardium, pericardium, and hepatic peritoneal sac--accompanied by septicemic lesions in the spleen and liver. Respiratory lesions (airsacculitis, pneumonia, and tracheitis) were noted in most chickens affected with acute septicemia and subacute serositis. Degenerative changes also were observed in the bursa of Fabricius.     

Systemic spindle-cell proliferative disease in broiler chickens

The major organs and tissues of 24 broiler chickens (70 or 71 days old) suspected of spindle-cell proliferative disease (SPD) because of showing the tumorous lesions distributed throughout the body at meat inspection were collected for histopathological and immunohistochemical examination. Macroscopically, liver, spleen and cecal tonsil showed severe enlargement and white nodules or plaques were observed in the liver, spleen, kidney, intestine and bone marrow of the femur. All chickens were diagnosed with SPD based on the histopathological examination. The lesions of SPD were observed in the liver, spleen, kidney, heart, lung, pancreas, proventriculus, gizzard, duodenum, jejunum, ileum, rectum, cecal tonsil, bursa of Fabricius, bone marrow of the femur and skin. Hemangioma was observed in the lung of 1 bird. Eight 1-day-old specific pathogen-free chicks were inoculated intraperitoneally with 0.25 ml of a 20% homogenate of the affected spleens of three naturally occurring cases. One inoculated bird, necropsied at 10 weeks of age, macroscopically had a white nodule in the kidney and histopathologically had spindle-cell proliferative lesions, a pattern similar to that seen in the naturally occurring cases, in the liver, spleen, kidney, heart, lung, pancreas, proventriculus, duodenum, cecal tonsil and bone marrow of the femur, and was diagnosed with SPD. Immunohistochemically, significant positive reactions with a rabbit antiserum against avian leukosis virus antigens were detected in all spindle cells in the proliferative lesions of all examined SPD cases and in tumor cells of the hemangioma of a field case.     

Histopathologic and bacteriologic evaluations of cellulitis detected in legs and caudal abdominal regions of turkeys

The objective of this study was to identify the causative agent of cellulitis in turkeys. Eighteen flocks from nine producers were sampled at the local processing plant, and 37 birds with cellulitis on legs or caudal thoracic area were obtained. None of the 37 birds with cellulitis had lesions in other organs. On gross examination, lesions were categorized into two groups: cellulitis with unopened skin lesions (type a) and cellulitis with opened skin lesions (type b). Histopathologically, cellulitis with unopened skin lesions had dermal necrosis with underlying fibrin and inflammatory exudate but cellulitis with open skin lesions had chronic granulomatous/granulation tissue-type reaction associated with foreign material. A complete bacteriologic study was conducted on 25 of 37 birds. Bacteria were isolated from 12 of the 25 birds with cellulitis lesions. No aerobic, microaerophilic, or anaerobic bacteria were isolated from the remaining 13 birds with cellulitis lesions. Escherichia coli was isolated in low numbers in mixed cultures with Proteus mirabilis, Lactobacillus spp., Klebsiella spp., and Staphylococcus spp. in 9 of 12 lesions. The remaining few cases yielded P. mirabilis in pure culture or in mixed culture with Pseudomonas aeruginosa. Types a and b cellulitis lesions in turkeys could be associated with primary contact dermatitis and skin abrasions, respectively. Their occurrence is likely associated with different management practices.     

Septicemia associated with Stenotrophomonas maltophilia in a West African dwarf crocodile (Osteolaemus tetraspis subsp. tetraspis).

A 17-year-old male captive West African dwarf crocodile (Osteolaemus tetraspis subsp. tetraspis) died 1 month after fighting with a penmate. Abrasions were present on the head and mandible. Necropsy revealed a vegetative valvular lesion of the left atrioventricular valve, miliary foci of necrosis in the endocardium and myocardium, multiple duodenal and rectal ulcers, and serous atrophy of body fat. Stenotrophomonas maltophilia was isolated in pure culture from lung, liver, and kidney. Gram-negative bacilli were seen histologically in the valvular lesion and in foci of necrosis in the myocardium, liver, spleen, pancreas, kidney, and intestine. Septic thrombi in multiple tissues, arteritis, and pneumonia were additional histologic lesions. Findings indicated that the crocodile died from acute S. maltophilia septicemia, although the primary site of infection was not determined. Stenotrophomonas maltophilia is ubiquitous in the environment and is recognized as an important nosocomial pathogen in humans.     

Pathology of experimental chlamydiosis in chicks

Twelve one-day-old chicks were experimentally inoculated with Chlamydia psittaci derived from turkeys. Acute chlamydial septicemic lesions were induced by the inoculation into the air sac and trachea. No lesions were produced by the esophageal injection. Clinically, the affected chicks showed emaciation and mouth breathing, and were inactive while some birds died. Grossly, they had hepatomegaly, splenomegaly and airsacculitis. Histopathologically, fibrinopurulent airsacculitis, pneumonia and bronchitis, multiple fibrinous serositis in the hepatic and splenic capsules, peri- and epicardium, and mesenterium, focal endoarteritis in the aortae, activation of reticuloendothelial cells in the spleen, and hepatic necrosis were noted. Immunohistochemically, chlamydial antigen granules were present in the cytoplasm of epithelial cells of the respiratory system, hepatocytes, macrophages in the air sac, lung, serous membrane, liver, spleen, aortae, reticuloendothelial cells in the spleen, and mesothelial cells in various organs or tissues. Chlamydial multiplication in the cells of the organs or tissues involved was preceded to form the lesions.     

Pathological changes in chickens, ducks and turkeys fed high levels of rapeseed oil.

Rations containing 25% of either regular rapeseed oil (36% erucic acid), Oro rapeseed oil (1.9% erucic acid), soybean oil or a mixture of lard and corn oil were fed to chickens, ducks and turkeys. The regular rapeseed oil ration caused growth depression, increased feed conversion and anemia in all species. All the ducks and some of the chickens fed the regular rapeseed oil ration died. These dead birds were affected with hydropericardium and ascites. No deaths in the turkeys could be attributed to the regular rapeseed oil ration but some turkeys fed this ration had degenerative foci characterized by infiltrations of histiocytic and giant cells in the myocardium. Severe fatty change in the heart, skeletal muscles, spleen and kidney was found at an early age in all birds fed the regular rapeseed oil ration. Less severe fatty change but no other lesions were found in birds fed the Oro rapeseed oil and soybean oil rations.     

Porcine salmonellosis. I. Gross and microscopic changes in experimentally infected animals

Renal vascular lesions associated with experimentally induced septicemic porcine salmonellosis consisted of fibrinoid necrosis of the vessel walls and fibrin thrombi within the lumina of interlobular arteries, afferent arterioles and glomerular capillary loops. Extrarenal vascular alterations were predominantly localized to the skin and the lungs. In these sites, too, mere fibrin thrombi were found in the capillaries, whereas mixed thrombi, consisting of fibrin, platelets, leucocytes and erythrocytes were present in larger vessels. The conclusion is drawn that the renal vascular injury is completely compatible to the generalized Shwartzman reaction, while the extrarenal vascular changes may only in part depend on this mechanism.     

猪弓形虫自然感染病例病理组织学观察

为探究猪弓形虫感染对猪器官组织学结构的影响,对信阳某猪场自然发病猪进行病理学诊断。处死病猪后采取肝脏组织用福尔马林固定,姬姆萨染色法进行染色。采集肺、肝、肾、淋巴结和心等组织,石蜡包埋,HE染色,光学显微镜下观察。在用姬姆萨染色的肝脏切片上能够观察到弓形虫的速殖子,分别在肺、肝、肾、脾脏、淋巴结和心脏等组织器官切片中发现弓形虫滋养体或假囊,表明该场疾病是由猪弓形虫引起的,各组织器官出现出血、炎性细胞浸润、嗜酸性粒细胞和中性粒细胞增多等病理变化。     

斑点叉尾(鱼回)疑似疱疹病毒感染的病理形态学观察

对四川省一些养殖场斑点又尾鮰大规模死亡的病鱼组织进行了光镜和电镜观察．在其肾和肝组织的细胞中发现一种圆形或椭圆形病毒颗粒，有囊膜的病毒颗粒存在于胞浆中，直径150～200nm．无囊膜的病毒颗粒既存在于胞浆中，也存在于胞棱中，直径为80～110nm，同时在细胞核内可见无病毒核心的空衣壳，根据其形态特征初步确定为一种疱疹病毒。病鱼主要表现为鳍条基部和皮肤（特别是腹部和尾柄）充血、出血，腹部膨大，眼球突出．鳃发白．腹腔内充有淡黄色或淡红色的腹水，胃肠道扩张，其内充满大量淡黄色的粘液，肝、脾和肾肿大。病理组织学变化主要为全身组织器官广泛性水肿、出血、变性、坏死和炎症细胞浸润，特别是肾、肝、胃肠道、脾和脑的损伤较为严重。肾间质水肿，造血组织坏死，巨噬细胞和中性拉细胞浸润．肾小管上皮细胞空泡变性和坏死；肝水肿，狄氏间隙增宽．肝细胞空泡变性及坏死；胃肠道粘膜上皮变性，坏死．脱落，固有膜，粘膜下层水肿，淋巴细胞、巨噬细胞和中性枉细胞浸润；脾淤血．出血．淋巴细胞减少，大量巨噬细胞和中性粒细胞浸润；脑水肿，神经细胞肿胀．甚至坏死固缩。超微结构上．被病毒感染的细胞发生明显的痛变，线粒体肿胀，嵴断裂．溶解，粗面内质网扩张，核糖体颗粒脱落．细胞核体积增大，染色质浓缩．边集。     

家兔暴发病毒性出血症的病理学诊断

对送检的9只家兔进行病理解剖,对心血、肝、脾及肠系膜淋巴结进行细菌分离培养,并选取心、肝、脾、肺等组织按常规病理制片进行病理组织学检查,应用免疫组化染色(ABC法)检测肝细胞内兔病毒性出血症病毒(RHDV)抗原,结果证实此次家兔自然暴发的传染病即是兔病毒性出血症(RHD)。其临床主要表现为最急性型及急性型,病理变化特点以全身微循环障碍为主;DIC形成,以实质器官淤血、水肿、出血、变性、坏死为主要特点,其中以肝、肾、脾等器官病变较重,尤其肝脏的病变具有特征性。综合病理学检测结果,确定此次家兔暴发的是RHD。     

An outbreak of influenza (H1N1) in turkey breeder hens

Outbreaks of influenza were diagnosed in two turkey breeder flocks on the same premises in eastern North Carolina during the "dark-out" period of recycling for a second lay. Clinical history included increased mortality from acute death with no apparent predisposing illness. Mortality attributed to the disease was 4.5% in one flock and 3.3% in the other. Necropsy findings included severe diffuse congestion and edema of both lungs, with little or no pleural exudate. Spleens were moderately to markedly enlarged and mottled, and kidneys were swollen and congested. Microscopic lesions included moderate to severe serofibrinous pneumonia with severe pulmonary congestion. Splenic changes included fibrin deposition and severe congestion, and severe congestion was noted in kidneys. Influenza virus (H1N1) was isolated from pools of tissues including lung, spleen, liver, and kidney, and both flocks seroconverted to influenza (H1N1) virus.     

Response of turkeys to simultaneous vaccination with hemorrhagic enteritis and Newcastle disease viruses.

The effects of single and combined vaccination of turkeys against hemorrhagic enteritis virus (HEV) and Newcastle disease virus (NDV) were investigated. Dual vaccination of turkeys with NDV-B1 and HEVp30 or marble spleen disease virus (MSDV) enhanced white mottling of the spleens and the apoptosis rate in spleen cells (P < 0.05). In addition, simultaneously vaccinated turkeys had fewer HEV-infected spleen cells at 4 days postvaccination than turkeys given HEVp30 or MSDV alone. The anti-HEV antibody response was significantly reduced at 14 days postvaccination (P < 0.05), whereas the anti-NDV antibody response was enhanced (P < 0.05) in turkeys vaccinated with HEVp30 + NDV-B1. Further, the effect of dual vaccination on macrophage function was studied. Spleen cells from NDV-B1-vaccinated turkeys were primed to produce nitric oxide (NO) after stimulation in vitro with lipopolysaccharide. Spleen cells from HEVp30- or MSDV-vaccinated turkeys did not produce NO after in vitro stimulation. In dual-vaccinated turkeys, the priming effect of NDV-B1 was reduced in comparison with single-inoculated birds.     

Pathology of adenoviral infection in turkeys (Meleagris gallopavo) with respiratory disease and colisepticemia.

Nuclear inclusion bodies typical of the adenovirus group were widespread in in the spleen and other tissues of 8-week-old turkeys with severe respiratory disease and concomitant evidence of colisepticemia. Adenoviral virions were seen in affected nuclei of splenic tissue and in negatively stained preparations of ground spleen. In splenic tissue, inclusions were most prominent in reticular cells and macrophages in the periarterial lymphoid sheaths, the red pulp and the marginal zones of the periarteriolar reticular sheaths. Marked reticuloendothelial hyperplasia, lymphoid atrophy and granulocytic splenitis characterized the splenic changes. There were inclusions in the respiratory tract, intestinal tract, liver, kidney and pancreas. Inoculation of young turkeys, especially when immunosuppressed, resulted in evidence of infection and respiratory disease. The viruses produced cytopathic changes in primary turkey kidney cell cultures but did not affect embryonating chicken eggs. Concentrated viral suspensions induced precipitin lines in agar gel immunodiffusion tests with known antisera against known turkey adenoviruses but did not show an antigenic relationship to chicken adenoviruses.     

Fatal herpesvirus infection in commercial rabbits

Acute mortality occurred in two unrelated rabbitries. In the rabbits examined, an unidentified herpesvirus caused lesions that have not been reported previously in this species. The primary lesions were multifocal hemorrhagic dermatitis on the face and back, localized pneumonia, and severe splenic necrosis. Large eosinophilic, intranuclear inclusion bodies that were observed in tissue sections of skin, spleen, and lung were identified as herpes-like viral particles by electron microscopy, and herpesvirus was cultured on rabbit kidney cells. Intramuscular injection of tissue culture fluid containing virus resulted in mortality and severe illness in two seven-week-old domestic rabbits four and six days postinfection, respectively. The gross and microscopic lesions were reproduced and herpeslike viral inclusions were observed in skin lesions. Herpesvirus was recovered from lung, trachea, spleen, liver, and from the thigh muscle at the site of inoculation. The experimental infection also activated severe pasteurella septicemia. The herpesvirus isolate needs further characterization.     

CELLULAR FEATURES OF SONOGRAPHIC TARGET LESIONS OF THE LIVER AND SPLEEN IN 21 DOGS AND A CAT

Target lesions are seen in ultrasound images of the liver or spleen as nodules or masses with a hypoechoic rim and a hyperechoic or isoechoic center. To assess the diagnostic significance of finding a target lesion, the cytologic and/or histopathologic findings were reviewed in a series of 21 dogs and a cat that had hepatic and/or splenic target lesions noted during abdominal ultrasonography. Twelve of 16 hepatic target lesions and 5 of 7 splenic target lesions were malignant. In this series, the finding of one or more target lesions in the liver or spleen had a positive predictive value for malignancy of 74%; for the finding of multiple target lesions in one organ, the positive predictive value for malignancy was 81%. Benign lesions associated with target lesions were nodular hyperplasia of the liver and spleen, pyogranulomatous hepatitis, cirrhosis, and chronic active hepatitis.     

Safety and efficacy of the avirulent Mycoplasma gallisepticum strain K5054 as a live vaccine in poultry

A Mycoplasma gallisepticum (MG) isolate from an atypically mild outbreak in turkey breeders was found to be similar to house finch isolates by DNA analyses. A preliminary study in turkeys showed that this isolate (K5054) caused very mild lesions and protected turkeys against subsequent challenge with a virulent MG strain. In this study, K5054 was further evaluated as a potential vaccine strain in commercial layer-type chickens and turkeys. The safety of K5054 was evaluated by aerosol challenge followed by evaluation of gross and histopathologic lesions as well as serologic reactions and isolation of MG from the trachea and air sacs. Infection of chickens (trial 1) and turkeys (trial 2) with K5054 resulted in little evidence of MG lesions. There was weak seroconversion, and K5054 was consistently reisolated from the tracheas of chickens and turkeys. The efficacy of K5054 as a vaccine was evaluated by aerosol challenge of vaccinated chickens (trial 3) and turkeys (trial 4) with virulent R strain. There was evidence of protection from lesions associated with MG.