Secondary skull fractures in head wounds inflicted by captive bolt guns: autopsy findings and experimental simulation

Apart from one article published by Rabl and Sigrist in 1992 (Rechtsmedizin 2:156-158), there are no further reports on secondary skull fractures in shots from captive bolt guns. Up to now, the pertinent literature places particular emphasis on the absence of indirect lesions away from the impact point, when dealing with the wounding capacity of slaughterer's guns. The recent observation of two suicidal head injuries accompanied by skull fractures far away from the bolt's path gave occasion to experimental studies using simulants (glycerin soap, balls from gelatin) and skull brain models. As far as ballistic soap was concerned, the dimensions of the bolt's channel were assessed by multi-slice computed tomography before cutting the blocks open. The test shots to gelatin balls and to skull-brain models were documented by means of a high-speed motion camera. As expected, the typical temporary cavity effect of bullets fired from conventional guns could not be observed when captive bolt stunners were discharged. Nevertheless, the visualized transfer of kinetic energy justifies the assumption that the secondary fractures seen in thin parts of the skull were caused by a hydraulic burst effect.

Stocking of captive-bred fish can cause long-term population decline and gene pool replacement: predictions from a population dynamics model incorporating density-dependent mortality

Releasing captive-bred fish into natural environments (stocking) is common in fisheries worldwide. Although stocking is believed to have a positive effect on fish abundance over the short term, little is known about the long-term consequences of recurrent stocking and its influence on natural populations. In fact, there are growing concerns that genetically maladapted captive-bred fish can eventually reduce the abundance of natural population. In this study, we develop a simple model to quantitatively investigate the condition under which recurrent stocking has long-term effects on the natural population. Using a population dynamics model that takes into account a density-dependent recruitment, a gene responsible for the fitness difference between wild and captive-bred fish, and hybridization between them, we show that there is little or no contribution of recurrent stocking to the stock enhancement without a replacement of the wild gene pool by the captive-bred gene pool. The model further predicted that stocking of an intermediate level causes a reduction, rather than enhancement, of population size over the long term. The population decline due to stocking was attributed to the fitness disadvantage of captive-bred fish and strong overcompensation at recruitment stage. These results suggest that it would be difficult to simultaneously attain population size recovery and conservation of the local gene pool when captive-bred fish have fitness disadvantage in the wild, although caution is needed when applying the predictions from the simplified model to a specific species or population.

Glomerulonephropathy in Aged Captive Key Largo Woodrats (Neotoma floridana smalli)

A retrospective review of mortality records of Key Largo woodrats (Neotoma floridana smalli) in a captive breeding program revealed chronic renal disease in 5 of 6 woodrats older than 4 years of age. Two of the 5 woodrats with chronic renal disease also had clinical evidence of diabetes mellitus. Kidneys from all 5 woodrats were examined via light microscopy, histochemical staining, immunohistochemical staining, and transmission electron microscopy. The dietary histories of the affected animals were examined as well. The most striking histopathologic abnormality in the affected kidneys was the presence of large protein casts within cortical and medullary tubules in combination with lesions of membranous glomerulopathy and glomerulosclerosis. Transmission electron microscopy revealed thickening and undulation of the tubular and glomerular mesangial basement membranes with the variable presence of electron-dense deposits within the capillary endothelial basement membrane. Patchy glomerular immunoreactivity for IgG was noted in 2 cases, but IgA and IgM immunoreactivity were not present. The pathologic changes in the kidneys of the Key Largo woodrats mirrored many of the features of chronic progressive nephropathy commonly diagnosed in laboratory rats. Woodrats in the captive population were fed an ad libitum high-protein diet similar to diets that have been shown in laboratory rats to exacerbate the development and progression of chronic progressive nephropathy. It is concluded that Key Largo woodrats develop glomerulonephropathy with features similar to chronic progressive nephropathy described in laboratory rats. Age, concomitant disease, and dietary factors may contribute to the development and severity of this potentially age-limiting disease in Key Largo woodrats.

Immunocompetence of nestling great tits in relation to rearing environment and parentage

Theoretical models of host-parasite coevolution assume a partially genetic basis to the variability in susceptibility to parasites among hosts, for instance as a result of genetic variation in immune function. However, few empirical data exist for free-living vertebrate hosts to support this presumption. In a cross-fostering experiment with nestling great tits, by comparing nestlings of the same origin we investigated (i) the variance in host resistance against an ectoparasite due to a common genetic origin, (ii) the effect of ectoparasite infestation on cell-mediated immunity and (iii) the variance in cell-mediated immunity due to a common genetic origin. Ectoparasitic hen fleas can impair the growth of nestling great tits and nestling growth was therefore taken as a measure of host susceptibility. A common origin did not account for a significant part of the variation in host susceptibility to fleas. There was no significant overall effect of fleas on nestling growth or cell-mediated immunity, as assessed by a cutaneous hypersensitivity response. A common rearing environment explained a significant part of the variation in cell-mediated immunity among nestlings, mainly through its effect on nestling body mass. The variation in cell-mediated immunity was also related to a common origin. However, the origin-related variation in body mass did not account for the origin-related differences in cell-mediated immunity. The results of the present study thus suggest heritable variation in cell-mediated immunity among nestling great tits. [References: 49]

Anaesthesia with medetomidine-ketamine-isoflurane with and without midazolam, in eight captive Chimpanzees (Pan troglodytes) premedicated with oral zuclopenthixol

In 8 captive adult chimpanzees of various ages premedicated with oral zuclopenthixol anaesthesia was induced intramuscularly with a combination of medetomidine and ketamine (40 or 50 µg/kg and 5 mg/kg, IM, respectively), with and without midazolam (0.05 mg/kg), and maintained with isoflurane in oxygen. At the end of the procedure, sedation was reversed with atipamezole (0.25 mg/kg, IM) and sarmazenil (0.005 mg/kg, IM) when midazolam had been administered. Oral zuclopenthixol resulted in tranquillization of the whole group and only one animal required a second dart injection to achieve adequately deep anaesthesia. Effective and reliable anaesthesia was achieved in all apes; the depth of hypnosis was stable and sudden arousal did not occur. Physiological parameters remained within normal ranges in the majority of the animals; however, manageable anaesthesia-related complications, namely apnoea after darting, hypotension, hypoventilation, hypoxemia and prolonged recovery, occurred in 6 out of 8 animals. The use of monitoring devices was essential to guarantee adequate management of these complications.

Factors influencing the onset and progression of pododermatitis in captive flamingos (Phoenicopteridae).

Pododermatitis is a worldwide problem in captive flamingos. We performed an evaluation of different influence factors (age, sex, weight, origin, breeding status) and a comparison of foot lesions between several zoological institutions and the feet of free-ranging Greater flamingos (Phoenicopterus roseus). A scoring system was used to determine the prevalence and types of lesions and severity. Cracks and nodules developed as early as 3 months of age and papillomatous growths as early as 6 to 7 months of age in captivity. Nodules with ulceration occurred significantly more often in birds older than 31 years and heavier than 4 kg. The comparison of different institutions revealed that birds kept in enclosures with natural-floored water ponds had significantly less severe lesions than birds kept in concrete water ponds. None of the free-ranging flamingos, which live on a muddy underground, showed any lesion. This study demonstrates that flooring, weight and age are important in the onset and progression of pododermatitis in flamingos.

Feather-pecking response of laying hens to feather and cellulose-based rations fed during rearing.

Recent studies in laying hens have shown that feather peckers eat more feathers than nonpeckers. We hypothesized that food pellets containing feathers would decrease the birds' appetite for feathers and thereby also decrease feather pecking. To separate the effect of feathers from that of insoluble fiber per se, additional control groups were fed pellets containing similar amounts of cellulose. Sixty (experiment 1) and 180 (experiment 2) 1-d-old Lohmann-Selected Leghorn birds were divided into 12 groups of 5 (experiment 1) and 15 (experiment 2) birds, respectively, and kept on slatted floors. During the rearing period, 4 groups each had ad libitum access to either a commercial pelleted diet, a pelleted diet containing 5% (experiment 1) or 10% (experiment 2) of chopped feathers, respectively, or a pelleted diet containing 5% (experiment 1) or 10% (experiment 2) of cellulose, respectively. In the consecutive laying period, all groups received a commercial pelleted diet. In experiment 1, feather pecking was recorded weekly from wk 5 to wk 16. In the laying period, observations were made in wk 18, 20, 22, 23, 24, 25, 26, 27, 28, and 30. In experiment 2, feather pecking was recorded weekly from wk 5 to 11, in wk 16 to wk 18, and in wk 20 and 21. At the end of the rearing period, plumage condition per individual hen was scored. Scores from 1 (denuded) to 4 (intact) were given for each of 6 body parts. The addition of 10% of feathers to the diet reduced the number of severe feather-pecking bouts (P < 0.0129) and improved plumage condition of the back area (P < 0.001) significantly compared with control diets. The relationship between feather pecking/eating and the gastrointestinal consequences thereof, which alter feather pecking-behavior, are unclear. Understanding this relationship might be crucial for understanding the causation of feather pecking in laying hens.

Patterns and Correlates of Expressed Emotion, Perceived Criticism, and Rearing Style in First Admitted Early-Onset Schizophrenia Spectrum Disorders

The aim of this study was to assess patterns and correlates of family variables in 31 adolescents treated for their first episode of a schizophrenia spectrum disorder (early-onset schizophrenia [EOS]). Expressed emotion, perceived criticism, and rearing style were assessed. Potential correlates were patient psychopathology, premorbid adjustment, illness duration, quality of life (QoL), sociodemographic variables, patient and caregiver "illness concept," and caregiver personality traits and support. Families were rated as critical more frequently by patients than raters (55% vs. 13%). Perceived criticism was associated with worse QoL in relationship with parents and peers. An adverse rearing style was associated with a negative illness concept in patients, particularly with less trust in their physician. Future research should examine perceived criticism as a predictor of relapse and indicator of adolescents with EOS who need extended support and treatment. Rearing style should be carefully observed because of its link with patients' illness concept and, potentially, to service engagement and medication adherence

Pododermatitis in Captive and Free-Ranging Greater Flamingos (Phoenicopterus roseus)

Pododermatitis is frequent in captive flamingos worldwide, but little is known about the associated histopathologic lesions. Involvement of a papillomavirus or herpesvirus has been suspected. Histopathologic evaluation and viral assessment of biopsies from 19 live and 10 dead captive greater flamingos were performed. Selected samples were further examined by transmission electron microscopy and immunohistochemistry. Feet from 10 dead free-ranging greater flamingos were also evaluated. The histologic appearance of lesions of flamingos of increasing age was interpreted as the progression of pododermatitis. Mild histologic lesions were seen in a 3-week-old flamingo chick with no macroscopic lesions, and these were characterized by Micrococcus-like bacteria in the stratum corneum associated with exocytosis of heterophils. The inflammation associated with these bacteria may lead to further histologic changes: irregular columnar proliferations, papillary squirting, and dyskeratosis. In more chronic lesions, hydropic degeneration of keratinocytes, epidermal hyperplasia, and dyskeratosis were seen at the epidermis, as well as proliferation of new blood vessels and increased intercellular matrix in the dermis. Papillomavirus DNA was not identified in any of the samples, while herpesvirus DNA was seen only in a few cases; therefore, these viruses were not thought to be the cause of the lesions. Poor skin health through suboptimal husbandry may weaken the epidermal barrier and predispose the skin to invasion of Micrococcus-like bacteria. Histologic lesions were identified in very young flamingos with no macroscopic lesions; this is likely to be an early stage lesion that may progress to macroscopic lesions.

Genetic identification of an oxyurid from a captive, black-handed spider monkey—implications for treatment and control

Parasites are of major clinical significance in captive primates in zoos, particularly those with direct life cycles. Oxyurid nematodes can be a persistent problem, as infection intensity and environmental contamination with infective eggs are usually high. Observations at the Basel Zoo in Switzerland have revealed that particularly black-handed spider monkeys (Ateles geoffroyi) exhibit continuous oxyurid nematode infection(s), despite regular deworming with anthelmintics. In the present study, using a molecular approach, we were able to identify the nematode (Trypanoxyuris atelis) causing this ongoing problem, and we are now evaluating a practical treatment and control regimen to tackle this parasite problem.

Evaluation of liver parenchyma and perfusion using dynamic contrast-enhanced computed tomography and contrast-enhanced ultrasonography in captive green iguanas (Iguana iguana) under general anesthesia.

BACKGROUND Contrast-enhanced diagnostic imaging techniques are considered useful in veterinary and human medicine to evaluate liver perfusion and focal hepatic lesions. Although hepatic diseases are a common occurrence in reptile medicine, there is no reference to the use of contrast-enhanced ultrasound (CEUS) and contrast-enhanced computed tomography (CECT) to evaluate the liver in lizards. Therefore, the aim of this study was to evaluate the pattern of change in echogenicity and attenuation of the liver in green iguanas (Iguana iguana) after administration of specific contrast media. RESULTS An increase in liver echogenicity and density was evident during CEUS and CECT, respectively. In CEUS, the mean ± SD (median; range) peak enhancement was 19.9% ± 7.5 (18.3; 11.7-34.6). Time to peak enhancement was 134.0 ± 125.1 (68.4; 59.6-364.5) seconds. During CECT, first visualization of the contrast medium was at 3.6 ± 0.5 (4; 3-4) seconds in the aorta, 10.7 ± 2.2 (10.5; 7-14) seconds in the hepatic arteries, and 15 ± 4.5 (14.5; 10-24) seconds in the liver parenchyma. Time to peak was 14.1 ± 3.4 (13; 11-21) and 31 ± 9.6 (29; 23-45) seconds in the aorta and the liver parenchyma, respectively. CONCLUSION CEUS and dynamic CECT are practical means to determine liver hemodynamics in green iguanas. Distribution of contrast medium in iguana differed from mammals. Specific reference ranges of hepatic perfusion for diagnostic evaluation of the liver in iguanas are necessary since the use of mammalian references may lead the clinician to formulate incorrect diagnostic suspicions.

Magnetic resonance imaging and computer tomography of brain lesions in water buffaloes and cattle stunned with handguns or captive bolts

Owing to the demand for genuine mozzarella, some 330 water buffaloes are being slaughtered every year in Switzerland albeit a stunning procedure meeting animal welfare and occupational safety requirements remains to be established. To provide a basis for improvements, we sized anatomical specifics in water buffaloes and cattle and we assessed brain lesions after stunning with captive bolts or handguns by diagnostic imaging. In water buffaloes and cattle, the median distance from the frontal skin surface to the inner bone table was 74.0 mm (56.0–100.0 mm) vs 36.6 mm (29.3–44.3 mm) and from skin to the thalamus 144.8 mm (117.1–172.0 mm) vs 102.0 (101.0–121.0 mm), respectively. Consequently, customary captive bolt stunners may be inadequate. Free bullets are potentially suitable for stunning buffaloes but involve occupational safety hazards. The results of the present study shall be used to develop a device allowing effective and safe stunning of water buffaloes.