[Carbofuran poisoning in mallard ducks]. / Carbofuran-Vergiftung bei wildlebenden Stockenten.

Carbofurane, a pesticide from the group of carbamates, has been employed against soil nematodes on a small meadow at the lake of Lugano, Switzerland. On the next morning, the first cases of death involving a total of 19 mallard ducks (Anas platyrhynchos) have been reported. By inhibiting the enzymatic breakdown of the neurotransmitter acetycholine, carbamates lead to excessive activation of the parasympathicus. In addition, paralysis of skeletal muscles is caused by continued stimulation of neuromuscular junctions. Death may occur by asphyxia. In the present case report, the diagnosis of poisoning could be confirmed by the chemical detection of carbofuran in the stomach, blood, muscle and kidney tissue of the affected mallard ducks.

Phaeohyphomycosis in a snow leopard (Uncia uncia) due to Cladophialophora bantiana.

Phaeohyphomycosis caused by Cladophialophora bantiana was diagnosed in a 5-month-old snow leopard with spastic paralysis of the hind legs and inability to defaecate or urinate. At post-mortem examination, a greenish soft mass resembling an abscess was found on one side of the epidural space at the fourth lumbar vertebral body. Histological examination revealed a purulent meningitis with myelomalacia. Dematiaceous fungal hyphae, present within the inflammatory infiltrate, were identified as C. bantiana by culture and sequence analysis of the 18S ribosomal RNA gene. This neurotropic fungus rarely affects organs other than the brain in human beings and cats, and has been reported only occasionally in Europe. The case described suggests that phaeohyphomycosis due to C. bantiana infection may be recognized more frequently in the future and the possible involvement of organs other than the brain should be borne in mind.

Alveolar echinococcosis in the zoological garden Basle.

Alveolar echinococcosis (AE) is a rare, but potentially severe zoonotic disease caused by Echinococcus (E.) multilocularis. Recent findings indicated an increasing importance of AE for non-human primates living in regions endemic for E. multilocularis. The death of five cynomolgus monkeys (Macaca fascicularis) and a lowland gorilla (Gorilla g. gorilla) due to AE raised concern about the incidence of this parasite in the Basle Zoo. Consequently, a project was initiated to investigate the prevalence amongst an affected group of cynomolgus monkeys, as well as in foxes and mice. Three out of 46 monkeys were seropositive for E. multilocularis antigen. In two of these monkeys and in another three animals, which were seronegative, structures compatible with metacestodal cysts were observed using ultrasonography. Seven out of 35 free roaming foxes caught at the zoo were positive for an intestinal E. multilocularis copro-antigen ELISA, four of them shed taeniid eggs simultaneously. No lesions compatible with AE were present in 50 necropsied mice from the zoo area. These results indicate that the fox population is a potential source to introduce E. multilocularis and may thus represent a risk for the zoo animals.

Hepatic alveolar echinococcosis in cynomolgus monkeys (Macaca fascicularis).

Alveolar echinococcosis was diagnosed in 12 cynomolgus monkeys (Macaca fascicularis) at postmortem examination within a period of 6 years. Besides consistent involvement of the liver, parasitic lesions were also present in mesenteric lymph nodes, pancreas, lung, and kidney. In the liver, various patterns of host's responses to parasitic tissue could be distinguished. Infiltration of macrophages, often multinucleated, around usually intact metacestodes was the main feature of one pattern. A second pattern was characterized by the presence of abundant, normally degenerate granulocytes in addition to macrophages surrounding collapsed laminated structures. Finally and as a third pattern, some cysts were surrounded by marked collagen deposition, which was usually not a significant feature of the other foci. Parasitic cysts with protoscolices were observed in foci with the first and third pattern but not in the second one. The simultaneous occurrence of all three patterns was observed in most animals. Type AA amyloid was identified either in the space of Dissé, macrophages or blood vessel walls in nine animals using immunohistochemistry. Identity of parasitic structures such as metacestodes of Echinococcus multilocularis was confirmed immunohistochemically. All animals that could be tested serologically (7/12) had detectable antibodies against the E. multilocularis-specific Em2 antigen. Liver lesions of six animals were additionally analyzed by polymerase chain reaction, yielding the amplification of a specific E. multilocularis DNA fragment in each case.

Metastatic gastric adenocarcinoma and diffuse hyperplastic gastritis resembling human Menétrier's disease in a camel (Camelus ferus bactrianus).

A captive 16-year-old male camel (Camelus ferus bactrianus) was euthanized after a prolonged period of inappetence leading to cachexia. At necropsy, there was a 7 cm large, tan, firm, well-demarcated nodule in the tunica muscularis and serosa of the distal region of C3. Histologically, a gastric adenocarcinoma was diagnosed. Numerous metastases were found in the liver and the hepatic lymph nodes, in the wall of the portal vein and the aorta, in the lung, heart, and pleura parietalis. Osseous metaplasia was found within the pleural and aortic metastases. In the mucosa of the glandular region of the C3 compartment a diffuse marked hypertrophy of rugae resembling cerebral convolutions was observed. The lesion was characterized by glandular hyperplasia and stromal inflammation and oedema. These changes closely resembled Menétrier's disease described in humans. To our knowledge, this is the first report of concomitant metastatic gastric adenocarcinoma and gastric hyperplasia in a camel.

Echinococcus multilocularis in two lowland gorillas (Gorilla g. gorilla).

An unusual presentation of alveolar echinococcosis was observed in two lowland gorillas (Gorilla g. gorilla). Clinical signs included progressive abdominal enlargement, apathy and anorexia. Macroscopical changes consisted of severe peritonitis and foci of hepatic necrosis with large cavities replacing most of the normal tissue. Additionally, a few structures resembling hydatid cysts were present. Histologically, some necrotic areas contained fragments of a laminated wall characteristic of echinococcal metacestodes. Only a few areas showed the multiloculated architecture typical of Echinococcus multilocularis. Serum antibodies against E. multilocularis antigen were detected in both animals, and granulomatous and necrotizing hepatitis with severe peritonitis due to E. multilocularis was diagnosed. The pathological changes in alveolar echinococcosis in gorillas appear to resemble more closely those found in human beings than those in other non-human primates.

Immunohistochemical localization of Clostridium perfringens beta2-toxin in the gastrointestinal tract of horses.

Clostridia-associated intestinal disease in horses was generally reported to be due to infection with Clostridium perfringens type A, which harbors the cpa-encoded alpha-toxin. A recent study demonstrated a high incidence of beta2-toxigenic C. perfringens in horses suffering or dying from typhlocolitis, suggesting that this novel type of C. perfringens might play an important role in typhlocolitis and possibly other equine intestinal diseases. A retrospective study was conducted to assess the presence of the beta2-toxin in tissues of the equine gastrointestinal tract. Monospecific polyclonal antibodies against recombinant beta2-toxin were produced in rabbits and used to demonstrate the beta2-toxin in sections of the gastrointestinal tract by immunohistochemical methods. Sections from 69 horses were stained and beta2-toxin was observed immunohistochemically in 40 animals. Sections from the stomach, small intestine, and large intestine were positive. Immunopositivity for beta2-toxin was significantly associated with presence of beta2-toxigenic bacteria. This investigation demonstrates local production of beta2-toxin and suggests that immunohistochemistry using antitoxin antibodies represents a useful diagnostic method in those cases where isolation of bacteria and polymerase chain reaction typing is not feasible. Although the association between the presence of beta2-toxin and development of gastrointestinal disease in horses remains uncertain, the findings of this study indicate that the potential causal relationship warrants further investigation.

Immunohistochemical study of retinol-binding protein in livers of polar bears (Thalarctos maritimus).

Liver tumors of unknown cause have frequently been described in polar bears. Concurrent decrease of vitamin A levels and chronic liver disease are associated with hepatic carcinogenesis in humans. More than 90% of the body's vitamin A is stored in the liver, where it is bound to an intracellular retinol-binding protein (RBP). Therefore, in this retrospective study, RBP was assessed by immunohistochemistry in liver sections of 11 polar bears. Two of these polar bears had hepatocellular carcinoma, four showed other chronic liver changes, and five had normal livers. In normal livers, the cytoplasm stained diffusely positive with intensely staining cytoplasmic granules. RBP staining was evaluated and the abundance of diffuse cytoplasmic staining and intracytoplasmic large granules was determined. All cases with pathologic liver changes had markedly decreased staining intensities for RBP compared with normal livers. The findings of this study suggest that in polar bears, as in humans, vitamin A metabolism may play a role in hepatic carcinogenesis.

Clostridium perfringens beta2-toxin in an African elephant (Loxodonta africana) with ulcerative enteritis.

A 22-year-old female African elephant (Loxodonta africana) developed diarrhoea of unknown cause which lasted for two days. The animal was euthanased after it remained recumbent and refused to get up. Gross pathological changes were present mainly in the gastrointestinal tract. The intestinal contents were watery and dark brown. Several areas of the mucosa of the small intestine were covered minimally to moderately with fibrin and had a few 0.1 x 10 to 15 cm linear ulcerations. Microscopical lesions consisted of discrete areas of necrosis of the surface and crypt epithelium without overt inflammatory infiltrates. Culture of the small intestinal contents resulted in a moderate growth of Clostridium perfringens. No salmonella were found in the small or large intestine. PCR of the isolate of C. perfringens revealed the presence of the beta2-toxin gene cpb2 and the alpha-toxin gene cpa but no other known toxin genes. The expression of the beta2-toxin gene in vivo was demonstrated by the immunohistochemical localisation of the beta2-toxin to the microscopical lesions in the small intestine.

Isolation and characterization of an iridovirus from Hermann's tortoises (Testudo hermanni).

A virus was isolated from tissues of 2 diseased Hermann's tortoises (Testudo hermanni) and preliminarily characterized as an iridovirus. This conclusion was based on the presence of inclusion bodies in the cytoplasm of infected cells, sensitivity to chloroform, inhibition of virus replication by 5-iodo-2'-desoxyuridine and the size and icosahedral morphology of viral particles. The virus was able to replicate in several reptilian, avian and mammalian cell lines at 28 degrees C, but not at 37 degrees C. Restriction enzyme analysis showed resistance of the ral DNA to digestion with HpaII due to methylation of the internal cytosine at CCGG sequences. Part of the genomic region encoding the major capsid protein was amplified by PCR and subjected to sequence analysis. Comparative analysis of the obtained nucleotide sequence revealed that the isolate is closely related to frog virus 3, the type species of the genus Ranavirus.

Nocardia nova causing pulmonary nocardiosis of black crakes (Limnocorax flavirostra).

Natural nocardial infection has been reported in many different species including mammals and fish, but reports in birds remain uncommon. Eight juvenile Black Crakes (Limnocoraxflavirostra) died unexpectedly at the Basle Zoo. Necropsy revealed disseminated white, firm nodules, 1-3 mm in diameter, throughout the lung parenchyma. Histologically, the lungs contained multiple, often confluent granulomas with central necrosis. Delicate, gram-positive, 0.5- to 1.0-microm-wide, branching, occasionally beaded, filamentous organisms were visible in necrotic centers. These organisms were acid fast when stained with Fite-Faraco. No histologic lesions were seen in other organs. Nocardia nova was isolated from liver, spleen, kidney, and lung. Granulomatous and necrotizing nocardial pneumonia with agonal septicemia was diagnosed, suggesting an aerogenous infection. To our knowledge, this is the first reported epizootic outbreak of nocardiosis in birds, which is additionally unusual because it was caused by N. nova.

Sporotrichosis in a nine-banded armadillo (Dasypus novemcinctus).

An adult female nine-banded armadillo (Dasypus novemcinctus) died in the quarantine station of a private Swiss zoo. Multifocal ulcerative skin lesions and multiple hemorrhages in the lungs were found at necropsy. The spleen was enlarged and dark red. Histologically, there was diffuse granulomatous infiltration, including multinucleated giant cells, of the skin lesions, lungs, spleen, liver, heart, and kidneys. Abundant periodic acid-Schiff-positive yeastlike cells were demonstrated intracellularly in giant cells and extracellularly scattered throughout the tissues. Morphology of the cells varied, with some nonbudding cells resembling Cryptococcus neoformans and others resembling Sporothrix schenckii. A diagnosis of sporotrichosis was confirmed by immunofluorescence studies. This is the first report of sporotrichosis in an armadillo in a zoological garden and the third report of sporotrichosis in D. novemcinctus.