Frequent Occurrence of Simultaneous Infection with Multiple Rotaviruses in Swiss Pigs

Rotavirus (RV) infections are the most important viral cause of diarrhea in piglets in Switzerland and are thought to cause substantial economic losses to the pig industry. However, no data are available on the occurrence and dynamics of the main porcine RV species, namely RVA, RVB, and RVC, and the diversity of the circulating strains. We therefore tested fecal samples from a cross-sectional (n = 95) and a longitudinal (n = 48) study for RVA, RVB, and RVC by real-time RT-PCR and compared the results of the cross-sectional study to postmortem findings. In addition, eight samples were fully genotyped by using next-generation sequencing. In the cross-sectional study, triple RV infections significantly correlated with diarrhea and wasting and were most frequent in the weaned age group. In the longitudinal study, the shedding of RV peaked one week after weaning and decreased thereafter. Here, mainly double infections were seen, and only a few animals showed diarrhea. The full-genome sequencing revealed a genotype pattern similar to other European countries and, importantly, co-infection by up to four RVA strains. Our results imply that the weaning of piglets may trigger not only RV shedding but facilitate co-infection of multiple RV species and strains in the same host.

Suitability of testicular tissue fluid from castrated piglets to verify sow -vaccination status and herd monitoring

INTRODUCTION

In a proof of concept, PCV2-specific IgG-antibodies from testicular tissue fluid of seven-day-old castrated piglets were measured to verify the vaccination status of their mothers. Twelve randomly selected sows were vaccinated twice during the last third of gestation with a PCV2 vaccine, while ten controls received only adjuvant. PCV2- specific IgG-antibody titers of serum and colostrum from the sows were correlated with PCV2-specific IgG-antibody titers of serum and testicular tissue fluid of their castrated male offspring. Vaccinated sows showed significantly higher average PCV2-specific IgG-antibody titers in serum (29250 ELISA units, EU) and colostrum (65410 EU) compared to 980 EU and 2630 EU of the control group, respectively. Moreover, significantly higher average concentrations of antibodies were also measured in the serum (9362 EU vs. 247 EU) and the testicular tissue fluid (4022 EU vs. 354 EU) of piglets from vaccinated compared to piglets from adjuvant administered sows. Importantly, a strong linear correlation between PCV2-specific IgG-antibodies in the serum of the piglets and in their testicular tissue fluid was found (rs = 0.9148). PCV2-specific IgG-antibody titers of testicular tissue fluid from five randomly selected piglets allowed the determination of the vaccination status of the herd with a reliability of 98% for vaccinated and 73% for unvaccinated sows. Furthermore, using castration waste products is a very animal friendly method to replace painful and time-consuming blood samplings for herd monitoring or to verify vaccination status.

Chlamydia pecorum-Induced Arthritis in Experimentally and Naturally Infected Sheep

Chlamydia pecorum is an obligate intracellular pathogen with a wide host range including livestock such as sheep, cattle, goats, and pigs as well as wildlife species such as koalas. Chlamydial polyarthritis is an economically important disease resulting in swollen joints, lameness, stiffness, and weight loss in young sheep. In the present study, tissues from sheep experimentally or naturally infected with Chlamydia pecorum were assessed by histopathology and immunohistochemistry. Carpal, hock, and stifle joints as well as spleen, liver, kidney, lymph nodes, lung, and brain of 35 sheep from different inoculation groups were available. Two different C. pecorum strains (IPA and E58), different routes of administration (intraarticular or intravenous), UVA-irradiated IPA strain, and corresponding noninfected control groups were investigated. Similar investigations on tissues from 5 naturally infected sheep were performed. The most obvious inflammatory lesions were observed in synovial tissues and, notably, in the renal pelvis from the experimentally infected group and naturally infected animals. This resulted in chronic or chronic-active arthritis and pyelitis. Intralesional chlamydial inclusions could be demonstrated by immunohistochemistry in both tissues. Immunohistochemical evaluation of the presence and distribution of macrophages, T and B cells in synovial tissues revealed macrophages as the most prevalent inflammatory cell population. Previous observations indicated that C. pecorum isolates can infect circulating monocytes. Together with the finding of the histological lesions in synovial tissues and internal organs alongside the presence of C. pecorum DNA, these observations suggest chlamydial arthritis in lambs is the result of hematogeneous spread of C. pecorum.

Porcine Circovirus Type 2 Pathogenicity Alters Host's Central Tolerance for Propagation

Porcine circovirus type 2 (PCV2) infections and resulting diseases are a worldwide threat to pig production. PCV2 bears a uniqueness that allows for us to understand more about chronic infections and the immune system in general. The virus can be phylogenetically subdivided into PCV2a to PCV2h genotypes. Although vaccination against PCV2 has been seen to prevent the manifestation of PCV disease, PCV2 still lingers as subclinical infections in all developmental stages of pigs. The “slow and low” tactic gives PCV2 a particular advantage in a host’s immune surveillance. Since the inception of the PCV2 associated panzootic, research scientists have been trying to understand the pathogenicity of PCV2. Different research groups found that one genotype group member was more pathogenic than others. We found, in our weaner infection model with in vivo transfection of different recombinant PCV2 genotype group members that these viruses alter T cell maturation in the thymus, including host’s central tolerance. Here, we extend these original observations by showing that PCV2 infected cells were also found in proximity within the female and male reproductive organs of stillborn pig fetuses. These PCV2 pools were sufficient in infecting three and half-day-old embryos in sows. Furthermore, the dominant PCV2 group member was more pathogenic in our weaner infection model. PCV2 pre-immunocompetence infection makes PCV2 recognized by central immune tolerance as belonging to the host. This also explains why pathogenicity is not a genetically intrinsic characteristic of PCV2; however, the dominance of any one PCV2 genotype group member leads to a more efficient deletion of the T cells against that specific genotype group member in the thymus.

Endocardial fibroelastosis in a dog with congestive heart failure

In a 6-month-old, intact female, Japanese spitz presenting with severe dyspnea, lung ultrasonography revealed confluent B lines associated with severe echocardiographic left sided volume overload and systolic dysfunction. A congenital shunt or valvular dysplasia was not demonstrable. On electrocardiogram, there was a constant sinus rhythm, respectively sinus tachycardia. Cardiac troponin I was normal. Within 2 days of admission, the dog died of heart failure. On macroscopic postmortem examination, the left ventricle and atrium were markedly dilated, and the left ventricular endocardium had a mild diffuse whitish appearance. Histopathology revealed moderate to severe thickening of the left ventricular endocardium, composed mostly of abundant elastic fibers and fewer collagen fibers, diagnostic for endocardial fibroelastosis. In addition, there were mild degenerative changes of the atrioventricular valves. Endocardial fibroelastosis is a rare congenital disease and should be considered in a young dog if more common causes of echocardiographic dilated cardiomyopathy phenotype are ruled out.

Reviving post-mortem diagnostics as a tool to increase porcine herd health and strengthen early detection of pig diseases - the PathoPig project 2014-2016

INTRODUCTION

Post-mortem diagnostics are an important tool for disease diagnosis and therefore early detection of (re-)emerging animal diseases and zoonoses as well as nationwide disease surveillance programs. To counteract the decline of porcine necropsies in Switzerland over the last ten years, the Federal Food Safety and Veterinary Office (FSVO) launched a national project in 2014 called PathoPig. Post-mortem examinations of pigs from herds with health problems were financially supported by the FSVO. During the first 3 years of the project, the number of pig necropsies increased by 195% (mean). An underlying cause of disease was identified in 74% of the cases. These findings resulted in specific recommendations by the attending veterinarians or by the Swiss Porcine Health Service. A follow-up survey revealed that herd health had improved in 90% of the farms implementing the recommendations.

Clinical cystoisosporosis associated to porcine cytomegalovirus (PCMV, Suid herpesvirus 2) infection in fattening pigs

Cystoisospora (syn. Isospora) suis is the causative agent of neonatal porcine coccidiosis and one of the main causes of diarrhoea in suckling piglets worldwide. Infection with porcine cytomegalovirus (PCMV, Suid herpesvirus 2) causes inclusion body rhinitis in pigs. In a Swiss pig herd (n = 2 boars, 7 sows, 2 gilts, 18 finishing pigs, 30 fattening pigs, 54 suckling piglets), an outbreak of PCMV infection with high morbidity in all age categories, characterized by fever, anorexia, reduced general condition, respiratory signs and increased piglet mortality, was diagnosed by histopathology and molecular methods. Five fattening pigs (age ~ 17 weeks) additionally showed diarrhoea, not typical for PCMV infections, and one fattener had to be euthanized due to poor condition. Histopathologically, severe fibrinopurulent jejunoileitis with extensive atrophy and fusion of intestinal villi, loss of goblet cells and crypt abscesses associated to C. suis infection were present. In the liver, herpesvirus intranuclear inclusion bodies were observed and PCMV was confirmed by PCR/sequencing. No further infectious causes of diarrhoea (i.e. Rotavirus A; TGEV; PEDV; PCV-2; enterotoxigenic Escherichia coli or Lawsonia intracellularis) were detected in the euthanized fattener. Coproscopically, C. suis oocysts were identified in the faeces from further fatteners with diarrhoea. While C. suis usually produces disease only in suckling piglets, its association with severe intestinal lesions and diarrhoea in ~ 17-week-old fatteners was surprising. It is supposed that the underlying PCMV infection might have contributed to the presentation of clinical cystoisosporosis in fattening pigs. The interaction mechanisms between these two pathogens are unknown.

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A Porcine Cytomegalovirus (PCMV) outbreak was diagnosed in a Swiss pig herd

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Cystoisospora suis caused diarrhoea in 17 week-old fattening pigs co-infected with PCMV

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PCMV infection may produce immunosuppression in pigs

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PCMV may have contributed to presentation of clinical cystoisosporosis in fattening pigs

Lethal Gastric Mucosal Necrosis due to Administration of Oral Ferrous Bisglycinate Chelate to Suckling Piglets

The oral application of a newly developed ferrous bisglycinate paste for suckling piglets at a dose of 180 mg/kg body weight led to increased death rates in 10% (n = 10) of Swiss test pig breeding farms (n = 100). Necropsy examination of suckling piglets (n = 12), selected randomly from the test farms with increased death rates, demonstrated severe gastric mucosal ulceration and necrosis. Due to the presence of crystalline iron surface coating within the gastric lesions, the iron was considered as the toxic principle and cause of death. To demonstrate the direct toxicity of ferrous bisglycinate, the paste was administered experimentally to a litter of suckling piglets (n = 11). Different time points (24, 48 and 72 h post partum) and doses (180 mg/kg and 360 mg/kg) were investigated. The manufacturer's recommended dose of 180 mg/kg corresponded to approximately 36 mg Fe/kg and to 6.4 % of the acute lethal dose₅₀ of oral iron in rats. In all piglets the lesions were reproduced and most severe at the earliest time point (24 h post partum) and with the highest applied dose (360 mg/kg). The lesions were in accordance with those described from oral iron intoxication in man, suggesting pigs as an ideal animal model for oral iron toxicity studies.

Occurrence, clinical involvement and zoonotic potential of endoparasites infecting Swiss pigs

In order to estimate the diversity, clinical involvement and zoonotic potential of parasites in pigs submitted for diagnosis to the PathoPig project of the Swiss Federal Food Safety and Veterinary Office, faeces (n=125) from suckling piglets (n=39), weaners (n=60) and piglets beginning fattening (n=26) from 74 Swiss farms were examined by 3 coproscopical methods (i.e. sedimentation/zinc chloride-flotation; SAFC and Ziehl-Neelsen staining). Samples microscopically positive for Cryptosporidium were further tested by PCR/sequencing for species assessment. The most frequently detected parasite was Balantidium coli, a facultative pathogenic ciliate with zoonotic potential, in 5.1, 36.7 and 50.0% of suckling, weaners and fatteners and 43.2% of farms; however, no association with disease was observed. Isospora (syn. Cystoisospora) suis infections were detected in 13.3 and 11.1% of suckling piglets with and without diarrhoea, and in 10.0 and 13.3% of weaners and fatteners with diarrhoea, respectively, and were significant associated with emaciation. Cryptosporidium infections were detected in 10.3, 15.0 and 19.2% of sucklings, weaners and fatteners, respectively, and in 18.9% of the farms. Interestingly, two age-related species were identified: C. suis in younger piglets (2 to 6weeks) and C. scrofarum in older ones (6 to 17weeks). None of the pigs infected with C. scrofarum (n=8), but 3 of 4 piglets infected with C. suis (co-infection with I. suis in 2 cases) had diarrhoea. The zoonotic species C. parvum was not detected, nevertheless, sporadic cases of human infection with the porcine-adapted species have been reported. Ascaris suum, Trichuris suis and Strongylida were rarely detected (<4%) in all age categories.

[Lung and pleural lesions before and after implementation of a national eradication program against enzootic pneumonia and actinobacillosis as well as changes of slaughter carcass organs in slaughter pigs in Switzerland]

In a representative cross-sectional study during 12 months of the years 2008/2009 in four abattoirs in Switzerland, lung and pleura lesions as well as lesions of slaughter carcasses and organs of 34 706 pigs were studied for frequency and type of macroscopic lesions. Of the 24276 examined pigs, 91.2% of the lungs, 94.4% of the heart and 95.5% of the livers showed no macroscopically visible lesions. Pigs that were produced for a label program had significantly less bronchopneumonia and pneumonia residuals, pleuritis and liver lesions due to echinococcosis. Pigs supervised by the Swiss Pig Health Service (SGD), showed significantly less bronchopneumonia and pneumonia residuals, diffuse pleuritis, pleuritis/pericarditis and milkspots compared to the non-SGD supervised farms. Thanks to the national eradication program for enzootic pneumonia (EP) and actinobacillosis, the health-status of lungs has been considerably improved and the prevalence of pleurisy decreased considerably. The results of this study indicate a good herd health in Swiss pig production.

Rumen perforation caused by horn injury in two cows

Post-operative complications of trocarisation and rumenotomy are the most common causes of peritonitis associated with a rumen disorder. Since horn injury leading to rumen perforation has not previously been reported in the literature, two cows with this condition are reported. Small superficial skin lesions were observed in one of the cows and the other had a perforating skin lesion in the left abdomen. Both cows had signs of hypovolaemic shock. Ultrasonography revealed hypoechoic fluid, echoic lesions and occasional fibrinous septa caudoventral to the reticulum. Caudally the fluid extended to the left flank fold and occupied about one third of the peritoneal cavity. The area of the skin perforation in the left abdomen was swollen and the muscle layers could not be differentiated using ultrasonography. Diffuse fibrino-purulent peritonitis was diagnosed in both cows, and because of a poor prognosis, they were euthanased and necropsied. Perforation of the abdominal wall and rumen with diffuse fibrino-purulent peritonitis was present. Ultrasonography is a suitable tool to characterise the inflammatory lesions between the rumen and left abdominal wall and objectify the interpretation of clinical findings. Horn injury should be included in the rule outs for cattle with left abdominal skin wounds and diffuse peritonitis.

Latent porcine circovirus type 2-infected domestic pigs: A potential infection model for the effective development of vaccines against latent or chronic virus induced diseases

Until recently, knowledge of the pathogenicity of Circoviridae and Anelloviridae family members was limited. Our previous discoveries provided clues toward resolving this issue based on studies of the latent nature of porcine circovirus type 2 (PCV2) genotype group members. We developed a conventional pig infection model that indicated that weaners already harbored latent PCV2 infection in the thymus, which enabled the viruses to specifically modulate the maturation of T-helper cells. This finding raised the possibility that the thymi of normal fetuses were already infected with PCV2. The present findings further substantiate our hypothesis that PCV2 masquerades as the host by infecting fetuses before they acquire immune-competence. We provide the first demonstration that all domestic pig fetuses preferentially harbor latent PCV2-infected cells in their thymi. These PCV2-infected cells are different from thymocytes and are located in the medulla of the fetal thymus. These latent PCV2-infected cells in fetuses are found at the same location and share characteristics with the infected cells observed in adolescent pigs. Moreover, fetuses also harbor these infected cells in other lymph system organs. We provide the first demonstration that the fetal thymus virus pools are minimally affected by sow vaccination, highlighting the immune-privileged character of this organ. Furthermore, we found a striking reduction in virus-infected cells in the fetal spleen and an increase in PCV2-infected cells in the fetal intestine of anti-PCV2-vaccinated mothers. These data indicate that specific immune response interactions occur between mothers and their progeny that are not dependent on the humoral immunity of the mother and cannot be attributed to the rudimentary humoral responses of the fetuses because these pig fetuses do not have any PCV2-specific antibodies. These shifts in our understanding of the PCV2-infected cell pool will lead to different avenues in the search for effective vaccination strategies against latent and chronic pathogens.

T-cell lymphoma in the nasal cavity of a Brown Swiss heifer

Background

Tumours of the upper respiratory tract are relatively common in cattle, but to our knowledge, there have been no reports of lymphoma of the nasal cavity. This case report describes the findings in a 22-month-old Brown Swiss heifer with T-cell lymphoma of the nasal cavity.

Case presentation

The main clinical findings were lacrimation and swelling of the head above and below the right eye, mild exophthalmos, third eyelid prolapse, purulent ocular discharge and congestion of scleral blood vessels. An endoscope could only be introduced a few centimetres into the right nasal cavity because of an obstructing mass in the nasal passage. Radiographs showed a mass in the right nasal cavity and maxillary sinus. A tentative diagnosis of neoplasia of the right nasal cavity was made and the heifer was euthanased and necropsied. A firm, tan mass measuring 10 by 13 by 15 cm in the right half of the head occupied the entire right nasal cavity. A final diagnosis of high-grade, malignant, small-sized T-cell lymphoma was made based on histological and immunohistochemical evaluation. A distinction between αβ T-cell or γδ T-cell lymphoma was not made.

Conclusions

This report on T-cell lymphoma in the nasal cavity of a cow suggests that nasal lymphoma should be included in the list of differential diagnosis of conditions associated with dyspnoea and stertorous breathing in cattle.

Malignant peripheral nerve sheath tumour in the nasopharynx of a cow

This case describes the findings in a Swiss Braunvieh cow with a malignant peripheral nerve sheath tumour (MPNST) in the nasopharynx. The major clinical signs were mixed dyspnoea with inspiratory and expiratory noises. Radiographic views of the head revealed an irregular mass with soft-tissue density in the nasopharynx originating from the dorsal pharynx and occupying and restricting the pharyngeal cavity. Endoscopic examination showed a lobulated mass obstructing almost the entire lumen of the aboral nasal passages and nasopharynx. Postmortem examination revealed a lobulated mass in the choanae with a broad attachment to the dorsal pharynx and histologically a soft tissue sarcoma with tumour cells positive for the S-100 and p75NTR (neurotrophin receptor) proteins and negative for CNPase. Electron microscopic examination showed few structures that indicated that the tumour originated from Schwann cells.

[Economic impact of Circovac® - vaccination in a PCV2 subclinically infected farm in Switzerland on performance parameters]

Vaccination of dams in a PCV2 subclinically infected farm 2 and 4 weeks before insemination, with a booster at 12 weeks of gestation did not influence fertility parameters of the dams. However, growth parameters of offspring of vaccinated sows improved significantly (+ 51 g/d), resulting in a shorter growing period of 9 days and a massively improved economy. Mortality of weaners and fattening pigs was not significantly influenced by dam vaccination. Nevertheless, compared to a period of 6 months before vaccination, the mortality rate declined in the weaning period by 0,3 % and in the fattening period by 5,5 %. The Return on Investment (ROI) was calculated with 1:9.5. Even, the historically low pork prices in 2011 led to a ROI of 1:7.

Risk factors causing postweaning multisystemic wasting syndrome (PMWS) onset in Swiss pig farms

Postweaning multisystemic wasting syndrome (PMWS) was epizoozic between 2003 and 2008 in Switzerland. Nevertheless, infectious risk factors including porcine reproductive and respiratory syndrome virus (PRRSV) were missing at all or were seen only sporadically (enzootic pneumonia and actinobazillosis). In a case-control study, 30 farms with PMWS affected pigs were compared to 30 inconspicious farms ("matched pairs"). The case-control allocation was verified by PCV2 DNA measurements of 5 healthy weaned pigs in each control farm, 5 healthy and 5 PMWS affected weaners in each PMWS affected farm. Diseased pigs showed in average 1.8x10(8) DNA templates per ml serum significantly higher than healthy pigs from control farms with 1x10(6) DNA templates per ml serum. Virus load in healthy pigs did not differ between control- and PMWS affected farms. PMWS mainly emerged among affected pigs in the 5th to 8th week of age. In a logistic regression model risk factors were identified such as high occupancy in weaning pens (p = 0.002), large groups in gestation facilities (p = 0.03) as well as reduced birth weight < 1.3 kg (p = 0.04). We suggest these factors might have lead to chronic stress e.g. through influencing negatively social interaction in pigs or disturbances of the maturing immune system. Heavy fly and rodent infestation might not only be viewed as a vector for disease transmission, but, also as a stress factor.

[Postweaning multisystemic wasting syndrome (PMWS) and porcine dermatitis and nephropathy syndrome (PDNS) in Switzerland in the years 2003 - 2006]

In Switzerland postweaning multisystemic wasting syndrome (PMWS), caused by porcine circovirus type 2, was detected for the first time in 2001. To comprise the PMWS epizooty in 2003 - 2006 retrospectively, individual animals were diagnosed according to internationally accepted criteria and temporal and regional patterns of the epizooty were reconstructed. Occurrence of PMWS was predominantly in regions with a high frequency of swine farms (central and eastern Switzerland). Apparently it was spread to other, less affected regions, through trade of infected fattening pigs. Concurrently, disease was found in different establishments of production. Affected were mainly weaners or fattening pigs. In 40 % of the breeding farms and in 25 % of the fattening farms mortality rate was higher than 5 %. Starting in 2003, also a higher frequency of porcine dermatitis and nephropathy syndrome (PDNS) diseased pigs was diagnosed. In the years 2004 to 2006 they accounted for about 10 % of the diagnosed PCV2-associated diseases. Besides the characteristic skin- and kidney lesions approximately half of the PDNS cases showed wasting and lymphoid lesions with high quantities of PCV2 antigen. We termed these mixed forms PMWS-PDNS-hybrid forms.

Efficacy of simultaneous vaccination with Enterisol® Ileitis and Ingelvac® CircoFLEXTM in a Swiss breeding farm

This study explores administration of two piglet vaccines as compared to the mono- and adjuvant-application. A vaccine against the Porcine Circovirus Type 2 (PCV2) cap protein subunit and a vaccine with attenuated live culture against Lawsonia (L.) intracellularis were applied to piglets aged 23.5 days on average. 1'405 animals were divided randomly into four groups. One piglet group was immunized with both vaccines while two other groups were immunized with a combination of one vaccine and adjuvants of alternate vaccination protocol and vice versa. These piglet groups were also compared to a control group supplemented with both adjuvants only. During fattening, pigs, which were simultaneously immunized with Enterisol(®) Ileitis and Ingelvac(®) CircoFLEX(TM) vaccine, gained significantly more weight (792 g/day) when compared to piglet groups mono-vaccinated with Ingelvac® CircoFLEXTM (772 g/day) or either with Enterisol® Ileitis (774 g/day). Moreover, immunized piglet groups showed significantly higher daily weight gain when compared to adjuvants only inoculated control group (751 g/day). Additionally, during fattening the control group displayed higher mortality (6,3 %) than the three vaccinated groups (Ingelvac(®) CircoFLEX(TM) 2,5 %, Enterisol(®) Ileitis 2,3 % and the combination of both vaccines 1,1 %). These data imply that simultaneous immunization with PCV2- and L. intracellularis specific vaccines positively benefit piglet growth observed by an additive effect on growth parameters in farms harboring both pathogens. Return of investment was calculated of 2.10 on the additional Enterisol(®) Ileitis vaccination.

[Ultrasonographic finding and treatment of a cow with pyelonephrosis]

Ultrasonography of a six-year-old Simmental cow revealed an abscess like structure, approximately 15 cm in diameter, in place of the right kidney. The cow had a history of colic for 4 days and was referred to our clinic with a tentative diagnosis of caecal dilatation. The cow voided dark opaque urine with white floccules. Laboratory examination yielded increased haematocrit, leukocytosis with left shift, hyperbilirubinaemia and azotaemia. The diagnosis was confirmed, the caecum emptied surgically and the pus-filled structure at the site of the right kidney removed. A diagnosis of pyonephrosis was made after pathological examination of the pus-filled structure.

Bovine besnoitiosis in Switzerland: imported cases and local transmission

Bovine besnoitiosis is an economically important disease of cattle, caused by Besnoitia besnoiti (Protozoa, Apicomplexa). A considerable spreading of this parasitic infection has been observed in Europe in the last ten years, mainly related to animal trade. In order to investigate the possibility of B. besnoiti being unnoticed introduced and getting established in Switzerland through the import of breeding cattle from France, a total of 767 animals (650 cattle imported from France and 117 cattle that had contact with B. besnoiti positive cattle in Swiss farms) were screened for antibodies against B. besnoiti by both a commercial ELISA and by the indirect fluorescent antibody test (IFAT). A total of 101 (13.17%) samples showed a positive reaction in ELISA (cut-off: percent of positivity [PP] ≥ 15) and 16 (2.09%) samples had IFAT titers ≥ 1:100. Eight of those samples reacted positive in Western blot (WB), corresponding to five imported Limousin cattle (two cows and one bull from France and two cows from Germany) and to three cattle born in Switzerland (one Limousin heifer born from one of the positive German cows, and two adult Braunvieh cows, that had been in contact with one of the French cows at a Swiss farm). Seven of those animals were subclinically infected and one animal showed only very mild signs. They were subsequently slaughtered, and the serological diagnosis could be confirmed by real-time PCR and/or histopathology in seven animals. The most frequent parasite localizations were the tendons and surrounding connective tissue of the distal limbs and the skin of the head region. Furthermore, B. besnoiti could be successfully isolated in vitro from one French, one German and one Swiss cattle (isolates Bb-IPZ-1-CH, Bb-IPZ-2-CH and Bb-IPZ-3-CH). In the current situation in Switzerland, prophylactic and control measures should include a serological examination of cattle to be imported from endemic areas and the culling of all confirmed positive animals from the herd. The evidence of B. besnoiti infection in both imported and locally born cattle shows that the conditions for the establishment and dissemination of this parasite in Switzerland seem to be adequate.

Situs ambiguus in a Brown Swiss cow with polysplenia: case report

Background

Laterality defects are rare in cattle and usually manifest as asplenia or polysplenia syndrome. These syndromes may be associated with situs ambiguus, which is a dislocation of some but not all internal organs. The objective of this report was to describe the clinical and post-mortem findings including the macroscopic and microscopic anatomy of selected organs in a cow with polysplenia and situs ambiguus.

Case presentation

A 3.5-year-old Brown Swiss cow was referred to the Department of Farm Animals, Vetsuisse Faculty, University of Zurich, because of poor appetite and recurrent indigestion. A diagnosis of situs ambiguus was based on the results of physical examination, ultrasonography, exploratory laparotomy and post-mortem examination. The latter revealed that the rumen was on the right side and lacked compartmentalisation. There were two spleens, one on the left (26.5 x 12.0 cm) and one on the right (20.5 x 5.5 cm), and the omasum was located craniolateral to the ruminoreticulum on the left. The abomasum was located on the right, although it had initially been displaced to the left. The three-lobed liver occupied the left and central cranioventral aspect of the abdominal cavity (cavum abdominis). Only the right and left hepatic veins (vena hepatica dextra and sinistra) drained into the thoracic segment of the caudal vena cava (vena cava caudalis), and histological changes in the liver were indicative of impaired haemodynamics. The mesojejunum was not fused with the mesentery of the spiral loop (ansa spiralis) of the ascending colon (colon ascendens). The latter was folded and the transverse colon (colon transversum) ran caudal to the cranial mesenteric artery (arteria mesenteria cranialis). Fibrotic constrictions were seen in the lumen of the caecum and proximal loop (ansa proximalis) of the ascending colon. Both kidneys were positioned retroperitoneally in a lumbar position. The lumbar segment of the caudal vena cava did not descend to the liver and instead drained into the right azygous vein (vena azygos dextra).

Conclusions

Recurrent digestive problems and poor production in this patient may have been caused by a lack of rumen compartmentalisation, abnormal abomasal motility, constrictions in the large intestine (intestinum crassum) and fibrosis of the liver. The abomasum had abnormal motility most likely because it was anchored inadequately and only at its cranial aspect to the liver by the lesser omentum (omentum minus) and to the dorsal abdominal wall and rumen by a short greater omentum (omentum majus).

Porcine circovirus as a possible cause of postweaning wasting in pigs in Switzerland

Postweaning wasting is a major worldwide problem in pig production, particularly with respect to the disease termed postweaning multisystemic wasting syndrome (PMWS). In addition to wasting, PMWS symptoms include respiratory distress, diarrhoea, pallor and occasional cases of jaundice. The causative agent is porcine circovirus type 2 (PCV-2). The objective of the present study was to determine the significance of PMWS and similar conditions in Switzerland. A total of 72 weaned piglets from 26 farms showing wasting were examined for the presence of PCV-2 by immunohistochemical and histological analysis and 57 piglets from 21 farms were examined serologically. Possible causes for wasting other than PCV-2 were investigated by macroscopic, histological and bacteriological methods. PCV-2 antigen was identified immunohistochemically in the lymphatic organs in 11 of these 72 piglets. However, only 4 animals showed histological changes typical of PMWS. PCV-2 antibodies were found in 70% of the piglets. Piglets with wasting syndrome not associated with PCV-2 infection suffered from conditions including porcine proliferative enteropathy, gastric ulcers, polyserositis and polyarthritis. The most frequent condition was chronic enteritis not associated to circovirus infection. The results from the serological analyses indicate a wide distribution of PCV-2 in the Swiss pig population. However, confirmed cases of PMWS were rare in the investigated piglets.

Importierte Coenurose beim Schaf

Thirteen sheep from a milk producing farm in the Canton of Grisons that presented chronic coenurosis were examined and subjected to treatment trials at the veterinary hospital in Zurich. Symptoms were first observed around two months after the import of two dogs from Italy (Abruzza) of which one was infected with Taenia multiceps and Echinococcus granulosus. The most frequently observed clinical symptoms of the sheep were reduced general condition, circling, reduced menace reflex, apathy, unsteady gait and head tilt. Analyses of cerebrospinal fluid revealed an increased leucocyte count in 3 sheep and eosinophilia in 4 sheep. In 4 animals that underwent computertomography, one or more hypodense, definable lesions were found in the brain. In 2 sheep surgical treatment and in 10 animals medical treatment with either Praziquantel (n=8) or Oxfendazol (n=2) was attempted. Only one animal treated with Praziquantel needed not to be euthanized. At necropsy, one or two coenurus cysts could be found either in a side ventricle (n=2), in the cerebellum (n=3) or in the cerebrum (n=7). The locations corresponded with the clinical findings. Despite Praziquantel or Oxfendazol treatment, living protoscoleces could be found in the parasite cysts.

Zerebrospinale Nematodose beim Schaf in der Schweiz

In December 2005 three sheep, originating from Canton Tessin, were presented with cerebrospinal nematodosis. The animals had a history of progressive pelvic limb ataxia and recumbency. The most important clinical findings were an abnormal gait (wide stance, pelvic limb paresis) and decreased sensitivity of the pelvic limbs. The general condition was slightly or moderately disturbed, appetite was normal. Examination of the cerebrospinal fluid revealed mononuclear cells and eosinophils, suggesting a helminthic infection of the central nervous system. Postmortem findings confirmed the clinical diagnosis in one animal as parts of a nematode were found in the thoracic spinal cord. Even though the nematode could not be identified, infection with Elaphostrongylus cervi seems very likely, as the sheep are in close contact with deer on the pastures and the parasite is known to infect goats in Switzerland. This is the first description of cerebrospinal nematodosis in sheep in Switzerland.

Bromadiolon-Vergiftung bei Füchsen

Bromadiolone is an anticoagulant rodenticide that inhibits the reactivation of vitamin K1 by the enzyme vitamin K1-epoxide reductase. The present case report originated from the application of bromadiolone against water voles (Arvicola terrestris) in northeastern Switzerland. At least 40 foxes (Vulpes vulpes) were found dead after the inappropriate use of a bait that contained 0.02 % bromadiolone. Anticoagulant rodenticide poisoning was suspected on the basis of the postmortem examination and subsequently confirmed by the detection ofbromadiolone both in the blood and in samples from thoracic and abdominal fluids.

[Biphasic mesothelioma in a Swiss Braunvieh cow: clinical, histological, immunohistochemical and electron microscopical findings]

A 10-year-old Swiss Braunvieh cow near term was referred to our clinic because of severe abdominal distension, which caused loss of demarcation between the udder and ventral abdominal wall. Ultrasonographic examination revealed marked ascites and multiple echogenic nodules in the greater omentum. Based on the findings, non-inflammatory ascites attributable to neoplasia was diagnosed. Rupture of the prepubic tendon from the pubic symphysis was also suspected. Because of a grave prognosis, parturition was induced and a live calf was delivered. The cow was euthanized and a postmortem examination was carried out. The abdominal cavity contained 248.5 litres of clear fluid. The greater omentum was thickened and oedematous and regionally contained fluid-filled cystic structures, which varied in size with a maximum diameter of 10 centimetres. Based on the histological, immunohistochemical and electron microscopical findings, biphasic mesothelioma with cyst formation affecting the entire abdominal cavity was diagnosed.

Chlamydiaceae family, Parachlamydia spp., and Waddlia spp. in porcine abortion

At present, despite extensive laboratory investigations, most cases of porcine abortion remain without an etiological diagnosis. Due to a lack of recent data on the abortigenic effect of order Chlamydiales, 286 fetuses and their placentae of 113 abortion cases (1–5 fetuses per abortion case) were investigated by polymerase chain reaction (PCR) methods for family Chlamydiaceae and selected Chlamydia-like organisms such as Parachlamydia acanthamoebae and Waddlia chondrophila. In 0.35% of the cases (1/286 fetuses), the Chlamydiaceae real-time PCR was positive. In the Chlamydiaceae-positive fetus, Chlamydia abortus was detected by a commercial microarray and 16S ribosomal RNA PCR followed by sequencing. The positive fetus had a Porcine circovirus-2 coinfection. By the Parachlamydia real-time PCR, 3.5% (10/286 fetuses of 9 abortion cases) were questionable positive (threshold cycle values: 35.0–45.0). In 2 of these 10 cases, a confirmation by Chlamydiales-specific real-time PCR was possible. All samples tested negative by the Waddlia real-time PCR. It seems unlikely that Chlamydiaceae, Parachlamydia, and Waddlia play an important role as abortigenic agents in Swiss sows.

Primary leiomyosarcoma in the heart of a guinea pig

Leiomyosarcoma was diagnosed in the heart of a 3-year-old female guinea pig. Neoplastic tissue was located in the ventricular septum extending into the right ventricular lumen, but was not obvious grossly. Microscopically, the mass was nodular and infiltrative and was composed of streams and bundles of spindle cells. Immunohistochemically, the neoplastic cells expressed vimentin and α-smooth muscle actin. There was no cross striation of the muscle cells. This is the first report of cardiac leiomyosarcoma in a guinea pig.

[Bursitis with severe tendon and muscle necrosis on the lateral stifle area in cattle]

In 21 animals, chronic swelling on the lateral aspect of the stifle also known as «perigonitis», «stable-syndrome» or «bursitis bicipitalis femoris» were evaluated. Ultrasonography showed increased fluid in the distal subtendinous bursa of the biceps femoris muscle and structural changes in the tendons, muscles, subcutis and fasciae. Soft tissue swelling and an irregular contour of the lateral tibial condyle were typical signs on radiographs. Macroscopic changes were found at the insertion of the biceps femoris muscle, the distal subtendinous bursa of the biceps femoris muscle, the lateral collateral ligament of the stifle, the origin of muscles on the lateral femoral condyle and the lateral tibial condyle. They mainly consisted of tendon and muscle tissue necrosis with granulation tissue. Histology revealed areas of coagulation necrosis in tendons and ligaments, in which occasionally Onchocerca spp. were seen. The severity of lesions correlated well with the clinical signs, which were associated with a poor prognosis in advanced cases.

[Polychondritis: a new disease in Swiss Braunvieh?]

Over the last 10 years Swiss Braunvieh cattle with malformations of the pinnae have repeatedly been reported. Endoscopy revealed a shortened and thickened epiglottis and malformations of the arytenoid cartilage in some of these animals. In most cases the elastic cartilage was replaced by fibrocartilage and hyaline cartilage. The direct cause and pathogenesis of the malformations could not be determined.

Ultrasonographic findings in a cow with abomasal lymphosarcoma: case report

Background

This case report describes the clinical and ultrasonographic findings in a Swiss Braunvieh cow with lymphosarcoma of the abomasum.

Case Presentation

The main clinical findings were vomiting in response to eating and melena. The results of serum biochemistry and rumen fluid analysis were indicative of abomasal reflux syndrome. The main ultrasonographic findings were two enlarged lymph nodes caudal to the reticulum and a severely enlarged abomasum with thickening of the abomasal wall and folds. Based on all the findings, pyloric stenosis caused by lymphosarcoma was tentatively diagnosed and later confirmed at postmortem examination.

Conclusions

This is an interesting case, which broadens the spectrum of abomasal reflux syndrome.

[Conjunctival changes in a Swiss Braunvieh heifer with malignant lymphoma]

This report describes a 2.8-year-old Swiss Braunvieh heifer with conjunctival changes as the lead clinical signs of malignant lymphoma. The heifer was referred to our clinic because of conjunctivitis that did not respond to treatment with antibiotics. The patient had bilateral lacrimation, severe swelling of the third eyelids and prolapse of the conjunctivae, which were erythematous and covered with haemorrhagic crusts. A clinical examination revealed enlarged prescapular and prefemoral lymph nodes. Based on cytological examination of a fine needle aspirate from a prescapular lymph node, a tentative diagnosis of malignant lymphoma was made. The heifer was euthanased and a postmortem examination carried out. The conjunctival lesions consisted of diffuse multifocal nodules of varying size. There was generalised lymphadenopathy and beige nodules were seen in several internal organs. Histological and immunohistological examinations confirmed the diagnosis of multicentric leukosis characterised by T-cell lymphoblasts, which had also infiltrated the conjunctivae. Examination of a blood sample for enzootic bovine leukosis virus yielded a negative result.

[Ultrasonographic findings in a cow with extraskeletal chondroblastic osteosarcoma of the neck region]

This case report describes the clinical, ultrasonographic and pathological findings in a five-year-old Swiss Braunvieh cow with extraskeletal chondroblastic osteosarcoma of the neck region. The cow was referred because of a firm, non-painful swelling, approximately 25 cm in diameter, which was situated mainly on the lower left side of the neck but extended to the right. Ultrasonographic examination of the mass revealed a chambered structure containing echoic material that was separated by hyperechoic septa. Chondroblastic osteosarcoma was diagnosed based on histological evaluation of a biopsy sample, and the diagnosis was confirmed by postmortem examination.

[Feed-related selenium poisoning in swine]

The following case report describes a selenium toxicosis in a pig-fattening farm of two finisher groups. The diseased animals partly showed ataxia and paresis or intense lameness in connection with band-like ablation of the epidermis at the coronary band. Some of them suffered from alopecia. Foot-and-mouth disease and swine vesicular disease were excluded by serological tests. Dissection revealed a multifocal bilateral symmetric poliomyelomalacia. Histological changes in the claws ranged from severe cell-decay in the germinative layer to distinctive decay of the stratum corneum. Due to damage of the claw epidermis the corium was partly exposed. Feed analysis revealed 100-fold increased selenium content in the finishing premix from the feed mill and as a result 20- to 60-fold increased selenium values in feed samples from the farm-made finisher mixture. Selenium concentration in the blood of diseased animals was 4- to 10-fold higher than normal values, which confirmed the tentative diagnosis of a selenium toxicosis.

Sonographic findings in an alpaca with Mycobacterium kansasii infection

This case report describes the clinical, ultrasonographic and postmortem findings in an alpaca with Mycobacterium kansasii infection. The alpaca was referred because of chronic weight loss and weakness. The results of clinical examination, haematology and serum biochemistry were not diagnostic. Ultrasonography of the liver revealed multiple, hyperechogenic lesions with a diameter of 1 to 3 cm. Histological evaluation of a liver biopsy sample showed acute, multifocal, suppurative, necrotising hepatitis. Despite treatment with antibiotics, the alpaca died. Postmortem examination revealed nodular to coalescing lesions in the liver, lungs, mediastinum, pleura and greater omentum, which could not be differentiated macroscopically or histologically from lesions caused by tuberculosis. Ziehl-Neelsen staining showed massive numbers of rods within epithelioid macrophages, which were identified as Mycobacterium kansasii by polymerase chain reaction analysis.