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.

Investigation into diseases in free-ranging ring-necked pheasants (Phasianus colchicus) in northwestern Germany during population decline with special reference to infectious pathogens.

The population of ring-necked pheasants (Phasianus colchicus) is decreasing all over Germany since the years 2008/2009. Besides impacts of habitat changes caused by current rates of land conversion, climatic influences or predators, a contribution of infectious pathogens needs also to be considered. Infectious and non-infectious diseases in free-living populations of ring-necked pheasants have been scarcely investigated so far. In the present study, carcasses of 258 deceased free-ranging pheasants of different age groups, predominantly adult pheasants, collected over a period of 4 years in the states of Lower Saxony, North Rhine-Westphalia and Schleswig-Holstein, were examined pathomorphologically, parasitologically, virologically and bacteriologically, with a focus set on infectious pathogens. A periocular and perinasal dermatitis of unknown origin was present in 62.3% of the pheasants. Additional alterations included protozoal cysts in the skeletal musculature (19.0%), hepatitis (21.7%), enteritis (18.7%), gastritis (12.6%), and pneumonia (11.7%). In single cases, neoplasms (2.6%) and mycobacteriosis (1.7%) occurred. Further findings included identification of coronaviral DNA from trachea or caecal tonsils (16.8%), siadenoviral DNA (7.6%), avian metapneumoviral RNA (6.6%), and infectious bursal disease viral RNA (3.7%). Polymerase chain reaction (PCR) on herpesvirus, avian influenza virus (AIV), paramyxovirus type 1 (PMV-1), avian encephalomyelitis virus (AEV), and chlamydia were negative. Based on the present results, there is no indication of a specific pathogen as a sole cause for population decline in adult pheasants. However, an infectious disease can still not be completely excluded as it may only affect reproduction effectivity or a certain age group of pheasants (e.g., chicks) which were not presented in the study.

[Peripheral keratinizing ameloblastoma in a dwarf rabbit (Oryctolagus cuniculus f. dom.)]. / Peripheres keratinisierendes Ameloblastom bei einem Zwergkaninchen (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.

Delayed onset of graft-versus-host disease in immunodeficent human leucocyte antigen-DQ8 transgenic, murine major histocompatibility complex class II-deficient mice repopulated by human peripheral blood mononuclear cells.

Haematopoietic humanization of mice is used frequently to study the human immune system and its reaction upon experimental intervention. Immunocompromised non-obese diabetic (NOD)-Rag1(-/-) mice, additionally deficient for the common gamma chain of cytokine receptors (γc) (NOD-Rag1(-/-) γc(-/-) mice), lack B, T and natural killer (NK) cells and allow for efficient human peripheral mononuclear cell (PBMC) engraftment. However, a major experimental drawback for studies using these mice is the rapid onset of graft-versus-host disease (GVHD). In order to elucidate the contribution of the xenogenic murine major histocompatibility complex (MHC) class II in this context, we generated immunodeficient mice expressing human MHC class II [human leucocyte antigen (HLA)-DQ8] on a mouse class II-deficient background (Aß(-/-) ). We studied repopulation and onset of GVHD in these mouse strains following transplantation of DQ8 haplotype-matched human PBMCs. The presence of HLA class II promoted the repopulation rates significantly in these mice. Virtually all the engrafted cells were CD3(+) T cells. The presence of HLA class II did not advance B cell engraftment, such that humoral immune responses were undetectable. However, the overall survival of DQ8-expressing mice was prolonged significantly compared to mice expressing mouse MHC class II molecules, and correlated with an increased time span until onset of GVHD. Our data thus demonstrate that this new mouse strain is useful to study GVHD, and the prolonged animal survival and engraftment rates make it superior for experimental intervention following PBMC engraftment.

Spontaneous obesity-linked type 2 diabetes in the absence of islet amyloid in a cynomolgus monkey infected with bovine spongiform encephalopathy.

A 9-year-old cynomolgus monkey (Macaca fascicularis) infected orally with bovine spongiform encephalopathy (BSE) was presented for necropsy following euthanasia 4 years post infection (p.i.). This macaque R984 was exposed to a BSE dose that causes a simian form of variant Creutzfeldt-Jakob disease (vCJD) within 5 years p.i. in other macaques. All orally BSE-infected macaques developed a significant weight gain within the first 2 years p.i. compared with non-BSE-infected age- and sex-matched control animals, suggesting increased risk of type 2 diabetes (T2D). In contrast, macaque R984 developed rapid weight loss, hyperglycemia, and glucosuria and had to be euthanatized 4 years p.i. before clinical signs of vCJD. Pancreas histopathological evaluation revealed severe islet degeneration but, remarkably, no islet amyloid deposits were present. Immunostaining of pancreas sections for insulin and glucagon confirmed the loss of endocrine cells. In addition, prions were present in the adenohypophysis but not in other areas of the brain, indicating centripetal prion spread from the gut during the preclinical phase of BSE infection. Plasma glucose and insulin concentrations of macaque R984 became abnormal with age and resembled T2D. This unusual case of spontaneous T2D in the absence of islet amyloid deposits could have been due to early prion spread from the periphery to the endocrine system or could have occurred spontaneously.