Search

This study was designed to identify the cause of mutilation and death in 32 cats, part of a larger cohort found dead in Greater London, the United Kingdom, between 2016 and 2018. At the time, discussion in the media led to concerns of a human serial cat killer (dubbed The Croydon Cat Killer) pursuing domestic cats, causing a state of disquietude. Given the link between animal abuse and domestic violence, human intervention had to be ruled out. Using a combination of DNA testing, computed tomography imaging, and postmortem examination, no evidence was found to support any human involvement. Instead, a significant association between cat carcass mutilation and the presence of fox DNA was demonstrated. Gross examination identified shared characteristics including the pattern of mutilation, level of limb or vertebral disarticulation, wet fur, wound edges with shortened fur, and smooth or irregular contours, and marks in the skin, muscle, and bone consistent with damage from carnivore teeth. Together these findings supported the theory that the cause of mutilation was postmortem scavenging by red foxes ( Vulpes vulpes). The probable cause of death was established in 26/32 (81%) carcasses: 10 were predated, 8 died from cardiorespiratory failure, 6 from blunt force trauma, one from ethylene glycol toxicity, and another from liver failure. In 6 carcasses a cause of death was not established due to autolysis and/or extensive mutilation. In summary, this study highlights the value of a multidisciplinary approach to fully investigate cases of suspected human-inflicted mutilation of animals.

Adenoviruses cause a range of major diseases across many diverse animal species including ruminants. They are classified into six genera in the family Adenoviridae. In deer species, two adenoviruses are currently recognized: deer adenovirus 1 in the Atadenovirus genus, and deer adenovirus 2 in the Mastadenovirus genus. Deer adenovirus 1 causes adenovirus haemorrhagic disease with high fatality in black-tailed and mule deer in North America. Conversely, deer adenovirus 2 was incidentally detected from a healthy white-tailed deer fawn, but experimentally it has been shown to cause pyrexia, cough and moderate to severe haemorrhage. Here, we detected a novel adenovirus, reindeer adenovirus 1, from lung lesions of a 5-year-old male reindeer (Rangifer tarandus). This animal presented with aspiration pneumonia and necrotizing bronchiolitis following a period of clinical weakness, nasal discharge and wasting. Histopathological examination of the lung revealed large intranuclear basophilic inclusions associated with the areas of necrotizing bronchiolitis. Next generation sequencing of the lung tissue identified a novel mastadenovirus with close similarity to deer adenovirus 2 and bovine adenovirus 3. To our knowledge, this is the first report of a deer mastadenovirus associated with necrotizing bronchiolitis in captive reindeer.

Summary Background Haematopoietic stem cells expressing the CD34 surface marker have been posited as a niche for Mycobacterium tuberculosis complex bacilli during latent tuberculosis infection. Our aim was to determine whether M tuberculosis complex DNA is detectable in CD34-positive peripheral blood mononuclear cells (PBMCs) isolated from asymptomatic adults living in a setting with a high tuberculosis burden. Methods We did a cross-sectional study in Ethiopia between Nov 22, 2017, and Jan 10, 2019. Digital PCR (dPCR) was used to determine whether M tuberculosis complex DNA was detectable in PBMCs isolated from 100 mL blood taken from asymptomatic adults with HIV infection or a history of recent household or occupational exposure to an index case of human or bovine tuberculosis. Participants were recruited from HIV clinics, tuberculosis clinics, and cattle farms in and around Addis Ababa. A nested prospective study was done in a subset of HIV-infected individuals to evaluate whether administration of isoniazid preventive therapy was effective in clearing M tuberculosis complex DNA from PBMCs. Follow-up was done between July 20, 2018, and Feb 13, 2019. QuantiFERON-TB Gold assays were also done on all baseline and follow-up samples. Findings Valid dPCR data (ie, droplet counts >10 000 per well) were available for paired CD34-positive and CD34-negative PBMC fractions from 197 (70%) of 284 participants who contributed data to cross-sectional analyses. M tuberculosis complex DNA was detected in PBMCs of 156 of 197 participants with valid dPCR data (79%, 95% CI 74–85). It was more commonly present in CD34-positive than in CD34-negative fractions (154 [73%] of 197 vs 46 [23%] of 197; p

This study was designed to identify the cause of mutilation and death in 32 cats, part of a larger cohort found dead in Greater London, the United Kingdom, between 2016 and 2018. At the time, discussion in the media led to concerns of a human serial cat killer (dubbed The Croydon Cat Killer) pursuing domestic cats, causing a state of disquietude. Given the link between animal abuse and domestic violence, human intervention had to be ruled out. Using a combination of DNA testing, computed tomography imaging, and postmortem examination, no evidence was found to support any human involvement. Instead, a significant association between cat carcass mutilation and the presence of fox DNA was demonstrated. Gross examination identified shared characteristics including the pattern of mutilation, level of limb or vertebral disarticulation, wet fur, wound edges with shortened fur, and smooth or irregular contours, and marks in the skin, muscle, and bone consistent with damage from carnivore teeth. Together these findings supported the theory that the cause of mutilation was postmortem scavenging by red foxes (

The recent increase in new technologies to analyze host-pathogen interaction has fostered a race to develop new methodologies to assess these not only on the cellular level, but also on the tissue level. Due to mouse-other mammal differences, there is a desperate need to develop relevant tissue models that can more closely recapitulate the host tissue during disease and repair. Whereas organoids and organs-on-a-chip technologies have their benefits, they still cannot provide the cellular and structural complexity of the host tissue. Here, precision cut tissue slices (PCTS) may provide invaluable models for complex ex-vivo generated tissues to assess host-pathogen interaction as well as potential vaccine responses in a “whole organ” manner. In this mini review, we discuss the current literature regarding PCTS in veterinary species and advocate that PCTS represent remarkable tools to further close the gap between target identification, subsequent translation of results into clinical studies, and thus opening avenues for future precision medicine approaches.

Cellular (CD3+ T cell and CD68+ macrophages), cytokines (IFN-γ+ and TNF-α+) and effector molecule (iNOS+) responses were evaluated in the lymph nodes and tissue of cattle naturally infected with Mycobacterium bovis. Detailed post mortem and immunonohistochemical examinations of lesions were performed on 16 cows positive for single intradermal cervical comparative tuberculin test (SICCTT) and identified from dairy farms located around the Addis Ababa City. The severity of the gross lesion was significantly higher (p=0.003) in M. bovis culture positive (n=12) cows than in culture negative (n=4). Immunohistochemical techniques showed that the mean percentage labelling of CD3+ T cells decreased as the stage of granuloma increased from stage I to stage IV in culture positive cows (pM. bovis, as the stage of granuloma increases from stage I to stage IV, the proportion of CD3+ cells decreases while the immunolabeling fraction of CD68+ macrophages, IFN-γ+, TNF-α and iNOS+ increases.

Background: Haematopoietic stem cells expressing the CD34 surface marker have been posited as a niche for M. tuberculosis complex (MTBC) bacilli during latent tuberculosis infection (LTBI). Methods: We conducted a cross-sectional study in Ethiopia to determine whether MTBC DNA was detectable in peripheral blood mononuclear cells (PBMC) isolated from 100 ml blood taken from 197 asymptomatic adults with a history of recent household TB contact and/or HIV infection, using digital polymerase chain reaction (dPCR). A nested prospective study was conducted in a sub-set of 43 HIV-infected individuals to evaluate whether administration of isoniazid preventive therapy (IPT) was effective in clearing MTBC DNA from PBMC. Results: MTBC DNA was detected in PBMC of 156/197 participants (79.2%; 95% CI 73.5% to 84.9%). Where present, it was found more frequently in CD34-positive vs. CD34-negative PBMC (154/155 [99.4%] vs. 46/155 [29.7%], P

Angiostrongylus vasorum is a nematode parasite of the pulmonary arteries and heart that infects domestic and wild canids. Dogs (Canis familiaris) and red foxes (Vulpes vulpes) are the most commonly affected definitive hosts. Recent studies suggest that angiostrongylosis is an emerging disease, and that red foxes may play an important role in the epidemiology of the parasite. Genetic analyses of parasites collected from dogs and foxes throughout Europe have shown that the same parasite haplotypes are commonly shared between different host species. However, the extent of genetic diversity within local A. vasorum populations and individual hosts is unknown. The objective of the present study was to assess the occurrence of genetic diversity among A. vasorum (a) recovered from different foxes within the Greater London area (a localised population, single worm per fox dataset); and (b) hosted within single foxes (multiple worms per fox dataset). During 2016, A. vasorum worms were collected from foxes culled for other purposes in London. DNA was extracted from each parasite and a partial fragment of the mitochondrial cytochrome oxidase subunit 1 (mtCOI) gene was amplified and sequenced. Sequences from the single worm dataset were compared with those published elsewhere. Combined, 19 haplotypes were described of which 15 were identified from foxes found in London, indicating that considerable genetic diversity can be detected within a local geographic area. Analysis of the multiple worm dataset identified 22 haplotypes defining worms recovered from just six foxes, emphasising the relevance of wild canines as reservoirs of genetic diversity. This is the first study to explore the genetic complexity of individual fox-hosted A. vasorum populations.

A 10-week-old African grey parrot ( Psittacus erithacus erithacus ) presented with a two-day history of weakness, anorexia, vomiting and diarrhoea. Radiography and endoscopy revealed opacities within the lungs and air sacs and the bird died despite supportive therapy. Gross postmortem examination found the bird to be in poor body condition. The lungs were multifocally consolidated and the air sacs were opaque. Impression smears from the lungs revealed septate fungal hyphae, confirming the suspicion of pneumonia and air sacculitis. The hyphae were suggestive of Aspergillus species, but culture was declined by the owner. Histological examination of the bursa of Fabricius identified …

A neurofibroma of granular cell subtype is described in a 7-year-old horse. The horse had a 3-month history of ataxia affecting the forelimbs and hindlimbs, suggesting a C1-C6 neuroanatomical localization. Post-mortem examination revealed an intradural mass arising from the right sixth cervical spinal nerve and compressing the spinal cord. Histologically, the mass was composed largely of wavy spindle cells (a mixture of Schwann cells, perineurial cells and fibroblasts) intimately associated with ropy collagen fibres. Approximately 25% of the spindle cells were swollen and contained densely-packed, eosinophilic and periodic acid-Schiff-positive cytoplasmic granules. Immunohistochemistry for S100 and glial fibrillary acidic protein antigens labelled a proportion of neoplastic cells, while the cytoplasmic granules were positive for S100 and neuron specific enolase. This is the first report of a neurofibroma with granular cell differentiation in an animal. Granular cell differentiation in other peripheral nerve sheath tumours of animals is briefly discussed.

A 9-month-old domestic shorthair cat had progressive ambulatory paraparesis, proprioceptive ataxia, and thoracolumbar hyperesthesia. An extradural mass affecting the left pedicle and lamina of the second lumbar vertebra (L2) causing marked spinal cord impingement was identified in magnetic resonance (MR) images. The mass was predominantly calcified in computed tomographic (CT) images. A hemilaminectomy was performed to resect the mass. Clinical signs were greatly improved at 12-month follow-up. The histopathologic diagnosis was vascular hamartoma. To our knowledge, this is the first report describing the MR characteristics of a vascular hamartoma associated with the vertebral column.

Ovine pulmonary adenocarcinoma is a chronic respiratory disease of sheep caused by jaagsiekte sheep retrovirus (JSRV). OPA is a significant economic problem for sheep farmers in many countries and is a valuable animal model for some forms of human lung cancer. Here, we examined the changes in host gene expression that occur in the lung in response to JSRV infection. We identified a large number of genes with altered expression in infected lung, including factors with roles in cancer and immune system function. We also compared the data from OPA to previously published data from human lung adenocarcinoma and found a large degree of overlap in the genes that were dysregulated. The results of this study provide exciting new avenues for future studies of OPA and may have comparative relevance for understanding human lung cancer., Jaagsiekte sheep retrovirus (JSRV) is the etiologic agent of ovine pulmonary adenocarcinoma (OPA), a neoplastic lung disease of sheep. OPA is an important economic and welfare issue for sheep farmers and a valuable naturally occurring animal model for human lung adenocarcinoma. Here, we used RNA sequencing to study the transcriptional response of ovine lung tissue to infection by JSRV. We identified 1,971 ovine genes differentially expressed in JSRV-infected lung compared to noninfected lung, including many genes with roles in carcinogenesis and immunomodulation. The differential expression of selected genes was confirmed using immunohistochemistry and reverse transcription-quantitative PCR. A key finding was the activation of anterior gradient 2, yes-associated protein 1, and amphiregulin in OPA tumor cells, indicating a role for this oncogenic pathway in OPA. In addition, there was differential expression of genes related to innate immunity, including genes encoding cytokines, chemokines, and complement system proteins. In contrast, there was little evidence for the upregulation of genes involved in T-cell immunity. Many genes related to macrophage function were also differentially expressed, reflecting the increased abundance of these cells in OPA-affected lung tissue. Comparison of the genes differentially regulated in OPA with the transcriptional changes occurring in human lung cancer revealed important similarities and differences between OPA and human lung adenocarcinoma. This study provides valuable new information on the pathogenesis of OPA and strengthens the use of this naturally occurring animal model for human lung adenocarcinoma. IMPORTANCE Ovine pulmonary adenocarcinoma is a chronic respiratory disease of sheep caused by jaagsiekte sheep retrovirus (JSRV). OPA is a significant economic problem for sheep farmers in many countries and is a valuable animal model for some forms of human lung cancer. Here, we examined the changes in host gene expression that occur in the lung in response to JSRV infection. We identified a large number of genes with altered expression in infected lung, including factors with roles in cancer and immune system function. We also compared the data from OPA to previously published data from human lung adenocarcinoma and found a large degree of overlap in the genes that were dysregulated. The results of this study provide exciting new avenues for future studies of OPA and may have comparative relevance for understanding human lung cancer.

Eimeria tenella can cause the disease coccidiosis in chickens. The direct and often detrimental impact of this parasite on chicken health, welfare, and productivity is well recognized; however, less is known about the secondary effects that infection may have on other gut pathogens. Campylobacter jejuni is the leading cause of human bacterial foodborne disease in many countries and has been demonstrated to exert negative effects on poultry welfare and production in some broiler lines. Previous studies have shown that concurrent Eimeria infection can influence the colonization and replication of bacteria, such as Clostridium perfringens and Salmonella enterica serovar Typhimurium. Through a series of in vivo coinfection experiments, this study evaluated the impact that E. tenella infection had on C. jejuni colonization of chickens, including the influence of variations in parasite dose and sampling time after bacterial challenge. Coinfection with E. tenella resulted in a significant increase in C. jejuni colonization in the cecum in a parasite dose-dependent manner but a significant decrease in C. jejuni colonization in the spleen and liver of chickens. The results were reproducible at 3 and 10 days after bacterial infection. This work highlights that E. tenella not only has a direct impact on the health and well-being of chickens but can have secondary effects on important zoonotic pathogens.

Internationally, forensic medicine and pathology are increasingly recognized as an important aspect of work done by veterinary clinicians and veterinary pathologists. In this article, a forensic veterinary clinician, a forensic veterinary pathologist in private practice, and a forensic veterinary pathologist at a veterinary school discuss the interactions among veterinary clinicians, veterinary pathologists, and law enforcement agencies and how future interactions can be improved. The focus is on the United Kingdom, but many of the principles, challenges, and suggestions are applicable to other jurisdictions. Clinicians and pathologists require forensic training to enable them to apply their veterinary knowledge to suspected cases of animal abuse and to subsequently present their findings and conclusions to a court of law in a concise, professional, and unbiased manner, and some opportunities for such advanced training in the United Kingdom are indicated. It is important that forensic veterinary clinicians and pathologists interact in an unbiased and collegial manner to answer the questions posed by courts of law. Opportunities for improved training, communication, and interaction among forensic veterinarians, forensic scientists, and law enforcement are discussed.

An opportunistic bacterial infection preceded by weather of unusually high humidity and temperature caused mass death of saigas., In 2015, more than 200,000 saiga antelopes died in 3 weeks in central Kazakhstan. The proximate cause of death is confirmed as hemorrhagic septicemia caused by the bacterium Pasteurella multocida type B, based on multiple strands of evidence. Statistical modeling suggests that there was unusually high relative humidity and temperature in the days leading up to the mortality event; temperature and humidity anomalies were also observed in two previous similar events in the same region. The modeled influence of environmental covariates is consistent with known drivers of hemorrhagic septicemia. Given the saiga population’s vulnerability to mass mortality and the likely exacerbation of climate-related and environmental stressors in the future, management of risks to population viability such as poaching and viral livestock disease is urgently needed, as well as robust ongoing veterinary surveillance. A multidisciplinary approach is needed to research mass mortality events under rapid environmental change.

Highlights • PCV2 is the underlying cause for an economically devastating disease of pigs. • Vaccine construct was PCV2b Cap protein expressed on the surface of yeast. • Oral vaccination of freeze-dried yeast-Cap did not induce negative side effects. • Application protected pigs from subsequent PCV2b challenge. • Vaccination reduced pro-inflammatory but increased antiviral cytokine expression., Porcine circovirus type 2 (PCV2) is now endemic in every major pig producing country, causing PCV-associated disease (PCVAD), linked with large scale economic losses. Current vaccination strategies are based on the capsid protein of the virus and are reasonably successful in preventing PCVAD but fail to induce sterile immunity. Additionally, vaccinating whole herds is expensive and time consuming. In the present study a “proof of concept” vaccine trial was employed to test the effectiveness of powdered freeze-dried recombinant Saccharomyces cerevisiae yeast stably expressing the capsid protein of PCV2b on its surface as an orally applied vaccine. PCV2-free pigs were given 3 doses of vaccine or left un-vaccinated before challenge with a defined PCV2b strain. Rectal temperatures were measured and serum and faeces samples were collected weekly. At the end of the study, pigs were euthanized, tissue samples taken and tested for PCV2b load by qPCR and immunohistochemistry. The peak of viraemia in sera and faeces of unvaccinated pigs was higher than that of vaccinated pigs. Additionally more sIgA was found in faeces of vaccinated pigs than unvaccinated. Vaccination was associated with lower serum concentrations of TNFα and IL-1β but higher concentrations of IFNα and IFNγ in comparison to the unvaccinated animals. At the end of the trial, a higher viral load was found in several lymphatic tissues and the ileum of unvaccinated pigs in comparison to vaccinated pigs. The difference between groups was especially apparent in the ileum. The results presented here demonstrate a possible use for recombinant S. cerevisiae expressing viral proteins as an oral vaccine against PCV2. A powdered freeze-dried recombinant S. cerevisiae used as an oral vaccine could be mixed with feed and may offer a cheap and less labour intensive alternative to inoculation with the additional advantage that no cooling chain would be required for vaccine transport and storage.

Hypoxia and regulatory T cells (Tregs) in tumours are both known to be negative prognostic factors in cancer, and this study demonstrated a correlation between the two factors in canine neoplasia. Samples of 57 canine tumours and 29 canine lymph nodes categorized as tumour-draining, with or without metastasis, or reactive and not tumour-associated, were examined. Sequential sections were labelled by immunohistochemistry for glucose transporter 1 (Glut1) and FoxP3 as markers of hypoxia and Tregs, respectively. Up to 21 regions of interest (ROI) were selected in each section in a representative pattern and were assigned a semiquantitative score based on Glut1 labelling. The number of FoxP3(+) cells within each ROI was counted. A generalized estimating equation with negative binomial log link function was used to determine an association between Glut1 expression and FoxP3(+) cell count. Higher Glut1 immunoreactivity was correlated with significantly higher numbers of FoxP3(+) cells in the total tumour sample pool and total lymph node sample pool. Analysis of various subcategories of tumours and lymph nodes showed that this correlation was also present within samples characterized as malignant, haemopoietic mesenchymal tumours, non-haemopoietic mesenchymal tumours, epithelial tumours, lymphoma, lymph nodes containing metastases and reactive lymph nodes. These results indicate that hypoxia in canine tumours may result in an increased infiltration by Tregs.

Summary Reasons for performing study: Gastric ulceration is now widely recognised as an important disease in high performance horses. Little is known about gastric histopathology in healthy or diseased animals; a comprehensive assessment would enhance interpretation of gross findings through assessment of their accuracy and allow for identification of lesion variety and pathogenesis in different anatomical regions of the stomach. Objectives: To investigate the true extent and variety of gastric lesions in a mixed population of mature horses at post mortem. Methods: Stomachs were removed from a mixed population of 21 horses at post mortem. Mucosal abnormalities were recorded in photographic and written form. Representative samples from all gross lesions were taken for histopathology and processed routinely. Special stains including Gram, PAS and Warthin Starry, were used when appropriate. Pathological classification of lesion type using both gross and histological appearances was performed. Results: Classification of lesions within the squamous region included hyperkeratosis, punctate scars, diffuse erosions/ulcerations and margo injuria; and within the glandular region, hyperaemia, focal erosions and ulcerations. Glandular metaplasia was recognised for the first time in the equine stomach. No Helicobacter-like organisms were detected in association with lesion development. Conclusions and potential relevance: This study used gross and histological examination to highlight the large variety of naturally occurring gastric lesions in a mixed population of horses. Analysis of the pathogenesis of lesion development is now possible. Further research regarding the range of pathology in larger, more diverse groups of horses is required.

Highlights • Environmental stress increases viral load of PCV2b in serum and tissue. • Environmental stress exacerbates PCV2b induced weight loss. • Environmental stress and PCV2b reduce ADG and impact negatively on FCR., Porcine circovirus type 2 (PCV2) has been identified as the essential, but not sole, underlying infectious component for PCV-associated diseases (PCVAD). Several co-factors have been suggested to convert an infection with PCV2 into the clinical signs of PCVAD, including co-infection with a secondary pathogen and the genetic background of the pig. In the present study, we investigated the role of environmental stressors in the form of changes in environmental temperature and increased stocking-density on viral load in serum and tissue, average daily weight gain (ADG) and food conversion rate (FCR) of pigs experimentally infected with a defined PCV2b strain over an eight week period. These stressors were identified recently as risk factors leading to the occurrence of severe PCVAD on a farm level. In the current study, PCV2-free pigs were housed in separate, environmentally controlled rooms, and the experiment was performed in a 2 × 2 factorial design. In general, PCV2b infection reduced ADG and increased FCR, and these were further impacted on by the environmental stressors. Furthermore, all stressors led to an increased viral load in serum and tissue as assessed by qPCR, although levels did not reach statistical significance. Our data suggest that there is no need for an additional pathogen to develop PCVAD in conventional status pigs, and growth retardation and clinical signs can be induced in PCV2 infected pigs that are exposed to environmental stressors alone.

This case report describes an unusual presentation of histiocytic sarcoma in a domestic shorthair cat. Initial investigation revealed a haemodynamically insignificant hypertrophic cardiomyopathy, bronchitis and a mild irregularity of the cervical trachea. The cat's disease progressed over a two-week period. Repeat radiography and tracheoscopy revealed a marked dynamic tracheal collapse associated with a raised plaque-like lesion within the cervical trachea. Subsequent post-mortem examination and histopathology revealed disseminated histiocytic sarcoma involving the trachea and kidneys. This is the first reported case of a histiocytic sarcoma involving the trachea in either dogs or cats.

Budd-Chiari-like syndrome (BCLS) is a rare clinical entity characterised by portal hypertension and ascites. This report describes a case of BCLS in a cat due to obstruction at the level of the hepatic veins. The diagnosis was based on the clinical findings and a histopathological assessment of the liver demonstrating perivenular fibrosis around the central and sublobular veins. Although these lesions are similar to those observed in man with BCLS, the aetiology in this case remains unknown.

Case summary A 15-year-old female cat was presented for investigation of progressive behavioural changes, polyuria, polydipsia and periuria. An ovarian granulosa cell tumour was identified and the cat underwent therapeutic ovariohysterectomy (OHE). The cat’s clinical signs resolved, but 6 months later it was diagnosed as having an anaplastic astrocytoma and was euthanased. Serum anti-Müllerian hormone (AMH) concentration prior to OHE was increased vs a control group of entire and neutered female cats. Following OHE, serum AMH concentration decreased to Relevance and novel information Serum AMH measurement may represent a novel diagnostic and monitoring tool for functional ovarian neoplasms in cats.

Understanding the factors governing host species barriers to virus transmission has added significantly to our appreciation of virus pathogenesis. Jaagsiekte sheep retrovirus (JSRV) is the causative agent of ovine pulmonary adenocarcinoma (OPA), a transmissible lung cancer of sheep that has rarely been found in goats. In this study, in order to further clarify the pathogenesis of OPA, we investigated whether goats are resistant to JSRV replication and carcinogenesis. We found that JSRV induces lung tumors in goats with macroscopic and histopathological features that dramatically differ from those in sheep. However, the origins of the tumor cells in the two species are identical. Interestingly, in experimentally infected lambs and goat kids, we revealed major differences in the number of virus-infected cells at early stages of infection. These differences were not related to the number of available target cells for virus infection and cell transformation or the presence of a host-specific immune response toward JSRV. Indeed, we also found that goats possess transcriptionally active endogenous retroviruses (enJSRVs) that likely influence the host immune response toward the exogenous JSRV. Overall, these results suggest that goat cells, or at least those cells targeted for viral carcinogenesis, are not permissive to virus replication but can be transformed by JSRV.

IN a paper published in Veterinary Record in March last year, Bidewell and others (2012) highlighted the susceptibility of dry Jersey cows in a mixed herd to pre- and post-haemolytic copper poisoning (HCP). The authors speculated that an abrupt change of diet to barley straw for ‘drying off’ may have been a predisposing factor. In our own study of a pure Jersey herd receiving more supplementary copper, particularly during the dry period (41 or 46 mg Cu/kg dry matter [DM] v 20 mg Cu/kg DM) (Hunter and other 2013), there was no evidence of either pre- or post-HCP in dry or lactating cows, before or after intervention. Supplementary …

This study investigates epithelial cell differentiation and proliferation in specific anatomical regions of the ovine lung during prenatal and postnatal development. Immunohistochemistry was used to identify ciliated epithelial cells, Clara cells, neuroepithelial bodies and type II pneumocytes in the lungs of preterm (67, 127 and 140 days of gestation), full-term (147 days) and postnatal (9, 16 and 91 days old) lambs. Differentiation of ciliated epithelial cells was seen at 67 days of gestation and at term for Clara cells. Neuroepithelial bodies were first detected at 127 days of gestation. From 16 to 91 days of age there was a significant (P

WE are undertaking a prospective study based at the Royal Veterinary College with the aim of answering the question: ‘Are changes in the femoral head and/or neck of cats due to chronic capital physeal fracture, secondary to previous capital physeal fracture, …

Ovine pulmonary adenocarcinoma (OPA) is a transmissible lung cancer of sheep caused by Jaagsiekte sheep retrovirus (JSRV). The details of early events in the pathogenesis of OPA are not fully understood. For example, the identity of the JSRV target cell in the lung has not yet been determined. Mature OPA tumors express surfactant protein-C (SP-C) or Clara cell-specific protein (CCSP), which are specific markers of type II pneumocytes or Clara cells, respectively. However, it is unclear whether these are the cell types initially infected and transformed by JSRV or whether the virus targets stem cells in the lung that subsequently acquire a differentiated phenotype during tumor growth. To examine this question, JSRV-infected lung tissue from experimentally infected lambs was studied at early time points after infection. Single JSRV-infected cells were detectable 10 days postinfection in bronchiolar and alveolar regions. These infected cells were labeled with anti-SP-C or anti-CCSP antibodies, indicating that differentiated epithelial cells are early targets for JSRV infection in the ovine lung. In addition, undifferentiated cells that expressed neither SP-C nor CCSP were also found to express the JSRV Env protein. These results enhance the understanding of OPA pathogenesis and may have comparative relevance to human lung cancer, for which samples representing early stages of tumor growth are difficult to obtain.

Reasons for performing study: High numbers of racehorses in training are reported to have gastric ulceration. Gross lesion scoring systems exist, but there is no fixed protocol with which to record gastric microscopic findings. In man, the histological classification of stomach lesions helps in the identification of recognised and emerging aetiologies of gastric disease and aids accurate comparison of findings between studies. In horses, the development of such a system would therefore be of benefit. Objectives: To develop a pathological scoring system that can be applied to examine samples of the equine stomach at biopsy and post mortem. Methods and results: The equine gastritis grading (EGG) system was developed initially using horse stomachs at post mortem. The protocol involved sampling tissue from 5 fixed locations within the squamous and glandular regions. Histological examination recorded both type and degree of inflammatory infiltrate and the presence of erosions, ulceration or any other reactive change in each slide. These results were combined and an overall diagnosis of gastritis type given for each stomach. Conclusions and potential relevance: This is the first example of a complete pathological scoring system developed specifically for recording gastric lesions in the horse. It provides a thorough and repeatable method with which to examine the equine stomach in microscopic detail. It can be used in diagnostic or research situations and the consistency of the information gathered will enable accurate comparison of data between different studies. It aims to give an indication as to the currently undetermined pathological variations seen in the stomach of healthy and diseased horses, as well as increasing the understanding of the pathogenesis of gastritis and gastric ulceration. Using this information, interpretation of biopsy samples is improved.

Ovine pulmonary adenocarcinoma (OPA), also known as jaagsiekte, is a transmissible lung cancer of sheep caused by jaagsiekte sheep retrovirus (JSRV). JSRV induces neoplastic transformation of alveolar and bronchiolar secretory epithelial cells and the resulting tumours can grow to occupy a significant portion of the lung. Tumour growth is frequently accompanied by the over-production of fluid in the lung, which further compromises normal respiration. The period between infection and the appearance of clinical signs may be several months or years, and many JSRV-infected sheep do not exhibit clinical signs at all during their lifespan. This allows the spread of OPA into new flocks through contact with infected but apparently normal animals. OPA was first described in the early 19 th century. However, it has still not been possible to devise effective methods for controlling its spread and it remains an important problem in most countries where sheep are farmed. This is due in part to the absence of an immunological response to JSRV in infected animals which has hindered the development of serological diagnostic tests and vaccines. In addition to its veterinary importance, OPA is regarded as a potential large animal model for human lung adenocarcinoma and this has stimulated research into the pathogenesis of the ovine disease. This work has produced some significant results, including the finding that one of the JSRV structural proteins is directly involved in oncogenesis. The recent advances in understanding JSRV and the pathogenesis of OPA should lead to novel strategies for diagnosis and control of this disease and for its exploitation as a comparative model for human lung cancer.

Ribonucleic acid (RNA) interference (RNAi) is a recently discovered phenomenon whereby the introduction of double stranded (ds) RNA into the cytoplasm of the cell results in the specific and efficient degradation of complementary messenger (m) RNA and, therefore, reduced protein production. It was discovered by chance during attempts to develop flowers with increased colour intensity. The specific nature of the inhibition of protein production of cells has resulted in an explosion of research to understand and exploit RNAi. The technique is now established in in vitro systems, and much work is focussed in adapting RNAi for in vivo application. The potential of the technology in understanding physiological and pathological processes is significant, while its development as a therapeutic agent holds much promise as targeted agents. This review will describe the basic biological processes that drive RNAi, indicate current areas of areas research, and forecast future areas of development.

A four-year-old, female neutered domestic shorthair cat had a history of chronic intermittent vomiting and lymphocytosis. B cell chronic lymphocytic leukaemia was diagnosed by flow cytometry, which revealed abnormally large numbers of mature B lymphocytes in the peripheral blood. The cat was treated conservatively with antiemetic drugs and remained stable without chemotherapy for over a year.

A 5-year-old, male German shepherd dog was evaluated for a 5-week history of vomiting, diarrhea, lethargy, and weight loss. In abdominal radiographs, there was an unusual corrugated appearance within a loop of intestine. Sonographically, this loop also had a similar corrugated appearance with alternating hyperechoic and hypoechoic bands. Lymph nodes within the abdomen and thorax were enlarged, and a thoracic mass was also detected. Ultrasound-guided fine-needle aspirates of the mesenteric lymph nodes were highly suggestive of lymphoma. After postmortem examination, a diagnosis of multicentric lymphoma with involvement of the gastrointestinal tract was made.

High winter mortality (28 per cent) in female Jersey calves (one month) characterised by mild hepatopathy and enteropathy was investigated. Liver copper (Cu) was very high in casualties, but also high in culled, newborn males (19.2 ± 1.54 and 12.0 ± 2.74 sd mmol/kg dry matter (DM) respectively). Serum glutamate dehydrogenase (GLDH) was80 IU/l in healthy females aged 3-24 weeks, and correlated with serum aspartate transaminase (AST). Copper supplementation of total mixed rations during lactation was excessive (40-60 mg added Cu/kg DM) and reduced to 16-28 mg Cu/kg, but supplementation of milk replacer and creep feed (10 and 35 mg added Cu/kg DM, respectively) continued. The syndrome recurred two years later, and liver Cu remained high in casualties (13.6 ± 2.6) and culled cows (6.38 ± 2.38 mmol/kg DM) prompting withdrawal of all Cu supplements. Mortality remained low (6-9 per cent) thereafter. Three years after removal of all Cu supplements, six culled newborn were examined postmortem; five had normal liver Cu (4.5 ± 1.73), but a sixth had 11.65 mmol/kg DM. In live, healthy calves (1-6 months old) sampled at the same time, GLDH and AST increased with age to levels found five years earlier, indicating possible subclinical hepatopathy. Causative links between Cu supplementation, high calf mortality and hepatopathy are plausible, and reductions in Cu supplementation may prove beneficial in other dairy herds.

Background Jaagsiekte sheep retrovirus (JSRV) is the causative agent of ovine pulmonary adenocarcinoma (OPA), a transmissible neoplastic disease of sheep. OPA is an economically important veterinary disease and is also a valuable naturally occurring animal model of human lung cancer, with which it shares a similar histological appearance and the activation of common cell signaling pathways. Interestingly, the JSRV Env protein is directly oncogenic and capable of driving cellular transformation in vivo and in vitro. Previous studies of JSRV infection in cell culture have been hindered by the lack of a permissive cell line for the virus. Here, we investigated the ability of JSRV to infect slices of ovine lung tissue cultured ex vivo. Results We describe the use of precision cut lung slices from healthy sheep to study JSRV infection and transformation ex vivo. Following optimization of the culture system we characterized JSRV infection of lung slices and compared the phenotype of infected cells to natural field cases and to experimentally-induced OPA tumors from sheep. JSRV was able to infect cells within lung slices, to produce new infectious virions and induce cell proliferation. Immunohistochemical labeling revealed that infected lung slice cells express markers of type II pneumocytes and phosphorylated Akt and ERK1/2. These features closely resemble the phenotype of natural and experimentally-derived OPA in sheep, indicating that lung slice culture provides an authentic ex vivo model of OPA. Conclusions We conclude that we have established an ex vivo model of JSRV infection. This model will be valuable for future studies of JSRV replication and early events in oncogenesis and provides a novel platform for studies of JSRV-induced lung cancer.