The effect of hypovitaminosis A on the pathogenesis of Pasteurella multocida in turkeys

It has been proposed that Pasteurella multocida can invade the host tissues via the mucous membrane. Vitamin A (VitA) deficiency has been associated with mucous membrane damage, such as squamous metaplasia. The objective of this study was to determine the early stages in the pathogenesis of P. multocida in VitA-deficient turkeys and clinically healthy turkeys. Fifteen-week-old VitA-deficient and clinically healthy turkeys were inoculated with P. multocida P-1059, a virulent strain, and the portal of entry, invasion, and localization of P. multocida were studied by microbial examination of the trachea, liver, and lung and histologic examinations of internal organs. Higher mortality was found in VitA-deficient turkeys. Pasteurella multocida was first reisolated from the trachea, secondarily from the liver and blood, and finally from the lung in both groups. Invasion of P. multocida into tissues occurred between 3 hr and 24 hr postinoculation in both groups. Our findings suggest that altered membrane integrity in VitA-deficient birds did not appear to change the time course of the systemic spread of P. multocida infection in turkeys and that the increased mortality seen in the VitA-deficient turkeys may be associated with immune system impairment.     

Correlation between low gastric pH and the formation of gizzard erosions in chicks

1. The inner lining of the gizzard was degraded by in vitro pepsin treatment at pH values lower than 2. 2. A significant linear regression was observed between the pH values on the surface of the inner lining and those on the gizzard mucous layer just under the lining. 3. The control chicks had a specific distribution pattern of pH values on the lining of the gizzard. By feeding a gizzard erosion inducer, pH values were lowered and the distribution pattern disappeared. In the latter case, however, a gastric erosion was observed consistently at the area which showed the lowest pH value in the control chicks. 4. From the results, possible mechanisms of the formation of gizzard erosions are discussed.     

Gizzard erosion in broiler chicks by group I avian adenovirus

Incidences of mortality without any clinical signs occurred in growing chicks in a broiler flock. Five 17-day-old dead broilers with gizzard erosions were investigated pathologically. Macroscopically, the gizzards were found to be dilated with bloody fluids. The koilin layer of the gizzards showed multifocal black patches (erosions). Histologically, there was necrosis of the koilin layer, degeneration and depletion of the gizzard glandular epithelium with intranuclear inclusion bodies, and hyperplasia of the macrophages in the lamina propria. An immunohistochemical analysis revealed intranuclear inclusion bodies in the degenerating gizzard glandular epithelial cells that stained positively for group I avian adenovirus antigen. Ultrastructurally, numerous viral particles (an average of 72 nm in diameter, from 63 to 88 nm) were in the intranuclear inclusions of glandular epithelium. This study suggests that the gizzard erosions may have been caused by group I avian adenovirus. In addition, the degeneration and depletion of gizzard glands secreting koilin substances, by adenovirus, may induce a reduction of koilin substances, which may then cause gizzard erosion (focal loss of the koilin layer).     

鸡肾型IBV引起病理形态学的电镜观察

本试验通过扫描电镜与透电镜，观察了鸡肾型传生支气管炎病毒（ＩＢＶ）在气管、肺、肾人的分布以及对器官组织的损伤作用，观察结果表明，肾型ＩＢＶ主要分布于气管粘膜上皮、肺呼吸毛细管上皮和肾上管上皮细胞浆内，还分布于毛细血管周围。肾型ＩＢＶ对器官组织的损伤作用主要表现为：气管粘膜纤毛上皮细胞的纤毛脱落，有的缠结成簇，甚至严重倒伏。肺呼吸滤过膜增厚，并发生纤维化。肾小管质液化，线粒体变萎缩，有的线粒体溶解呈     

Pili-mediated attachment of Corynebacterium renale to mucous membrane of urinary bladder of mice

Corynebacterium renal strain 115 with numerous pili became attached in vivo to the mucous membrane of the urinary bladder of mice 10 to 30 times more frequently than did that of C renale American Type Culture Collection 19412, which showed few pili. Antipili serum-treated C renale strain 115 was not recovered from the membrane in as large amounts as was untreated bacteria. Antisomatic serum-treated strain 115, on the other hand, was recovered from the membrane in amounts similar to untreated bacteria. Untreated organisms became attached to the mucous membrane of the urinary bladder more effectively than did the antipili serum-treated bacteria, as seen on scanning electron micrographs. It may be concluded that C renale strain 115 attaches itself to the mucous membrane of the urinary bladder om mice by the pili.     

Variability in the localization of cryptosporidia in the intestines of spontaneously infected calves

31 to 37 localities were examined in the small and large intestines of 48 calves spontaneously infected with cryptosporidiosis. It was found that cryptosporidia occurred the most frequently in the distal part of small intestine, within the range of six metres of small intestine, in front of the ostium ileocecale (OIC); at the ileocecal valve the incidence of cryptosporidia dropped rapidly. In none case were the protozoans revealed in duodenum and in the adjacent four to six metres of proximal jejunum. The small intestine was invaded by cryptosporidia in a variable manner, in some cases a major part was continuously invaded, in other cases only one or two metres of distal jejunum without any changes in the ileum and vice versa. Approximately half the calves had cryptosporidia in the cecum, fewer cryptosporidia were found in the transverse colon. Cryptosporidia in the rectum were found in about 25% of cases. Some calves had cryptosporidia only in the large intestine. The intensity of the mucous membrane invasion varied: mass incidence of cryptosporidia was found only in caudal parts of small intestine, with high variability of the extent and with sudden cases of negative findings. In the large intestine only the cecum was invaded more intensively and in a diffusive manner, in the transverse colon and in the rectum the groups of parasites were usually found at the openings and in the wall of Lieberk uhn 's crypts.     

Biology, pathogenicity, diagnosis and control of Ancylostoma caninum]

Infections with Ancylostoma caninum are transmitted orally or percutaneously. The transmission of infectious stages with the milk of particular importance for the distribution of the species. It occurs during the dissemination of larvae that follows every infection as well as after reactivation of resting somatic larvae in the bitch at the end of the pregnancy. The galactogenic transmission of larvae occurs even when, due to existing immunity, no patent infections develop in the bitch. Immunity does not or only to a low extent influence impatient infections or the migration of reactivated somatic larvae. It also allows a limited reestablishment of a deposit of larvae in the bitch. Following percutaneous infection dermatitis occurs in the area of larval penetration and the lung is affected by migrating larvae. Intestinal stages of Ancylostoma caninum damage the host by ingestion of the mucosa of the small intestine and withdrawal of blood. Main symptoms of ancylostomiasis are a mucous haemorrhagic diarrhoea and anaemia, that become visible 8 to 10 days post infection. The examination for impatient infections with Ancylostoma caninum can be done by immunofluorescence and ELISA. With both methods antibodies against third stage larvae can be detected from the first or second week post infection onward. Patent infections with Ancylostoma caninum can easily be detected by faecal examination for the presence of the characteristic oval, thin-walled eggs containing few blastomeres. Galactogenic infections with Ancylostoma caninum can be prevented or reduced by a regular treatment of the bitch with albendazole, fenbendazole or oxfendazole during the activation of larvae in the last third of the pregnancy or by repeated treatment with ivermectin shortly before and after birth. To prevent patent infections, galactogenic infected puppies have to be treated early and repeatedly.     

Experimental infection of specific-pathogen-free chickens with serotype-1 fowl adenovirus isolated from a broiler chicken with gizzard erosions

Gizzard lesions were formed in specific-pathogen-free (SPF) white leghorn chickens inoculated with fowl adenovirus (FAV). The virus, serotype 1 FAV 99ZH strain (FAV-99ZH), was originally isolated from the gizzard mucosa of commercial broiler chickens exhibiting gizzard erosion with intranuclear inclusion bodies. Five-day-old and 53-day-old SPF white leghorn chickens were inoculated with FAV-99ZH by both oral and ocular routes and then examined at necropsy on days 3, 5, 7, 10, 14, and 21 postinoculation (PI). There were no clinical signs in any of the chickens after the inoculation. Focal gizzard lesions occurred macroscopically, however, in inoculated chickens at several experimental periods. FAV was recovered from tissue samples of the proventriculus, gizzard, pancreas, and rectum by day 10 or 7 PI but was not recovered from liver samples of any of the chickens. These results indicate that FAV isolated from gizzard erosion is able to reproduce gizzard lesions as necrosis and erosion in SPF white leghorn chickens and that it may have a greater degree of tissue tropism in gizzards and other digestive organs than in the liver.     

Comparison of the polymerase chain reaction-restriction fragment length polymorphism pattern of the fiber gene and pathogenicity of serotype-1 fowl adenovirus isolates from gizzard erosions and from feces of clinically healthy chickens in Japan.

The fiber gene sequence and pathogenicity of the serotype-1 fowl adenovirus (FAdV-1) isolated from gizzard erosions and from clinically normal chickens were compared among isolates. The FAdV-99ZH strain, which induced gizzard erosions, had a nucleotide sequence of the long fiber gene that was different from that of the Ote strain, which did not induce gizzard erosions. The differences could be distinguished by use of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. The long fiber gene of 16 FAdV-1 isolates from gizzard erosions and 10 FAdV-1 isolates from the feces of clinically normal chickens was examined by use of PCR-RFLP analysis. All 16 FAdV-1 isolates from gizzard erosions had the same restriction patterns as those of strain 99ZH; however, 10 FAdV-1 isolates from normal chickens were classified into 3 groups. Specific-pathogen-free (SPF) chickens were inoculated orally with 2 FAdV-1 isolates from gizzard erosions or 3 FAdV-1 isolates from clinically normal chickens to determine the pathogenicity of each strain. Two of 2 FAdV-1 isolates from gizzard erosions induced gizzard erosions. Two of 3 FAdV-1 isolates from normal chickens had the same PCR-RFLP patterns as those of the Ote strain, but did not induce any gizzard erosions. However, 1 FAdV-1 isolate from clinically normal chickens had the same PCR-RFLP pattern as that of strain 99ZH and induced gizzard erosions. These results indicate that there are FAdV-1 strains that have different pathogenicity; one strain induces gizzard erosions, and the other does not. Use of PCR-RFLP analysis of long fiber genes may be able to distinguish between these two strains.     

Airway inflammation is associated with mucous cell metaplasia and increased intraepithelial stored mucosubstances in horses

This study was performed to determine if a peripheral sample of lung from the site where biopsy is conducted is representative of the rest of the lung and to investigate the relationship between airway inflammation and intraepithelial mucous production in the peripheral airways. Lung parenchyma samples were collected from five different regions of the lung in five control and five heaves-affected horses. Horse groups were defined by clinical response to stabling. Tissue sections were used for semi-quantitative scoring of lesions, to count the number of airways, to quantify the amount of stored mucosubstances (Vs) within the epithelium, and to count the number of epithelial cells in terminal airways. No significant differences were found between lung regions or between groups of horses. Lack of regional differences in airway structures means that a biopsy sample can be used for diagnosis and investigation of diffusely distributed diseases. Airway inflammation was correlated with mucous cell metaplasia and Vs. Therefore, in horses, mucus accumulation is partly caused by increased number of mucous cells and is associated with airway inflammation. Therapy targeted to reduce airway inflammation will help reduce the excessive mucous accumulation in horses.     

Role of Insoluble Fiber on Gizzard Activity in Layers

Effect of access to wood shavings on gizzard activity was examined for birds fed pelleted wheat and oat diets with or without whole cereal inclusion. Layers on litter floor fed wheat diets with access to coarse wood shavings showed up to 60% higher weight of the gizzard and its content than caged layers fed the same diets without access to wood shavings. No such effect was found by feeding oat diets. Thus, a significant interaction was found, indicating that the appetite for wood shavings may be dependent of fiber level of the diet. Appetite for wood shavings and paper was examined for birds fed wheat and oat diets in 2 other experiments. The intake of wood shavings and paper by birds fed a wheat-based diet was numerically twice as high as in birds fed an oat-based diet. However, the individual variation was remarkably high. Neutral detergent fiber (NDF) concentration in the gizzard of birds fed the oat diet was up to twice (P < 0.05) the fiber concentration in the gizzard of birds fed the wheat diet. Passage of structural fibers through the gizzard and the appetite for feathers in the absence of structural fibers were also studied in an experiment using diets based on rice and casein. Coarse fiber structures were observed to accumulate in the gizzard. In the absence of fiber, birds ate feathers, indicating that birds may eat feathers to compensate for the lack of structural components in the feed.     

Production of antibodies to recombinant antigens from Lucilia cuprina following cutaneous immunisation of sheep

Immunological control of cutaneous myiasis of sheep caused by Lucilia cuprina larvae has been an elusive goal. Antibody to antigens derived from the peritrophic membrane can stunt or kill larvae in a dose dependent fashion. Thus efficacy of vaccines employing these antigens may be limited by the amount of antibody in skin available for ingestion by larvae. The potential for elevating antibody concentrations in skin by intradermal immunisation with the recombinant peritrophic membrane antigens peritrophin-44, peritrophin-48 and peritrophin-95 was therefore examined. Using within-animal comparisons, specific antibody was significantly higher in skin transudates from locally immunised sites than from adjacent adjuvant control sites. It was concluded that cutaneous immunisation may assist immunological control of blowfly larvae.     

利福昔明子宫注入剂稳定性及其对家兔阴道黏膜刺激性研究

为研究利福昔明子宫注入剂的稳定性,从而初步确定其保质期,本试验取3批利福昔明子宫注入剂进行稳定性试验考察,包括影响因素、高温加速及长期稳定性,利用高效液相色谱法测定试验过程中利福昔明含量及有关物质的含量,从而初步确定利福昔明子宫注入剂的保质期。根据相关技术指导原则对家兔进行阴道刺激性试验。稳定性试验结果表明,根据面积归一化法计算有关物质的含量均不超过3%,注入剂的性状、沉降、粒度未发生明显变化,主成分利福昔明的含量变化在拟定标示量90.0%~110.0%范围内,从而确定本品的有效期为2年。家兔阴道刺激性试验结果显示,利福昔明子宫注入剂给药部位（阴道）和生理盐水对照组给药部位都没有出现红斑和水肿,刺激强度的评分为0;试验组和对照组的阴道黏膜没有出现明显的充血、水肿及异常分泌物流出的现象,阴道黏膜刺激指数为0.25。因此,利福昔明子宫注入剂对家兔的阴道无刺激性。本品的临床安全性良好,可进一步推广使用。     

The afferent innervation of the face of sheep and goats

The sensory innervation of the maxillary hairy skin and buccal mucous membrane was studied in anaesthetised sheep and goats. An electrophysiological technique isolated 47 single afferent units from the infraorbital nerve under chloralose or halothane anaesthesia. Mechanoreceptors of hairy skin were located in association with the following features: sinus hairs (n = 9); central primary hairs (n = 18); clear marginal hairs (n = 7) and skin-not-hair (n = 3). Units responded to hair tip displacement of 35 to 50 microm. Afferent units were also located in the mucous membrane of the cheek either associated with conical papillae (n = 8), or unassociated with papillae (n = 1). Receptor responses associated with hairs were classified as rapidly adapting (n = 18) and slowly adapting (n = 18) mechanoreceptor responses during sustained hair deflection. Seven mechanoreceptors of hairy skin and mucous membrane were excited by a fall in surface temperature. Two specific cold thermoreceptors were found: one in hairy skin and one in the mucous membrane. These units had phasic discharges during abrupt thermal depression and static discharges at constant surface temperatures. All afferent units had myelinated axons as indicated by their conduction velocities (range 20 to 57 m sec-1, mean 34 m sec-1). It is concluded that the mechanoreceptors identified had similarities with those of other mammalian species and some distinct differences. An interesting feature of mechanoreceptors in the buccal mucosa was their cold sensitivity. They therefore shared characteristics with mechanoreceptors in the penile mucosa of the ram and tongue of the sheep.     

Incidence of Haemonchus spp. and effect on haematocrit and eye colour in goats farmed under resource-poor conditions in South Africa.

The diversity and predominance of nematode genera in goats of resource-poor farmers at Rust de Winter, Gauteng Province, Impendle, KwaZulu-Natal Province, and Kraaipan, North-West Province, South Africa, was determined by means of a longitudinal study of the nematode faecal egg counts (FECs) and differential third-stage nematode larvae. The animals were bled for haematocrit determination and scored for pallor of ocular mucous membranes using the FAMACHA( Copyright) method, an assay for clinical evaluation of anaemia caused by Haemonchus spp. Animals considered to be in danger of dying from anaemia caused by haemonchosis were selectively treated with an anthelmintic.Lower haematocrit values were registered during periods of heavier Haemonchus infection, which occurred from December/January to March for Rust de Winter; from December to March/April for Impendle; and from November/December to February or April for Kraaipan. There was agreement too between the lower haematocrits and paler mucous membranes scored according to the FAMACHA( Copyright) method. The use of this system may be recommended as part of an integrated approach to worm control in goats kept in the resource-poor areas studied.     

Histologic features and clinical outcomes of melanomas of lip, haired skin, and nail bed locations of dogs.

Outcomes, signalments, and the relationship of histologic features with the outcome of melanomas located in lip, nail bed, and haired skin of dogs were reviewed. These melanomas were diagnosed as benign or malignant based on histologic features. Melanomas of the lip arose from mucous membrane in most cases. 32 dogs with lip melanomas that had histologic features of malignancy, 22 died because of the tumor within 1 year and 10 were tumor free for at least 1 year following removal. Of 10 dogs with melanomas with benign histologic features on the mucous membrane of the lip, 9 were tumor free for at least 1 year. Of 4 dogs with benign appearing tumors of the haired skin of the lip, 3 were tumor free for at least 1 year. Melanomas with histologic features of malignancy occurred in many locations of haired skin, and 11 of 24 dogs were tumor free for at least 1 year. All nail bed melanomas had histologic features of malignancy and all invaded the third phalanx, but 6 of 14 dogs were tumor free for at least 1 year after amputation of the digit. Among these dogs, the 1-year survival rates for tumors classified as malignant by histologic features were 69% for lip, 46% for haired skin, and 43% for nail bed. However, the clinical outcome of an individual malignant tumor could not be predicted accurately by any specific histologic features.     

支气管炎型H9亚型禽流感病毒的分离与鉴定

广东省某鸡场发生一起以严重呼吸困难、急性死亡为特征的病例,5000只鸡在1周内连续死亡400多只。通过病理剖检,几乎所有病死鸡支气管都充满干酪样物质,导致支气管严重阻塞,气管及支气管黏膜严重出血。采集病死鸡的肝脏、脾、肺和气管干酪样物质,病料经处理后通过SPF鸡胚绒毛尿囊膜接种获得一株病毒。通过琼脂凝胶免疫扩散(AGP)试验,该病毒能与禽流感标准阳性血清形成明显沉淀线,初步确定该病毒为禽流感病毒;通过血凝HA试验,该病毒能够凝集鸡红细胞,但此血凝现象不能被抗NDV血清、抗EDSV-76血清、抗H 5亚型流感单因子血清、抗H 7亚型流感单因子血清所抑制,而能被抗H 9亚型禽流感单因子血清所抑制,以及通过H 9亚型流感病毒的RT-PCR分子生物学诊断方法,最终确诊该病毒为H 9亚型禽流感病毒。动物回归试验,攻毒鸡表现与临床发病鸡一致的症状及典型病理变化,患鸡支气管被干酷样物严重阻塞,气管、支气管黏膜较严重出血,通过病料的病毒分离与鉴定,能再次分离到该病毒。     

Experimental gizzard erosions in specific-pathogen-free chicks by serotype 1 group I avian adenoviruses from broilers

The pathogenicity of serotype 1 group I avian adenovirus (GIAAV) strains isolated from gizzard erosions for 1-wk-old specific-pathogen-free (SPF) chickens was investigated. In Experiment 1, SPF chickens inoculated orally with a serotype 1 strain (Tokushima2000/GE) of GIAAV isolated from gizzard erosion in broilers were euthanatized and necropsied from 3 to 12 days after inoculation. Clinically, there were no significant signs in the chickens inoculated with Tokushima strain. The gizzards were found macroscopically to be dilated with liquefied contents. The koilin layer of the gizzard exhibited multifocal white lesions with occasional erosions. Gross lesions of the koilin layer (white foci and erosion) appeared at 3 days after inoculation and persisted until 12 days after inoculation. The gross lesions were most severe at 9 days after inoculation. Histologically, multifocal degeneration, necrosis, and loss of the glandular epithelial cells with intranuclear inclusions, liquefactive change of koilin substance, and erosive lesions of koilin layers and surface epithelium of the gizzards were observed. Macrophages increased in the focal areas of the lamina propriabelow the liquefactive koilin substances. Immunohistochemically, intranudear inclusions were positive against GIAAV antigen. Histologic lesions of gizzards were most severe at 7 and 9 days after inoculation, but the frequency of intranuclear inclusions was greatest at 5 days after inoculation. In Experiment 2, the pathogenicities of four strains of serotype 1 GIAAV for 1-wk-old SPF chickens were compared. Three strains isolated from gizzard erosion had similar pathogenicities but one strain from a normal chicken was not pathogenic for chickens. These results suggest that gizzard erosions by serotype 1 GIAAV infection may occur in broiler chickens in Japan.     

Density of selected enzymes in the goblet cells of the small intestine in piglets experimentally infected with the coccidium Isospora suis

The density of selected enzymes in the goblet cells of the mucous membrane of the small intestine was studied in a group of 12 gnotobiotic piglets experimentally infected with the coccidium Isospora suis one day after parturition (DPP), using the Vickers M-786 scanning and integrating microdensity meter. At an infecting dose of 100,000 oocysts of I. suis, the histochemistry of the goblet cells of the mucous membrane of the piglets changed significantly in the period of 4 to 10 days after infection (DPI). Increases occur in the density of non-specific esterase (EC. 3.1.1.1.) and acid phosphatase (EC. 3.13.2.). The density of acid and neutral muco-substances declines and the densities of alkaline phosphatase (EC. 3.1.3.1.) and aminopeptidase M (EC. 3.4.11.2) are significantly high. The goblet cells of the mid and posterior parts of jejunum are very similar in their histochemistry in the experimentally infected gnotobiotic piglets. In the duodenum and ileum the histochemical picture of the goblet cells shows no substantial difference from the data recorded in the goblet cells of the mucous membrane of the small intestine of the four control piglets at an age of two to seven days.     

Validity of indicators of dehydration in working horses: a longitudinal study of changes in skin tent duration, mucous membrane dryness and drinking behaviour

REASONS FOR PERFORMING STUDY: Dehydration is a serious welfare concern in horses working in developing countries. Identification of a valid and practical indicator of dehydration would enable more rapid treatment and prevention. OBJECTIVES: To examine changes in bodyweight, clinical and blood parameters during rehydration of working horses, identify a 'gold standard' criterion for dehydration and use this to validate a standardised skin tent test, drinking behaviour and mucous membrane dryness as potential field indicators. METHODS: Fifty horses with a positive skin tent test, working in environmental temperatures of 30-44 degrees C in Pakistan, were rested and offered water to drink ad libitum. Bodyweight, clinical and blood parameters, mucous membrane dryness, drinking behaviour and skin tent duration at 6 anatomical locations were measured at 0, 30, 60, 120, 180, 240 and 300 min. RESULTS: Skin tent duration was affected by side of animal (P = 0.008), anatomical location and coat moisture (both P < 0.001). Younger animals had shorter skin tents at all time points (P = 0.007). There was no significant association between plasma osmolality (P(osm)) or water intake and skin tent duration. Horses with a higher P(osm) drank significantly more water (P < 0.001), and had longer (P < 0.001) and more frequent (P = 0.001) drinking bouts. Neither P(osm) nor water intake affected qualitative and semi-quantitative measurements of mucous membrane dryness significantly. CONCLUSIONS AND POTENTIAL RELEVANCE: The standardised skin tent test and measures of mucous membrane dryness investigated in this study were not valid or repeatable indicators of dehydration when compared with P(osm) as a 'gold standard' criterion. The volume of water consumed and the number and duration of drinking bouts were the most reliable guide to hydration status currently available for mature working horses. Offering palatable water to drink ad libitum provides both the diagnosis and the remedy for dehydration in working horses.