Disease Risk Analysis and Post-Release Health Surveillance for a Reintroduction Programme: the Pool Frog Pelophylax lessonae.

There are risks from disease in undertaking wild animal reintroduction programmes. Methods of disease risk analysis have been advocated to assess and mitigate these risks, and post-release health and disease surveillance can be used to assess the effectiveness of the disease risk analysis, but results for a reintroduction programme have not to date been recorded. We carried out a disease risk analysis for the reintroduction of pool frogs (Pelophylax lessonae) to England, using information gained from the literature and from diagnostic testing of Swedish pool frogs and native amphibians. Ranavirus and Batrachochytrium dendrobatidis were considered high-risk disease threats for pool frogs at the destination site. Quarantine was used to manage risks from disease due to these two agents at the reintroduction site: the quarantine barrier surrounded the reintroduced pool frogs. Post-release health surveillance was carried out through regular health examinations of amphibians in the field at the reintroduction site and collection and examination of dead amphibians. No significant health or disease problems were detected, but the detection rate of dead amphibians was very low. Methods to detect a higher proportion of dead reintroduced animals and closely related species are required to better assess the effects of reintroduction on health and disease.

Renal calculi in wild Eurasian otters (Lutra lutra) in England.

Macroscopic renal calculi were seen in 50 of 492 (10.2 per cent) wild Eurasian otters found dead in England from 1988 to 2007. Forty-eight adults and two subadults were affected. Calculi were present in 15.7 per cent (31 of 197) of adult males and 12.7 per cent (17 of 134) of adult females. There was an increase in prevalence in the study population over time; no calculi were found in 73 otters examined between 1988 and 1996, but in most subsequent years they were observed with increased frequency. Calculi occurred in both kidneys but were more common in the right kidney. They varied greatly in shape and size; larger calculi were mostly seen in the calyces while the smallest ones were commonly found in the renal medulla. Calculi from 45 cases were examined by x-ray diffraction analysis; in 43 (96 per cent), they were composed solely of ammonium acid urate. Affected otters had heavier adrenal glands relative to their body size than unaffected otters (P<0.001). There was no significant association between body condition index and the presence of calculi (P>0.05). Many otters had fresh bite wounds consistent with intraspecific aggression. The proportion bitten increased over time and this coincided with the increased prevalence of renal calculi.

Brain tumours in two Bactrian camels: a histiocytic sarcoma and a meningioma.

Primary brain tumours were identified in two Bactrian camels (Camelus bactrianus) living at the Zoological Society of London's two zoos. Histology and immunohistochemistry were used to diagnose a histiocytic sarcoma in a 16-year-old female and a fibroblastic meningioma in a 13-year-old male. Before one died and the other was euthanased both camels had shown progressive neurological signs, including circling and ataxia.

Prevalence, distribution and pathological significance of the bile fluke Pseudamphistomum truncatum in Eurasian otters (Lutra lutra) in Great Britain.

Postmortem examinations on 160 otters found dead in Great Britain from 2005 to 2007 showed a high prevalence of infection with the bile fluke Pseudamphistomum truncatum in otters from Somerset and Dorset but no infection in otters from other areas, including Cornwall, the western half of Devon, north-east England and Scotland. Cases were also recorded for the first time in Gloucestershire and East Anglia. Eighteen of the 28 infected otters were male and no cubs were infected, but there was no significant correlation between infection status and sex or age. There was a strong positive correlation between bile fluke infection and gall bladder pathology. Thirty otters had thickened gall bladders resulting from hyperplasia of the epithelial and smooth muscle layers, fibrosis and infiltration by inflammatory cells and 19 of these were infected. No flukes were detected in the other 11 otters with abnormal gall bladders, possibly as a result of a successful immune response. The majority of otters with thickened gall bladders were in good physical condition but a positive association was not confirmed statistically. Fluke infection was also detected in nine of the 130 otters with apparently normal gall bladders. Liver pathology ranged from mild bile duct hyperplasia and periportal fibrosis to severe sclerosing cholangitis, hepatocyte necrosis and bile stasis. No otters were found to have died as a result of fluke infection, but there was a negative association, approaching significance, between infection and body condition.

High serum concentrations of iron, transferrin saturation and gamma glutamyl transferase in captive black rhinoceroses (Diceros bicornis).

Iron storage disease (haemochromatosis) is thought to be the cause of many disorders unique to captive black rhinoceroses (Diceros bicornis). To establish reliable reference ranges for iron parameters, serum samples from 27 eastern black rhinoceroses (Diceros bicornis michaeli) from a translocation programme in Kenya were analysed and compared with the samples from 17 captive individuals. The transferrin saturation, serum iron concentration and gamma glutamyl transferase were significantly higher in the captive rhinoceroses, but these elevations were not evident when the results were compared with previously published data.