Cases of mortality in little penguins (Eudyptula minor) in New Zealand associated with avian malaria

CASE HISTORY A little penguin (Eudyptula minor) of wild origin, in captivity at Wellington Zoo, became inappetent and lethargic in March 2013. Despite supportive care in the zoo's wildlife hospital, the bird died within 24 hours. CLINICAL FINDINGS Weight loss, dehydration, pale mucous membranes, weakness, increased respiratory effort and biliverdinuria were apparent on physical examination. Microscopic evaluation of blood smears revealed intra-erythrocytic stages of Plasmodium spp. and a regenerative reticulocytosis in the absence of anaemia. PATHOLOGICAL FINDINGS Post-mortem findings included reduced body condition, dehydration, pulmonary congestion and oedema, hepatomegaly, splenomegaly, hydropericardium and subcutaneous oedema. Histopathological findings included protozoal organisms in sections of lung, liver and spleen. A marked, diffuse, sub-acute interstitial histiocytic pneumonia was present. Accumulation of haemosiderin was noted in the Kupffer cells of the liver and in histiocytic-type cells in the spleen. MOLECULAR TESTING DNA was extracted from frozen portions of the liver. Nested PCR results and DNA sequencing confirmed infection of the deceased little penguin with Plasmodium (Huffia) elongatum lineage GRW06. DIAGNOSIS Avian malaria due to Plasmodium (Huffia) elongatum GRW06 RETROSPECTIVE INVESTIGATION A retrospective analysis of 294 little penguin cases in the Massey University post-mortem database revealed three other potential avian malaria cases. Analysis of archived tissues using a nested PCR for Plasmodium spp. followed by DNA sequencing revealed that a little penguin which died at Auckland Zoo was infected with P. elongatum GRW06 and two wild little penguins found dead on New Zealand beaches were infected with P. relictum SGS1 and Plasmodium. sp. lineage LINN1. Therefore, the overall frequency of deaths in little penguins associated with avian malaria was 4/295 (1.36%). CLINICAL RELEVANCE Our results suggest that avian malaria is associated with sporadic mortality in New Zealand's little penguins both in the wild and in captivity, but there is no evidence of mass mortality events due to Plasmodium spp. infection.

Ventral dermatitis in rowi (Apteryx rowi) due to cutaneous larval migrans

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Rowi on a crèche island showed loss of feathers and dermatitis.

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We identified cutaneous larval migrans, possibly due to Trichostrongylus.

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This is the first instance of cutaneous larval migrans to be recorded in birds.

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Fatal complications resulted in the death of eight birds from aspergillosis.

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Intensive conservation management can result in pathways for novel infections.

The rowi is a critically endangered species of kiwi. Young birds on a crèche island showed loss of feathers from the ventral abdomen and a scurfy dermatitis of the abdominal skin and vent margin. Histology of skin biopsies identified cutaneous larval migrans, which was shown by molecular sequencing to be possibly from a species of Trichostrongylus as a cause of ventral dermatitis and occasional ulcerative vent dermatitis. The predisposing factors that led to this disease are suspected to be the novel exposure of the rowi to parasites from seabirds or marine mammals due to the island crèche and the limited management of roost boxes. This is the first instance of cutaneous larval migrans to be recorded in birds. Severe and fatal complications of the investigation resulted in the death of eight birds of aspergillosis and pulmonary complications associated with the use of bark as a substrate in hospital. Another bird died of renal failure during the period of hospitalisation despite oral and intravenous fluid therapy. The initiating cause of the renal failure was not determined. These complications have the potential to undermine the working relationship between wildlife veterinarians and conservation managers. This case highlights that intensive conservation management can result in increased opportunities for novel routes of cross-species pathogen transmission.