Journal of Comparative Pathology

Published by Elsevier
Print ISSN: 0021-9975
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The population dynamics of H. rubidus infections in 307 growing pigs have been studied, with single infection doses of larvae ranging from 2500 to 40 000. Five groups of growing pigs (1 to 5) were infected with 2500, 5000, 10 000, 20 000 and 40 000 infective larvae of H. rubidus respectively and the establishment, rate of worm loss, worm growth and fecundity studied. It was found that the numbers of larvae established were directly related to the initial size of larval dose administered, more becoming established with increasing dose. The infections were patent earlier and the loss of adult worms was more rapid the higher the rate of infection. By the 6th week of infection slightly less than 99 per cent of the worms in the two highest infection groups (4 and 5), about 96 per cent in group 3 and 94 per cent in groups 1 and 2 had been lost. At necropsy the female worm length and numbers of eggs contained in the uterus were not related to the size of the larval dose. More female than male worms were recovered at slaughter, the sex ratio widening as the infection progressed. The faecal egg count on the day of slaughter did not correlate with the worm burden at necropsy, nor did the absence of eggs in the faeces indicate the absence of egg-bearing worms in the gut.
 
Two experiments on the effects on sheep of prolonged repeated (5 days in every week) infection with 10 000 infective larvae of Haemonchus contortus are reported. In the first experiment 7 sheep were infected for 6 months. Regular observations were made of haematocrit and faecal egg count. Two sheep required anthelmintic treatment once, 2 sheep required 3 treatments, the remaining 3 sheep required no anthelmintic support. At the end of the 6-month period all 7 sheep had acquired a high level of resistance.In the second experiment, this acquisition of resistance while subject to a weekly intake of 5 × 10 000 L3 was studied in 7 sheep which were fitted with abomasal cannulae. These sheep were infected repeatedly for 8 to 22 weeks. The acquired resistance was not associated with an abnormally high gastric pH.Large numbers of globule leucocytes were present in the fundic mucosa of all 14 sheep at the conclusion of the experiments.
 
The aim of this study was to describe and report the prevalence of conditions found at necropsy examination of UK donkeys. Records from 1,444 donkeys over a 7-year period were included in the analysis. Sixty-one categories of post-mortem finding were identified from 9,744 observations. The four most prevalent conditions noted were dental disorder (78.7%), vascular disease other than aneurysm (60.9%), arthritis (55.4%) and foot disorder (44.8%). Gastric ulceration was found in 42% of the donkeys and gastrointestinal impaction in 18.6%. The most frequent combination of two post-mortem findings in the same animal was arthritis and dental disorder. The most common disorders were associated with age, body weight and/or body condition post mortem and, for some disorders, gender. For many of the post-mortem findings, crude associations were found between the presence of one finding and the odds of also having certain other post-mortem findings. This study is the first to summarize all conditions noted at necropsy examination for a large group of donkeys. The findings increase knowledge of diseases and conditions of this species and may be useful when investigating the relevance of various pathological conditions in the live animal.
 
Morphometric methods were used in the study of muscular pulmonary arteries in cattle living at an altitude of 1,600 metres in Denver, Colorado. Ligation of one pulmonary artery, performed either at Denver or at sea level at Houston, Texas, with subsequent transport of the animals to the higher altitude, resulted in pronounced medial hypertrophy of the arteries of the contralateral lung. This generally coincided with marked pulmonary hypertension. An immediate and abrupt decrease in pulmonary arterial pressure in one of the animals following transport to sea level, showed that vasoconstriction contributes to the medial thickening. Our results strongly suggest a marked individual reactivity of the pulmonary vasculature, especially in young individuals.On the side of the ligation medial atrophy of the muscular pulmonary arteries developed in all animals and intimal fibrosis, probably of thrombotic origin, in some. A collateral circulation at the side of the ligation was almost always demonstrated; early indications of such a circulation were already present in a calf aged 7 days.
 
Immunocytochemistry was used to examine 26 cases of composite lymphoma in the mouse mesenteric lymph node. The diagnosis was made by light microscopic criteria. A selection of polyclonal antibodies to light (Kappa and Lambda) and heavy chain (IgD, IgM, IgC, IgA, IgE) antigens was used together with three monoclonal antibodies to T cells, B cells (HLA-DR) and macrophages. Twenty lymphomas were classified as B cell and six as T cell. The B cells were subdivided into IgM and IgD (five), IgD (five), IgM (three) and IgA (one), three undifferentiated and, in three, there was insufficient tissue for further typing. There did not appear to be any correlation between the morphological appearance and the immunophenotype.
 
Mutations with permanent activation of the stem cell factor receptor KIT have been identified as one potential cause for canine cutaneous mast cell tumours (MCTs). The exact changes in global gene expression patterns associated with permanent activation of KIT in these tumours are unknown. The present study compares, by the use of two dimensional difference gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, the proteomes of canine MCTs, with and without KIT exon 11 tandem duplication. Fifteen differentially expressed proteins were identified in mutated MCTs. These are mainly involved in cytoskeleton structure and cell motility (ACTR2, ACTB and CAPPA1), cell signalling (ARHGDIA) and lipid metabolism (ALOX15 and ACSBG4), or are serum proteins. The results therefore support the notion that KIT mutation is associated with changes in the proteome of affected cells with a major effect on the composition of the cytoskeletal proteome and cell motility proteins. No overlaps were identified when the results were compared with a recent study on the proteomic differences between low- and high-grade tumours, suggesting that KIT-mutated tumours may be regarded as a separate entity of high-grade tumours with potential relevance to therapeutic strategies.
 
Eleven dogs with canine transmissible venereal tumour (CTVT) were given vincristine sulphate chemotherapy to induce tumour regression. Biopsy specimens were collected from tumours during the growth phase, before chemotherapy, and again from the same dogs during the regression induced by chemotherapy. Laboratory assessment included cytology, histology, the number of tumour cells in relation to the number of intratumoral leucocytes, proliferative and apoptotic fractions of tumour cells, intratumoral vessel density, and fibrosis. The results revealed that during regression, tumour cell proliferation ceased, apoptosis increased, leucocytes increased (with increased proportion of T lymphocytes), tumour parenchyma collapsed around intratumoral vessels, and fibrosis increased. These results, which were similar to findings in dogs with spontaneous regression of CTVT, suggest that tumour immunity plays a role in tumour regression after modest chemotherapy.
 
Two strains of bluetongue virus serotype 11 (BTV 11), UC-2 avirulent and UC-8 neurovirulent in newborn mice, were inoculated into late-term bovine fetuses to investigate whether infection with these two BTV strains in late gestation would produce congenital infection and pathological changes. Fetuses were inoculated by intramuscular injection through the uterine wall at 243 days gestation and recovered after spontaneous delivery. In calves inoculated with UC-8, births occurred 15 to 27 days before expected parturition, resulting in small, weak calves. These calves had a mild encephalitis and were unthrifty at birth. Calves inoculated with UC-2 appeared healthy when born 7 to 11 days prior to expected parturition. No lesions were found in these calves at necropsy. All calves seroconverted by the time of birth. Viraemia was present in the calves inoculated with UC-8 and in one calf inoculated with UC-2. Plasma cortisol concentrations were prematurely elevated, particularly in the calves inoculated with UC-8, indicating that they were stressed by the infection. The elevated cortisol, associated with an active congenital infection caused by bluetongue virus serotype 11 strain UC-8, is capable of causing premature delivery of low birth-weight, weak calves.
 
Exposure of the 120-day sheep foetus to louping-ill virus resulted in generalized infection of neurons, severe neuropathological changes and death. Virus was detected in the cerebrospinal fluid as early as 2 days after intravenous inoculation. Levels of viraemia were generally low and few cells in lymphoid tissue synthesized viral antigen. Immunologically the foetus was competent to louping-ill virus in that neutralizing antibody, initially IgM and later IgG, was found in serum from 4 days after inoculation. Haemagglutination inhibiting antibody was, however, not detected at any stage. Non-specific neutralizing substances occurred in all sera from infected and control animals. Cells containing globulins were present in lymphoid tissue from every case, including the controls. Early inflammatory foci in nervous tissue consisted largely of polymorphonuclear cells. Immuno-globulins could not be demonstrated in perivascular inflammatory cells at any stage.
 
One hundred and twenty-three cases of mycobacterioses were diagnosed in psittacine birds from a total of 9,241 submissions for necropsy examination or histopathology made to the California Animal Health and Food Safety Laboratory System between 1990 and 2007. The species affected most commonly were Amazon parrots (Amazona spp.)(n = 32; 26%) and grey-cheeked parakeets Brotogeris pyrrophterus (n = 23; 18.7%). The main gross findings on necropsy examination were enlarged and mottled pale livers and spleens and thickening of the small intestinal wall with numerous pale miliary nodules on the mucosa. Microscopical examination revealed infiltration of foamy macrophages and giant cells containing acid-fast bacteria in various organs. The gene encoding mycobacterial 65 kDa heat shock protein (hsp65) was amplified by nested polymerase chain reaction (PCR) from DNA extracted from 22 cases. The species of Mycobacterium involved was determined by analysis of restriction endonuclease patterns of the PCR products. Mycobacteriumgenavense was detected in 19 cases and Mycobacteriumavium in two cases. One parrotlet (Touit spp.) had a mixed infection of both species of mycobacteria. It is concluded that M. genavense is the primary cause of mycobacteriosis in psittacine birds and the potential for zoonotic disease should be considered, especially for immunocompromised owners.
 
An iodinated marker, 125I-PVP K·60, (polyvinyl pyrrolidone) of mean molecular weight, 160 000, was shown to be well absorbed from the intestine of the newly born foal. The absorption was maximal (22 per cent.) 3 h. after birth, but fell rapidly in a linear decline to less than 1 per cent. by 20 h. of life. There was reduced absorption (10 per cent.) when the foals were deprived of colostrum although the time of cessation of uptake did not alter. The figures for the percentage absorption represented only the apparent efficiency of absorption as only intravascular PVP was measured. The real efficiency would be expected to be approximately doubled taking into account the extravascular pool of PVP.PVP introduced into the stomach of newly born foals reached peak levels of radioactivity 6 h. after administration. There was apparently no degradation of the PVP molecule during the process of uptake and transfer to the systemic circulation. However high levels of PVP were excreted in the urine up to 9 h. after birth. After this time the levels declined until by 28 h. very little radioactivity was detectable in the urine. The molecular size of the urinary PVP was 11 000 to 20 000.
 
It is clear from the literature that confusion exists over the toxicity for tissue culture cells of 125I-labelled Iododeoxyuridine (IUdR), an intranuclear cell label commonly used in immunological investigations in cancer research. The rate of death of test tube cultures of 14 canine tumour and other cell cultures was monitored during 3 to 6 days after labelling with various concentrations of 125IUdR. Cell types could be divided into those susceptible to the radiotoxic effects of 125IUdR and those where no toxic effect was apparent. The susceptibility of a cell type to 125IUdR toxicity does not appear to be dependent upon histological type, length of time in culture, rate of culture growth, or actual uptake of isotope. A chemotoxic effect of IUdR was ruled out.
 
The use of fluorodeoxyuridine (FUdR) to increase the uptake of 125I-iododeoxyuridine (125IUdR) into tissue culture cells was investigated. FUdR was found to be chemically toxic in itself to 2 canine tissue culture lines at doses used in the literature to increase 125IUdR uptake. FUdR had a cytocidal effect on one cell line, but a cytostatic effect on the other, so that measurement of only cell viability or death in the latter would not have shown a toxic effect. FUdR was shown to mask the radiotoxic effects of 125IUdR and so its use in investigations of the toxicity of 125IUdR may have produced misleading results.
 
Some canine rheumatic and neoplastic diseases bear a striking clinical and serological resemblance to their counterparts in man. In the present study, human 125I-Clq was employed in a radioimmunoassay for detection of immune complexes in sera of normal dogs and those with rheumatic and neoplastic diseases. Human 125I-Clq showed binding of 16·7±5·73 per cent in a group of normal dog sera with binding of 32·5±17·3 per cent and 43·0±16·0 per cent in sera of dogs with rheumatic and neoplastic diseases respectively. Human 125I-Clq bound similar quantities of heat-aggregated canine and human gamma-globulin over a broad range of concentrations and human 125I-Clq binding in canine sera was effectively inhibited by similar quantities of heat aggregated canine and human gamma-globulin. Seven of 12 dogs with elevated levels of Clq binding had active clinical and serological rheumatic disease (SLE or rheumatoid arthritis), while none of 7 dogs with values within the normal range had active clinical disease. All 5 dogs with widespread osteogenic sarcoma and all 4 dogs with high grade adenocarcinoma of the mammary gland had elevated Clq binding values while 2 animals with low grade malignancies without evident metastases did not. Thus, it appears that human 125I-Clq may be employed to assay immune complexes in canine sera and may be a valuable technique for the study of dogs with various rheumatic and neoplastic diseases.
 
Mixed germ cell sex cord stromal tumours (MGSCTs) are composed of seminiferous tubules, filled with admixed neoplastic Sertoli cells (SCs) and germ cells (GCs). The aim of the present study was to describe 13 canine testicular MGSCTs and to investigate the histochemical features and the immunophenotype of the neoplastic GCs and SCs. Neoplastic SCs were always diffusely labelled for vimentin (VIM), neuron specific enolase (NSE), inhibin (INH)-α and anti-Müllerian hormone (AMH). Cytokeratins AE1/AE3 (CK) and desmin (DES) were expressed in 6/13 and 8/13 cases, respectively. Neoplastic GCs were labelled for placental alkaline phosphatase (PLAP) in 7/13 cases and for CD117 (KIT) in 8/13 cases, while 10 cases were stained uniformly by periodic acid-Schiff (PAS). Immature canine SCs are known to express CK, DES, INH-α and AMH, while immature GCs are stained by PAS and express PLAP and KIT. This GC phenotype also distinguishes between classical and spermatocytic seminoma, with the latter being negative for these markers. The results of the present study show that both neoplastic SCs and GCs in MGSCTs have a de-differentiated phenotype. Copyright © 2014 Elsevier Ltd. All rights reserved.
 
Homeobox genes are known to be examples of the intimate relationship between embryogenesis and tumourigenesis. Specifically, the HOXA13 gene plays a fundamental role in the development of the urogenital tract and external genitalia and in prostate organogenesis. There are no reports on the expression of HOXA13 in normal, hyperplastic or neoplastic canine prostate tissue or in other types of tumours. Six normal, 16 hyperplastic and 12 neoplastic canine prostates were examined microscopically and immunohistochemically with a polyclonal antibody specific for human HOXA13. An immunohistochemical score was generated. HOXA13 was expressed in the cytoplasm of epithelial cells in normal, hyperplastic and neoplastic prostates. The percentage of immunolabelled cells in all prostatic carcinomas (PCs) was greatly increased, with a score of 85.3 (±5.25) compared with normal (2 ± 0.71) and hyperplastic prostates (6.08 ± 2.21). The increase in HOXA13 expression in canine PCs suggests the involvement of this transcription factor in carcinogenesis and promotion of tumour growth.
 
Individual colonies of Str. agalactiae strain S 13 were isolated from the milk of goats after the introduction of a culture into the udder. An enhancement in the lethal effect on mice was related to rises in body temperature and to the viable count per ml. of milk at the time of isolation.
 
Previous studies showed that in hamsters the 139H, but not the 263K, scrapie strain caused a marked increase in pancreatic size and led to obesity, hypoglycaemia and striking hyperinsulinaemia. In the preceding paper (Ye et al., 1994), the islets of Langerhans in 139H-affected hamsters showed cellular atrophy, fibrosis, cytoplasmic vesicles and nuclear pathological changes. In the present study, the profiles of pancreatic islets were classified into three sizes with an image analyzer. The number and total area covered by "small" islet profiles were less in 139H-affected than in normal hamsters. In contrast, the number and the area of "medium" and "large" islet profiles were significantly greater in 139H than in normal hamsters. With antibodies to insulin, glucagon, somatostatin and pancreatic polypeptide, the proportions of B, A, D and F cells were determined. With somatostatin-positive cells arbitrarily given a value of 1, the ratio of B:A:D:F cells in the islets was 27:5:1:0.04 in normal hamsters and 122:7:1:0.04 in 139H-affected hamsters. The increase in B cells would account for the islet enlargement and the hypoglycaemia-hyperinsulinaemia seen in 139H-affected hamsters.
 
Previous studies in hamsters showed that the 139H strain of scrapie injected intracerebrally caused a generalized endocrinopathy and marked hypoglycaemia and hyperinsulinaemia. The low scrapie infectivity levels in the pancreas suggested that the changes noted in that organ were of neuroendocrine origin. In the current study, female weanling Syrian hamsters were inoculated intracerebrally with scrapie strain 139H or 263K, or with homogenate of normal hamster brain. Coronal sections of the pituitary gland were stained with haematoxylin and eosin, Gomori's one-step trichrome, Congo red, thioflavin-S, and antibodies specific for several pituitary hormones. Sections were examined by light microscopy. The hamsters inoculated with scrapie strain 139H showed extensive pituitary vacuolization. Most vacuoles were located in the ventral or ventrolateral parts of the pars distalis. The pituitary glands of 139H-infected hamsters also showed cellular changes, namely, hypertrophy, atrophy and cytoplasmic vesicles. Nuclear changes such as swelling, vesicle formation, chromatin increase, pyknosis, karyorrhexis and karyolysis also occurred. The cellular and nuclear changes were most pronounced in the regions with vacuolation. Hamsters infected with the 263K strain did not show these changes. Immunocytochemical examination suggested that parenchymal cell types which produce different hormones were affected in areas of vacuolation. The changes produced by 139H were not seen in hamsters infected with strain 263K. This study provides the first evidence of cytopathological changes in the pituitary glands of scrapie-infected animals and suggests a relationship between the pituitary changes and the pathological findings in the pancreas and other endocrine organs of 139H-infected hamsters.
 
Previous studies showed that the 139H strain of scrapie injected into hamsters caused obesity, a marked hypertrophy of the islets of Langerhans, generalized endocrinopathy and marked hypoglycaemia-hyperinsulinaemia. In the current study, female weanling Syrian hamsters (LVG/LAK strain) were inoculated intracerebrally with scrapie strain 139H or 263K, or with normal hamster brain. Sections of the pancreas stained with haematoxylin and eosin or Gomori's one-step trichrome were examined by light microscopy. The 139H-affected hamsters showed extensive vacuolization, cellular hypertrophy, cellular atrophy, cytoplasmic vesicles and nuclear pathological changes in the islets of Langerhans. Also observed were abnormal structures, termed blood vessel cores, in the islets of 139H-affected hamsters. These structures were almost always centrally located within islets and were surrounded by B cells, some of which were abnormally elongated. None of these pathological changes were seen in the islets of Langerhans in control or 263K-affected hamsters. The level of scrapie-specific protease resistant protein (PrPSc) in pancreas was much lower than that in brain, a finding consistent with previous data showing low scrapie infectivity titres in pancreas.
 
The islets of Langerhans in hamsters infected with the 139H strain of scrapie contain large masses of red blood cells not surrounded by the usual arterial, venous or capillary wall cells. We have referred to these structures as "blood vessel cores" (BVCs). BVCs were almost always centrally located within the islets and surrounded by pancreatic B cells. Margination and diapedesis of inflammatory cells were observed at the BVC walls in 139H-infected hamsters. The cells consisted of the following types: single or clustered lymphocytes; and mixtures of lymphocytes and macrophages or neutrophils. Interaction observed between groups of inflammatory cells and B cells at the BVC walls and inside the islets of Langerhans indicated an inflammatory process. We refer to this interaction as the "linkage-reaction", and to the inflammatory cells as "linkage-inflammatory cells". These phenomena were not observed in other organs (adrenal, uterus, ovary, spleen, liver, kidney, oesophagus, trachea, intestine or pituitary) in 139H-affected hamsters or in the islets of Langerhans of animals infected with other scrapie strains (263K-infected hamsters; 139A-, ME7- and 22L-infected SJL mice). This appears to represent the first clear evidence of an inflammatory reaction in any organ in scrapie-infected animals.
 
Endocarditis was produced in 18 of 36 pigs within 14 days of a single intravenous inoculation of a group L streptococcus; in several pigs the lesions were well established within 5 days. Valves on the left side of the heart were affected 3 times as often as those on the right. Myocardial infarction was found in 10, renal infarction in 13 and polyarthritis in all the 18 pigs that developed endocarditis. In most pigs with endocarditis there was a persistent bacteraemia but in those that did not have endocarditis, bacteraemia was of shorter duration. Possible reasons for the occurrence of endocarditis in 50 per cent of inoculated pigs are discussed and experimentally-induced and naturally occurring heart valve lesions in pigs are compared.
 
Fifty adult cattle were subdivided in 2 equal groups and inoculated with foot and mouth disease vaccines containing either 5 micrograms or 0.01 microgram of O1BFS 1860 140S antigen per 3 ml dose. Four months later they were subdivided into groups of 5 and injected with vaccines containing concentrations of the 140S antigen ranging from 54 micrograms to 7 ng per 3 ml dose. Bleedings were carried out periodically and the serum neutralizing antibody titres showed that the revaccination responses were influenced by the dose of 140S antigen in both the primary and secondary vaccinations. A linear log relationship was demonstrated between the anamnestic serum antibody log response and the dose of antigen in the secondary vaccines.
 
In the epizootic of bovine spongiform encephalopathy (BSE) in Great Britain, the cattle in which a positive diagnosis was made numbered almost 180 000, but strain characterization was performed on only a very small sample of these cases. This report describes the results of BSE transmission to Prnp(a) mice from 150 transmission experiments at the Veterinary Laboratories Agency (VLA) over the last decade. These data, derived from a large sample of BSE-affected cattle, confirmed previous reports that show no evidence for diversity in BSE isolates. The agent was readily transmitted to mice, with a mean incubation period of 408 days in the RIII strain. Because the incubation period was related to the titre of the inoculum, it is not a reliable characteristic of strain type on primary isolation. Consistent neuropathological changes associated with infection by the BSE agent in RIII and C57Bl mice included focal vacuolation in the dorsal cochlear nuclei, vacuolation of the granule cell layer of the cerebellum, absence of lesions in the hippocampus and in the molecular layer of the cerebellum, and a fine particulate distribution of disease-specific PrP (demonstrated immunohistochemically), with few or no amyloid plaques. These features, together with the conventional lesion profile, will be of use in distinguishing the agents of BSE and scrapie in sheep.
 
Sixteen captive adult horned vipers (Vipera ammodytes ammodytes) were submitted for necropsy examination following a 2-week history of lethargy, anorexia and dyspnoea. Gross lesions included widespread haemorrhage, serosanguineous effusions in the body cavities and multiple pinpoint white to yellow foci in the liver. Microscopically, there was multifocal hepatic coagulative necrosis associated with intranuclear acidophilic inclusion bodies in sinusoidal endothelial cells. Similar endothelial lesions were observed in the myocardium, fat bodies, kidneys and spleen. Transmission electron microscopy revealed numerous virions (100-110 nm) in the nuclei of endothelial cells and intracytoplasmic enveloped virions (140-150 nm) were also found. The gross and histological findings and the ultrastructural features of the intranuclear inclusions and viral particles were consistent with herpesviral infection. To the best of our knowledge, these are the first reported cases of a lethal herpesvirosis in horned vipers and the second report in snakes.
 
Renal lesions of the type usually found in claudin-16 (CL-16) defective Japanese Black cattle (homozygous for CL-16 deficiency) were identified in six animals of this breed, aged 28-59 months, which were either heterozygous for CL-16 deficiency (type 1) or normal, as judged by a DNA-based test associated with the CL-16 gene. Histopathologically, all six cases showed elongated focal lesions which ran through the cortex to terminate in the outer zone of the medulla. The lesions contained components that included: (1) immature tubules, (2) small irregularly shaped tubules with thickening of the basement membrane, (3) mesenchymal cells in an increased interstitium, (4) small atrophic glomeruli, and (5) immature glomeruli. The glomeruli were noticeably reduced in number, and large glomeruli with an increased number of mesangial cells were observed throughout the entire cortical area. Cystic dilation of tubules and flattening of the epithelium were noted in all areas of the kidney. Histopathologically, the renal lesions in the six cases were indistinguishable from those reported previously in cattle homozygous for CL-16 deficiency. These findings demonstrate that such renal lesions in Japanese Black cattle are not necessarily associated with homozygous deletion of the CL-16 gene.
 
This paper describes experiments with Mycoplasma mobile 163 K in tench inoculated via the gills, skin, peritoneal cavity or whole body surface and kept at two different temperatures (20 and 25 degrees C). Gill tissues from experimentally infected tench and rainbow-trout gill tissue explants infected in vitro were compared by transmission electron microscopy, revealing that M. mobile was capable of producing gill epithelial cell necrosis in both, but that it was much more severe in the explants. M. mobile was found attached to chloride cells in the tench and between necrotic epithelial cells in the trout gill explants. M. mobile was recovered from the gills for up to 28 days after inoculation, from the skin and swim bladder for up to 14 days, and from the hind gut, kidneys and spleen for up to 8 days. There was no significant difference between the results at 20 and 25 degrees C.
 
The pathogenic role of Rhodococcus equi in pigs remains controversial. Small numbers of pigs were inoculated intravenously (i.v.), or intramuscularly (i.m.) around the mouth, with a virulent, an intermediately virulent, or an avirulent strain of R. equi and killed 14 days later. None showed clinical signs other than transient fever and weight loss. The virulent and intermediately virulent strains were recovered in culture from various organs and lymph nodes of pigs inoculated i.v., but only from the mandibular lymph nodes of pigs inoculated i.m. The avirulent strain was not recovered from any site. None of the pigs developed macroscopically visible lesions, but they showed reactive hyperplasia of the mandibular lymph nodes. The latter contained scattered phagocytic cells, which were labelled immunohistochemically for virulence-associated antigens (15- to 17-kDa antigens or 20-kDa antigen). Intermediately virulent and virulent strains of R. equi were isolated from mandibular lymph nodes of 5.5% of apparently healthy abattoir pigs (n = 1615). Virulence-associated antigens were detected in phagocytic cells of culture-positive nodes, but the latter showed no lesions other than reactive lymphoid hyperplasia. The results would seem to question the pathogenic role of R. equi in pigs, and it is speculated that the organism survives in the lymph nodes without causing pathognomonic lesions.
 
On the basis of studies in laboratory rats, mast cells were originally classified into two subgroups, namely, mucosal mast cells (MMCs), which contained chymase, and connective tissue mast cells (CTMCs), which contained both tryptase and chymase. This classification has been applied to other animal species, despite the fact that the MMCs and CTMCs of such species sometimes consist of mixed populations of mast cells in terms of tryptase and chymase constitution. This report describes the protease constitution of mast cells in 17 species of nine genera (Acomys, Apodemus, Cricetulus, Meriones, Millardia, Mus, Rattus, Sigmodon and Vandeleuria) of the family Muridae. MMCs with negative tryptase activity were detected only in the intestinal mucosa of six subspecies of Mus musculus, two Rattus spp. and Vandeleuria oleacea, and only Apodemus sylvaticus possessed CTMCs with no tryptase activity. Since mast cells conforming to the conventional classification were observed only in three of the nine genera examined, we propose that mast cells of rodents of the family Muridae should be classified by their protease constitution rather than by their location.
 
This report details clinical, histopathological and immunohistochemical findings in 18 cats with chronic nasal disease diagnosed as nasal lymphoma. Eight of the cats were female and 10 were male, with a median age of 10.5 years (range 7-14 years). Three of the cats were Siamese, one was Burmese, and the rest were non-pedigree. The duration of clinical signs before referral ranged from 30 to 540 days (median 88.5 days). The most common clinical signs were nasal discharge, stertor and sneezing. Nasal radiographs were abnormal in 14/16 cases examined. Abnormal masses were detected endoscopically in 13/18 cases. Nine cats received multi-agent chemotherapy or radiation therapy, or both, with survival times ranging from 14 to >541 days. Biopsy material from these 18 cats was examined by light microscopy, and serial sections were subjected to immunohistochemical labelling for the T lymphocyte marker CD3 and the B lymphocyte marker CD79a. In 13 tissues, expression of class II molecules of the major histocompatibility complex and the myelomonocytic antigen MAC387 was also determined. Twelve of the tumours were classified as diffuse large B-cell lymphomas, four as lymphoblastic B-cell lymphomas, and one as a follicular B-cell lymphoma. The tumour cells within these lesions all expressed CD79a, and (where tested) most also expressed MHC class II. One tumour was an anaplastic large cell neoplasm, in which the neoplastic cells expressed MHC class II alone in the absence of either lymphoid marker. There was a variable infiltration of reactive small T lymphocytes into these tumours, and zones of necrosis within the tumour tissue were sometimes heavily infiltrated by MAC387+ phagocytic cells.
 
Endocarditis, involving the left atrioventricular valve, was produced in 6 of 10 pigs as early as 18 h after a single intravenous inoculation of a group L streptococcus. Macroscopic vegetations were not detected in pigs killed at 12 or 15 h after inoculation. The number of streptococci in the blood during the course of infection was monitored at 3-h intervals. No significant increase in the number of bacteria coincident with the early stages of the development of lesions was found. It is suggested that non-bacterial thrombotic endocarditis is not a prerequisite for the development of bacterial endocarditis. The development of heart valve vegetations is possibly initiated immediately after the intravenous inoculation of streptococci.
 
[185W] thiotungstates were synthesized in-vitro and purified by techniques developed for thiomolybdates. [185W] trithiotungstate (15 mg W) injected intravenously into cattle was mainly associated with albumin albumin. The presence of the compound in plasma when injected in larger amounts (0.2 to 1 gW) caused an increase in albumin-bound copper and transiently depressed ceruloplasmin diamine oxidase activity. It is suggested that the long-lived, less costly 185W could prove a convenient alternative to 99Mo for tracer studies with labelled thio-compounds in animals.
 
The clinical and pathological findings in 19 ferrets (Mustela putorius furo) with malignant lymphoma are reviewed. Peripubescent ferrets had rapidly progressive stage IV high grade immunoblastic or small non-cleaved cell lymphoma. Adult ferrets had stage II or IV low grade diffuse small lymphocytic (DSL) lymphoma, stage IV high grade small non-cleaved cell lymphoma, or stage IV high grade immunoblastic polymorphous (IBP) lymphoma. Three ferrets had concurrent IBP and DSL lymphoma involving different organs. The IBP admixture of immunoblasts, large atypical lymphocytes, Reed-Sternberg-like cells, lymphoblasts and small lymphocytes has been associated with certain retrovirally associated lymphomas and nodal hyperplasias in man, non-human primates and cats. Aleutian disease, a parvovirus-induced lymphoproliferative disease, also involves clinical and histological features similar to certain lymphomas in ferrets. Seven ferrets tested were seronegative for feline leukaemia virus antigen. Only one of eight ferrets was positive for Aleutian parvovirus antibody. The clinical and pathological findings are suggestive of a viral aetiology for certain lymphomas in ferrets.
 
The three methods which have been described for assaying the potency of Brucella abortus S.19 vaccines by challenge tests in guinea-pigs comprise constant vaccine/graduated challenge, graduated vaccine/constant challenge, and single level vaccine and challenge. A dose response curve was obtained by the first method and it was found that the infective dose (ID50) of the challenge strain W.544 was 89 organisms; this value was increased approximately 2,000-fold by vaccination with S.19 at cattle dose. Using a wide range of vaccine dilutions, a dose response curve was obtained with the second method. The protection dose (PD50) in vaccinated guinea-pigs challenged with 5,000 W.544 organisms was 127 S.19 organisms. It was concluded that in the potency test specified in the British Veterinary Codex Supplement (1970), the vaccinal dose is too high or the challenge dose too low to present a critical test. The results suggest that the single level vaccine and challenge dose method would be satisfactory if used within the range where the protection is proportional to the dose.
 
Fenvalerate, a widely used pesticide, was administered orally to goats at a dose rate of 15 mg/kg body weight, daily for 270 days. After 90 days of dosing, the animals, together with appropriate controls, were vaccinated with Brucella abortus strain 19. The fenvalerate reduced both the humoral and cell-mediated immune responses, as assessed by the standard tube agglutination test and delayed hypersensitivity test, respectively.
 
In an attempt to associate the clinical neurological syndromes with the neuropathological features of canine distemper (CD), 19 spontaneous cases with neurological involvement were examined, before and after euthanasia. Seventeen dogs were less than one year of age and all except two (89.4%) were unvaccinated against CD. Various extraneural signs associated with CD encephalomyelitis (CDE) were seen in 15 dogs. Generalized or localized myoclonus was the most common sign observed (13/19). Seventeen of the dogs presented with signs suggestive of one neuroanatomical location of lesions. Of these animals, seven had signs of cerebral, two of cerebellar, four of cervical, one of cervicothoracic, two of thoracolumbar and two of lumbosacral syndrome. The diagnosis of CD was confirmed immunohistochemically (detection of CD viral antigen), serologically (neutralizing serum antibody titre > or = 16) and histopathologically (CDV inclusion bodies, type of central nervous system lesions). An association of the neuroanatomical lesion location and the histopathological findings was noted in 14 out of 17 dogs (82.3%). Myoclonus could be attributed to lower motor neuron damage in eight out of 13 dogs (61.5%).
 
The pathology of natural Schistosoma spindale infections in cattle in Sri Lanka was studied. Hepatic lesions were moderate with periportal cell infiltration and periportal epithelioid cell granulomas within perilobular zones. Submucosal and mucosal granulomas accompanied by cellular changes were present in the small and large intestine. Two unusual observations included the migration of an adult worm from the mesenteric veins to the mucosa of the small intestine in one bull and the presence of epithelioid cell granulomas containing slender living eggs in the urinary bladder of one animal. Intensities of infections, histopathological changes and immunological responses are discussed and comparison is made with other schistosome species.
 
The account of the Journal's first 53 years (Pattison, 1988), also reproduced in this issue, closed by noting the interruption of publication brought about by wartime exigencies and the death in 1941 of its founder and owner, Sir John McFadyean (Fig. 1). The present article considers the further development of the Journal from that time to the present day, a period of 65 years.
 
Diagnostic records are a key feature of any cancer epidemiology, prevention or control strategy for man and animals. Therefore, the information stored in human and animal cancer registries is essential for undertaking comparative epidemiological, pathogenic and therapeutic research. This study presents the Swiss Canine Cancer Registry, containing case data compiled between 1955 and 2008. The data consist of pathology diagnostic records issued by three veterinary diagnostic laboratories in Switzerland. The tumours were classified according to the guidelines of the International Classification of Oncology for Humans on the basis of tumour type, malignancy and body location. The dogs were classified according to breed, age, sex, neuter status and place of residence. The diagnostic data were correlated with data on the Swiss general dog population and the incidence of cancer in dogs was thus investigated. A total of 67,943 tumours were diagnosed in 121,963 dogs and 47.07% of these were malignant. The most common tumour location was the skin (37.05%), followed by mammary glands (23.55%) and soft tissue (13.66%). The most common tumour diagnoses were epithelial (38.45%), mesenchymal (35.10%) and lymphoid tumours (13.23%). The results are compared with data in other canine registries and similarities in tumour distribution and incidence are noted. It is hoped that this study will mark the beginning of continuous registration of dog tumours in Switzerland, which, in turn, will serve as a reference for research in the fields of animal and human oncology. Copyright © 2015 Elsevier Ltd. All rights reserved.
 
Top-cited authors
Seamus Kennedy
  • Agri-Food and Biosciences Institute
Martin Jeffrey
  • Department for Environment, Food and Rural Affairs
Zhidong Zhang
  • Chinese Academy of Agricultural Sciences
Soren Alexandersen
  • Deakin University
Lorenzo Gonzalez
  • Department for Environment, Food and Rural Affairs