[Food hygiene and safety - What is your diagnosis?]

INTRODUCTION

A healthy, 1,5 year old female wild boar (Sus scrofa) was shoot in a hunting district in Switzerland on June 22, 2023. The meat inspection revealed noticeable skin changes on all four distal extremities which were described histologically as multifocal epidermal hyperplasia and moderate orthokeratotic hyperkeratosis. The rest of the animal body, the organs and the lymph nodes were without any obvious lesions. The diagnosis of papilloma virus-associated exophytically growing papillomas was made. The venison was approved as fit for human consumption.

Virus discovery in dogs with non-suppurative encephalitis reveals a high incidence of tick-borne encephalitis virus infections in Switzerland

INTRODUCTION

Viral infections are a frequent cause of disseminated non-suppurative encephalitis in dogs. However, using routine diagnostic methods, the specific virus may remain unknown due to extensive or complete viral clearance or because the virus is unexpected or new. A metatranscriptomics-based approach of combining high-throughput sequencing (HTS) and bioinformatics analysis was used to investigate the viral etiology in archival cases of dogs with non-suppurative encephalitis. In formalin-fixed paraffin embedded (FFPE) brain material from the years 1976 to 2021 a high incidence of tick-borne encephalitis virus (TBEV) was detected. Moreover, canine distemper virus (CDV) was identified without typical demyelinating lesions and canine vesivirus (CaVV) was detected as an unexpected virus associated with non-suppurative encephalitis. We demonstrated the viral presence in brain tissues at the sites of inflammation by immunohistochemistry (IHC) and in situ hybridization (ISH). These results highlight the value of emerging sequencing technologies in veterinary diagnostics and expand our knowledge on the etiologies of encephalitis in dogs.

A case series highlighting the role of different gamma-herpesviruses in Equine Multinodular Pulmonary Fibrosis

INTRODUCTION

This case series describes three cases of equine multinodular pulmonary fibrosis (EMPF) diagnosed at the Clinic for Equine Internal Medicine at the University of Zurich between 2012 and 2017. Current information on etiology and treatment options are presented. Two horses showed mild signs of chronic lower respiratory tract disease and one horse was presented with acute signs of disease including recurrent fever spikes and tachypnea. Diagnosis was achieved by physical examination, radiographic findings, and PCR testing for equine herpesviruses (EHV) of bronchoalveolar lavage (BAL) fluid or lung tissue obtained by biopsy. All horses were euthanized due to continuing deterioration after attempted treatment. Post mortem histological examination of lung tissue showed severe multifocal diffuse to confluent fibrosis in two cases and in another horse a discrete nodular fibrosis pattern. Panherpes nested PCR revealed the presence of equine herpesvirus 5 (EHV-5) DNA in lung tissue of one horse whereas in two other horses, asinine herpes virus 5 (AHV-5) was detected. EMPF should be considered as a differential diagnosis in horses with acute and chronic respiratory disease, including horses non-responsive to treatment for equine asthma.

Clinical, laboratory and ultrasonographic findings in 94 cows with type-1 abomasal ulcer

INTRODUCTION

This study included 94 cows aged 2.1 to 12.0 years (5.2 ± 2.05 years) that were examined at a referral clinic because of type-1 abomasal ulcer. The most common clinical findings were poor general health status (94%), partial or complete anorexia (93%), congested scleral vessels (89%), decreased skin surface temperature (76%), decreased or absent faecal output (72%), abdominal guarding (59%), tachypnoea (56%), rumen atony (53%) and positive percussion and simultaneous auscultation and/or ballottement and simultaneous auscultation on the right side (53%). The most common laboratory findings were hypokalaemia (68%), positive base excess (60%) and azotaemia (51%). The chloride concentration of rumen fluid was increased in 48% of the cows. The diagnosis of type-1 ulcer was made during laparotomy and/or postmortem examination. One or more concurrent diseases were diagnosed in 97% of the cows. Seventy-eight (83%) cows were euthanased immediately after the initial examination, during laparotomy or after unsuccessful treatment, and eight (8.5%) cows died, and all were examined postmortem. Eight (8.5%) cows were discharged and six of these made a complete recovery.

Hair cortisol concentration in clinically healthy slaughter calves with and -without chronic bronchopneumonic -lesions

INTRODUCTION

The hypothesis of this study was that healthy calves undergo less stress and thus have lower hair cortisol concentrations than calves with chronic bronchopneumonic lesions. Fifty healthy calves (group 1) and 50 calves with chronic bronchopneumonic lesions (group 2) were used immediately after slaughter, at which time hair samples and both adrenal glands were collected. The hair samples and the left adrenal gland were used for cortisol measurement and the right adrenal gland was used for histological and morphometrical examinations. The median hair cortisol concentrations of calves in groups 1 and 2 were 1.6 and 1.9 pg/mg hair, respectively, and did not differ significantly. The same was true for the mean cortisol concentration of the adrenal gland (1.1 and 1.4 µg/g tissue) and for the adrenal cortisol content (3.7 and 4.6 µg). The weights of the cortex (3.3, mean, and 3.5 g, median) and medulla (1.7 and 1.8 g, both median) did not differ significantly between the groups. This study did not detect differences in hair and adrenal cortisol concentrations between clinically healthy slaughter calves with and without chronic bronchopneumonic lesions. In further studies, calves with clinical signs should be taken into account.

Clinical and laboratory findings in 60 cows with type-3 abomasal ulcer

INTRODUCTION

This study involved 60 cows aged 1.9 to 13 years (mean 4.8 ± 2.3 years) with type-3 abomasal ulcer. The most common clinical signs were, in decreasing order of frequency, partial or complete anorexia (98%), obtunded demeanour (95%), decreased skin surface temperature (78%), congested scleral vessels (73%), abdominal guarding (61%), tachypnoea (58%), fever (58%) and tachycardia (55%). One or more concomitant disorders were diagnosed in 86% of the cows. The most common abnormal laboratory findings were hypokalaemia (75%), shortened glutaraldehyde test time (46%) and hyperfibrinogenaemia (43%). The diagnosis of type-3 abomasal ulcer was made in all cows during laparotomy and/or at postmortem examination. Forty-eight (80%) cows were euthanased immediately after the initial examination, during laparotomy or after unsuccessful treatment. Twelve (20%) cows were treated with a solution of sodium chloride and glucose administered via an indwelling jugular catheter, antibiotics, metamizole or flunixin, and discharged from the clinic. Ten cows were still in production two years later.

Transient benign osteopetrosis in a calf persistently infected with bovine virus diarrhoea virus

A two-day-old Simmental calf was admitted suffering from a fracture of the right femur. The radiographs showed striking changes in all bones, evident as alternating zones of dense and less dense tissue (bone-inbone) in the right femur and striped densities in the vertebral bodies. A stainless steel plate was used to repair the fracture, which healed well. The calf developed normally but was diagnosed as persistently infected with bovine virus diarrhoea (BVD) virus. It was kept in isolation and examined physically and radiographically during the following 13 months. The radiographic changes diminished during the first three months and at 13 months were barely visible. The animal was euthanatized, and immunohistochemistry revealed BVD virus antigen in numerous tissues. The radiographic abnormalities seen in this case are similar to those of the transient form of osteopetrosis in humans. Osteopetrosis in humans is currently thought to have a genetical cause, whereas it appears to be associated with viral disease in animals.

Variation in fat content between liver lobes and comparison with histopathological scores in dairy cows with fatty liver

Background

The assessment of a liver biopsy remains the gold standard for diagnosing and staging fatty liver in dairy cows, which is often necessary for diagnostic and research purposes. Accuracy of the diagnosis relays on the quality of the biopsy, the assumed representativeness of a small tissue sample for a disease process throughout the liver and accurate human evaluation of histologic specimens. The objective of the present study was to assess the distribution of triacylglycerol (TAG) infiltration throughout the parenchyma of livers with different degrees of fatty liver in dairy cows. In addition, histopathological scores from the corresponding specimens were compared to a quantitative measurement of TAG, as well as the agreement between two observers.

Methods

Thirty livers with different degrees of lipid infiltration were selected and 10 different locations throughout the liver were assessed. The TAG content was measured enzymatically, calculated in % or mg/g wet weight, and assigned to a scoring system. Corresponding tissue specimens were stained with hematoxylin-eosin (H&E) and Oil red O (ORO) for histopathological evaluation, using a scoring system.

Results

The difference in TAG content between any locations was less than 2%. Based on the scoring system the TAG concentration was even distributed in 79.3% of the livers. Based on kappa statistics the agreement between two pathologists and staining technique in scoring histological specimens was moderate to fair.

Conclusions

Overall the distribution of TAG throughout the liver and the accuracy of human evaluation of liver biopsies may lead to acceptable diagnoses for clinical purposes. Within the liver lobules a common pattern of lipid distribution depending on severity could be observed. For the staging of lipid infiltration for research projects, some degree of variation needs to be considered.

Neuronal ceroid lipofuscinosis (NCL) is caused by the entire deletion of CLN8 in the Alpenländische Dachsbracke dog

Neuronal ceroid lipofuscinoses (NCLs) are inherited lysosomal storage diseases that have been described in a variety of dog breeds, where they are caused by different mutations in different genes. However, the causative gene defect in the breed Alpenländische Dachsbracke remained unknown so far. Here we present two confirmed cases of NCL in Alpenländische Dachsbracke dogs from different litters of the same sire with a different dam harboring the same underlying novel mutation in the CLN8 gene. Case 1, a 2-year-old male Alpenländische Dachsbracke was presented with neurological signs including disorientation, character changes including anxiety states and aggressiveness, sudden blindness and reduction of food intake. Magnetic resonance imaging (MRI) scans showed cerebral atrophy with dilation of all cerebral ventricles, thinning of the intermediate mass of the thalamus and widening of the cerebral sulci. Postmortem examination of the central nervous system (CNS) showed neuronal loss in the cerebral cortex, cerebellum and spinal cord with massive intracellular deposits of ceroid pigment. Additional ceroid-lipofuscin deposits were observed in the enteric nervous system and in macrophages within spleen, lymph nodes and lung. Ultrastructural analyses confirmed NCL with the presence of osmiophilic membrane bounded lamellar-like structures. Case 2, a 1,5-year old female Alpenländische Dachsbracke was presented with progressive generalized forebrain disease including mental changes such as fearful reactions to various kinds of external stimuli and disorientation. The dog also displayed seizures, absence of menace reactions and negative cotton-ball test with normal pupillary light reactions. The clinical and post mortem examination yielded similar results in the brain as in Case 1. Whole genome sequencing of Case 1 and PCR results of both cases revealed a homozygous deletion encompassing the entire CLN8 gene as the most likely causative mutation for the NCL form observed in both cases. The deletion follows recessive inheritance since the dam and a healthy male littermate of Case 1 were tested as heterozygous carriers. This is the first detailed description of CLN8 gene associated NCL in Alpenländische Dachsbracke dogs and thus provides a novel canine CLN8 model for this lysosomal storage disease. The presence of ceroid lipofuscin in extracerebral tissues may help to confirm the diagnosis of NCL in vivo, especially in new dog breeds where the underlying mutation is not known.

Comparison of Clinical and Pathological Diagnoses in Cats and Dogs

The comparison of clinical ante-mortem and pathological post-mortem diagnoses is a prerequisite for quality control, but is rarely done in veterinary medicine. This study reports the occurrence and concurrence of clinical and pathological diagnoses linked to death in 1,000 cats and 1,000 dogs examined and subjected to necropsy examination at the University of Zurich, Switzerland. Potential factors influencing the correlation between diagnoses were examined retrospectively. In 5.8% of cats and 5.2% of dogs no diagnosis was made; in 2.6% and 3.8% of cases only a clinical, and in 17.8% and 11.2%, respectively, only a pathological diagnosis was available. Of the 73.8% of cats and 79.8% of dogs with both diagnoses present, 38.3% and 36.2% were in agreement, while there was disagreement in 17.9% and 16.0%, respectively. The remaining cases (43.8% and 47.8%) had different levels of further diagnostic procedures following necropsy examination. In both species, the manner of death, the clinical discipline submitting the animal for necropsy examination and the quality of the necropsy submission request, as well as the timespan between death and necropsy examination in dogs, proved to influence the concurrence between diagnoses. In contrast, the organ system affected and the type of disease entity were, for both species, the most influential factors in the concurrence of diagnoses. Therefore, in veterinary medicine, even in times of improving diagnostic abilities, necropsy examination still reveals important information for quality control and education.

Comparison of Serum Spec fPL(™) and 1,2-o-Dilauryl-Rac-Glycero-3-Glutaric Acid-(6'-Methylresorufin) Ester Assay in 60 Cats Using Standardized Assessment of Pancreatic Histology

BACKGROUND

Feline pancreas-specific lipase (Spec fPL) is considered a useful test for the antemortem diagnosis of pancreatitis in cats. A recent study found good agreement between the results of the Spec fPL and catalytic 1,2-o-dilauryl-rac-glycero-3-glutaric acid-(6'-methylresorufin) ester (DGGR) lipase assay. Prospective studies evaluating their sensitivity and specificity are lacking.

OBJECTIVES

To compare the results of the Spec fPL and the DGGR assays with a standardized histologic assessment of the pancreas.

ANIMALS

Sixty client-owned cats presented for necropsy.

METHODS

PROSPECTIVE STUDY

Spec fPL concentrations and serum DGGR lipase activity were measured from the same blood sample. The pancreas was removed within 3 hours after euthanasia; serial transverse sections were made every 0.5 cm throughout the entire pancreas and reviewed using a histologic grading scheme. Sensitivity and specificity for the Spec fPL and DGGR assay results were determined.

RESULTS

The sensitivity and specificity for the Spec fPL assay (cutoff value ≥5.4 μg/L) was 42.1 [95% confidence interval (95% CI), 29.4-55.9%] and 100% (95% CI, 31.0-100.0%). The sensitivity and specificity for the DGGR assay (cutoff value >26 U/L) was 36.8 (95% CI, 24.7-50.7%) and 100% (95% CI, 31.0-100.0%). When lymphocytic inflammation up to 10% of a section was considered normal, the sensitivity and specificity for Spec fPL assay (cutoff value ≥5.4 μg/L) was 61.1 (95% CI, 36.1-81.7%) and 69.0% (95% CI, 52.8-81.9%) and the sensitivity and specificity for the DGGR assay (cutoff value >26 U/L) was 66.7 (95% CI, 41.2-85.6%) and 78.6% (95% CI, 62.8-89.2%).

CONCLUSIONS AND CLINICAL IMPORTANCE

Both lipase assays performed similarly well, but their agreement with histologic pancreatic inflammation was limited.

Clinical and echocardiographic findings in an 8 year old Brown Swiss cow with myocardial abscess

Intramyocardial abscesses are rare in cattle and may lead to unspecific clinical signs. This case report describes the clinical and echocardiographic findings in an 8 year old Brown Swiss cow presented with an intramural myocardial abscess. The main clinical findings were anorexia, drop in milk yield, fever, tachycardia, and hyperfibrinogenemia. Neither heart murmurs nor cardiac arrhythmias were present on auscultation. Transthoracic echocardiographic examination revealed a prominent intramural mass embedded in the left ventricular free wall and bulging into the lumen of the left ventricle. Diagnosis was confirmed at necropsy. A culture of the abscess grew Trueperella pyogenes.

[Spina bifida aperta in a sheep lamb]

The case report describes the symptoms and diagnostic methods of a spina bifida aperta in a new born lamb. The most relevant clinical findings were recumbency immediately after birth with normal consciousness and suckling reflexes, alterations of the skin and coat in the lumbosacral region as well as dysuria. The biochemical and haematological screening of the blood indicated no abnormalities. While the radiological examination of the spine showed no clear evidence of the cause of the clinical sings the ultrasound and computed tomography examination revealed an incomplete closure of the vertebral arch between the 4th lumbar and the 3rd sacral vertebrae. Additionally, a hernia with similar density to the spinal cord was present in the same region of the spine. Based on the findings the lamb was euthanized. The pathological examination confirmed the incomplete closure of the vertebral arch and moreover a myelomeningocele has been diagnosed. In the histopathological examination the white and grey matter were separated in the area of the macroscopic visible lesions. Due to non-specific clinical symptoms imagining diagnostics can be crucial to confirm the diagnosis of this rare syndrome.

[Ulcerative colitis and proctitis in two Swiss Braunvieh cows]

Two Swiss Braunvieh cows were referred to our clinic because of narrowing of the rectum and difficult rectal examination attributable to restricted arm movement within the pelvic cavity. Cow 1 also had perforation of the cranial rectum and cow 2 had multiple small funnel-shaped depressions in the rectal mucosa. Both cows had ultrasonographic evidence of peritonitis with thickening of the intestinal wall and fibrin and fluid accumulation in the abdominal cavity. A diagnosis of peritonitis was made in both cows, most likely caused by rectal perforation; they were euthanized and a post-mortem examination was carried out. Both cows had proctitis and ulcerative colitis with three or four perforated ulcers which were associated with fibrinopurulent peritonitis. The final diagnosis was ulcerative colitis and proctitis of unknown aetiology. Infectious causes of colitis and proctitis, including bovine viral diarrhoea, adenovirus infection and salmonellosis, and trauma and poisoning were ruled out.

Pulmonary Arterial Lesions in New World Camelids in Association With Dicrocoelium dendriticum and Fasciola hepatica Infection

In Switzerland, dicrocoeliasis is regarded as the most significant parasitic infection of llamas and alpacas. Fasciola hepatica infestation is also a problem but less common. The aim of the present retrospective study was to evaluate the lungs of New World camelids (NWCs) for evidence of arterial hypertension in association with liver changes due to liver fluke infestation. The lungs of 20 llamas and 20 alpacas with liver fluke infestation were histologically evaluated. The hematoxylin and eosin and van Gieson (VG)–elastica stains as well as immunohistology for the expression of α–smooth muscle actin (α-SMA) were used to visualize the structures of arterial walls. Parasitology of fecal matter (11 llamas and 17 alpacas) confirmed that most of these animals were infested with both Dicrocoelium dendriticum and other gastrointestinal parasites. In most cases (10/12 llamas, 4/6 alpacas), liver enzyme activity in serum was elevated. Histologically, arteries in the lungs of 9 of 20 llamas (45%) and 3 of 20 alpacas (15%) showed severe intimal and adventitial and slight to moderate medial thickening, which was confirmed with α-SMA and VG-elastica staining. All animals exhibited typical liver changes, such as fibrosis and biliary hyperplasia, in association with the presence of liver flukes. This study shows that liver flukes can induce proliferative changes in lung arteries in NWCs that resemble those seen with pulmonary arterial hypertension due to liver parasites in humans. However, the degree of liver fluke infestation was not correlated with the extent of liver damage, or with the amount of thoracic or abdominal effusion or pulmonary arterial changes.

[First cases of besnoitiosis in cattle in Switzerland]

Bovine besnoitiosis has been diagnosed in neighboring countries but not in Switzerland so far. This disease occurs endemically in France and focal outbreaks have been reported in Germany and Italy. To determine if Besnoitia besnoiti is introduced into Switzerland through the import of breeding cattle from France, a systematic serological survey was performed. A total of 412 breeding cattle (from 114 farms) imported from France into Switzerland between 2005 and 2011, were serologically examined for antibodies against B. besnoiti using a commercial ELISA kit (PrioCHECK© Besnoitia Ab 2.0, Prionics AG, Zurich, Switzerland). Sixty-four (15.5 %) animals reacted positive in ELISA. The serologic diagnosis was confirmed by an indirect immunfluorescence test (IFAT) and a Western blot (WB) in only 2 Limousin cows imported from France on a farm in Eastern Switzerland. Subsequently, this whole herd (n = 16) was examined clinically and serologically and 2 additional Limousin cows imported from Germany also reacted positive in the three serological tests. One of these cows presented B. besnoiti tissue cysts in the scleral conjunctiva and typical skin lesions in the head region. The infection was further confirmed cytologically, histopathologically and by PCR. It can be concluded that the parasite is most likely being introduced into Switzerland through the import of infected animals.

Acinar cell carcinoma of exocrine pancreas in two horses

Two horses were presented with non-specific clinical signs of several weeks' duration and were humanely destroyed due to a poor prognosis. At necropsy examination, both horses had multiple small, white nodules replacing pancreatic tissue and involving the serosal surface of the abdominal cavity, the liver and the lung. Microscopically, neoplastic cells were organized in acini and contained abundant (case 1) or sparse (horse 2) intracytoplasmic zymogen granules. Immunohistochemically, both tumours expressed amylase and pan-cytokeratin, but not insulin or neuron-specific enolase. In case 2, a low percentage of neoplastic cells expressed glucagon and synaptophysin. The presence of zymogen granules was confirmed in both cases by electron microscopy and occasional fibrillary or glucagon granules were observed in cases 1 and 2, respectively. A diagnosis of pancreatic acinar cell carcinoma was established in both horses.

Histomorphological and immunohistochemical findings in testes, bulbourethral glands and brain of immunologically castrated male piglets

The aim of this study was the histological and immunohistochemical evaluation and comparison of testicular, bulbourethral and brain tissue in immunized and intact control boars. Fourteen male piglets, aged between 10 and 16 weeks, were vaccinated twice subcutaneously 4 to 5 weeks apart with Improvac, an anti-GnRH vaccine. The pigs were sacrificed 1 to 16 weeks following the second injection. Testicular weight was recorded and various tissue samples were collected and fixed in formalin and Bouin's fixative for histological examination. In addition, 2 boars were immunized five times and slaughtered 60 weeks after the last injection. Histological and immunohistological studies performed on testes and epididymes showed clear signs of atrophy in the immunized animals and a significant reduction in paired testes weight was seen in treated boars. Microscopically, the mean diameter of the seminiferous tubules was markedly reduced. Spermatogonia as well as few spermatocytes were visible between the Sertoli cells and Leydig cells were atrophic. None or only few spermatozoa were detected in the epididymis. The bulbourethral glands of immunocastrated pigs were smaller than in control pigs and showed histological evidence of atrophy. Immunohistological detection of LH and FSH in the pituitary gland of treated and control boars showed no quantifiable difference in the amount of these two gonadotropins and no lesions were visible in the hypothalamus and the pituitary gland. From our findings it can be concluded that the anti-GnRH vaccine Improvac induces severe atrophy of testes and bulbourethral glands in immunized pigs. This effect appears to be reversible, depending on the immune response of each animal and the time elapsed after the last booster injection.

Lesion profiles and gliosis in the brainstem of 135 Swiss Cows with Bovine Spongiform Encephalopathy (BSE)

Lesion profiles are considered to be an important tool for the comparison of the various animal and human spongiform encephalopathies and to obtain information upon prion strain variations. Histological and immunohistochemical reactions (PrPsc, GFAP) in 13 brain areas at 4 levels in the brainstem from 135 BSE-positive and 45 BSE-negative cases were retrospectively evaluated. In this retrospective study a lesion profile based on histological features was worked out on the basis of BSE cases originating from Switzerland over a period of ten years. They were confirmed post mortem by histology and immunohistology. Our findings were reviewed in comparison with lesion profiles published in England. No striking differences comparing type and quality of lesions in the relevant areas between the Swiss and the English cases were evident. Moreover, the lesion profiles and the character of the lesions did not differ between animals born before or after the offal feeding ban, which supports the hypothesis that the Swiss epidemic is sustained by the same single, stable strain of the BSE agent, which is probably the same as in the English epidemic. There was a good correlation between PrPsc accumulation and spongiform changes, in particular in those areas which were morphologically most affected. Astrocytosis in BSE was quantified. A significant rise in GFAP-positive cells could be shown comparing the brain stem nuclei of BSE affected with BSE-unaffected cattle, despite considerable variation between the cases and between the nuclei. The observed astrocytosis did correlate with vacuolation of the neuropil and of perikarya as well as with PrPsc accumulation.

Transcriptional targeting of DCs with lentiviral vectors induces antigen-specific tolerance in a mouse model of multiple sclerosis

The aim of this work was to induce permanent tolerance toward self-antigens involved in autoimmune diseases, such as multiple sclerosis (MS). We hypothesized that the stable auto-antigen presentation by dendritic cells (DCs) would tolerize auto-reactive T cells and, therefore, prevent disease development in a mouse model of experimental autoimmune encephalomyelitis (EAE), which closely resembles MS. Specifically, our strategy included the ex vivo modification of hematopoietic stem cells (HSCs) with self-inactivating (SIN) lentivirus vectors that transcriptionally target the expression of myelin antigens to DCs. As SIN lentivirus vectors support the genomic integration of transgene sequences in HSC, the transduced and transplanted HSC may provide a constant supply of antigen expressing steady-state DCs. Here, we demonstrate that targeting myelin oligodendrocyte glycoprotein (MOG) expression to DCs indeed resulted in complete and stable protection from EAE. No histological signs of EAE, such as demyelination, axonal damage, or infiltration of leukocytes in brain, spinal cord and optical nerve, were observed in tolerized mice. Tolerance induction was concomitant with the efficient deletion of MOG-specific T cells and the generation of Foxp3(+) regulatory T cells and, most importantly, directed toward a specific self-antigen while T-cell reactivity to unrelated foreign antigens was fully preserved.

[Squamous cell carcinoma of the reticulum and liver in a Simmental cow]

This report describes an 8.8-year-old Simmental cow with squamous cell carcinoma of the reticulum and liver. The cow had calved recently and was referred to our clinic because of intractable fever, anorexia and progressive indigestion. The general condition and mental status were moderately affected and rectal temperature and respiratory rate were significantly elevated. There were no ruminal sounds and pinching of the withers consistently elicited a grunt. Serum activities of gamma glutamyl transferase, glutamate dehydrogenase and sorbitol dehydrogenase were elevated. Radiographic examination of the reticulum and ultrasonographic examination of the reticulum, liver and abdominal cavity revealed multifocal, poorly demarcated, heterogeneous and echogenic changes in the liver. Biopsy of these lesions yielded a diagnosis of squamous cell carcinoma. The cow was euthanized and a postmortem examination confirmed the diagnosis. A 15 by 15 cm neoplasm was found in the reticular wall, and histological examination showed squamous cell carcinoma. It was assumed that the reticular mass was the primary tumour, which metastasized to the liver via the portal vein.

Apoptosis in Bovine viral diarrhea virus (BVDV)-induced mucosal disease lesions: a histological, immunohistological, and virological investigation

Cattle persistently infected with a noncytopathic Bovine viral diarrhea virus (BVDV) are at risk of developing fatal "mucosal disease" (MD). The authors investigated the role of various apoptosis pathways in the pathogenesis of lesions in animals suffering from MD. Therefore, they compared the expression of caspase-3, caspase-8, caspase-9, and Bcl-2L1 (Bcl-x) in tissues of 6 BVDV-free control animals, 7 persistently infected (PI) animals that showed no signs of MD (non-MD PI animals), and 11 animals with MD and correlated the staining with the localization of mucosal lesions. Caspase-3 and -9 staining were markedly stronger in MD cases and were associated with mucosal lesions, even though non-MD PI animals and negative controls also expressed caspase-9. Conversely, caspase-8 was not elevated in any of the animals analyzed. Interestingly, Bcl-x also colocalized with mucosal lesions in the MD cases. However, Bcl-x was similarly expressed in tissues from all 3 groups, and thus, its role in apoptosis needs to be clarified. This study clearly illustrates ex vivo that the activation of the intrinsic, but not the extrinsic, apoptosis pathway is a key element in the pathogenesis of MD lesions observed in cattle persistently infected with BVDV. However, whether direct induction of apoptosis in infected cells or indirect effects induced by the virus are responsible for the lesions observed remains to be established.

[Effect of vaccination against GnRH (Bopriva®) in the male pubertal calf]

The objective of this experiment was to investigate the effectiveness of a newly developed bovine anti-GnRH vaccine (Bopriva®, Pfizer Animal Health, Australia). A total of 12 peripubertal bull calves aged between 6 and 8 months were used, 2 randomly selected animals served as controls. Animals were vaccinated twice at an interval of 4 weeks with 1ml of Bopriva® (400 μg GnRH-protein-conjugate) subcutaneously in the neck and observed for a total of 36 weeks. Scrotal circumference was measured every week and blood samples were also taken weekly for the determination of testosterone and GnRH antibodies. Three months after the second injection (booster), 5 animals were slaughtered and their testes histologically examined. GnRH antibody titers rapidly began to rise after the second vaccination and reached peak values 3 weeks later. Testosterone concentrations decreased to values below 0.5 ng/ml serum 1 week after the booster and remained at this low level for at least 10 weeks. The following increase of testosterone occurred individually within 11 and 23 weeks after the booster injection. Histological examination of testes in vaccinated animals showed an incomplete spermatogenesis with impaired or no production of spermatids and a reduced diameter of seminiferous tubules. From our results we conclude that in the peripubertal bull two injections with the new bovine anti-GnRH vaccine 4 weeks apart is effective in suppressing testicular growth and testosterone secretion during at least 10 weeks after the booster injection.

Distribution of Borna disease virus antigen and RNA in tissues of naturally infected bicolored white-toothed shrews, Crocidura leucodon, supporting their role as reservoir host species

Borna disease is a severe viral-induced disorder of the central nervous system of horses, sheep, and a few other animal species, occurring in certain areas of central Europe. Pathogenesis and epidemiology of natural Borna disease virus (BDV) infections are still not fully understood; several unique epidemiologic features, however, point toward the existence of BDV reservoir populations other than the final hosts. In this study, 69 mice and 12 shrews were trapped and examined. The virus distribution was investigated in detail in 2 BDV-positive bicolored white-toothed shrews, Crocidura leucodon, by immunohistochemistry and TaqMan real-time reverse transcription polymerase chain reaction (RT-PCR). RT-PCR amplification products were sequenced, and the sequences were compared. These shrews had been collected in a BDV-endemic geographical region using live traps and did not show obvious clinical or pathological disease signs. BDV antigen and nucleic acid were identified in several organs, including the brain, mainly in nerve tissue and neurons, respectively, but also in parenchymal cells (eg, hepatocytes, Leydig cells) and epithelial cells, particularly of the respiratory and urogenital tract.

Mucosal lesions in a sheep infected with the Border Disease Virus (BDV)

A 28-week-old sheep was presented at the animal hospital because of chronic emaciation, anemia and slight diarrhea. Due to poor general condition and bad prognosis the animal was euthanized and submitted for postmortem investigation. Multiple erosions and ulcerations were found in the dorsal region of the tongue, the pharynx, the hard palate, in the esophagus and the ruminal pillars. Histologically, these lesions consisted of necrosuppurative inflammation. The animal was tested positive for pestivirus antigen both by immunohistochemical and by virological examination (cell culture, antigen capture ELISA and RT-PCR). A non-cytopathic Border Disease Virus was identified, and sequencing revealed a virus belonging to the BDV-3 cluster. Based on the macroscopical, histological, immunohistological and virological results this case was diagnosed as Border Disease with mucosal lesions. This is the first report of such a case in Switzerland.

[Ultrasonographic findings and treatment in a cow with a haemangiosarcoma of the urinary bladder]

A 4.5-year-old Swiss Braunvieh cow was presented to the Department of Farm Animals, University of Zurich, because of severe haematuria. All other clinical findings were within normal ranges. Transrectal ultrasonography revealed a 1 cm x 1 cm echogenic, irregularly-shaped, raised mass in the wall of the urinary bladder. Endoscopy identified the mass as a proliferation, approximately 0.5 cm in diameter, which was bleeding continuously. Thermocautery of the bleeding site was carried out twice five days apart via endoscopy. Clinical signs resolved for the remainder of the cow's life; she was slaughtered 15 months later because of infertility. Histological examination of the mass revealed a haemangiosarcoma.

Immunohistochemical diagnosis of persistent infection with Bovine Viral Diarrhea Virus (BVDV) on skin biopsies

Detection of persistent infection with BovineViral Diarrhea Virus (BVDV) is essential for both epidemiological and clinical reasons. In addition to the classical virological methods such as virus isolation in tissue culture, ELISA and RT-PCR, immunohistochemistry of skin biopsies has become a useful and reliable tool. Assuming that the presence of BVDV antigen in skin structures is restricted to persistent infection, this method could differentiate from transient infection. In order to answer this question, 6 calves were experimentally infected orally with a non-cytopathic genotype 1 BVDV strain belonging to the subtype k.The calves developed fever, mucopurulent nasal discharge, coughing and leucopenia with relative lymphopenia. Immunohistochemistry of skin biopsies taken daily up to day 13-post infection did not reveal any evidence of BVDV infection. BVDV was, however, isolated from blood samples on cell cultures. Anti-NS3-antibody-ELISA and serum neutralization tests showed that all six calves seroconverted. We conclude that in acute BVDV infections, with genotype 1 and the subtypes found in Switzerland (b, e, h and k) viral antigen is not found in epidermal structures of the skin. In contrast, persistently infected animals test positive for BVD viral antigen by immunohistochemistry of the skin.

Pituitary Macroadenoma in a Cat with Diabetes Mellitus, Hypercortisolism and Neurological Signs

A 13-year-old neutered male European short-hair cat was presented because of blindness and behavioural abnormalities. On physical examination, abnormal behaviour, compulsive walking, circling, continuous vocalization and blindness were the main neurological signs. In addition, abdominal alopecia, thin and inelastic skin, weight loss despite polyphagia, polyuria and polydipsia were present. Laboratory investigation revealed diabetes mellitus and pituitary-dependent hypercortisolism. Diagnostic imaging showed bilaterally enlarged adrenals and a large pituitary mass. Histopathological and immunohistochemical examination confirmed the clinical diagnosis of an ACTH-producing pituitary macroadenoma.