Laryngeal and oropharyngeal adenocarcinoma with pulmonary metastases in a common raven (Corvus corax)

A captive 15-year-old male common raven (Corvus corax) was presented for post-mortem examination. It had been previously presented to a local veterinarian due to a 3-4 weeks long history of abnormal respiratory sounds. Upon admission, the bird demonstrated severe dyspnea and a massive amount of mucous in the oropharynx. After symptomatic treatment, dyspnea deteriorated dramatically, and euthanasia was elicited because of poor prognosis. The necropsy revealed a 2.65 x 2.15 x 2.18 cm expansile and poorly delineated cauliflower-shaped mass around the glottis and extending inside the tracheal lumen. Additionally, a dilated salivary gland in the adjacent tissue and multifocal reddish-fleshy areas in the lung parenchyma were detected. Histopathological examination identified the mass as moderately differentiated, tubular adenocarcinoma with invasive growth and moderate to marked cellular atypia and numerous mitoses. The presumptive origin of the neoplasia was one of the salivary glands. Multiple metastases were identified in the lung both macroscopically and histologically. Bacterial culture and molecular testing for West Nile and Usutu viruses were negative. To the authors' knowledge, this is the first report of metastatic laryngeal and oropharyngeal adenocarcinoma in a common raven.

Behavioral responses of terrestrial mammals to COVID-19 lockdowns

COVID-19 lockdowns in early 2020 reduced human mobility, providing an opportunity to disentangle its effects on animals from those of landscape modifications. Using GPS data, we compared movements and road avoidance of 2300 terrestrial mammals (43 species) during the lockdowns to the same period in 2019. Individual responses were variable with no change in average movements or road avoidance behavior, likely due to variable lockdown conditions. However, under strict lockdowns 10-day 95th percentile displacements increased by 73%, suggesting increased landscape permeability. Animals' 1-hour 95th percentile displacements declined by 12% and animals were 36% closer to roads in areas of high human footprint, indicating reduced avoidance during lockdowns. Overall, lockdowns rapidly altered some spatial behaviors, highlighting variable but substantial impacts of human mobility on wildlife worldwide.

The detection of Mycoplasma sturni and Mycoplasma moatsii from the choana of a barn swallow (Hirundo rustica): a case report

BACKGROUND

Mycoplasmas are found in many different species. Until now 26 avian mycoplasma species have been described, but in the most free ranging bird species the prevalence and significance of Mycoplasma spp. is still unclear.

CASE PRESENTATION

In May 2021 a barn swallow (Hirundo rustica) was brought to a veterinary clinic after it hit a window. As part of the routine exam a choanal swab was taken for mycoplasma culture and for the detection of mycoplasmas using a Mycoplasma-genus-specific Polymerase chain reaction. Six single colony subcultures were obtained by the cultivation. Obtained subcultures were investigated by sequencing the 16S rRNA and the 16S-23S rRNA intergenic transcribed spacer region sequence. The 16S rRNA gene sequence from one subculture had a homology of 99.03% and the 16S-23S rRNA intergenic transcribed spacer region sequence of 100% with the sequence of Mycoplasma sturni. The 16S rRNA gene sequence from the other five subcultures shared a homology of 99.89% and the 16S-23S rRNA intergenic transcribed spacer region sequence of 99.81% with the sequence of Mycoplasma moatsii.

CONCLUSIONS

According to the available literature this is the first report about the detection of M. moatsii, in the respiratory tract of a barn swallow. M. moatsii was previously only found in grivit monkeys (Cercopithecus aethiops), Norway rats (Rattus norvegicus) and a mute swan (Cygnus olor). The role of mycoplasmas in barn swallows is still unknown, especially as in the present case both mycoplasma species do not seem to cause clinical symptoms.

Hidden impacts of conservation management on fertility of the critically endangered kākāpō

Background

Animal conservation often requires intensive management actions to improve reproductive output, yet any adverse effects of these may not be immediately apparent, particularly in threatened species with small populations and long lifespans. Hand-rearing is an example of a conservation management strategy which, while boosting populations, can cause long-term demographic and behavioural problems. It is used in the recovery of the critically endangered kākāpō (Strigops habroptilus), a flightless parrot endemic to New Zealand, to improve the slow population growth that is due to infrequent breeding, low fertility and low hatching success.

Methods

We applied Bayesian mixed models to examine whether hand-rearing and other factors were associated with clutch fertility in kākāpō. We used projection predictive variable selection to compare the relative contributions to fertility from the parents' rearing environment, their age and previous copulation experience, the parental kinship, and the number of mates and copulations for each clutch. We also explored how the incidence of repeated copulations and multiple mates varied with kākāpō density.

Results

The rearing status of the clutch father and the number of mates and copulations of the clutch mother were the dominant factors in predicting fertility. Clutches were less likely to be fertile if the father was hand-reared compared to wild-reared, but there was no similar effect for mothers. Clutches produced by females copulating with different males were more likely to be fertile than those from repeated copulations with one male, which in turn had a higher probability of fertility than those from a single copulation. The likelihood of multiple copulations and mates increased with female:male adult sex ratio, perhaps as a result of mate guarding by females. Parental kinship, copulation experience and age all had negligible associations with clutch fertility.

Conclusions

These results provide a rare assessment of factors affecting fertility in a wild threatened bird species, with implications for conservation management. The increased fertility due to multiple mates and copulations, combined with the evidence for mate guarding and previous results of kākāpō sperm morphology, suggests that an evolutionary mechanism exists to optimise fertility through sperm competition in kākāpō. The high frequency of clutches produced from single copulations in the contemporary population may therefore represent an unnatural state, perhaps due to too few females. This suggests that opportunity for sperm competition should be maximised by increasing population densities, optimising sex ratios, and using artificial insemination. The lower fertility of hand-reared males may result from behavioural defects due to lack of exposure to conspecifics at critical development stages, as seen in other taxa. This potential negative impact of hand-rearing must be balanced against the short-term benefits it provides.

Factors Influencing Vertical Transmission of Psittacine Bornavirus in Cockatiels (Nymphicus hollandicus)

The transmission of parrot bornavirus is still not fully understood. Although horizontal transmission through wounds can be one route, vertical transmission is still discussed. PaBV RNA and PaBV antigen were detected in psittacine embryos, but isolation of the virus failed, raising doubts about this route. In this study, cockatiels were infected either as adults (adult group) or during the first 6 days after hatching (juvenile group) and raised until sexual maturity to breed and lay eggs. A total of 92 eggs (adult group: 49, juvenile group: 43) were laid and incubated until day 17. The embryos and yolk samples were examined by RT-PCR for PaBV RNA and by infectivity assay for infectious virus. In the adult group, 14/31 embryos (45.2%) and 20/39 (51%) of the yolk samples demonstrated PaBV RNA in the PCR. Isolation of PaBV was not possible in any embryo of this group, but it was achieved in six yolk samples from one female. Anti-PaBV antibodies were detected in the yolk samples after seroconversion of all female parents. In the juvenile group, 22/29 embryos (74.9%) were positive for PaBV RNA. In 9/21 embryos (42.9%), PaBV isolation was possible. PaBV RNA was detected in 100% and infectious virus in 41% of the yolk samples. Anti-PaBV antibodies were detected in all yolk samples. For the first time, successful vertical transmission of PaBV was proven, but it seems to depend on the age when the parent birds are infected. Therefore, the age of the bird at time of infection may be an important factor in the occurrence of vertical transmission.

Cardio-pulmonary parasites of the European wildcat (Felis silvestris) in Germany

BACKGROUND

In the last years, research on feline cardio-pulmonary parasites has considerably increased in Europe. Not only domestic cats (Felis catus), but also European wildcats (Felis silvestris) can serve as definitive hosts for these nematodes. The F. silvestris population in Germany has been growing rapidly within the last decades; therefore, the assessment of its cardio-pulmonary parasite status is of importance to unravel whether the wildcat population serves as a substantial reservoir for these nematodes and might pose a health threat to domestic cats.

METHODS

As part of a nature conservation project for European wildcats in the German federal state Rhineland-Palatinate, lungs (n = 128) and hearts (n = 111) of 128 F. silvestris found dead were examined for cardio-pulmonary parasites. All isolated parasites were identified morphologically, and results were confirmed by molecular analysis of a total of 3-11 specimens of each worm species.

RESULTS

A total of 70.3% (90/128) wildcats were positive for at least one lungworm species. Angiostrongylus chabaudi was most common (53.1% [68/128]), followed by Aelurostrongylus abstrusus (42.2% [54/128]), Troglostrongylus brevior (31.3% [40/128]) and Capillaria spp. (3.1% [4/128]). Of note, about two-thirds of the infected wildcats harboured coinfections. Infection intensities ranged from 1 to 167 nematodes per wildcat. Generalised linear models revealed a strong correlation between A. chabaudi and A. abstrusus infection, and prevalences were higher in adult than in younger wildcats, except for T. brevior. Moreover, the T. brevior prevalence varied significantly with nutritional status.

CONCLUSIONS

This study shows that feline cardio-pulmonary nematodes are common parasites in European wildcats in Germany but do not appear to have a serious impact on the overall health of the population. Due to presumed spillover events via prey, cardio-pulmonary nematodes may circulate between the wildcat population and domestic cats and might therefore pose a health risk to individual domestic cats.

Experimental Infection of Embryonic Cells and Embryonated Eggs of Cockatiels (Nymphicus hollandicus) with Two Parrot Bornavirus Isolates (PaBV-4 and PaBV-2)

Parrot bornavirus (PaBV) might be transmitted vertically. Cockatiel embryonic brain cells and embryonated eggs of cockatiels (ECE) were infected with PaBV-2 and PaBV-4. In embryonic brain cells, PaBV-2 and PaBV-4 showed no differences in viral spread despite the slower growth of PaBV-2 compared with PaBV-4 in CEC-32 cells. ECE were inoculated with PaBV-4 and 13–14 dpi, organs were sampled for RT-PCR, immunohistochemistry/histology, and virus isolation. In 28.1% of the embryos PaBV-4-RNA and in 81.3% PaBV-4-antigen was detected in the brain. Virus isolation failed. Division of organ samples and uneven tissue distribution of the virus limited the results. Therefore, 25 ECE were inoculated with PaBV-4 (group 1) and 15 ECE with PaBV-2 (group 3) in the yolk sac, and 25 ECE were inoculated with PaBV-4 (group 2) and 15 eggs with PaBV-2 (group 4) in the chorioallantoic membrane to use the complete organs from each embryo for each examination method. PaBV-RNA was detected in the brain of 80% of the embryos in groups 1, 2, 3 and in 100% of the embryos in group 4. In 90% of the infected embryos of group 1, and 100% of group 2, 3 and 4, PaBV antigen was detected in the brain. PaBV antigen–positive brain cells were negative for anti-neuronal nuclear protein, anti-glial fibrillary acidic protein, and anti S-100 staining. Virus was not re-isolated. These results demonstrated a specific distribution pattern and spread of PaBV-4 and PaBV-2 in the brain when inoculated in ECE. These findings support a potential for vertical transmission.

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.

Absence of Mycoplasma spp. in nightingales (Luscinia megarhynchos) and blue (Cyanistes caeruleus) and great tits (Parus major) in Germany and its potential implication for evolutionary studies in birds

Mycoplasma spp. are important pathogens in poultry and cause high economic losses for poultry industry worldwide. In other bird species (e.g. white storks, birds of prey, and several waterfowl species), Mycoplasma spp. are regularly found in healthy individuals, hence, considered apathogenic or part of the microbiota of the upper respiratory tract. However, as Mycoplasma spp. are absent in healthy individuals of some wild bird species, they might play a role as respiratory pathogen in these bird species, e.g. Mycoplasma gallisepticum in house finches. The knowledge on the occurrence of Mycoplasma spp. in wild birds is limited. To evaluate the relevance of Mycoplasma spp. in free-ranging nightingales and tits, 172 wild caught birds were screened for the presence of mycoplasmas. The birds were sampled via choanal swabs and examined via molecular methods (n = 172) and, when possible, via culture (n = 142). The Mycoplasma sp. was determined by sequencing the 16S rRNA gene and 16S-23S Intergenic Transcribed Spacer Region. All birds were tested negative for mycoplasmas via PCR and/or mycoplasmal culture. Hence, free-ranging nightingales and tits do not show any mycoplasma in their microbial flora of the respiratory tract. Therefore, these songbird species may suffer from clinical mycoplasmosis when being infected. We hypothesize that birds relying on their vocal ability for reproduction have excluded mycoplasmas from their respiratory flora compared to other bird species.

Determining the Effects of Serial Injections of Pregnant Mare Serum Gonadotropin on Plasma Testosterone Concentrations, Testicular Dynamics, and Semen Production in Leopard Geckos (Eublepharis macularius)

Reptiles are highly susceptible to anthropogenic activities as a result of their narrow geographical ranges and habitat specialization, making them a conservation concern. Geckos represent one of the mega-diverse reptile lineages under pressure; however, limited assisted reproductive technologies currently exist for these animals. Exogenous pregnant mare serum gonadotropin (PMSG) has been found to exhibit follicle stimulating hormone-like action and has been routinely used to alter reproductive hormones of vertebrates in assisted reproductive protocols. The purpose of this study was to determine the effects of serial injections of 20 IU and 50 IU PMSG on circulating testosterone concentrations, testicular dynamics, and semen production in a model species of gecko. Twenty-four captive-bred, adult, male leopard geckos (Eublepharis macularius) were divided into three treatment groups and administered a once-weekly injection of either PMSG or saline for a total of nine weeks. Ultrasonographic testicular measurements, electrostimulation for semen collection, and venipuncture were performed on days 0, 21, 42, and 63. Right unilateral orchidectomies and epididymectomies were performed in all animals on day 63; tissues were submitted for histopathology. PMSG treated geckos had significantly higher testicular volumes and weights, spermatozoa motility, and spermatozoa concentrations compared with controls. However, there were no significant differences in testosterone concentrations by treatment or time. Under the conditions outlined, PMSG is effective at stimulating spermatogenesis and increasing testicular size, but not effective at increasing testosterone concentrations in the leopard gecko between October-December in the Northern hemisphere.

Seroprevalences of specific antibodies against avian pathogens in free-ranging ring-necked pheasants (Phasianus colchicus) in Northwestern Germany

Infectious diseases in captive pheasants (Phasianus colchicus) are well known, but there is a lack of knowledge about occurrence and distribution of pathogens in free-ranging pheasants in Germany. We investigated 604 sera from hunted pheasants and 152 sera from wild caught pheasants between 2011 to 2015, with the aim to determine the prevalence of specific antibodies against different viruses: Avian influenza virus (AIV) of subtypes H5, H7, H9, paramyxovirus type 1 (PMV-1), avian encephalomyelitis virus (AEV), infectious bursitis disease virus (IBDV), infectious bronchitis virus (IBV), infectious laryngotracheitis virus (ILTV), avian metapneumovirus (aMPV) and Salmonella sp., Mycoplasma synoviae (MS) and Mycoplasma gallisepticum (MG). In addition, 178 caeca were investigated for Histomonas meleagridis. The study reveals an ongoing circulation of IBV in the wild pheasant population during the study. Also high seroprevalences of specific antibodies against aMPV depending on the area and a strong increase in prevalence of IBDV antibodies in sera of pheasants in Lower Saxony were detected. ILTV antibody prevalences differed between areas and AEV antibody detection differed between years significantly, whereas specific antibodies against PMV-1 could not be detected and antibodies against AIV-H5, -H7 and -H9 and Mycoplasma spp. were detected in very few cases.

Wounds as the Portal of Entrance for Parrot Bornavirus 4 (PaBV-4) and Retrograde Axonal Transport in Experimentally Infected Cockatiels (Nymphicus hollandicus)

In this study, we investigated the natural route of infection of psittacine bornavirus (PaBV), which is the causative agent of proventricular dilatation disease (PDD) in psittacines. We inoculated two infection groups through wounds with a PaBV-4 isolate. In nine cockatiels (Nymphicus hollandicus) we applied a virus suspension with a titer of 103 50% tissue culture infection dose (TCID50) via palatal lesions (Group P, P1-9). In a second group of three cockatiels, we applied a virus suspension with a titer of 104 TCID50 to footpad lesions (Group F, F1-3). In two cockatiels, the control (or "mock") group, we applied a virus-free cell suspension (Group M, M1-2) via palatal lesions. The observation period was 6 mo (Groups P and M) or 7 mo (Group F). We monitored PaBV-4 RNA shedding and seroconversion. At the end of the study, we examined the birds for the presence of inflammatory lesions, PaBV-4 RNA, and antigen in tissues, as well as virus reisolation of brain and crop material. We did not observe any clinical signs typical of PDD during this study. We also did not see seroconversion or PaBV RNA shedding in any bird during the entire investigation period, and virus reisolation was not successful. We only found PaBV-4 RNA in sciatic nerves, footpad tissue, skin, and in one sample from the intestine of Group F. In this group, the histopathology revealed mononuclear infiltrations mainly in skin and footpad tissue; immunohistochemistry showed positive reactions in spinal ganglia and in the spinal cord, and slightly in skin, footpad tissues, and sciatic nerves. In Groups P and M we found no viral antigen or specific inflammations. In summary, only the virus application on the footpad lesion led to detectable PaBV RNA, mononuclear infiltrations, and positive immunohistochemical reactions in tissues of the experimental birds. This could suggest that PaBV spreads via nervous tissue, with skin wounds as the primary entry route.

Assessment of avian sperm DNA fragmentation using the sperm chromatin dispersion assay

Herein we report a simple method for assessing avian sperm DNA fragmentation (SDF) using the sperm chromatin dispersion test (SCDt). The presence of sperm DNA damage was confirmed indirectly by correlating results of the SCDt determined in three bird species with results of a corresponding neutral comet assay (r=0.99; P<0.005). Frozen-thawed spermatozoa of each species were also incubated at 37°C for 5h and the within- and between-species variation of SDF, as an indicator of sperm DNA longevity, examined. The dynamic assessment of SDF using the SCDt revealed species and individual bird (rooster and turkey) differences in sperm DNA longevity.

Age-dependent development and clinical characteristics of an experimental parrot bornavirus-4 (PaBV-4) infection in cockatiels (Nymphicus hollandicus)

Parrot bornavirus (PaBV) is a pathogen often found in psittacine populations. Infected, clinically healthy carrier birds are of major importance for epidemiology, but the underlying pathomechanism of this carrier status is poorly understood. The age, implying the maturation status of the immune system, at the time of infection might be significant for the clinical outcome. Therefore, two groups of 11 cockatiels of different ages (adult and newly hatched) were inoculated with a PaBV-4 isolate intravenously. The trial lasted for 233 days and all birds were observed for clinical signs, PaBV-RNA shedding and anti-PaBV antibody production. At the end of the trial, histopathology, immunohistochemistry, PCR and virus re-isolation were performed. All 22 birds seroconverted and shed PaBV-RNA during the investigation period; the juvenile group earlier and more homogeneously. Nine of 11 birds of the adult group developed clinical signs; five birds died or had to be euthanized before the end of the study. In the juvenile group none of the birds developed clinical signs and only one bird died due to bacterial septicaemia. Eight birds of the adult group, but none of the juvenile group, showed a dilatation of the proventriculus. PaBV-RNA detection and virus re-isolation were successful in all birds. Immunohistochemically, PaBV antigen was found in all birds. Histopathology revealed mononuclear infiltrations in organs in birds of both groups, but the juveniles were less severely affected in the brain.Thus, PaBV infection at an age with a more naïve immune system makes the production of carrier birds more likely.RESEARCH HIGHLIGHTS PaBV infection at a young age might favour the development of carrier birds.Cockatiels infected at a very young age showed inflammation but no clinical signs.The juvenile group started seroconversion and PaBV-RNA shedding earlier.Seroconversion and PaBV-RNA shedding occurred more homogeneously in the juveniles.

Seroprevalence of avian influenza in Baltic common eiders (Somateria mollissima) and pink-footed geese (Anser brachyrhynchus)

Blood plasma was collected during 2016-2018 from healthy incubating eiders (Somateria molissima, n = 183) in three Danish colonies, and healthy migrating pink-footed geese (Anser brachyrhynchus, n = 427) at their spring roost in Central Norway (Svalbard breeding population) and their novel flyway through the Finnish Baltic Sea (Russian breeding population). These species and flyways altogether represent terrestrial, brackish and marine ecosystems spanning from the Western to the Eastern and Northern part of the Baltic Sea. Plasma of these species was analysed for seroprevalence of specific avian influenza A (AI) antibodies to obtain information on circulating AI serotypes and exposure. Overall, antibody prevalence was 55% for the eiders and 47% for the pink-footed geese. Of AI-antibody seropositive birds, 12% (22/183) of the eiders and 3% (12/427) of the pink-footed geese had been exposed to AI of the potentially zoonotic serotypes H5 and/or H7 virus. AI seropositive samples selected at random (n = 33) showed a low frequency of serotypes H1, H6 and H9. Future projects should aim at sampling and isolating AI virus to characterize dominant serotypes and virus strains (PCR). This will increase our understanding of how AI exposure may affect health, breeding and population viability of Baltic common eiders and pink-footed geese as well as the potential spill-over to humans (zoonotic potential).

Evaluation of Newcastle Disease antibody titers in backyard poultry in Germany with a vaccination interval of twelve weeks

Newcastle Disease (ND) is a viral disease spread worldwide with a high impact on economy and animal welfare. Vaccination against Newcastle Disease is one of the main control measures in countries such as Germany with endemic occurrence of Newcastle Disease virus in the free ranging bird population. The German Standing Veterinary Committee on Immunization (StIKo Vet) recommends to revaccinate chickens at intervals of six weeks against Newcastle Disease with attenuated live vaccines via drinking water or spray in line with the SPCs (Summary of Product Characteristics) of current vaccines. However, it is still common practice to revaccinate only every twelve weeks because the SPCs of former vaccines proposed a revaccination after checking the antibody titer which based on practical knowledge was typically sufficient for twelve weeks. The aim of this study was to evaluate if a vaccination interval of twelve weeks against Newcastle Disease under field conditions results in sufficient seroconversion to protect flocks. Antibody titers of 810 blood samples from 27 backyard flocks of chickens were analyzed by ELISA- and HI-tests between 69 and 111 days after vaccination of the flocks with attenuated live vaccines of the ND strain Clone 30. Furthermore, data on the flocks such as breed, sex and age were collected through a questionnaire. In this study a sufficient antibody titer was found in 26 of these flocks. Therefore, a vaccination interval of every twelve weeks with the live vaccines tested is suitable for a vaccination protocol against Newcastle Disease. The lack of seroconversion of one flock also emphasizes the need for regular vaccination monitoring by serological testing and re-evaluation of the vaccination process if needed.

Viability assessment of spermatozoa in large falcons (Falco spp.) using various staining protocols

Viability assessment is an important part of semen analysis, and various live/dead staining protocols have been used in semen of avian species. Results of live/dead count differed between dyes, staining protocols and bird species, impeding comparability between studies and requiring species-specific comparisons of viability stains. In raptor semen, similar comparisons are absent. Thus, the aim of the present study was to compare eight conventional viability stains. Eosin blue 2% [EB], eosin blue 2% with the addition of 3% sodium citrate [EB2], eosin blue-nigrosin 5% [EBN5], eosin yellow-nigrosin 5% [EYN5], eosin yellow-nigrosin 10% [EYN10], eosin blue-aniline blue [EBA], eosin yellow-aniline blue [EYA] and bromophenol blue-nigrosin [BBN] were evaluated in comparison with the fluorescence stain SYBR^® Green-propidium iodide [SYBR-PI] in spermatozoa of falcons. The comparison was performed using conventional light microscopy which is applicable in breeding centres, veterinary practices and field studies. Additionally, live/dead stains were correlated to motility values of the same samples to validate sperm viability. Light microscopy using EB and using SYBR-PI enabled an effective and clear differentiation between alive and dead spermatozoa of falcons. Motility values correlated significantly and strongly with EB only (r = .629; p < .001), but not with any other stain used in the study. Therefore, our results suggest EB as the most suitable stain for viability assessment in the semen of large falcons.

Description, occurrence and significance of Mycoplasma seminis sp. nov. isolated from semen of a gyrfalcon (Falco rusticolus)

The Mycoplasma strain ARNO was isolated from the semen of a clinically healthy gyrfalcon (Falco rusticolus). Colonies of strain ARNO grew in fried-egg shape on Mycoplasma agar plates (SP4). The organism did not ferment glucose or hydrolyze arginine or urea; hence, organic acids are assumed as energy source. Growth was sterol-dependent and optimal growth temperature 42 °C, with a temperature range from 20 to 44 °C. Strain ARNO was not identified as a representative of any of the currently described Mycoplasma species by alignment of the 16S rRNA gene sequence and 16 S-23 S intergenic transcribed spacer region, or immunobinding assay. Hence, strain ARNO represents a novel Mycoplasma species for which the name Mycoplasma seminis sp. nov. is proposed (DSM 27653, NCTC 13927). After developing a species-specific PCR, the prevalence of M. seminis sp. nov. was determined in adult and juvenile falcons in a commercial breeding center for falcons. Semen samples (n = 171) were obtained from 113 male adults, due to repeated sampling of 39 birds. Female adults (n = 26) were sampled once, while 105 of the 152 juvenile birds were sampled twice via choanal swabs. Mycoplasma seminis sp. nov. was found in the semen of clinically healthy adult males (3.5 %) as well as in the respiratory tract of female (34.6 %) and juvenile birds (59.2 %). After comparison of semen samples with (2.9 %) and without M. seminis sp. nov. identification, no indications for a potential influence on the semen quality were demonstrated. Hence, M. seminis sp. nov. seems likely to be of commensal character in falcons.

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.

Central nervous signs, blindness and cerebral vermicosis in free-ranging peregrine falcons (Falco peregrinus) associated with aberrant larval migrations

Four free-ranging peregrine falcons (Falco peregrinus) were submitted with a history of unilateral or bilateral blindness and central nervous signs to a veterinary clinic in Germany. There were no indications of trauma or ocular disease. Likewise, other differential diagnoses for CNS signs were ruled out within the diagnostic process. The clinical diagnostic panel in live falcons included general examination, radiography, endoscopy, hematology, ophthalmoscopy and parasitological examination of the feces, blood gas analysis and blood chemistry as well as computed tomography, and magnetic resonance imaging (MRI). A complete pathological and histopathological examination was performed post-mortem. The only common finding in all birds was an infection with the nematode parasite Serratospiculum tendo. The parasite was confirmed morphologically and via PCR. In two falcons intracerebral vermicoses was suspected in MRI and confirmed in subsequent histopathology, but molecular biological identification of the parasite species failed from brain tissue. Until today, S. tendo had been reported to affect the respiratory system, the liver and different parts of the gastrointestinal tract and to cause cachexia, inappetence, regurgitation, dyspnea and general signs of illness such as lethargy, poor plumage, and reduced reproduction. Our findings indicate that aberrant migration should be considered as cause for CNS signs in falcons. As S. tendo might be a possible cause for this, CNS signs might be included in the list of clinical signs of serratospiculiasis in falcons.

Monitoring of free-ranging and captive Psittacula populations in Western Europe for avian bornaviruses, circoviruses and polyomaviruses

Avian pathogens such as bornaviruses, circoviruses and polyomaviruses are widely distributed in captive collections of psittacine birds worldwide and can cause fatal diseases. In contrast, only little is known about their presence in free-ranging psittacines and their impact on these populations. Rose-ringed parakeets (Psittacula krameri) and Alexandrine parakeets (Psittacula eupatria) are non-native to Europe, but have established stable populations in parts of Western Europe. From 2012-2017, we surveyed free-ranging populations in Germany and France as well as captive Psittacula individuals from Germany and Spain for avian bornavirus, circovirus and polyomavirus infections. Samples from two out of 469 tested free-ranging birds (0.4%; 95% confidence interval [CI-95]: 0.1-1.5%) were positive for beak and feather disease virus (BeFDV), whereas avian bornaviruses and polyomaviruses were not detected in the free-ranging populations. In contrast, avian bornaviruses and polyomaviruses, but not circoviruses were detected in captive populations. Parrot bornavirus 4 (PaBV-4) infection was detected by RT-PCR in four out of 210 captive parakeets (1.9%; CI-95: 0.7-4.8%) from four different holdings in Germany and Spain and confirmed by detection of bornavirus-reactive antibodies in two of these birds. Three out of 160 tested birds (1.9%; CI-95: 0.5-5.4%) possessed serum antibodies directed against budgerigar fledgling disease virus (BuFDV). PaBV-4 and BuFDV were also detected in several psittacines of a mixed holding in Germany, which had been in contact with free-ranging parakeets. Our results demonstrate that Psittacula parakeets are susceptible to common psittacine pathogens and their populations in Western Europe are exposed to these viruses. Nevertheless, the prevalence of avian bornaviruses, circoviruses and polyomaviruses in those populations is very low.RESEARCH HIGHLIGHTS Psittacula parakeets are susceptible to bornavirus, circovirus and polyomavirus infection.Introduced Psittacula populations in Europe have been exposed to these viruses.Nevertheless, they may be absent or present at only low levels in free-ranging Psittacula populations.Free-ranging populations in Europe pose a minor threat of transmitting these viruses to captive Psittaciformes.

Evidence for West Nile Virus and Usutu Virus Infections in Wild and Resident Birds in Germany, 2017 and 2018

Wild birds play an important role as reservoir hosts and vectors for zoonotic arboviruses and foster their spread. Usutu virus (USUV) has been circulating endemically in Germany since 2011, while West Nile virus (WNV) was first diagnosed in several bird species and horses in 2018. In 2017 and 2018, we screened 1709 live wild and zoo birds with real-time polymerase chain reaction and serological assays. Moreover, organ samples from bird carcasses submitted in 2017 were investigated. Overall, 57 blood samples of the live birds (2017 and 2018), and 100 organ samples of dead birds (2017) were positive for USUV-RNA, while no WNV-RNA-positive sample was found. Phylogenetic analysis revealed the first detection of USUV lineage Europe 2 in Germany and the spread of USUV lineages Europe 3 and Africa 3 towards Northern Germany. USUV antibody prevalence rates were high in Eastern Germany in both years. On the contrary, in Northern Germany, high seroprevalence rates were first detected in 2018, with the first emergence of USUV in this region. Interestingly, high WNV-specific neutralizing antibody titers were observed in resident and short-distance migratory birds in Eastern Germany in 2018, indicating the first signs of a local WNV circulation.

Identification and differentiation of avian Mycoplasma species using MALDI-TOF MS

The identification of avian Mycoplasma spp. by conventional immunologic, phenotypic, and molecular methods can be demanding and time-consuming. We evaluated MALDI-TOF MS for its suitability to identify avian mycoplasmas at the species level. We generated a mycoplasma spectral database of 36 main spectrum profiles (MSPs) representing 23 avian Mycoplasma spp. using 23 type and reference strains, 1 live vaccine strain, and 8 clinical isolates. We then used 112 avian Mycoplasma clinical isolates of different avian mycoplasmas, 4 Mycoplasma live vaccine strains, and 1 Mycoplasma type strain, previously cultured and identified to the species level by molecular methods, to evaluate the MSP database. Protein extraction and MALDI-TOF MS analysis were performed with a maximum of 3 repetitions per isolate. MALDI-TOF MS resulted in accurate species-level identification with a score of ≥2.0 for 112 of 117 (96%) isolates. The MALDI-TOF MS analysis of 4 of 5 isolates that did not yield a score of ≥2.0 resulted in best-match identifications that were still concordant at species level with the molecular method used for previous identification. Therefore, MALDI-TOF MS is a promising tool for reliable identification of avian Mycoplasma spp.

Sperm morphology and evidence for sperm competition among parrots

Sperm competition is an important component of post‐copulatory sexual selection that has shaped the evolution of sperm morphology. Previous studies have reported that sperm competition has a concurrently directional and stabilizing effect on sperm size. For example, bird species that show higher levels of extrapair paternity and larger testes (proxies for the intensity of sperm competition) have longer sperm and lower coefficients of variation in sperm length, both within and between males. For this reason, these sperm traits have been proposed as indexes to estimate the level of sperm competition in species for which other measures are not available. The relationship between sperm competition and sperm morphology has been explored mostly for bird species that breed in temperate zones, with the main focus on passerine birds. We measured sperm morphology in 62 parrot species that breed mainly in the tropics and related variation in sperm length to life‐history traits potentially indicative of the level of sperm competition. We showed that sperm length negatively correlated with the within‐male coefficient of variation in sperm length and positively with testes mass. We also showed that sperm is longer in sexually dichromatic and in gregarious species. Our results support the general validity of the hypothesis that sperm competition drives variation in sperm morphology. Our analyses suggest that post‐copulatory sexual selection is also important in tropical species, with more intense sperm competition among sexually dichromatic species and among species that breed at higher densities.

[Surgical removal of a follicular carcinoma of the thyroid gland in a snakehead (Channa barca, HAMILTON, 1822)]

Inflammatory processes, neoplastic growths or rare dysontogenetic malformations may cause mass formation in the gills of fish. In the present case, a follicular carcinoma of the thyroid gland in a Barca snakehead and its surgical removal are reported, and neoplasms in fish are discussed. Following clinical, radiological, cytological and sonographic examinations, the gill-associated partly cystic mass was incompletely removed surgically. The subsequent histological examination identified the mass partly as a follicular carcinoma of the thyroid gland. Because the main alterations of the surgical specimen were non-neoplastic, the development from a rare preexisting hamartoma is discussed. No bacteriological or mycological secondary infections were identified. This report is the first description of a follicular carcinoma and its surgical removal in a snakehead.

High prevalence of Sarcocystis calchasi in racing pigeon flocks in Germany

The apicomplexan parasite Sarcocystis calchasi (Coccidia: Eimeriorina: Sarcocystidae) is the causative agent of Pigeon Protozoal Encephalitis (PPE) and infects birds of the orders Columbiformes, Piciformes and Psittaciformes. Accipiter hawks (Aves: Accipitriformes) are the definitive hosts of this parasite. Infections of S. calchasi have been detected in Germany, the United States and Japan. However, the prevalence of the parasite in racing pigeon flocks has not yet been determined. Here, the first cross-sectional prevalence study to investigate S. calchasi in pigeon racing flocks was accomplished including 245 pigeon flocks across Germany. A total of 1,225 muscle biopsies, were taken between 2012 and 2016 and examined by semi-nested PCR for S. calchasi DNA targeting the ITS gene. Additionally, a questionnaire on construction of the aviary as well as management and health status of the flock was conducted. In 27.8% (95% C.I. = 22.3-33.8%) of the flocks, S. calchasi DNA was detected in at least one pigeon. Positive flocks were located in 15 out of 16 federal states. A significant increase of infected racing pigeons was seen in spring. Half-covered or open aviary constructions showed a trend of increase of the prevalence rate, while anti-coccidian treatment and acidified drinking water had no effects. The high prevalence and the geographical distribution of S. calchasi suggest a long-standing occurrence of the parasite in the German racing pigeon population. For pigeons presented with neurological signs or other symptoms possibly related to PPE, S. calchasi should be considered as a potential cause throughout Germany.

Semen collection, semen analysis and artificial insemination in Columbian sharp-tailed grouse (Tympanuchus phasianellus columbianus) as part of a species conservation project

Columbian sharp-tailed grouse (Tympanuchus phasianellus columbianus; hereafter CSTG) have experienced substantial decreases in population numbers and geographic range during the early 20th century, primarily due to habitat loss. The conservation aim of this project was to re-establish a self-sustaining population of CSTG within an unoccupied portion of their historic range in northeastern Nevada via reintroduction from source populations in Idaho, USA. Female nest initiation rates post-translocation due to low fertilization rates are believed to be one limiting factor in the establishment of some translocated CSTG populations. However, studies on semen collection and artificial insemination in this species are absent. Assisted reproduction was evaluated as an additional tool in this species conservation project in order to gain knowledge on the reproductive status of yearling and adult male CSTG, establish orientation values for semen parameters and evaluate artificial insemination procedures on female CSTG. In two consecutive breeding seasons, semen collection was attempted 51 times in 47 males using the established massage method, and a novel electro-stimulation technique. Semen collection was successful in all attempts, even in yearling grouse, which represents a novel confirmation that yearling male CSTG can produce live spermatozoa in their first breeding season. Volume, color, consistency, contamination, pH of semen, and the motility, concentration, viability and morphology of spermatozoa were analyzed. Extracted semen volume ranged between 6 and 74 μl and the mean pH was 6.9 ± 0.5 (x¯ ± SD). Morphology analysis revealed that on average, 42.8% of sperm was morphologically normal, but 34.8% had malformed tails. Additionally, artificial insemination was practiced in 17 females (sham-insemination group; insemination lacking spermatozoa) and performed in 17 females. Intravenous catheters G20 1.0 mm × 32 mm enabled safe intravaginal insemination under visual control. Significant (p ≤ 0.05) differences in semen parameters between adult and yearling birds were detected. It is well established that adult males receive a majority of copulations during lekking, but our novel findings also indicate that they produce significantly more spermatozoa which is of higher quality than yearling males. This finding offers insights into male reproductive biology in a lekking grouse species.

The role of Virus "X" (Tortoise Picornavirus) in kidney disease and shell weakness syndrome in European tortoise species determined by experimental infection

Tortoise Picornavirus (ToPV) commonly known as Virus "X" was recently discovered in juvenile European tortoises suffering from soft carapace and plastron as well as kidney disease. Therefore, this virus was a potential candidate to be a causative agent for these disease patterns. Spur thighed tortoises (Testudo graeca) seemed to be more susceptible to establish clinical symptoms than other European species like T. hermanni. Thus this trial investigated the role of ToPV in the described syndrome. Two groups of juvenile European tortoises (T. graeca and T.hermanni) each of 10 animals, were cloacally, oronasally and intracoelomically inoculated with an infectious dose (~ 2000 TICD) of a ToPV strain isolated from a diseased T. graeca. A control group of two animals of each species received non-infected cell culture supernatant. The tortoises were examined daily and pharyngeal and cloacal swabs for detection of ToPV-RNA by RT-PCR were taken from each animal every six days for a period of 6 months. At the end of the study the remaining animals were euthanised and dissected. Bacteriological and parasitological tests were performed and organ samples of all tortoises were investigated by RT-PCR for the presence of ToPV and histopathology. Animals that were euthanised at the end of the experiment, were examined for presence of specific anti-ToPV antibodies. Several animals in both inoculated groups showed retarded growth and a light shell weakness, in comparison to the control animals. Three animals were euthanised during the trial, showing reduced weight gain, retarded growth, severe shell weakness and apathy, in parallel to clinical observations in naturally infected animals. In all inoculated animals of both species an intermittent virus shedding, starting from 18 days post inoculation (d.p.i.), till 164 d.p.i. was detected, while the control animals remained negative. The virus was successfully reisolated in terrapene heart cell culture in 16 of 20 inoculated animals of both species. Histopathology of most inoculated animals revealed a lack of bone remodeling and vacuolisation in kidney tubuli which supports the described pathogenesis of nephropathy and osteodystrophy. Anti- ToPV antibody titres ranged from 1:2 to >1:256 in 13 of 20 animals, whereas all control animals were seronegative. The study proofed the Henle Koch`s postulates of ToPV as causative agent for shell dystrophy and kidney disease in both testudo species. The proposed species specific sensitivity towards clinical disease was not observed.

Mycoplasma hafezii sp. nov., isolated from the trachea of a peregrine falcon (Falco peregrinus)

Mycoplasma species are well known pathogens in avian medicine, especially in poultry. However, several Mycoplasma species have been regularly found in the respiratory tract of birds of prey which seem to be commensals in these bird species. In previous studies, an unknown Mycoplasma species which caused false positive results in a Mycoplasma meleagridis-specific PCR, was isolated from a tracheal swab of a clinically healthy, captive, adult peregrine falcon (Falco peregrinus). The isolate appeared in typical fried-egg-shaped colonies on SP4 agar plates and was dependent on sterol for growth. Acid was produced from glucose, but no arginine or urea was hydrolysed. The temperature range for growth was 28-44 °C, with an optimum at 37 °C. Strain M26^T was serologically distinct from all species of the genus Mycoplasma with 16S rRNA gene sequence similarity ≥94 %. Biochemical, serological and molecular biological properties demonstrate that this organism represents a novel species of the genus Mycoplasma, for which the name Mycoplasma hafezii sp. nov. is proposed; the type strain is M26^T (NCTC 13928, DSM 27652).

Post-release breeding of translocated sharp-tailed grouse and an absence of artificial insemination effects

Context Translocation has become a widely used method to restore wildlife populations following extirpation. For some species, such as lekking grouse, which breed at traditional mating grounds, reproduction is linked to culturally established geographic locations. Cultural centres are lost upon extirpation, making restoration into otherwise rehabilitated habitats especially challenging. The process by which species with culturally dependent reproduction sometimes become re-established is poorly understood and merits investigation to improve conservation strategies. Historically, population restoration of North American lekking grouse (Tympanuchus spp. and Centrocercus spp.) via translocation has yielded poor results, in part because translocation sites lack leks, culturally determined breeding locations for which breeding adults form a high degree of philopatry. Columbian sharp-tailed grouse (Tympanuchus phasianellus columbianus; CSTG) occurs in &lt;10% of its historic range, but the existence of rehabilitated historic habitat provides for the potential of population restoration via translocation. Aims We reintroduced CSTG to vacant habitat in north-central Nevada, USA, from 2013 to 2017, with concordant goals of promoting females to nest and males to lek. We tested the utility of performing artificial insemination (AI) on females before translocation and we conducted paternity analyses to understand male reproduction. Methods We monitored females for the effects of AI on nest initiation, nest survival and egg fertility. We used post-hatch extra-embryonic membranes and other tissues to evaluate paternity of chicks produced at the restoration site. Key results Artificial insemination had no effect on female survival or nest initiation, and did not fertilise any eggs within nine sampled clutches (n=102 eggs). Most paternity was attributable to male residents that had survived for ≥1 year at the restoration site before the arrival of translocated females. Conclusions Artificial insemination neither aided nor harmed female reproduction. A small number of translocated, resident adult males sired reproduction following female release. Implications The presence of resident males at restoration sites may be more likely to result in post-translocation reproduction than is pre-translocation AI. Restoring CSTG to vacant habitat should focus on translocating females into suitable nesting habitat while simultaneously ensuring that reproductively capable males are available within or adjacent to the nesting habitat.

Investigations on different Semen Extenders for Cockatiel Semen

The aim of the present study was the modification and evaluation of three different semen extenders for cockatiel semen in order to achieve a long survival time for transport, examination purpose and for potential cryopreservation, respectively. Therefore, individual and pooled semen samples of 30 cockatiels (Nymphicus hollandicus) were investigated for pH and osmolality values and subsequently pH and osmolality values of the semen extenders were adjusted to those values in the semen. Pooled semen samples were then partitioned into four equal parts and diluted with the three different semen extenders in 1:4 and 1:8 dilution. 1 % glucose-Ringer’s solution was used as control, respectively. A total of 64 incremental diluted semen samples were obtained for investigation. Each dilution was investigated regarding sperm motility immediately after dilution and another four times every 30 minutes. Sperm viability was evaluated 0 and 120 minutes after dilution via eosin B-stain on the diluted semen samples and in pure semen samples. Additionally, the fluorescence stain SYBR® Green/propidium iodide was used to assess sperm viability. The results indicate that cockatiel spermatozoa are highly sensitive to variations in pH and osmolality, requiring adjustment of commercial diluents to pH = 7.42 and osmolality = 300 mOsm/kg. Modified Lake diluent maintained higher viability and motility than other diluents tested. Sperm morphology was indicated to be least adversely affected by modified Lake diluent in 1:4 concentration compared to other semen extenders and concentrations used.

Investigations on the prevalence of tortoise picorna-virus in captive tortoises in Germany

Objective: Tortoise picornavirus (ToPV) has been speculated to play an important role in the frequently seen disease pattern of juvenile shell softening. This study aimed to determine ToPV prevalence among German tortoise collections. Material and methods: A total of 334 animals selected from 27 different collections were included. Seven species of four genera of the family Testudinidae (Testudo graeca, T. hermanni, T. marginata, T. horsfieldii, Centrochelys sulcata, Stigmochelys pardalis, Chelonoidis carbonarius) were sampled. The tortoises were clinically investigated and none of the adults showed any signs of shell softening. Seven hatchlings of a ToPV-positive T. graeca breeding pair showed retarded growth and a progressive shell weakness that resulted in death. Each animal was sampled by conjunctival, pharyngeal and cloacal swabs (990 swabs in total) and blood sampling (293 in total). All three swabs of one animal were pooled and tested by reverse transcriptase polymerase chain reaction (RT-PCR) for tortoise picornavirus RNA. Blood samples were investigated by virus neutralisation test (VNT) for specific anti ToPV antibodies. All titres equal to or higher than log2 = 2 were considered positive. Results: In total, 35 adult and 11 juvenile animals were tested positive for ToPV RNA. The serological investigation did detect specific antibodies against ToPV in 44 adult tortoises and one juvenile. In total, 76 animals were tested positive in either one of the investigations, 16 animals in both. The highest number of ToPV-positive animals was found for T. graeca, with a prevalence of 32 %. No specimens of C. carbonarius, C. sulcata, or S. pardalis were tested positive. Conclusion and clinical relevance: The results propose a predisposition in T. graeca, as well as a high prevalence of ToPV in T. graeca, whereas other species showed only single or no positive animals, but may function as virus carriers.

Prevalence of Sarcocystis calchasi in free-ranging host species: Accipiter hawks and Common Woodpigeon in Germany

The apicomplexan parasite Sarcocystis calchasi (S. calchasi) triggers pigeon protozoal encephalitis, a neurologic disease in columbids. Accipiter hawks have been identified as the final host, and Columbidae and Psittaciformes as intermediate hosts. In this study, 368 free-ranging Accipiter hawks and 647 free-ranging common woodpigeons were sampled in a country-wide study in order to identify the prevalence of S. calchasi in these populations. A semi-nested PCR specific for S. calchasi tested positive in 7.3% (4.9–10.5) of submitted samples from Accipiter hawks. Juvenile Accipiter hawks (13.7%; 7.7–22.0) had a significantly higher infection rate with S. calchasi than adult Accipiter hawks (5.8%; 2.7–9.3). The prevalence of S. calchasi in common woodpigeons was 3.3% (5.4–9.7). Positive pigeons were identified in 14/16 federal states, and a region-dependency was detected, with higher rates of infection in the eastern parts of Germany. The results of this study suggest that the common woodpigeon is a natural reservoir for S. calchasi. In a study of one region for four consecutive years, an increase in prevalence was not detected. Findings indicate that the parasite is not newly introduced to Germany, but rather long established. The prevalence suggests that there is a substantial risk of S. calchasi infections in other free-ranging as well as captive host species.

Lactococcus lactis, causative agent of an endocarditis valvularis and parietalis thromboticans in the allis shad, Alosa alosa (L.)

Since the 1940s, the anadromous allis shad, Alosa alosa (L.), has suffered population declines throughout its distribution range in Europe. In context of EU-LIFE projects for the reintroduction of the allis shad in the Rhine system, a comprehensive study was started in 2012 to investigate infectious diseases occurring in allis shad. In course of the study, 217 mature and young-of-the-year allis shad originating from the wild population from the Gironde-Garonne-Dordogne system (GGD-system) and the Rhine system as well as 38 allis shad from the breeding population were examined by use of bacteriological and histological methods. In 2012 and 2014, an endocarditis valvularis thromboticans caused by a coccoid bacterium was detected in 16% and 25% of mature allis shad originating from the GGD-system. Results of microbiologic examinations, including biochemical characteristics, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and 16S rRNA gene sequence analysis, revealed Lactococcus lactis as causative agent of this infection. This is the first report of an endocarditis valvularis and parietalis thromboticans caused by Lactococcus lactis in fish. Possible sources of infection as well as the impact for the reintroduction programme are discussed.

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.

Endoscopic assisted orchiectomy in Herman’s tortoises (Testudo hermanni sp.)

Objective: Male tortoises in captivity are often aggressive against other males or females, in particular during mating season related to hormonal influences (testosterone). Castration in males is the treatment of choice in many vertebrate species. A novel technique of minimal invasive castration is presented for Herman’s tortoises (Testudo hermanni).

Material and methods: The procedure was performed in ten mature males. An endoscope (2.7 mm/30° angled) was inserted into a prefemoral incision on each side. The testicle was resected after ligation of the gubernaculum testis and the spermatic cord using hemoclips.

Results: Each testicle could be removed in approximately 20 minutes. Complications like hemorrhage or damage of adjacent tissue did not occur and all animals recovered uneventfully.

Conclusions and clinical relevance: Using the bilateral prefemoral entrance offers an alternative option for orchiectomy in Herman’s tortoises without dissection of the shell. Thus complications like hemorrhage or impaired wound healing followed by sequestration of the bone flap are prevented. Because of the anatomical settings and the risk of tissue damage and time consumption, a unilateral approach is not recommended. Fasting the animals is necessary due to the voluminous gastrointestinal tract of this herbivorous tortoise and emptying the urinary bladder provides more space for manipulations in the coelomic cavity and prevents clipping and cutting of adjacent organs. The magnification via the endoscope is beneficial for orientation in the coelomic cavity, which is formed by the extremely convex carapace. Without this equipment it is challenging to visualize the dorsocaudally located gonads through the relatively small incision and the inserted instruments might block the view at the surgical field. Administration of hemoclips achieved a good hemostasis and the testicles could be resected without major blood loss. The described technique is a gentle method for resection of the testicles in this species and can be adapted to other European tortoise species of equal size.

Soft plastron, soft carapace with skeletal abnormality in juvenile tortoises

Objective: A disease is described in juvenile tortoises (Testudo graeca and Geochelone elegans) consisting mainly of a soft carapace, soft plastron and deformed skeleton. The aim of this study was to determine histopathological lesions and the biological properties of the isolated viruses. Materials and methods: Clinical signs and gross pathology were determined on diseased and healthy appearing tortoises. Paraffin sections were stained with HE, PAS and Prussian Blue and histologically examined. Terrapene heart (TH-1) cell cultures served for virus isolations from 64 tissues and 104 swabs. One isolate (isolate 1243/37 tongue) was used in neutralization tests on 19 sera. Results: Retarded growth and increasingly soft plastron and carapace were the prominent signs in diseased tortoises. Pathological lesions consisted of dilated urinary sac, enlarged kidneys and livers. Histopathologically, hepatic hemosiderosis, hypoplastic anaemia, congestive glomerulonephrosis and osteodystrophy were seen. A novel virus (“virus X”) was isolated from 64 organs and 79 of 104 swabs. The isolated viruses were identified as a novel chelonid picornavirus based on cytopathic effect, resistance to chloroform and stability at low pH. Co-cultivation with 5-iodo-2’-deoxyuridine and actinomycin D did not reduce virus titres. Electron microscopically, round, non-enveloped particles (25–30 nm) were detected. Neutralizing antibodies to the isolate 1243/37tongue were present in 17 of 19 sera from seven species of tortoises. Conclusion and clinical relevance: Nephropathy, osteodystrophy and virus isolations suggest a viral aetiology. Metabolic bone disease is the major differential diagnosis. Further investigations in vivo are needed to evaluate the likely effects of the picornavirus on tortoises.

Semen collection and artificial insemination in cockatiels (Nymphicus hollandicus) – A potential model for psittacines

Study: Since many psittacine species are endangered and also rare in captivity, the number of offspring produced from breeding is crucial. Many potential breeding birds in species conservation programs are force-paired, and the eggs of many clutches are frequently infertile. Furthermore, male infertility is a common problem. The use of artificial insemination may increase the number of fertile eggs. Material and methods: In this study, 32 cockatiels (Nymphicus hollandicus) were divided into two groups. In one group, the males were endoscopically sterilised. The males of the other group were used as semen donors. After collection using a novel massage technique, semen samples were examined microscopically to assess contamination and quality. Samples with medium to high sperm concentrations, medium to high motility and no contaminants were used for intracloacal artificial insemination of hens in the group with sterile males. Results: In total, 74.2% of all attempts to collect semen were successful. Insemination resulted in fertilisation of 17 of 23 eggs (73.9%), which was slightly lower than the natural fertilisation rate (88.4%). No negative effects were observed on the oviposition interval of the inseminated hens throughout the entire study. Clinical relevance: Easily applicable in veterinary practice, this study demonstrates that the use of artificial insemination may be a valuable tool to address reproductive failure of psittacines in breeding projects.

Laser therapy in a soft-shelled turtle ( Pelodiscus sinensis ) for the treatment of skin and shell ulceration

Skin and shell diseases in aquatic turtles are often associated with several underlying causes. The presented case report describes aetiology including differential diagnoses, diagnostic procedures and therapy of a soft-shelled turtle (Pelodiscus sinensis) suffering from a septicaemic ulcerative dermatitis. Central aspect hereby is the positive curing effect of laser therapy on skin and shell lesions.

Salmonella detection in poultry samples

Study: The efficiency of two commercial PCR methods based on real-time technology, the foodproof® Salmonella detection system and the BAX® PCR Assay Salmonella system was compared to standardized culture methods (EN ISO 6579:2002 – Annex D) for the detection of Salmonella spp. in poultry samples. Material and methods: Four sample matrices (feed, dust, boot swabs, feces) obtained directly from poultry flocks, as well as artificially spiked samples of the same matrices, were used. All samples were tested for Salmonella spp. using culture methods first as the gold standard. In addition samples spiked with Salmonella Enteridis were tested to evaluate the sensitivity of both PCR methods. Furthermore all methods were evaluated in an annual ring-trial of the National Salmonella Reference Laboratory of Germany. Results: Salmonella detection in the matrices feed, dust and boot swabs were comparable in both PCR systems whereas the results from feces differed markedly. The quality, especially the freshness, of the fecal samples had an influence on the sensitivity of the real-time PCR and the results of the culture methods. In fresh fecal samples an initial spiking level of 100 cfu/25 g Salmonella Enteritidis was detected. Two-days-dried fecal samples allowed the detection of 14 cfu/25 g. Both real-time PCR protocols appear to be suitable for the detection of Salmonella spp. in all four matrices. The foodproof® system detected eight samples more to be positive compared to the BAX® system, but had a potential false positive result in one case. In 7-days-dried samples none of the methods was able to detect Salmonella likely through letal cell damage. Clinical relevance: In general the advantage of PCR analyses over the culture method is the reduction of working time from 4–5 days to only 2 days. However, especially for the analysis of fecal samples official validation should be conducted according to the requirement of EN ISO 6579:2002 – Annex D.

Die neuropathische Drüsenmagendilatation der Psittaziden und das aviäre Bornavirus als potenzielle Ursache

Gegenstand: Die neuropathische Drüsenmagendilatation der Psittaziden (PDD) ist eine bedeutende Erkrankung von Papageien, die stets letal endet. Sie tritt bei zahlreichen Papageienspezies auf und bedroht ganze Zuchtbestände, kommt bei anderen Vogelfamilien dagegen sehr selten vor. Die Ursache dieser Erkrankung war bislang unklar, obwohl schon lange eine Virusätiologie vermutet wurde. Kürzlich gelang der Nachweis eines neuen Virus (aviäres Bornavirus [ABV]) aus an PDD erkrankten Papageien, das seitdem als wahrscheinlichste Ursache gilt. Obwohl auch klinisch gesunde Papageien eine ABV-Infektion aufweisen können, zeigen verschiedene Studien einen Zusammenhang zwischen der Virusinfektion und der klinischen Erkrankung der PDD auf. Neben dem direkten Virusnachweis eignen sich auch serologische Methoden zum Infektionsnachweis. Schlussfolgerungen: Das aviäre Bornavirus ist zurzeit der wahrscheinlichste Kandidat als Erreger der PDD. Zuchtbestände und Neuzugänge sollten daher molekularbiologisch und serologisch auf eine Infektion mit ABV überprüft werden. Der diagnostische Wert des ABV-Infektionsnachweises zur Absicherung der klinischen Diagnose PDD muss in weiteren Studien genauer abgeklärt werden.

Single tracheal inoculation of Aspergillus fumigatus conidia induced aspergillosis in juvenile falcons (Falco spp.)

Aspergillosis is a common and life-threatening respiratory disease in raptors with acute and chronic courses. Among raptors, gyrfalcons (Falco rusticolus) and their hybrids are often declared to be highly susceptible with juvenile individuals being the most susceptible. However, species- and age-specific experimental studies are lacking and minimal infective doses (IDs) for Aspergillus spp. conidia are unknown.Therefore, 8-week-old, healthy gyr-hybrid falcons (F. rusticolus X F. cherrug) (N = 18) were experimentally infected with Aspergillus fumigatus using a single intratracheal inoculation with varying dosages of conidia (10² to 10⁷ conidia). Over 28 days, clinical signs were monitored as well as haematological and serological parameters. Following euthanasia, necropsy, histopathology, bacteriology, and mycology were performed. Re-isolated fungi were compared to the inoculum using microsatellite length polymorphisms. During the trial, clinical signs and dyspnoea correlated significantly with the ID. Necropsy revealed fungal lesions in the upper and lower airways of 10/18 inoculated falcons, but not in the control birds. In 9/18 inoculated falcons, fungal granulomas were confirmed in histopathology and A. fumigatus was re-isolated from these granulomas. Except one nasal isolate all re-isolated fungal strains were identical to the inoculum strain. Based on mycology and histopathology a minimal ID of 50% was calculated to be MID_{50% (±S.E.)} = 10^4.52±0.67 for a single tracheal inoculation of A. fumigatus conidia. This study demonstrates for the first time that a single exposure is able to cause acute aspergillosis in juvenile falcons.

Examining the Role of Transmission of Chelonid Alphaherpesvirus 5

Marine turtle fibropapillomatosis (FP) is a devastating neoplastic disease characterized by single or multiple cutaneous and visceral fibrovascular tumors. Chelonid alphaherpesvirus 5 (ChHV5) has been identified as the most likely etiologic agent. From 2010 to 2013, the presence of ChHV5 DNA was determined in apparently normal skin, tumors and swab samples (ocular, nasal and cloacal) collected from 114 olive ridley (Lepidochelys olivacea) and 101 green (Chelonia mydas) turtles, with and without FP tumors, on the Pacific coasts of Costa Rica and Nicaragua. For nesting olive ridley turtles from Costa Rica without FP, 13.5% were found to be positive for ChHV5 DNA in at least one sample, while in Nicaragua, all olive ridley turtles had FP tumors, and 77.5% tested positive for ChHV5 DNA. For green turtles without FP, 19.8% were found to be positive for ChHV5 DNA in at least one of the samples. In turtles without FP tumors, ChHV5 DNA was detected more readily in skin biopsies than swabs. Juvenile green turtles caught at the foraging site had a higher prevalence of ChHV5 DNA than adults. The presence of ChHV5 DNA in swabs suggests a possible route of viral transmission through viral secretion and excretion via corporal fluids.

Investigation of Different Infection Routes of Parrot Bornavirus in Cockatiels

The aim of this study was to determine the natural infection route of parrot bornavirus (PaBV), the causative agent of proventricular dilatation disease (PDD) in psittacines. For this purpose, nine cockatiels ( Nymphicus hollandicus ) were inoculated orally, and nine cockatiels were inoculated intranasally, with a PaBV-4 isolate. To compare the results of the trials, the same isolate and the same experimental design were used as in a previous study where infection was successful by intravenous as well as intracerebral inoculation. After inoculation, the birds were observed for a period of 6 mo and tested for PaBV RNA shedding, virus replication, presence of inflammatory lesions, and PaBV-4 antigen in tissues, as well as specific antibody production. In contrast to the previous study involving intravenous and intracerebral infections, clinical signs typical for PDD were not observed in this study. Additionally, anti-PaBV antibodies and infectious virus were not detected in any investigated bird during the study. Parrot bornavirus RNA was detected in only four birds early after infection (1-34 days postinfection). Furthermore, histopathologic examination did not reveal lesions typical for PDD, and PaBV antigen was not detected in any organ investigated by immunohistochemistry. In summary, oral or nasal inoculation did not lead to a valid infection with PaBV in these cockatiels. Therefore it seems to be questionable that the formerly proposed fecal-oral transmission is the natural route of infection in immunocompetent adult or subadult cockatiels.

Parrot Bornavirus (PaBV)-2 isolate causes different disease patterns in cockatiels than PaBV-4

Psittaciform 1 bornavirus (PaBV) has already been shown to be the aetiologic agent of proventricular dilatation disease, a significant disease of birds. However, the pathogenesis of PaBV infection has not yet been resolved and valid data regarding the pathogenicity of different PaBV species are lacking. Thus, the present study was aimed to characterize the influence of two different PaBV species on the course of disease. Eighteen cockatiels were inoculated intracerebrally (i.c.) or intravenously (i.v.) with a PaBV-2 isolate under the same conditions as in a previous study using PaBV-4. Birds were surveyed and sampled for 33 weeks to analyse the course of infection and disease in comparison to that of PaBV-4. Similar to PaBV-4, PaBV-2 induced a persistent infection with seroconversion (from day 6 p.i. onwards) and shedding of viral RNA (from day 27 p.i. onwards). However, in contrast to PaBV-4, more birds displayed clinical signs and disease progression was more severe. After PaBV-2 infection, 12 birds exhibited clinical signs and 10 birds revealed a dilated proventriculus in necropsy. After PaBV-4 infection only four birds revealed clinical signs and seven birds showed a dilatation of the proventriculus. Clinically, different courses of disease were observed after PaBV-2 infection, mainly affecting the gastrointestinal tract. This had not been detected after PaBV-4 infection where more neurological signs were noted. The results provide evidence for different disease patterns according to different PaBV species, allowing the comparison between the infection with two PaBV species, and thus underlining the role of viral and individual host factors for disease outcome.