Patho-epidemiological and risk factor studies for detection of Neospora-associated abortion in cattle and buffaloes in Punjab, India.

The diagnosis of abortion in livestock is difficult. In this paper, Neospora caninumassociated abortion in cattle and buffaloes in India is reported for the first time. A total of 184 animals (cattle, n = 133; water buffaloes, n = 51) were randomly selected for seroprevalence studies from 28 farms with a history of abortion. Antibodies to N. caninum were detected using a commercial competitive enzymelinked immunosorbent assay (c-ELISA); the percentage seropositivity was 10.5% for cattle and 21.6% for buffaloes. Risk factors such as species, i.e. buffaloes in comparison to cattle (odds ratio [OR] = 2.33, calculated probability [p] = 0.05), disposal of foetus and foetal membranes by throwing them into the field, in comparison with burning/burial (OR = 2.63, p = 0.03), and origin of the animal, i.e. purchased from outside in comparison to born on the farm (OR = 4.69, p = 0.002), were significantly associated with N. caninum seropositivity in univariate logistic regression. In multivariate analysis, only two risk factors, animal purchased from outside (OR = 6.15, p = 0.001) and buffaloes (OR = 3.20, p = 0.01), were significantly associated with Neospora seropositivity at a p-value < 0.05. Histopathological examination of aborted foetal tissues (cattle, n = 13; buffaloes, n = 8) revealed N. caninum tachyzoites in the heart and liver of three foetuses, and the diagnosis was confirmed by positive immunoreactivity to anti-N. caninum polyclonal antibody in the placenta of one foetus. To the authors' knowledge, this is the first report of confirmed neosporosis abortion in cattle and buffaloes in India.

Les causes d'avortement chez le bétail sont difficiles à déterminer. Cet article constitue le premier rapport faisant état d'une association entre des avortements survenus chez des bovins et des buffles en Inde et le parasite Neospora caninum. Afin de déterminer la prévalence d'anticorps anti-N. caninum dans 28 élevages ayant présenté des cas d'avortement, 184 animaux provenant de ces élevages (bovins, n = 133 ; buffles domestiques, n = 51) ont été sélectionnés de manière aléatoire et soumis à une analyse sérologique. Une épreuve immuno-enzymatique commerciale de compétition (cELISA) a été utilisée pour la détection d'anticorps vis-à-vis de N. caninum ; la prévalence sérologique était de 10,5 % chez les bovins et de 21,6 % chez les buffles. Une analyse univariée appliquant un modèle de régression logistique a permis de déterminer les facteurs de risque suivants comme étant associés à la présence d'anticorps vis-à-vis de N. caninum : l'espèce (buffle vs bovin) (rapport de cotes ou odds ratio [OR] = 2,33, probabilité calculée [p] = 0,05), le mode d'élimination du foetus et des membranes foetales (rejetées au sol vs incinérées ou enfouies) (OR = 2,63, p = 0,03), et l'origine de l'animal (acheté à l'extérieur vs né dans l'élevage) (OR = 4,69, p = 0,002). L'analyse multivariée a fait apparaître une corrélation significative (valeur de p < 0,05) entre la présence d'anticorps vis-à-vis de Neospora et deux facteurs de risque seulement, à savoir l'achat de l'animal à l'extérieur (OR = 6,15, p = 0,001) et l'espèce bubaline (OR = 3,20, p = 0,01). L'examen histopathologique des tissus d'avortons (bovins, n = 13 ; buffles, n = 8) a révélé la présence de N. caninum sous forme de tachyzoïtes dans le coeur et le foie de trois foetus ; une réaction immunitaire déclenchée par des anticorps polyclonaux anti-N. caninum dans le placenta de l'un des foetus a confirmé ce diagnostic. À la connaissance des auteurs, il s'agit de la première observation rapportée et confirmée en Inde d'avortements dus à la néosporose chez des bovins et des buffles.

Diagnosticar las causas de un aborto en el ganado vacuno no es tarea fácil. Los autores describen, por primera vez en la India, casos de aborto ligados a Neospora caninum en ganado vacuno y búfalos. Tras seleccionar aleatoriamente un total de 184 animales (vacunos, n = 133; búfalos de agua, n = 51) en 28 explotaciones que habían sufrido casos de aborto, se efectuaron estudios de prevalencia sérica. Para detectar los anticuerpos contra N. caninum se empleó un ensayo inmunoenzimático (ELISA) de competición disponible en el mercado, que arrojó un porcentaje de seropositividad de un 10,5% en el caso del ganado y de un 21,6% en los búfalos. Analizando los resultados por regresión logística de una sola variable, se observó que la seropositividad para N. caninum presentaba una correlación significativa con factores de riesgo como: la especie, esto es, búfalos en comparación con vacunos (razón de probabilidades [OR] = 2,33, probabilidad calculada [p] = 0,05); la eliminación del feto y las membranas fetales arrojándolas al campo, en comparación con su incineración o inhumación (OR = 2,63, p = 0,03); y la procedencia del animal, esto es, los animales adquiridos del exterior respecto de los nacidos en la explotación (OR = 4,69, p = 0,002). Al efectuar un análisis multifactorial solo se encontraron dos factores de riesgo significativamente relacionados con la seropositividad para Neospora a un valor de p < 0,05: la adquisición de animales del exterior (OR = 6,15, p = 0,001); y el hecho de que fueran búfalos (OR = 3,20, p = 0,01). El estudio histopatológico de tejidos de fetos abortivos (vacunos, n = 13; búfalos, n = 8) reveló la presencia de taquizoítos de N. caninum en el corazón y el hígado de tres fetos, diagnóstico confirmado por la inmunorreactividad positiva frente a anticuerpos policlonales contra N. caninum en la placenta de un feto. Hasta donde saben los autores, se trata de los primeros casos de aborto por neosporosis en ganado vacuno y búfalos que se describen y confirman en la India.

Early migration pattern of Avibacterium paragallinarum in the nasal passage of experimentally infected chicken and Japanese quail by immunohistochemistry.

Infectious coryza (IC) is often a curse for poultry farmers when it occurs concurrently with several pathogens causing swollen head syndrome. The disease is caused by Avibacterium paragallinarum, which inflicts initial damage to the nasal and respiratory epithelium. This facilitates the progression of disease pathology across the nasal cavity, thereby providing a platform for multiplication of opportunistic microbes. In this study, we attempted to investigate the early entrance and migration pattern of A. paragallinarum in chicken and Japanese quail following experimental infection, by employing an in-house developed polyclonal antiserum against this pathogen. Antigenic-specificity of the raised antiserum was subsequently evaluated through immune-dot blot techniques and counter-current immunoelectrophoresis (CIE). The resultant antiserum characterized the antigen localization within formalin-fixed and partially decalcified nasal tissue sections though immunohistochemistry (IHC). Japanese quail showed prominent localization of the bacterial antigen at 12 h post-infection in anterior turbinates. However, the chicken exhibited a higher level of the bacterial pathogen with intense immuno-reactivity at 24 and 48 h post-inoculation. The decline in immunostaining intensity in the nasal tissue of chicken as well as Japanese quail by 72 h post-infection signifies either an attempt to resolve the infection by the resident immune cells across the nasal passage of the host, or its dissipation by certain inherent innate immune factors present across the nasal passage that are still unknown to us. In the present study, we used a moderately virulent pathogen (A. paragallinarum) that inflicted a mild to moderate degree of damage to histo-architecture of the nasal passage and provided a discernible migratory pattern with fewer alterations, along with provision toward unravelling basics of the immuno-pathogenetic mechanism. This knowledge will support efforts towards the development of a future mucosal nasal vaccine in birds affected with IC.

Sublethal chronic effects of oral dietary exposure to deltamethrin in Swiss albino mice.

The hazards of dietary exposure to environmentally relevant levels of deltamethrin are poorly understood though studies enunciate the acute toxicity hazards. In this study, prolonged exposure to low levels of deltamethrin in mice was investigated. The mice were exposed daily via gavage method for 60 days. Four doses (0.1, 0.05, 0.01, and 0.005 mg/kg bwt/d) were selected, which are equal to or less than the maximum residue limits for deltamethrin permitted in animal food/feed. Liver, kidney, lungs, spleen, and testes were collected on day 61 for histology, residue, and biochemical analysis (aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALKP), total bilirubin (TBIL), total proteins (TPs), cholesterol (CHOL), urea, and creatinine). No significant changes were observed in body weight gain in all treatment groups ( p > 0.05). The gas chromatography analysis indicated that none of the tissue samples contained deltamethrin residues above the limits of quantification. The significant differences in biochemical profile (AST, ALT, TBIL, and creatinine) reported in animals exposed to 0.1 and 0.05 mg/kg bwt/d deltamethrin ( p < 0.05) suggest respective tissue injury and lipid peroxidation; however, few significant changes in urea and CHOL were also reported in doses 0.01 and 0.005 mg/kg bwt. No significant differences in TP and ALKP were observed ( p > 0.05). The target organs for deltamethrin toxicity showed prominent histopathological changes in concentrations of 0.1 and 0.05 mg/kg bwt. Other two doses showed no or sporadic changes. Our findings suggest that chronic exposure to environmentally relevant levels of deltamethrin can have detrimental effects on vital organs in the circumstances allowing daily exposure, in congruence with available literature.

Hypervitaminosis D3 in broiler chicks: histopathological, immunomodulatory and immunohistochemical approach.

The present study was undertaken to investigate the toxic effects of higher doses (1,00,000 IU i.e. 2.5 mg/kg body weight (BW)) of vitamin D3, concomitantly with bacterial endotoxins (lipopolysaccharides: LPS) to study the immunomodulatory potential of vitamin D3 in IBL-80 broiler chicks. The chicks were divided into four groups [group I (NSS), group II (LPS), group III (Vit. D3 + NSS), and group IV (Vit. D3 + LPS)] containing eight chicks in each group, treated accordingly for 21 days. Birds were kept under close observation for apparent clinical signs and symptoms. Clinically, vitamin D3 treated chicks were dull, off feed, showed polydipsia, polyuria, watery faeces, rigidity of limbs, severe dehydration, weakness and significant progressive emaciation. Grossly, the bones were soft whereas most organs revealed congestion and hemorrhages in visceral organs. Histopathologically, renal tubular epithelium showed coagulative necrosis and metastatic calcification. The lung parenchyma and bronchi showed hemorrhages, congestion with diffuse heterophilic cell infiltration in inter-alveolar septa and infiltration of heterophils in alveoli along with proteinacious fluid in LPS treated chicks of treatment group, suggesting immunomodulatory action of vitamin D3. Vitamin D3 treated chicks showed strong expression of Calbindin D28k in intestine and kidney but weak expression in lung, which can be linked to nephrocalcinosis seen in kidney and from its prospective role in cellular calcium homeostasis.

Comparison of diagnostic tests for the detection of bovine brucellosis in the natural cases of abortion.

Rapid and precise diagnosis in natural field cases of bovine abortion caused by Brucella abortus warrants the use of the most sensitive and reliable diagnostic methods. In the present study, bacterial isolation, serology, gross, histopathology, immunohistochemistry and polymerase chain reaction technique(s) were applied. Sero-prevalence studies showed the rate of 28.86% positive cases using the competitive ELISA. Histopathological changes were mainly seen in the placenta, fetal lungs, kidney, liver and spleen. Immunohistochemical (IHC) staining of Brucella spp. was evident as brown, finely granular intracytoplasmic staining in trophoblasts of placental sections and in section(s) of liver, lung, kidney and spleen. Twenty-eight out of the 103 samples (17 from stomach contents, 3 from placental cotyledons, 2 from vaginal discharges and 6 from pooled fetal tissues) produced 193 bp amplicon specific for Brucella genus. Moreover, the species-specific primers amplified a 498 bp amplicon which corresponded to B. abortus. Comparison of diagnostic tests revealed PCR and IHC provide a reliable test for the diagnosis of bovine brucellosis in aborted fetal tissue and placental cotyledons whereas serology is most important for detection of Brucella positive animals in a herd.

Concomitant effect of low dose of lindane and intranasal lipopolysaccharide on respiratory system of mice.

Lindane is very commonly used organochlorine pesticide and has been reported to cause several toxic effects including respiratory insufficiency. However, effects of low concentration of lindane alone or in combination with microbial molecules on lungs are not fully understood. To understand the effects a preliminary study was designed on Swiss albino mouse. Male mice were divided into treatment and control group (20; each). Treatment mice were given lindane in ground nut oil orally at 0.25 mg kg-1 day-1 for 60 days. After treatment, 10 mice were challenged with intranasal Escherichia coli lipopolysaccharide (LPS; 80 µg per mice) and remaining 10 with normal saline. The mice were euthanized 16 h post-LPS exposure. Control mice (10 each) were given normal saline or the LPS alone. Mice exposed with lindane and in combination with LPS had increase in total cell counts and leukocyte counts in broncho-alveolar lavage. Histological examination showed lung injury in the lindane-treated mice. The histopathological changes were more pronounced in lindane along with LPS-exposed mice. Lindane alone and in combination with LPS showed expression of immunopositive Toll-like receptor (TLR)-4 and tumour necrosis factor-alpha (TNF-α) positive reaction in various cells of lungs. While LPS induced acute inflammation in the lungs, combination of lindane and LPS exacerbated histological signs of the inflammation. The data indicate that lindane alone or in combination with LPS caused changes in lung morphology and altered TLR-4 and TNF-α expression which may have led to altered response to LPS challenge.

Epidemiological and immunopathological studies on Porcine parvovirus infection in Punjab.

AIM: The aim of this study was to get the first-hand knowledge about the seroprevalence of Porcine parvovirus (PPV) in Punjab and a diagnosis of PPV from abortion cases of swine using gross, histopathological, and immunohistopathological techniques to observe the tissue tropism of the virus strain. MATERIALS AND METHODS: Tissue samples from the reproductive tract of pig (n=32), placental tissue (n=10), and aborted fetuses (n=18) were collected from Postmortem Hall of the Department of Veterinary Pathology, GADVASU, field outbreaks and from butcher houses in and around Ludhiana. These samples were processed for histopathological and immunohistochemical (IHC) studies. For seroprevalence study, 90 serum samples of different sex and age were collected from 15 swine farms of Punjab and were subjected to indirect enzyme linked immunosorbent assay using commercial kit. RESULTS: Overall, seroprevalence of PPV was found to be 41.1%. Sex and age related difference in the prevalence was noted. In abortion cases grossly congested and emphysematous lungs, congested internal organs with fluid in abdominal cavity and congestion in brain, changes were noted in fetuses, while diffuse hemorrhages and edema was observed in placental tissue. Histopathologically, the most frequent fetal lesions in aborted fetuses were noted in lungs, liver, and brain. IHC staining revealed PPV antigens in sections of heart, liver, lung, spleen, brain, lymph node of fetuses, placenta, and uterus of sow. Gross, histopathological, and IHC examination of the samples confirmed 5 fetus, 2 placenta and 3 female reproductive samples positive for parvovirus infection. CONCLUSIONS: Seroprevalence results may serve as a support either in prevention or control of the disease. IHC is the sensitive technique for diagnosis of PPV associated with the reproductive tract of swine and was found to supplement the gross and histopathological alterations, respectively, associated with the disease.

Histopathological and immunohistochemical diagnosis of infectious bursal disease in poultry birds.

AIM: The aim of the present study was to diagnose infectious bursal disease (IBD) using gross, histopathological, and immunopathological approaches and to compare efficacy of immunohistochemical techniques with conventional diagnostic techniques. MATERIALS AND METHODS: A total of 33 samples were collected from the six different poultry farms from Ludhiana and the nearby districts. Upon gross analysis of the necropsied birds, the relevant tissue samples such as bursa, kidney, junction of proventriculus and gizzard, heart, and muscles were then processed for histopathological and immunohistochemical studies. RESULTS: Varied macroscopic changes were noted in bursa, characterized as swollen, hemorrhages to atrophy in size. Nonetheless, hemorrhages over thigh muscles were rarely seen. Histologically, the bursa showed prominent fibrotic and atrophic changes. Rarefaction of bursal follicles with intermittent infiltration of lympho-mononuclear cells with chronic cystic changes was additional changes, considered to be paramount for IBD. Expression and localization of IBD specific viral antigens were noticed mainly intracellular to the rarefied areas of bursal follicle section(s), in conjunction to inner lining of the cystic cavities of affected follicles. In addition, the junction of proventriculus and gizzard, the heart muscle, respiratory ciliated epithelium, and proventriculus also revealed positive expression to IBD virus (IBDV) antigen. Advanced immunopathological techniques, i.e., immunofluorescence further testified the evidence of antigen as positive green signal within affected follicles. Further consideration to the reliability of various techniques employed, positive correlation (r=0.64623) was emerged out with conventional pathological scoring. CONCLUSION: It is concluded that the bursa acts as an organ of choice for demonstrating IBDV antigen for specific diagnosis of disease using immunohistochemistry (IHC), and IHC staining is a precise, specific, rapid, and reliable method to demonstrate the IBDV antigen in the altered tissues due to IBDV infection.

Comparison of diagnostic tests for diagnosis of infectious bovine rhinotracheitis in natural cases of bovine abortion.

Rapid and precise diagnosis plays a pivotal role in implementing suitable control measures in natural field cases of bovine abortion due to infection with bovine herpesvirus (BHV)-1. In the present study, serology, virus isolation, histopathology, immunohistochemistry (IHC) and real-time polymerase chain reaction (PCR) for amplification of the gene encoding glycoprotein B were applied for diagnosis of infectious bovine rhinotracheitis (IBR) in cases of abortion. The seroprevalence of IBR in the population studied was 26.3% as determined by indirect enzyme-linked immunosorbent assay. BHV-1 abortions occurred between 4 and 8 months of gestation with an average gestational age of 6 months. Affected placentae showed necrosis of chorionic villi and of the endothelium of small villous blood vessels with characteristic intranuclear (IN) acidophilic inclusion bodies. Similar inclusions were also seen in most of the tissues examined. BHV-1 antigen was identified immunohistochemically in necrotic foci in the liver, the endothelium of placental blood vessels, the bronchial epithelium and hepatocytes. Lesions in the brain also had IN inclusion bodies that labelled positively by IHC. Eighteen samples (nine of stomach content, two of placental cotyledons, five of pooled fetal tissue and two of vaginal discharge) out of 84 tested were positive by real-time PCR for BHV-1.

Veterinary urban hygiene: a challenge for India.

India is confronted with many hygiene problems in urban areas that are related to animal populations. While some of these issues have been present for many years, others are only now emerging. A livestock census in 2003 and another in 2007 revealed that populations of crossbred cattle, goats and poultry are all increasing in urban areas, since this enables easy market access, which, in turn, reduces transportation costs and adds to profits. The canine population has increased along with the human population, largely due to a lack of control measures such as impounding stray animals and euthanasia. These increases in populations of both food-producing animals and stray animals in cities exacerbate such public health hazards as the transmission of zoonoses, vector-borne diseases, occcupational health hazards and environmental pollution, as well as compromising animal welfare. At present, public health hazards due to urban animal husbandry practices are considerably under-estimated. To improve veterinary-related urban hygiene and to facilitate livestock production operations in urban areas, there is an urgent need to develop sound, science-based strategies enforced through stringent regulations. The use of One Health teams may provide an answer to these highly integrated public health problems.

Clinicopathological Studies on Vitamin D(3) Toxicity and Therapeutic Evaluation of Aloe vera in Rats.

A study was conducted to examine the clinical signs, hematological, biochemical and histopathological changes in vitamin D(3) toxicity at a dose rate 2 mg/kg b.wt. of vitamin D(3) and to assess the protective effect of Aloe vera in vitamin D(3) toxicity. The clinical signs observed were anorexia, progressive weight loss, difficulty in movement and respiration, diarrhea, epistaxis, subnormal body temperature and nervous signs before death. Mortality was observed in treated rats between day 10 and day 19 of treatment. The gross postmortem changes observed were severe emaciation, white chalky deposits on epicardial surface of heart, pin point white deposits on cortical surface of kidneys with pale yellow discoloration and diffused white deposits on serosal surface of stomach and intestine with bloody ingesta in lumen. The hematological changes included non-significant increase in hemoglobin and total leukocyte count and significant increase in relative neutrophil count. The biochemical changes observed were significant increase in plasma concentration of calcium, phosphorus and blood urea nitrogen, whereas a significant decrease in the concentration of albumin and total plasma protein was observed. The histopathological lesions included calcification of various organs, viz., tongue, stomach, intestines, kidney, heart, aorta, larynx, trachea, lungs, spleen, choroid plexus arteries of brain and vas deferens. The Aloe vera juice (2.5% in drinking water) has no protective effect on vitamin D(3) toxicity (2 mg/kg b.wt.).

Chlorpyrifos chronic toxicity in broilers and effect of vitamin C.

An experiment was conducted to study chlorpyrifos chronic toxicity in broilers and the protective effect of vitamin C. Oral administration of 0.8 mg/kg body weight (bw) (1/50 LD50) chlorpyrifos (Radar(®)), produced mild diarrhea and gross lesions comprised of paleness, flaccid consistency and slightly enlargement of liver. Histopathologically, chlorpyrifos produced degenerative changes in various organs. Oral administration of 100 mg/kg bw vitamin C partially ameliorated the degenerative changes in kidney and heart. There was insignificant alteration in biochemical and haematological profiles. It is concluded that supplementation of vitamin C reduced the severity of lesions induced by chronic chlorpyrifos toxicity in broilers.

Climate change, zoonoses and India.

Economic trends have shaped our growth and the growth of the livestock sector, but atthe expense of altering natural resources and systems in ways that are not always obvious. Now, however, the reverse is beginning to happen, i.e. environmental trends are beginning to shape our economy and health status. In addition to water, air and food, animals and birds play a pivotal role in the maintenance and transmission of important zoonotic diseases in nature. It is generally considered that the prevalence of vector-borne and waterborne zoonoses is likely to increase in the coming years due to the effects of global warming in India. In recent years, vector-borne diseases have emerged as a serious public health problem in countries of the South-East Asia region, including India. Vector-borne zoonoses now occur in epidemic form almost on an annual basis, causing considerable morbidity and mortality. New reservoir areas of cutaneous leishmaniosis in South India have been recognised, and the role of climate change in its re-emergence warrants further research, as does the role of climate change in the ascendancy of waterborne and foodborne illness. Similarly, climate change that leads to warmer and more humid conditions may increase the risk of transmission of airborne zoonoses, and hot and drier conditions may lead to a decline in the incidence of disease(s). The prevalence of these zoonotic diseases and their vectors and the effect of climate change on important zoonoses in India are discussed in this review.

Neuropathological studies of chickens following exposure to chlorpyrifos.

The objective of this study was to determine the putative neuropathological effects in young chickens after administration of a single dose of 55 mg/kg bw chlorpyrifos. The gross lesions of the nervous system comprised of congestions in the brain. Microscopic examination of brain showed mild congestion of cerebral blood vessels and mild perivascular cuffing of lymphomononuclear cells in the cerebral cortex and necrosis of the neurons. The interesting findings were the presence of cytoplasmic vacuolations of cerebral neurons and swelling of the endothelial cell of the cerebral capillaries. Cerebellum showed congestion and hemorrhages in the granular layer and necrosis of Purkinje cell. Sciatic nerve exhibited mild edema, swelling and degeneration of axons, and swelling of Schwann cells. There was a significant inhibition of plasma cholinesterase enzyme activity in chickens administered with chlorpyrifos compared to chickens of control group. The study revealed that administration of chlorpyrifos produces neuropathological lesions in chickens shortly after exposure.

A Case of Intranasal Hemangioma and Concurrent Tetracycline-induced Ulcerative Gastritis in Dogs.

Incidence of drug-induced gastritis and ulceration in human medicine is well established. Besides, unilateral hemangioma, a unique concurrent case of tetracycline induced gastric toxicity in a dog, characterized by gastritis and ulceration is being reported here. Grossly, the appearance of gastric ulcers mimicked the appearance of Italian pizza. Histological examination further supported drug-induced etiology in this case. This is probably the one of the few cases in the annals of veterinary medicine to be documented as drug-induced gastric toxicity in dog.

Prevalence of Cryptosporidium parvum infection in Punjab (India) and its association with diarrhea in neonatal dairy calves.

A prevalence study was contemplated to determine the prevalence of Cryptosporidium spp. in dairy farms in Punjab, India. The cryptosporidium oocysts were detected from 50 and 25.68% from 80 diarrheic and 74 non-diarrheic animals, respectively. Both shedding and intensity of shedding were significant in calves with diarrhea. The Cryptosporidium spp. appears to be common in dairy calves and an important contributor of calf diarrhea in the Punjab province. The prevalence of the infection peaked in young calves between 0 and 30 days in both the diarrheic and non-diarrheic groups (86.4 and 66.6%, respectively). The percentage distribution of positive samples, with reference to age groups of diarrheic and non-diarrheic animals was negatively correlated with increase in age. High mortality rate and case fatality rate of 35.2 and 44.4% were observed in young calves between 0 and 30 days of age.

The pathogenicity and pathogenesis of Mycoplasma capricolum subsp. capripneumoniae (F38) in the caprine mammary gland.

The right mammary gland of 12 lactating goats was inoculated intracisternally with 1 ml of Mycoplasma capricolum subsp. capripneumoniae (Mcc) containing 10(6) colony-forming units (CFU), while their left mammary halves received 1 ml of sterile PPLO broth only. Two goats served as uninfected controls. The clinical mastitis that developed in the infected mammary halves within 24 h was initially acute but became increasingly chronic by the end of the experiment at 24 days post inoculation (DPI). The disease was characterized by atrophy of the infected mammary halves, leading to marked agalactia and an increase in somatic cell counts, with a preponderance of neutrophils initially and lymphocytes later. The Mycoplasma was re-isolated from infected mammary secretions up to 16 DPI but not from blood. Histopathology revealed that the mastitis was acute and purulent initially, followed by infiltration of lymphonuclear cells and fibroplasia in the lymphomononuclear cells and fibroplasia in the interacinar tissue, and later by massive fibrosis. Immunohistology demonstrated the presence of Mycoplasma-like bodies localized mainly on the surface of acinar/duct epithelial cells. The studies showed that Mcc was highly pathogenic in the caprine mammary gland.

Sequential pathological studies in Asian water buffaloes infected intratracheally with Absidia corymbifera.

Zygomycosis was produced experimentally in Asian water buffalo calves (Bubalus bubalis) by intratracheal inoculation of sporangiospores of Absidia corymbifera. Infected animals exhibited dullness, depression, partial anorexia, initial pyrexia, mucopurulent nasal and ocular discharge and coughing during the first week. There was no mortality at any stage of the experiment, which continued for 30 days. The gross and microscopic lesions were restricted to the lungs and there was no dissemination of the fungus to other organs. Gross and microscopic changes in the lungs were observed up to the 20th day post-infection. Gross lesions consisted of pneumonic consolidation of the antero-ventral lobes of the lungs. Microscopic changes consisted of granulomatous reactions with well developed pulmonary granulomas. Distorted hyphae of A. corymbifera were demonstrated in tissue sections up to 15 days post inoculation. Re-isolation of the fungus was achieved consistently for up to 15 days. It is concluded that intratracheal inoculation of A. corymbifera in buffalo calves leads to significant pathological changes in the lungs, but the disease appears to be self limiting 20 days following inoculation.

Experimental candidal mastitis in goats: clinical, haematological, biochemical and sequential pathological studies.

The present study, first of its kind, was conducted with the objectives to understand hitherto little known aspects of candidal mastitis, like its sequential pathology, pathogenesis and clinico-biochemical changes. For this purpose, unilateral intramammary inoculation of 10 goats with Candida albicans (1.2 x 10(7) yeast cells) resulted in the development of mastitis, with gross and microscopic lesions being restricted to the infected udder halves only and without dissemination of infection to the opposite uninfected udder halves as well as other organs of the body. The experiment was continued for 40 days and after infection, there was sharp fall in milk yield and Candida albicans was directly demonstrated in the milk and re-isolated from the milk and udder tissues up to 30th day after inoculation. An increase in total immunoglobulins in the milk and plasma along with increase in total plasma proteins were also observed. Haematology revealed leukocytosis and neutrophilia. Microscopically, there was acute purulent mastitis, which later became chronic, nonpurulent and interstitial with formation of granulomas. It was concluded that Candida albicans was highly pathogenic to the lactating goat mammary gland even without immunosuppression or antibiotic treatment, resulting in severe irreversible tissue damage and nearly complete agalactia.