Blast injury on harbour porpoises (Phocoena phocoena) from the Baltic Sea after explosions of deposits of World War II ammunition

Harbour porpoises are under pressure from increasing human activities. This includes the detonation of ammunition that was dumped in large amounts into the sea during and after World War II. In this context, forty-two British ground mines from World War II were cleared by means of blasting in the period from 28 to 31 August 2019 by a NATO unit in the German Exclusive Economic Zone within the marine protected area of Fehmarn Belt in the Baltic Sea, Germany. Between September and November 2019, 24 harbour porpoises were found dead in the period after those clearing events along the coastline of the federal state of Schleswig-Holstein and were investigated for direct and indirect effects of blast injury. Health evaluations were conducted including examinations of the brain, the air-filled (lungs and gastrointestinal tract) and acoustic organs (melon, acoustic fat in the lower jaw, ears and their surrounding tissues). The bone structure of the tympano-periotic complexes was examined using high-resolution peripheral quantitative computed tomography (HR-pQCT). In 8/24 harbour porpoises, microfractures of the malleus, dislocation of middle ear bones, bleeding, and haemorrhages in the melon, lower jaw and peribullar acoustic fat were detected, suggesting blast injury. In addition, one bycaught animal and another porpoise with signs of blunt force trauma also showed evidence of blast injury. The cause of death of the other 14 animals varied and remained unclear in two individuals. Due to the vulnerability and the conservation status of harbour porpoise populations in the Baltic Sea, noise mitigation measures must be improved to prevent any risk of injury. The data presented here highlight the importance of systematic investigations into the acute and chronic effects of blast and acoustic trauma in harbour porpoises, improving the understanding of underwater noise effects and herewith develop effective measures to protect the population level.

Occurrence and relevance of Mycoplasma spp. in free-ranging pheasants from northwestern Germany

Since 2008/2009, the population of free-ranging ring-necked pheasants was recorded to decrease all over Germany. Various Mycoplasma (M.) spp. are causing severe respiratory signs in captive game bird species. Furthermore, M. gallisepticum is responsible for massive die-offs in consequence to severe conjunctivitis in house finches in the USA. Therefore, the prevalence of mycoplasmas in free-ranging pheasants was investigated and a potential impact on the population decline of pheasants discussed. Within this study, 150 free-ranging pheasants were sampled via tracheal swabs and tissue samples of the trachea and the periorbital skin, as the latter displayed inflammatory alterations in previous studies. In total, 177 samples were investigated for the presence of mycoplasmas using cultural and molecular biological methods. In 76 birds, necropsy was performed additionally. In total, 73.7% (51/76) of the examined pheasants had periorbital skin alterations. Furthermore, 64.4% (114/177) of the samples tested positive for mycoplasmas via PCR. Overall, 102/177 samples (57.6%, 78/105 tracheal swabs, 19/51 skin tissue, 5/21 trachea tissue) tested positive for mycoplasmas via culture. Mycoplasma gallinaceum (n = 50), M. pullorum (n = 45), M. glycophilum (n = 43), M. iners (n = 11), and M. gallinarum (n = 5) were frequently isolated. In 45 cases (45.9%), multiple Mycoplasma spp. were isolated from one sample. All examined samples tested negative for M. gallisepticum. Of 51 skin samples investigated for mycoplasmas, 24 (47.1%) showed inflammatory skin alterations in histology, and 58.3% (14/24) of these samples tested positive for Mycoplasma spp. additionally. Overall, there was a significant correlation between inflammatory altered skin samples and the detection of mycoplasmas in periorbital skin samples. Based on the present results, the isolated Mycoplasma spp. may play a role as facultative agents for the observed inflammatory skin alterations. However, additional investigation is needed to confirm this presumption.

Pathological Findings in Eurasian Otters (Lutra lutra) Found Dead between 2015-2020 in Schleswig-Holstein, Germany

In times of massive biodiversity loss and ongoing environmental crises, it is extremely important to ensure long-term conservation efforts of threatened species like Eurasian otters (Lutra lutra). To gain insights into the status of Northern Germany's otter population, 92 otters found dead in Schleswig-Holstein between 2015-2020 were collected and underwent detailed dissection with the aim to establish a monitoring program for this population. Examinations followed a protocol especially designed for otters, including various biological data assessments and extended sampling. The finding sites showed a clear concentration in the Continental region. Seasonal concentration differed among the years, yet peaks were seen from fall to winter. Overall, more males than females were found, although this differed among the years. The majority of otters that could be aged were between 1-3 years. Placental scars and pregnancy were recorded in only few females. Nutritional status was good in most cases. Infectious diseases found included Vagococcus lutrae, Toxoplasma gondii, and Emmonsia spp. A major cause of death was roadkill. Known sample bias in studies focusing on roadkill was considered in the finding interpretation. Continuation of the population health investigations is mandatory to analyze potential trends and to establish an actual monitoring program for Eurasian otters in Schleswig-Holstein.

Analysis of avian Usutu virus infections in Germany from 2011 to 2018 with focus on dsRNA detection to demonstrate viral infections

Usutu virus (USUV) is a zoonotic arbovirus causing avian mass mortalities. The first outbreak in North-Western Germany occurred in 2018. This retrospective analysis focused on combining virological and pathological findings in birds and immunohistochemistry. 25 common blackbirds, one great grey owl, and one kingfisher collected from 2011 to 2018 and positive for USUV by qRT-PCR were investigated. Macroscopically, most USUV infected birds showed splenomegaly and hepatomegaly. Histopathological lesions included necrosis and lymphohistiocytic inflammation within spleen, Bursa fabricii, liver, heart, brain, lung and intestine. Immunohistochemistry revealed USUV antigen positive cells in heart, spleen, pancreas, lung, brain, proventriculus/gizzard, Bursa fabricii, kidney, intestine, skeletal muscle, and liver. Analysis of viral genome allocated the virus to Europe 3 or Africa 2 lineage. This study investigated whether immunohistochemical detection of double-stranded ribonucleic acid (dsRNA) serves as an alternative tool to detect viral intermediates. Tissue samples of six animals with confirmed USUV infection by qRT-PCR but lacking viral antigen in liver and spleen, were further examined immunohistochemically. Two animals exhibited a positive signal for dsRNA. This could indicate either an early state of infection without sufficient formation of virus translation products, occurrence of another concurrent virus infection or endogenous dsRNA not related to infectious pathogens and should be investigated in more detail in future studies.

Detection of Systemic Canine Kobuvirus Infection in Peripheral Tissues and the Central Nervous System of a Fox Infected with Canine Distemper Virus

Canine kobuvirus (CaKV) is a globally distributed pathogen of dogs and is predominantly associated with infection of the gastrointestinal tract. However, an etiological link to enteric disease has not been established since CaKV has been identified in both asymptomatic dogs and animals with diarrheic symptoms. In this study, an extraintestinal CaKV infection was detected by next-generation sequencing in a fox (Vulpes vulpes) in Germany concomitant with a canine distemper virus (canine morbillivirus; CDV) co-infection. Phylogenetic analysis of the complete coding region sequence showed that this strain was most closely related to a CaKV strain detected in a dog in the United Kingdom in 2008. The tissue and cellular tropism of CaKV was characterized by the detection of viral antigens and RNA. CaKV RNA was detected by in situ hybridization in different tissues, including epithelial cells of the stomach and ependymal cells in the brain. The use of a new RT-qPCR assay for CaKV confirmed the systemic distribution of CaKV with viral RNA also detected in the lymph nodes, bladder, trachea, and brain. The detection of a CDV infection in this fox suggests that immunosuppression should be further investigated as a contributing factor to the enhanced extraintestinal spread of CaKV.

[Buiatrics: What's your diagnosis?]

INTRODUCTION

Therapy of a high-grade balanoposthitis with partial penile and preputial prolapse after unsuccessful initial therapy of a ten-year-old dexter bull. Two punctures, about 1 cm depth were found at the base of the prolapsed tissue, which were probably caused by partially perforating U-stitches by the local veterinarian. The highly inflamed and swollen tissue disabled the penis to retract. The prolapse was repositioned and the preputial opening was partially closed using a modified Buhner stitch. Consecutively, antibiotics and anti-inflammatory drugs were administered, and regular wound toilets were performed. After 14 days, the increase in circumference at the base of the prolapse was partially removed and histopathologically identified as pyogranulomatous inflammation. Surgery was repeated two weeks later. Potentia coeundi could thus be re-established. This case shows that regular breeding hygienic examinations are of great importance in order to identify morphological changes in early stages and to treat them adequately.

Swinepox Virus Strains Isolated from Domestic Pigs and Wild Boar in Germany Display Altered Coding Capacity in the Terminal Genome Region Encoding for Species-Specific Genes

Swinepox virus (SWPV) is a globally distributed swine pathogen that causes sporadic cases of an acute poxvirus infection in domesticated pigs, characterized by the development of a pathognomonic proliferative dermatitis and secondary ulcerations. More severe disease with higher levels of morbidity and mortality is observed in congenitally SWPV-infected neonatal piglets. In this study, we investigated the evolutionary origins of SWPV strains isolated from domestic pigs and wild boar. Analysis of whole genome sequences of SWPV showed that at least two different virus strains are currently circulating in Germany. These were more closely related to a previously characterized North American SWPV strain than to a more recent Indian SWPV strain and showed a variation in the SWPV-specific genome region. A single nucleotide deletion in the wild boar (wb) SWPV strain leads to the fusion of the SPV019 and SPV020 open reading frames (ORFs) and encodes a new hypothetical 113 aa protein (SPVwb020-019). In addition, the domestic pig (dp) SWPV genome contained a novel ORF downstream of SPVdp020, which encodes a new hypothetical 71aa protein (SPVdp020a). In summary, we show that SWPV strains with altered coding capacity in the SWPV specific genome region are circulating in domestic pig and wild boar populations in Germany.

Whale lice (Isocyamus deltobranchium & Isocyamus delphinii; Cyamidae) prevalence in odontocetes off the German and Dutch coasts - morphological and molecular characterization and health implications

Whale lice (Cyamidae; Amphipoda) are ectoparasitic crustaceans adapted to the marine environment with cetaceans as their host. There are few reports of cyamids occurring in odontocetes from the North Sea, and long-term studies are lacking. Marine mammal health was monitored along the German and Dutch coasts in the past decades, with extensive post mortem investigations conducted. The aim of this study was to analyse archived ectoparasite samples from stranded cetaceans from the North Sea (2010-2019), to determine species, prevalence and impact of ectoparasite infection. Ectoparasites were found on two cetacean species - harbour porpoises (Phocoena phocoena), as the most abundant cetacean species in the North Sea, and on a pilot whale (Globicephala melas), as a rare species here. Prevalence of ectoparasitic crustaceans in cetaceans was low: 7.6% in porpoises stranded in the Netherlands (n = 608) and 1.6% in porpoises stranded in Germany (n = 122). All whale lice infections were found on hosts with skin lesions characterised by ulcerations. Morphological investigations revealed characteristic differences between the cyamid species Isocyamus (I.) delphinii and I. deltobranchium identified. Isocyamus deltobranchium was determined in all infected harbour porpoises. I. delphinii was identified on only the pilot whale. Molecular analyses showed 88% similarity of mDNA COI sequences of I. delphinii with I. deltobranchium supporting them as separate species. Phylogenetic analyses of additional gene loci are required to fully assess the diversity and exchange of whale lice species between geographical regions as well as host specificity. Differing whale lice prevalences in porpoises stranded in the Netherlands and Germany could indicate a difference in severity of skin lesions between these areas. It should be further investigated if more inter- or intraspecific contact, e.g., due to a higher density of porpoises or contact with other cetaceans, or a poorer health status of porpoises in the southern North Sea could explain these differences.

Rhabdomyosarcoma on the Forelimb of a Common Musk Turtle (Sternotherus odoratus)

Malignant mesenchymal tumours are only rarely reported in turtles. In the present case, an 8-year-old female common musk turtle (Sternotherus odoratus) was presented with a solid, reddened, non-mobile mass on the right forelimb. The mass had a thin, membranous lining and a grey-white cut surface. Histological examination revealed a cell-rich, focally infiltrative neoplasm consisting of spindloid tumour cells arranged in bundles and streams. Rarely, indistinct cytoplasmic cross-striations were seen in the neoplastic cells. Transmission electron microscopy revealed cytoplasmic, disorganized muscle fibrils and haphazardly arranged, attenuated Z-lines in the neoplastic cells. The histological, histochemical and ultrastructural findings led to the diagnosis of a rhabdomyosarcoma. This is the first description of rhabdomyosarcoma in a freshwater turtle.

Complex Odontoma in a Young Captive Reticulated Giraffe (Giraffa camelopardalis reticulata)

Complex odontoma is a rare odontogenic lesion reported in rodents (order: Rodentia) and odd-toed ungulates (order: Perissodactyla), to name a few, and only in bovine animals of the order Artiodactyla. A 3-year-old female giraffe presented with a steadily proliferating, firm mass in the rostral mandible. With further expansion and ulceration of the mass, the general condition of the giraffe deteriorated and it was euthanized. Post-mortem examination revealed greyish-white tissue with an irregular arrangement of yellowish hard tissue arranged in thin plates and intermingled areas of greyish soft tissue. Histologically, irregular proliferated odontogenic epithelium and mesenchyme, dentin, cementum and empty spaces, suggestive of decalcified enamel, were present. These findings are consistent with a diagnosis of complex odontoma, which should be added to the differential diagnoses of oral tissue proliferations in giraffes. To our knowledge, this is the first description of a complex odontoma in a giraffe.

Aspects of transition cow metabolomics-Part II: Histomorphologic changes in the liver parenchyma throughout the transition period, in cows with different liver metabotypes and effects of a metaphylactic butaphosphan and cyanocobalamin treatment

The aims of this study were to evaluate histopathologic changes during the transition period, describe the histopathological features of the metabotypes identified in Part I (Schären et al., 2021b), and investigate effects of a metaphylactic treatment with butaphosphan and cyanocobalamin (BCC) on the liver parenchyma. Eighty German Holstein cows (mean 305-d production: 10,957 kg, range: 6,480-15,193 kg; mean lactation number: 3.9, range: 2-9) from a commercial dairy farm in Saxony, Germany, were enrolled in a randomized, prospective, triple-blinded study. Two groups received a treatment with BCC (5 or 10 mL/100 kg of body weight 10% butaphosphan and 0.005% cyanocobalamin, Catosal, Bayer Animal Health, n = 20 each) and one group a placebo treatment (NaCl 0.9%, n = 40). Liver biopsy specimens were collected 14 d antepartum (AP) and 7, 28, and 42 d postpartum (PP), routinely processed for histologic examination, and stained with hematoxylin and eosin, Sudan III, periodic acid-Schiff, and picrosirius red stains. The sections were assessed for fat and glycogen content and degenerative, inflammatory, fibrotic, and proliferative changes. The statistical analysis included the effects of the sampling day, the lactation number, the treatment, and the metabotype (A = medium, B = minor, C = large alterations in the liver metabolome profile between AP and PP status). There was mild to moderate fat infiltration in the liver of 37% of cows in the last 2 wk AP, and moderate to severe fat infiltration in 66% of cows in the first days PP. The degree of fat infiltration increased from 2 wk AP until the end of the first week PP, and then decreased until the end of the study period, at which time about 25% of cows had moderate to severe fatty infiltration. Lipidosis was positively correlated with the severity of liver cell degeneration, and negatively correlated with the degree of glycogen deposits. Complete glycogen depletion of hepatocytes was not observed in cows, even in the presence of severe hepatic lipidosis. Moderate to severe lymphocytic hepatitis was seen in 39% of cows throughout the study period, and cows with lactation numbers 5 or greater had perisinusoidal fibrosis more often than younger cows. Severe fibrosis and cirrhosis of the liver did not occur. Metabotype B animals exhibited a higher chance of fatty infiltration, lower glycogen storage, and perisinusoidal fibrosis and for this metabotype positive correlations were calculated between increased fat deposition in the liver and marked glycogen depletion, and increased degenerative, inflammatory, fibrotic, and proliferative changes of hepatic tissue. For the treatment with BCC, no significant effect was observed. In summary, during the transition period, the liver of dairy cows is characterized by fat accumulation and glycogen depletion and histologic signs of hepatitis and hepatocyte degeneration. These histomorphologic changes were accentuated in animals exhibiting little alterations in their liver metabolome profile across the transition period (metabotype B) and support the assumption of a decreased grass silage quality as a causative factor.

The Irrawaddy dolphin, Orcaella brevirostris from the Mekong river Cambodia: Preliminary health and toxicological investigations

The subpopulation of the Irrawaddy dolphin (Orcaella brevirostris) living in the Mekong River, Cambodia, is considered to be critically endangered. The aim of the investigation was to gain information about the genetic variation, health status and exposure to toxic compounds of these dolphins. Tissue samples from 27 Irrawaddy river dolphins found dead along the Mekong River between 2004 and 2009 were analysed with regards to genetics, pathology and ecotoxicology. Genetic maternal lineage detection, based on polymorphisms of the mitochondrial d-loop sequences, was performed. Data indicate a genetic separation of the Mekong dolphins from both the coastal population and the Mahakam dolphins. Pathological investigations revealed acute moderate multifocal suppurative bronchopneumonia, moderate periportal hepatic lipidosis, moderate diffuse hepatic atrophy and acute severe diffuse suppurative leptomeningitis. Residue levels of organochlorines and polybrominated diphenyl ethers in Irrawaddy dolphins from the Mekong River were lower than the concentrations reported for other cetaceans in the coastal and riverine waters of Asia, except for Dichlorodiphenyltrichloroethane. A high percentage of organic mercury compared to the immuno-toxic methylmercury was observed. Due to numerous confounding factors, it is not possible to relate levels of pollutants to observed morphological lesions. However, it is likely that chemical contaminants do adversely impact on the health of the Irrawaddy dolphins at present, and have also affected previous generations.

[Granulomatous pleuritis and chylothorax caused by calcite inhalation in a Galgo Español dog]

A 6-year-old, male Galgo Español dog was presented with severe dyspnea. Radiography and ultrasonography revealed pleural effusion. Approximately 4 l of a milky and slightly reddish fluid were aspirated and drained from the thoracic cavity. Clinical chemistry examination of the fluid indicated a modified transudate with a high amount of triglycerides. On cytological examination, degenerated neutrophilic granulocytes, small lymphocytes, macrophages and chylomicrons were found. A chest tube was placed and computed tomography was performed, which indicated thickening of parietal and visceral pleura and enlargement of the sternal lymph node without abnormal findings in the lungs. During subsequent thoracoscopy disseminated proliferative masses, appearing as small white nodules, covering nearly the entire pleural surface were found and biopsies were taken for further analysis. Histopathologic diagnosis was a granulomatous pleuritis with intralesional birefringent foreign material. Energy dispensive x-ray emission analysis was used to determine the origin of the material. Scanning electron microscopy revealed high amounts of calcium containing foreign material (calcite) within the granulomas. An extended clinical history of the dog gave evidence that the animal had lived next to a construction site 15 months earlier and may well have inhaled the calcium-containing dust. Treatment with prednisolone was initiated, however the dog developed gastro-intestinal side effects and treatment was stalled after 10 weeks. Dyspnea and liquidothorax re-occurred 4 months later. A further attempt of immunosupressive treatment was commenced, using a combination of prednisolone and ciclosporine, which again was not tolerated by the patient. The dog finally developed pneumonia and was euthanized by the owner's request.

Liver histopathology of Baltic grey seals (Halichoerus grypus) over three decades

The liver plays an important role in the metabolism and elimination of endogenic and exogenic lipid-soluble compounds. Multiple studies have shown that polychlorinated biphenyls (PCB) and dichlorodiphenyl trichloroethane (DDT) lead to morphological changes in liver cells. The aim of the present study was therefore to analyse liver changes over time in Baltic grey seals (Halichoerus grypus) and to correlate these with historical PCB and DDT contaminations. A total of 191 liver samples were collected between 1981 and 2015 in the Gulf of Bothnia and northern Baltic Proper. Six histological features were evaluated, including portal mononuclear cell infiltration, random mononuclear cell infiltration, lipid granulomas, hepatocellular fat vacuoles, hepatic stellate cells and mild multifocal bile duct hyperplasia accompanied by portal fibrosis. Three of the six lesions showed a significant correlation with age. Furthermore, a positive correlation between portal mononuclear cell infiltration and mild multifocal bile duct hyperplasia was found. Additionally, lipid granulomas were significantly correlated with hepatic stellate cells. More importantly, hepatic stellate cells and mild multifocal bile duct hyperplasia were correlated with adipose tissue (blubber) concentrations of ƩPCB, measured in a subsample (n = 34) of all individuals. No correlation with lesions and ƩDDT concentrations were found. These results show that age is an important factor for the development of these liver lesions, but PCBs burden may be an influencing factor. This is in agreement with previous studies of marine mammals in the Baltic Sea as well as in the Arctic. We therefore conclude that not only age of the animals, but also exposure to PCBs should be taken into account when understanding and evaluating the current health status of Baltic grey seals.

A 50-kb deletion disrupting the RSPO2 gene is associated with tetradysmelia in Holstein Friesian cattle

Background

Tetradysmelia is a rare genetic disorder that is characterized by an extremely severe reduction of all limb parts distal of the scapula and pelvic girdle. We studied a Holstein Friesian backcross family with 24 offspring, among which six calves displayed autosomal recessive tetradysmelia. In order to identify the genetic basis of the disorder, we genotyped three affected calves, five dams and nine unaffected siblings using a Bovine Illumina 50 k BeadChip and sequenced the whole genome of the sire.

Results

Pathological examination of four tetradysmelia cases revealed a uniform and severe dysmelia of all limbs. Applying a homozygosity mapping approach, we identified a homozygous region of 10.54 Mb on chromosome 14 (Bos taurus BTA14). Only calves that were diagnosed with tetradysmelia shared a distinct homozygous haplotype for this region. We sequenced the whole genome of the cases’ sire and searched for heterozygous single nucleotide polymorphisms (SNPs) and small variants on BTA14 that were uniquely present in the sire and absent from 3102 control whole-genome sequences of the 1000 Bull Genomes Project, but none were identified in the 10.54-Mb candidate region on BTA14. Therefore, we subsequently performed a more comprehensive analysis by also considering structural variants and detected a 50-kb deletion in the targeted chromosomal region that was in the heterozygous state in the cases’ sire. Using PCR, we confirmed that this detected deletion segregated perfectly within the family with tetradysmelia. The deletion spanned three exons of the bovine R-spondin 2 (RSPO2) gene, which encode three domains of the respective protein. R-spondin 2 is a secreted ligand of leucine-rich repeats containing G protein-coupled receptors that enhance Wnt signalling and is involved in a broad range of developmental processes during embryogenesis.

Conclusions

We identified a 50-kb deletion on BTA14 that disrupts the coding sequence of the RSPO2 gene and is associated with bovine tetradysmelia. To our knowledge, this is the first reported candidate causal mutation for tetradysmelia in a large animal model. Since signalling pathways involved in limb development are conserved across species, the observed inherited defect may serve as a model to further elucidate fundamental pathways of limb development.

Scratch the surface: Histopathology of foot-pad dermatitis in turkeys (Meleagris gallopavo)

Foot-pad dermatitis (FPD) is an important indicator of animal welfare in turkeys (Meleagris gallopavo). The present study aimed to evaluate the reliability and validity of a commonly used five-point visual score (VC), assessing FPD based on lesion size by implementing histopathological analysis. In 100 turkey feet (20 per scale scored by the VC), the size of both the foot-pad and the alteration were measured. Subsequently, a histopathological analysis was performed, examining the occurrence and severity grade of different parameters. The study addressed three main goals: (i) examining the reliability of the scoring system concerning the evaluated size of FPD; (ii) assessing histopathological parameters to analyse patterns, reflecting the categories of the scoring system; and (iii) finding threshold values to avoid the occurrence of ulcerations. The study found good observer reliabilities for the VC, but measuring the relative size of alterations resulted in divergent values according to the original specifications With regard to the histopathological parameters, no clear patterns were found in the respective VC scoring levels. However, ulcerations revealed a significant effect on the size of the alteration, showing a greater grade of severity with increasing lesion size. Regarding the occurrence of ulcerations, optimum threshold values could be identified even in very small lesions. This study helps contribute to a better understanding of the pathophysiology of FPD. It also raises the question as to whether, in light of animal welfare concerns, threshold values of visual systems should be adjusted to avoid ulcerations, considering the outcome of our histopathological assessment.

Spatiotemporal accumulation of fatal pharyngeal entrapment of flatfish in harbour porpoises (Phocoena phocoena) in the German North Sea

The evolution of a permanent separation of the upper respiratory and digestive tract is one of the adaptions cetaceans evolved for their aquatic life. Generally, it prevents odontocetes from choking on either saltwater or foreign bodies during ingestion under water. Nevertheless, several sporadic single case reports from different parts of the world show that this separation can be reversed especially by overly large items of prey. This incident can have a fatal outcome for the odontocetes. The German federal state of Schleswig-Holstein has a year-round, permanent and systematic stranding network that retrieves stranded marine mammals from its shorelines and constantly enables post-mortem examinations. In 2016, with nine affected animals, a high incidence of fatal pharyngeal entrapment of flatfish in harbour porpoises (Phocoena phocoena) occurred during spring and early summer on the German North Sea island of Sylt. All flatfish were identified as common sole (Solea solea). A retrospective post-mortem data analysis over a 30-year period from the North and Baltic Sea revealed similar yearly and seasonally case accumulations on the same island in the 1990s as well as several single case events over the whole timespan. All cases except one were caused by flatfish. When flatfish speciation was performed, only common sole was identified. From 1990 to 2019, of all examined harbour porpoises, 0.3% (2/713) from the Baltic Sea and 5.5% (45/820) from the North Sea died due to fish entrapped in the pharynx. On the North Sea coast, the occurrence of fatal obstruction shows high yearly variations from 0 to 33.3%. Years that stand out are especially 1990 to 1992, 1995, as well as 2016. The majority of all cases generally occurred between April and July, indicating also a seasonality of cases. This study evaluates the occurrence of fatal pharyngeal entrapment of fish in two geographically separated harbour porpoise populations. Additionally, common sole is clearly identified as a potentially risky item of prey for these small odontocetes.

Complex segregation analysis of familial amyloidosis in Oriental shorthair cats

Amyloidosis in Siamese/Oriental cats is a lethal condition with variable age of clinical onset. There is no sex predisposition and clinical signs of disease usually become apparent by 1-7 years of age. In the terminal stages, the liver is enlarged and pale, and contains parenchymal hemorrhages. In the present study, pedigree data from 17 cats with clinical signs consistent with amyloidosis underwent genetic analysis. Necropsy and histopathological data were available for 10 of the 17 cats. Necropsy findings included pale, fragile and enlarged livers with capsular ruptures and parenchymal hemorrhages, and sanguineous effusions in the abdominal cavity. Congo red staining with birefringence confirmed systemic amyloidosis mostly involving the liver and thyroid gland. In four of the 10 cases, protein deposits were classified as amyloid A protein (AA-amyloid) by immunostaining. Pedigree data for all 17 affected cats indicated a familial trait. Animal threshold model analysis demonstrated that the heritability for amyloidosis was 0.56 ± 0.09 (standard error). Complex segregation analysis was used for statistical comparisons among models to determine environmental or sex dependent effects, and Mendelian, polygenic, or mixed Mendelian and polygenic inheritance patterns. A mixed model with a Mendelian and polygenic component provided the best fit to the data and thus was most likely. All other models of inheritance were rejected due to their insufficient ability to explain segregation of amyloidosis. In conclusion, we found evidence for a complex genetic basis for amyloidosis in Oriental shorthair cats.

Health assessment of harbour porpoises (PHOCOENA PHOCOENA) from Baltic area of Denmark, Germany, Poland and Latvia

Harbour porpoise (Phocoena phocoena), the only resident cetacean species of the Baltic Sea is formed of two subpopulations populations, occurring in the western Baltic, Belt Seas and Kattegat and the Baltic Proper, respectively. Harbour porpoises throughout these areas are exposed to a large number of human activities causing direct and indirect effects on individuals, that might also harm this species on a population level. From Latvia, Poland, Germany and Denmark 385 out of 1769 collected dead harbour porpoises were suitable for extensive necropsy. The animals were collected between 1990 and 2015 and were either by-caught or found dead on the coastline. Following necropsies, histopathological, microbiological, virological and parasitological investigations were conducted. Females and males were equally distributed among the 385 animals. Most animals from the different countries were juveniles between 3 months and 3 years old (varying between 46.5 and 100% of 385 animals per country). The respiratory tract had the highest number of morphological lesions, including lungworms in 25 to 58% and pneumonia in 21 to 58% of the investigated animals. Of those with pneumonia 8 to 33% were moderate or severe. The alimentary, hearing, and haematopoietic systems had inflammatory lesions and parasitic infections with limited health impact. 45.5 to 100% of the animals from the different countries were known by-caught individuals, of which 20 to 100% varying between countries had netmarks. Inflammatory lesions, especially in the respiratory tract were found in higher numbers when compared to control populations in areas with less human activities such as arctic waters. The high number of morphological changes in the respiratory tract and of bycatches especially among immature animals before reaching sexual maturity is of serious concern, as well as the low number of adult animals among the material. Data on health status and the causes of death are valuable for management. A next step in this regard will combine data from health and genetic investigations in order to detect differences between the two populations of the Baltic.

Emergence and Epidemiology of Bovine Babesiosis Due to Babesia divergens on a Northern German Beef Production Farm

Babesia divergens, transmitted by the tick Ixodes ricinus, is the most common cause of bovine babesiosis in northern Europe and plays a role as a zoonotic pathogen. However, several studies have indicated a decline of B. divergens prevalence in Europe during the last decades. Here, we investigate the epidemiology of bovine babesiosis on a beef production farm in northern Germany, which had not been affected by babesiosis until an initial outbreak in 2018. In June 2018, 21 adult cattle died, showing classical symptoms of babesiosis. Babesia divergens merozoites were detected in blood smears of clinically affected animals and the species was confirmed by PCR and sequencing of a part of the 18S rRNA gene. In 2018, screening of the farm's entire stock by PCR revealed that Babesia-positive animals were present in only one of five herds grazing on different pastures. In the following year, further babesiosis cases occurred in multiple herds. In March 2020, 95 cattle were tested for anti-B. divergens antibodies and 36 of them (37.89%) had positive titres. To investigate the local Babesia prevalence in ticks, 1,430 questing I. ricinus ticks (555 larvae, 648 nymphs, 227 adults) were collected on the farm's pastures and subjected to PCR for Babesia detection. Babesia divergens DNA could not be detected, but Babesia microti showed an overall prevalence of 0.49% (7/1,430; 0.88% [2/227] of adult ticks, 0.77% [5/648] of nymphs, 0.00% [0/555] of larvae). Babesia venatorum was detected in 0.42% (6/1,430) of ticks (0.44% [1/227] of adult ticks, 0.77% [5/648] of nymphs, 0.00% [0/555] of larvae) and B. capreoli in 0.07% (1/1,430) of ticks (0.00% [0/227] of adult ticks, 0.15% [1/648] of nymphs, 0.00% [0/555] of larvae). Despite the fact that no B. divergens-positive ticks were found, the collected data suggest a geographical spread of the pathogen on the farm. Bovine babesiosis remains a disease of veterinary importance in Europe and may cause considerable economic losses when (re-)emerging in non-endemic areas, especially as awareness for the disease among veterinarians and farmers declines.

Indication of lethal interactions between a solitary bottlenose dolphin (Tursiops truncatus) and harbor porpoises (Phocoena phocoena) in the German Baltic Sea

Background

Aggressive interactions between bottlenose dolphins (Tursiops truncatus) and harbor porpoises (Phocoena phocoena) have been reported in different parts of the world since the late 1990s. In the Baltic Sea, harbor porpoises are the only native cetacean species, while bottlenose dolphins may appear there temporarily. In the fall of 2016, a solitary male photo-identified bottlenose dolphin stayed in the German Baltic Sea of Schleswig-Holstein for 3 months. During that time, the necropsies of the stranded harbor porpoises revealed types of trauma of varying degrees in six animals, which is unusual in this area. The purpose of this study was to determine if the appearance of the bottlenose dolphin could be linked to the trauma of the harbor porpoise carcasses.

Results

Pathological findings in these animals included subcutaneous, thoracic and abdominal hemorrhages, multiple, mainly bilateral, rib fractures, and one instance of lung laceration. These findings correspond with the previously reported dolphin-caused injuries in other regions. Moreover, public sighting reports showed a spatial and temporal correlation between the appearance of the dolphin and the stranding of fatally injured harbor porpoises.

Conclusion

Despite the fact that no attack has been witnessed in German waters to date, our findings indicate the first record of lethal interactions between a bottlenose dolphin and harbor porpoises in the German Baltic Sea. Furthermore, to our knowledge, this is the first report of porpoise aggression by a socially isolated bottlenose dolphin.

Bovine Babesiosis Diagnosed in Formalin-Fixed, Paraffin-Embedded Tissues by Using In Situ Hybridization

Bovine babesiosis, caused by Babesia divergens, is in general a rare disease in Europe. Nonetheless, local outbreaks can cause severe economic damage, and postmortem identification represents a diagnostic challenge. During a recent outbreak in May 2018 in northern Germany, 21 animals of a herd of 150 cattle died within 40 days having had clinical signs of fever and hemoglobinuria. Gross examination of 4 of the 21 deceased animals revealed a tick infestation, jaundice, and dark brown staining of urine and kidneys. Histologically, there were iron-positive deposits, hyperplasia of the red pulp of the spleen, and centrilobular necrosis of hepatocytes. In several locations, small basophilic granules suggestive of intraerythrocytic parasites were visible in hematoxylin-eosin- and Giemsa-stained sections. Peripheral blood smears from a living cow from the herd and polymerase chain reaction (PCR) of feeding ticks revealed B. divergens infection. In situ hybridization (ISH) was applied on formalin-fixed, paraffin-embedded (FFPE) tissue of the necropsied cattle to confirm babesiosis in these animals postmortem. Digoxigenin-labeled DNA probes were generated based on a specific nucleotide sequence for B. divergens, obtained by PCR and sequencing of DNA isolates from infected Ixodes ricinus ticks from deceased cattle. ISH using these probes allowed postmortem diagnosis of B. divergens infection in routinely fixed FFPE tissues.

[Lightning strike on a horse pasture - a diagnostic challenge?!]

During summer, permanent or temporary pasture keeping carries an increased risk of death caused by lightning strikes. Although - due to their body structure and pasture grazing - large animals are particularly susceptible to step voltage effects in consequence to a lightning strike to the ground there are only few published cases in the veterinary literature. Frequently in lightning-related accidents, a current flow through the heart occurs resulting in acute cardiac and circulatory failure. In the vast majority of cases, this is accompanied either by very unspecific lesions or even lacks any morphological alterations. Accordingly, the etiologic diagnosis in the absence of clear, lightning-related damage to the body represents a major diagnostic challenge. The evaluation of meteorological data as well as consideration of the pasture's location and positioning of the body when found may provide further key information in the clarification of fatalities caused by lightning strikes.This case report presents findings in a 7-year-old thoroughbred gelding found dead together with 3 other horses, all lying together in a group on the pasture. Pathological examination revealed a 2-3 mm wide line of singed, curled hair on the right front and hind limbs. Histologically, the pertaining skin areas displayed groups of elongated epithelial cells with herringbone-like elongation of the nuclei within the epidermis and the hair follicles. Coagulations of dermal proteins were present multifocally within the dermis.

Long-term radiographic and histological follow-up after resection of the distal interphalangeal joint using a plantar approach in German Holstein cows

Resection of the distal interphalangeal joint (DIJ) is a claw-preserving method for treatment of septic arthritis. This study presents the radiographic and histological findings of the surgically-treated area after resection of the DIJ using a plantar approach in seven German Holstein cows. Histological postmortem evaluation 439 to 710 days after surgery showed that there was extensive proliferation of connective tissue rich in collagen fibres in the space left after resection in three cows; this was classified as fibrous ankylosis. In the remaining four cows, histological evaluation 1010 to 1756 days after surgery showed extensive new bone formation in the joint cavity consistent with osseous ankylosis. Radiographs of the resected DIJ region obtained at the time of histological examination revealed no osseous ankylosis in two cows, partial ankylosis in one cow and complete osseous ankylosis in four cows. Formation of complete osseous ankylosis after resection of the DIJ did take longer than 1-2 years in three of our specimens indicating a longer time span compared to earlier studies.

Health status of free-ranging ring-necked pheasant chicks (Phasianus colchicus) in North-Western Germany

Being a typical ground-breeding bird of the agricultural landscape in Germany, the pheasant has experienced a strong and persistent population decline with a hitherto unexplained cause. Contributing factors to the ongoing negative trend, such as the effects of pesticides, diseases, predation, increase in traffic and reduced fallow periods, are currently being controversially discussed. In the present study, 62 free-ranging pheasant chicks were caught within a two-year period in three federal states of Germany; Lower Saxony, North Rhine-Westphalia and Schleswig-Holstein. The pheasant chicks were divided into three age groups to detect differences in their development and physical constitution. In addition, pathomorphological, parasitological, virological, bacteriological and toxicological investigations were performed. The younger chicks were emaciated, while the older chicks were of moderate to good nutritional status. However, the latter age group was limited to a maximum of three chicks per hen, while the youngest age class comprised up to ten chicks. The majority of chicks suffered from dermatitis of the periocular and caudal region of the head (57-94%) of unknown origin. In addition, intestinal enteritis (100%), pneumonia (26%), hepatitis (24%), perineuritis (6%), tracheitis (24%), muscle degeneration (1%) and myositis (1%) were found. In 78% of the cases, various Mycoplasma spp. were isolated. Mycoplasma gallisepticum (MG) was not detected using an MG-specific PCR. Parasitic infections included Philopteridae (55%), Coccidia (48%), Heterakis/Ascaridia spp. (8%) and Syngamus trachea (13%). A total of 8% of the chicks were Avian metapneumovirus (AMPV) positive using RT-PCR, 16% positive for infectious bronchitis virus (IBV) using RT-PCR, and 2% positive for haemorrhagic enteritis virus (HEV) using PCR. All samples tested for avian encephalomyelitis virus (AEV), infectious bursal disease virus (IBDV) or infectious laryngotracheitis virus (ILTV) were negative. The pool samples of the ten chicks were negative for all acid, alkaline-free and derivative substances, while two out of three samples tested were positive for the herbicide glyphosate. Pheasant chick deaths may often have been triggered by poor nutritional status, probably in association with inflammatory changes in various tissues and organs as well as bacterial and parasitic pathogens. Theses impacts may have played a major role in the decline in pheasant populations.