Mast cell tumour in a giant Galapagos tortoise (Geochelone nigra vicina).

A well-differentiated cutaneous mast cell tumour was diagnosed in a subadult female giant Galapagos tortoise. The tumour was a pedunculated, verrucose mass located near the base of the neck. The histological features, which were diagnostic for a mast cell tumour, included abundant intracytoplasmic granules that were stained metachromatically with Giemsa and toluidine blue stains. Mast cell tumours are rare in reptiles, and this is the first description of a mast cell tumour in a chelonian.

Diseases of the respiratory tract of chelonians.

Diseases of the respiratory tract commonly occur in captive chelonians, and several diseases also have occurred in wild chelonians. Infectious causes include viruses, bacteria, fungi, and parasites. Herpesviruses have surfaced as important pathogens of the oral cavity and respiratory tract in Hermann's tortoise (Testudo hermanii), spur-thighed tortoise (Testudo graeca), and other tortoises in Europe and the United States. Herpesvirus-associated respiratory diseases also have been reported in the green turtle, Chelonia mydas, in mariculture in the Cayman Islands. Of diseases caused by bacteria, an upper respiratory tract disease caused by Mycoplasma sp has been reported in free-hanging and captive gopher tortoises in the southeastern United States and in desert tortoises in the Mojave Desert of the southwestern United States. Mycotic pulmonary disease is commonly reported in captive chelonians, especially in those maintained at suboptimal temperatures. An intranuclear coccidia has been seen in several species of captive tortoises in the United States, and, in one case, a severe proliferative pneumonia was associated with organisms in the lung. The most common noninfectious cause of respiratory disease in chelonians results from trauma to the carapace. Although pulmonary fibromas commonly occur in green turtles with fibropapillomatosis, for the most part, tumors of the respiratory tract are uncommon in chelonians.

Pulmonary lesions in experimental ophidian paramyxovirus pneumonia of Aruba Island rattlesnakes, Crotalus unicolor.

Histologic and ultrastructural changes were observed in the respiratory portions of lung in five 29-40-month-old Aruba Island rattlesnakes, Crotalus unicolor, that were inoculated with an Aruba Island Rattlesnake virus (AIV) strain of ophidian paramyxovirus (OPMV) isolated from an Aruba Island rattlesnake. Lungs from one non-infected and three mock-infected Aruba Island rattlesnakes were examined also. From 4 to 22 days following intratracheal inoculation, progressive microscopic changes were seen in the lung. Initially, increased numbers of heterophils were observed in the interstitium followed by proliferation and vacuolation of epithelial cells lining faveoli. The changes appeared to progress from cranial to caudal portions of the respiratory lung following inoculation. Beginning at 4 days postinoculation, viral antigen was demonstrated in epithelial cells lining faveoli with an immunofluorescent technique using a rabbit anti-AIV polyclonal antibody. Electron microscopy revealed loss of type I cells, hyperplasia of type II cells, and interstitial infiltrates of heterophils and mononuclear cells. Viral nucleocapsid material was seen within the cytoplasm and mature virus was seen budding from cytoplasmic membranes of infected type I and type II cells from 8 to 19 days after infection. A virus consistent with AIV was isolated from lung tissues of infected rattlesnakes, thus fulfilling Koch's postulates.

Chlamydiosis in mariculture-reared green sea turtles (Chelonia mydas).

From August 1990 to June 1991, a moderate die-off of 4- to 5-year-old green sea turtles (Chelonia mydas) occurred at Cayman Turtle Farm, Grand Cayman, British West Indies. Clinical signs included lethargy, anorexia, and inability to dive. Many of the ill turtles floated on the surface of their tanks. There was no apparent sex predilection. Complete necropsies, including histopathologic examination of tissues, were performed on eight turtles. Necropsies revealed multiple irregular discrete to patchy 1-10 mm pale gray foci throughout the hearts of four turtles. By light microscopic examination, the most severe and consistent lesions were necrotizing myocarditis, histiocytic to fibrinous splenitis, and hepatic lipidosis and necrosis. A mixed leukocytic infiltrate of acidophils, macrophages, and lymphocytes was present in affected areas of the heart. Other lesions included lymphocytic/plasmacytic interstitial nephritis, subacute interstitial pneumonia, subacute mesenteric vasculitis, chronic/active enteritis of the small intestine, and occasional granulomas associated with spirorchid trematode ova. Chlamydiae could be demonstrated in macrophages in sections of paraffin-embedded heart, liver, and spleen and in myocardial fibers and hepatocytes using a modified Macchiavello's stain. Chlamydial antigen was detected by light microscopic examination in the cytoplasm of myocardial fibers and in occasional hepatocytes using a commercially available genus-specific antichlamydial monoclonal antibody and the avidin biotin peroxidase complex staining method. Electron microscopic examination of the heart of the most severely affected turtle revealed developmental stages of chlamydial organisms. A suspension of heart from this turtle was inoculated into the yolk sacs of chicken embryos.(ABSTRACT TRUNCATED AT 250 WORDS)

Papilloma-like virus infection in Bolivian side-neck turtles.

Five Bolivian side-neck turtles had multifocal small, round to confluent, white skin lesions distributed over the head. Several gram-negative microorganisms were isolated from the lesions. Light microscopy revealed hyperkeratosis and hyperplasia of the epidermis. Ultrastructural evaluation demonstrated crystalline aggregates of virus particles within nuclei of cells in the stratum granulosum and free within the stratum corneum. On the basis of size, location, arrangement, and tissue affected, the particles resembled papillomaviruses.