Novel canine bocavirus strain associated with severe enteritis in a dog litter

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An outbreak of fatal enteritis occurred in a dog litter.

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Major known causes of enteritis of young dogs were excluded.

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A novel canine bocavirus 2 strain was detected by random PCR and NGS.

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CaBoV-2 was detected in the intestinal tract and lymphoid tissue by ISH.

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No additional cases were identified by a small retrospective analysis.

Bocaviruses are small non-enveloped viruses with a linear ssDNA genome, that belong to the genus Bocaparvovirus of the subfamiliy Parvovirinae. Bocavirus infections are associated with a wide spectrum of disease in humans and various mammalian species. Here we describe a fatal enteritis associated with infection with a novel strain of canine bocavirus 2 (CaBoV-2), that occurred in a litter of German wirehaired pointers. Necropsy performed on three puppies revealed an enteritis reminiscent of canine parvovirus associated enteritis, accompanied with signs of lymphocytolytic disease in bone marrow, spleen, lymph nodes and thymus. While other major causes of enteritis of young dogs, including canine parvovirus, were excluded, by random PCR in combination with next-generation sequencing, a novel CaBoV-2 strain was detected. Phylogenetic analysis of the genome of this novel canine bocavirus strain indicated that this virus was indeed most closely related to group 2 canine bocaviruses. Infection with canine bocavirus was confirmed by in situ hybridization, which revealed the presence of CaBoV-2 nucleic acid in the intestinal tract and lymphoid tissues of the dogs. In a small-scale retrospective analysis concerning the role of CaBoV-2 no additional cases were identified. The findings of this study provide novel insights into the pathogenicity of canine bocaviruses.

Novel divergent nidovirus in a python with pneumonia

The order Nidovirales contains large, enveloped viruses with a non-segmented positive-stranded RNA genome. Nidoviruses have been detected in man and various animal species, but, to date, there have been no reports of nidovirus in reptiles. In the present study, we describe the detection, characterization, phylogenetic analyses and disease association of a novel divergent nidovirus in the lung of an Indian python (Python molurus) with necrotizing pneumonia. Characterization of the partial genome (>33 000 nt) of this virus revealed several genetic features that are distinct from other nidoviruses, including a very large polyprotein 1a, a putative ribosomal frameshift signal that was identical to the frameshift signal of astroviruses and retroviruses and an accessory ORF that showed some similarity with the haemagglutinin-neuraminidase of paramyxoviruses. Analysis of genome organization and phylogenetic analysis of polyprotein 1ab suggests that this virus belongs to the subfamily Torovirinae. Results of this study provide novel insights into the genetic diversity within the order Nidovirales.

[Rhinoorbitocerebral zygomycosis caused by Rhizopus microsporus in a roe deer (Capreolus capreolus)]

An one-year-old male roe deer (Capreolus capreolus) with abnormal behaviour was shot in order to exclude rabies virus infection. The 12.8 kg weighing animal was emaciated and revealed an asymmetric head with protruding left eye and expositional keratitis. There was a grey whitish soft mass within the caudal nasal cavity, which had infiltrated the frontal cerebrum through the cribriform plate and the retrobulbar tissue through the orbita. Histologically, the mass consisted of a chronic granulomatous inflammation with plentiful fungal hyphae. Fungal culture revealed mold fungi of the zygomycotic genus Rhizomucor, which were differentiated as Rhizopus microsporus by MALDI-TOF mass spectrometry and DNA-sequencing. Rhinoorbitocerebral zygomycosis has to be considered as a differential diagnosis for nasal and orbital tumour-like lesions and as a cause of abnormal behaviour of roe deer.

[First detection of psittacid herpesvirus 2 in Congo African grey parrots (Psittacus erithacus erithacus) associated with pharyngeal papillomas and cloacal inflammation in Germany]

Congo African Grey Parrots (GP; Psittacus erithacus erithacus) from four different avicultures, presented in the Clinic for Exotic Pets, Reptiles and Birds, University of Veterinary Medicine Hannover, Foundation, showed choanal papillomas or hyperemia of the cloacal mucosa. Histologically, the mucosal choanal proliferations were diagnosed as exophytic papillomas and a mild hyperplasia of the cloacal mucosa with lympho-histiocytic inflammation with no visible inclusion bodies was found. Herpesvirus genome was detected by nested PCR in pooled choanal and cloacal swabs from clinically diseased parrots and healthy contact animals. Sequencing of parts of the herpesvirus DNA-polymerase gene indicated 98-100% homology of the detected herpesviruses with the Psittacid Herpesvirus 2 (PsHV-2). In one aviculture with cloacal inflammation papillomavirus-DNA was concurrently found to a PsHV-2 infection. In addition to the four avicultures with clinical symptoms 25 more flocks of grey parrots, in total 57 Congo-GP and 13 Timneh-GP, were examined for a herpesvirus infection. A total of six out of 29 studied parrot avicultures were tested positive for PsHV-2. The detection of this virus also in flocks of GP, which were bred in Europe, shows the establishment of this infection in the GP population in captivity. As indicated in the literature as well as in our study PsHV-2 could be only detected in Congo-GP, independently if they were kept either alone or in mixed avicultures with amazon and macaw species. These findings suggest that PsHV-2 is adapted to this Psittacus species.

Endocrine testicular function and spermatogenesis persist in calves after partial scrotal resection but not Burdizzo castration

Bull calves for fattening are often castrated during the first weeks of life. Because androgens stimulate growth, there is an interest in males that are infertile but exposed to endogenous testicular steroids. Such a situation occurs in cryptorchids and has been imitated by shortening the scrotum to an extent that the testes are located in a near-inguinal position. In this study, effects of partial scrotal resection (SR) and Burdizzo castration (BZ) on endocrine testicular function, testes histology and on weight at slaughter were studied and compared to orchidectomized (OR) and gonad-intact calves (CO; n = 10 per group; age at castration, 54 ± 3 days; fattening period, 474 ± 11 days). Plasma testosterone concentrations were determined repeatedly, and testes were collected for histopathology at slaughter. We hypothesized that SR inhibits spermatogenesis without loss of testicular steroidogenesis. Group SR animals gained more weight than groups OR and BZ (P < 0.01). Plasma testosterone concentration increased in groups SR and CO (P < 0.01 vs. BZ and OR). Histologically, in all SR animals, testicular and epididymal tissue was identified with a seminiferous epithelium of up to three-cell layers in two animals. Germ cells including elongated spermatids were present in three animals. Shortening of the scrotum thus induced varying degrees of testicular degeneration but 3/10 animals had to be suspected as fertile. In one BZ animal, spermatids were identified whereas in the remaining BZ animals, testes and epididymides consisted of sclerotic fibrous tissue. Partial SR thus induced a cryptorchid-like status but fertility in individual animals must be assumed.

First report of a new alphaherpesvirus in a freshwater turtle (Pseudemys concinna concinna) kept in Germany

Herpesviruses represent important pathogenic agents in zoological chelonian collections. Infections in tortoises are actually most commonly associated with necrotizing lesions in the upper digestive tract. Herpesvirus infections in sea turtles are most commonly associated with fibropapillomatosis, although other disease complexes caused by other herpesviruses have been described. Herpesviruses are known to cause latent infections and may be reactivated upon various endogenous or exogenous stimuli resulting in acute and sometimes fatal disease. The present description represents the first report about a new alphaherpesvirus found in a fresh water turtle (Pseudemys concinna concinna). The animal died suddenly without showing clinical signs. Macroscopically, no lesions typically associated with a herpesvirus infection were found. Light microscopic examination showed hepatic lipidosis and countless numbers of intranuclear inclusion bodies in hepatocytes as the only significant light microscopic lesion. Transmission electron microscopy revealed typical herpesvirus particles in the nucleus of hepatocytes. To further substantiate these observations a molecular identification using PCR followed by sequencing of the obtained fragments was performed. Phylogenetic analysis indicated a new alphaherpesvirus called Emydid herpesvirus 1.

[Peripheral keratinizing ameloblastoma in a dwarf rabbit (Oryctolagus cuniculus f. dom.)]

A 3.5-year-old, male, neutered dwarf rabbit was presented with a history of a fast-growing gingival mass at the maxilla. The neoplasm was surgically completely excised. Histopathologically, an expansively growing, multilobulated, partially cystic, peripheral, keratinizing ameloblastoma was diagnosed. The immunohistochemical phenotyping of the tumour cells resulted in cytoplasmic labelling with various pan-cytokeratin antibodies. The cytokeratins 5/6, 7, 10 and 14 were expressed variably. Cytokeratin 20 was not detected. Vimentin was expressed in the cytoplasm of mesenchymal cells of the tumour stroma. In addition, in the nuclei of approximately 10% of the tumour cells the protein of the tumour suppressor gene p53 was expressed while in approximately 5% the proliferation marker Ki67 was expressed. Odontogenic tumours should be considered as a differential diagnosis of oral masses in rabbits.

Kongenitales embryonales Rhabdomyosarkom am Kopf eines rotbunten Deutsche-Holstein-Kalbes

Tumoren mit Skelettmuskeldifferenzierung sind bei den Haussäugetieren nur sehr selten zu beobachten. Es werden benigne Rhabdomyome von malignen Rhabdomyosarkomen unterschieden. Bei einem weiblichen Kalb der Rasse Deutsche Holstein wurde eine kongenitale, kugelförmige Umfangsvermehrung lateral in der Unterhaut des Kopfes festgestellt. Histologisch bestand die abgekapselte, expansive, zellreiche Umfangsvermehrung aus einem retikulären Maschenwerk kleiner, mäßig pleomorpher, spindelförmiger bis rundlicher Zellen in einem fibrovaskulären bis myxoiden Stroma sowie multifokalen, großen, plumpen, mehrkernigen, Myotuben-ähnlichen Zellen (strap cells). Mittels elektronenmikroskopischer Untersuchung wurden in den strap cells charakteristische zytoplasmatische Bündel von Myofilamenten und Z-Streifen nachgewiesen. Die kleinen spindelförmigen Zellen zeigten eine Immunreaktivität für Vimentin und die strap cells für Desmin. Die vorliegenden Ergebnisse entsprechen dem Befundspektrum eines bovinen kongenitalen embryonalen Rhabdomyosarkoms.

[Congenital embryonal rhabdomyosarcoma of the head in a red and white German Holstein calf]

Tumours with skeletal-muscle differentiation are rare in companion animals. They are differentiated into benign rhabdomyomas and malignant rhabdomyosarcomas. A female German Holstein calf displayed a congenital, spherical, subcutaneous mass at the lateral side of the head. Histology revealed an encapsulated, expansile, highly cellular mass consisting of a reticular meshwork of moderately pleomorphic, small spindle-shaped to round cells within a fibrovascular to myxoid stroma as well as multifocal, large, blunt, multinucleated myotube-like cells (strap cells). Electron microscopy demonstrated characteristic cytoplasmic bundles of myofilaments and Z-stripes within the strap cells. Immunoreactivity for vimentin was observed in the small spindle-shaped cells and for desmin in the strap cells. The results are consistent with the spectrum of findings characteristic for a bovine congenital embryonal rhabdomyosarcoma.

Cervical spinal intradural arachnoid cysts in related, young pugs

Seven related young pugs were diagnosed with cervical spinal intradural arachnoid cysts by magnetic resonance imaging (n = 6) and myelography (n = 1). All dogs were presented with skin abrasions on their thoracic limbs and non-painful neurological deficits, indicating a C1-T2 myelopathy. In all six dogs examined by magnetic resonance imaging not only the spinal arachnoid cyst but also a concomitant, most likely secondary, syringohydromyelia was confirmed. Pedigree analysis suggested a genetic predisposition for spinal arachnoid cysts in this family of pugs. Generalised proprioceptive deficits more pronounced in the thoracic limbs suggesting a focal cervical spinal cord lesion, with concomitant skin abrasions on the dorsal aspect of the thoracic limbs in a young pug, should alert veterinarians to the possibility of cervical spinal arachnoid cysts.

Influenza A virus infections in marine mammals and terrestrial carnivores

Influenza A viruses (IAV), members of the Orthomyxoviridae, cover a wide host spectrum comprising a plethora of avian and, in comparison, a few mammalian species. The viral reservoir and gene pool are kept in metapopulations of aquatic wild birds. The mammalian-adapted IAVs originally arose by transspecies transmission from avian sources. In swine, horse and man, species-adapted IAV lineages circulate independently of the avian reservoir and cause predominantly respiratory disease of highly variable severity. Sporadic outbreaks of IAV infections associated with pneumonic clinical signs have repeatedly occurred in marine mammals (harbour seals [Phoca vitulina]) off the New England coast of the U.S.A. due to episodic transmission of avian IAV. However, no indigenous marine mammal IAV lineages are described. In contrast to marine mammals, avian- and equine-derived IAVs have formed stable circulating lineages in terrestrial carnivores: IAVs of subtype H3N2 and H3N8 are found in canine populations in South Korea, China, and the U.S.A. Experimental infections revealed that dogs and cats can be infected with an even wider range of avian IAVs. Cats, in particular, also proved susceptible to native infection with human pandemic H1N1 viruses and, according to serological data, may be vulnerable to infection with further human-adapted IAVs. Ferrets are susceptible to a variety of avian and mammalian IAVs and are an established animal model of human IAV infection. Thus, a potential role of pet cats, dogs and ferrets as mediators of avian-derived viruses to the human population does exist. A closer observation for influenza virus infections and transmissions at this animal-human interface is indicated.

Immunophenotyping of inflammatory cells associated with Schmallenberg virus infection of the central nervous system of ruminants

Schmallenberg virus (SBV) is a recently discovered Bunyavirus associated mainly with abortions, stillbirths and malformations of the skeletal and central nervous system (CNS) in newborn ruminants. In this study, a detailed immunophenotyping of the inflammatory cells of the CNS of affected animals was carried out in order to increase our understanding of SBV pathogenesis. A total of 82 SBV-polymerase chain reaction (PCR) positive neonatal ruminants (46 sheep lambs, 34 calves and 2 goat kids) were investigated for the presence of inflammation in the brain and spinal cord. The study focused on 15 out of 82 animals (18.3%) showing inflammation in the CNS. All 15 neonates displayed lymphohistiocytic meningoencephalomyelitis affecting most frequently the mesencephalon and the parietal and temporal lobes. The majority of infiltrating cells were CD3-positive T cells, followed by CD79α-positive B cells and CD68-positive microglia/macrophages. Malformations like por- and hydranencephaly, frequently found in the temporal lobe, showed associated demyelination and axonal loss. SBV antigen was detected in 37 out of 82 (45.1%) neonatal brains by immunohistochemistry. In particular, SBV antigen was found in 93.3% (14 out of 15 ruminants) and 32.8% (22 out of 67 ruminants) of animals with and without encephalitis, respectively. Highest amounts of virus-protein expression levels were found in the temporal lobe. Our findings suggest that: (i) different brain regions display differential susceptibility to SBV infection; (ii) inflammatory cells in the CNS are found only in a minority of virus infected animals; (iii) malformations occur in association with and without inflammation in the CNS; and (iv) viral antigen is strongly associated with the presence of inflammation in naturally infected animals. Further studies are required to explore the cell tropism and pathogenesis of SBV infection in ruminants.

[Myocardiosis in a 6-month-old Lawson's Dragon (Pogona henrylawsonii)]

In a 6-month-old, chronically inappetent Lawsons's Dragon (Pogona henrylawsonii) with stunted growth a hyperdense cardiac region was found using radiology and computed tomography. At necropsy a profound necrosis of the myocardium with dystrophic calcification was diagnosed. In contrast to the frequently seen metastatic mineralisation of soft tissues, mainly due to poor husbandry, primary tissue destruction is the cause for dystrophic calcification. In reptiles, this is a rarely described form of calcification. Possible causes are infectious processes, nutritional or metabolic insufficiencies, intoxications or genetic components. In the presented case the aetiology could not be determined. In conclusion, dystrophic calcifications should be considered as a differential diagnosis in reptiles with soft tissue mineralisation.

Spontaneous degenerative polioencephalomyelopathy in feeder pigs--a new motor neuron disease?

A central nervous disorder occurred spontaneously in a herd of feeder pigs characterized by muscle fasciculations, convulsions, squealing, and acute death in numerous animals. Histopathology revealed a degenerative poliomyeloencephalopathy of brain stem and spinal cord consisting of neuronal hypertrophy, chromatolysis, neuronophagia, and satellitosis associated with Wallerian degeneration of ventral rootlets and neurogenic muscle atrophy of limb musculature. The sudden onset of clinical signs and the pattern of morphological findings were suggestive of intoxication. Though parathion was found in two animals, serum acetylcholine esterase activity and morphological findings were not compatible with an organophosphate poisoning. A hereditary disorder was excluded by genetic analysis. Summarized findings in the present cases are reminiscent of changes observed in ruminants suffering from patulin poisoning, a neuromycotoxicosis caused by Aspergillus clavatus. However, toxicological and microbiological investigations failed to identify the cause of this unusual and so far not described disease in pigs. Morphologically, lesion distribution and alterations of motor neurons resemble changes observed in equine motor neuron disease, spinal muscular atrophy of certain canine breeds, and amyotrophic lateral sclerosis (Lou Gehrig's disease) in man. Therefore, the term spontaneous porcine motor neuron disease (SPMND) is proposed for this new and unique entitiy.

Preorbital carcinoma in two Kirk's dik-diks (Madoqua kirkii)

Two Kirk's dik-diks suffered from chronic, unilateral, therapy-resistant enlargement of the preorbital gland. Computed tomographic imaging revealed a homogenous preorbital mass destroying the adjacent maxillary bone in one animal. Squamous cell carcinoma was diagnosed microscopically in both cases. Immunohistochemically, the neoplastic cells uniformly expressed cytokeratin (CK) 5/6 and CK14. Additionally, tumour cells were strongly labelled for p53 suggesting a possible role of this tumour suppressor gene in tumorigenesis. Chronic obstruction of the preorbital gland due to excessive accumulation of secretory products is considered as a likely cause of glandular and periglandular inflammation with subsequent malignant transformation.

Readability of branding symbols in horses and histomorphological alterations at the branding site

Identification of horses has traditionally been facilitated by hot iron branding, but the extent by which branding symbols and numbers can be identified has not been investigated. The local pathological changes induced by branding are also unknown. This study analysed the readability of branding symbols and histomorphological alterations at the branding sites. A total of 248 horses in an equestrian championship were available for identification of symbols and numbers. A further 28 horses, euthanased for other reasons, provided histological examination of the branding site. All except one horse had evidence of histological changes at the brand site, including epidermal hyperplasia, increase of dermal collagenous fibrous tissue and loss of adnexal structures. In two foals, an ulcerative to necrotizing dermatitis was observed and interpreted as a complication of recent branding lesions. Despite the fact that hot iron branding caused lesions compatible with third degree thermal injury, it did not allow unambiguous identification of a large proportion of older horses. While the breed-specific symbol was consistently identified by three independent investigators in 84% of the horses, the double-digit branding number was read correctly by all three investigators in less than 40%. In conclusion, hot iron branding in horses causes lesions compatible with third degree thermal injury but does not always allow identification of horses.