Acanthocephalan infection and sparganosis in a green tree snake (Dendrelaphis punctulata).

Acanthocephalan and spargana parasites were identified within a body wall mass during exploratory surgery in a wild green tree snake. Acanthocephalan parasites have not previously been reported in this species. Surgical excision, the treatment of choice, could not be achieved because of the extensive infiltration of the coelomic cavity.

Pathology of skin diseases in crocodiles.

OBJECTIVE: To establish which skin diseases occur in crocodiles, particularly those on farms, to indicate the relative frequency of each particular disease and to provide information on pathogenesis, especially in regard to lesions with two or more pathogens present. DESIGN: A gross and microscopic retrospective (period of 1989 to 1995) and current (1996 to 1997) examination of skin lesions in crocodiles in Queensland and the Northern Territory. RESULT: Skin lesions were obtained from crocodiles on nine farms, from a group of experimental animals and from one adult found dead in the wild. A total of 203 lesions from 180, mostly young, crocodiles was examined; 119 lesions were from retrospectively examined cases and 84 were recent. The relative frequencies of four presumed primary pathogens in lesions were Dermatophilus sp 28.1%, fungi 14.8%, poxvirus 3.4% and probable Mycobacterium sp 2.5%. In addition, other bacteria of unknown significance were present in many lesions, and there was one case of presumed Paratrichosoma crocodilus infection. In 32.5% of lesions, multiple pathogens were identified. CONCLUSION: Dermatophilosis is the most common and probably the most important skin disease of crocodiles in Australia, but it is frequently complicated by concurrent infection with fungi or other microorganisms.

Observations of fibropapillomatosis in green turtles (Chelonia mydas) in Indonesia.

OBJECTIVE: To determine the prevalence and manifestations of fibropapillomatosis in green turtles in Indonesia, to identify any relationship between fibropapillomatosis and concurrent parasitic infection, to ascertain the effect of fibropapillomatosis on health, and to examine whether environment might have an effect on the prevalence of fibropapillomatosis. PROCEDURE: 4407 green turtles (Chelonia mydas) and 401 hawksbill turtles (Eretmochelys imbricata) were examined. The occurrence of fibropapillomatosis was correlated with sex, maturity, curved carapace length, body weight/curved carapace length ratio, the number and distribution of tumours on the skin, parasite burdens, some haematological variables and the region of capture. RESULTS: Fibropapillomatosis was seen only in green turtles, and the overall prevalence in these was 21.5%. This prevalence increased with the curved carapace length up to 85 cm. The average number of tumours per affected turtle was 5 +/- SD 4.1 (range, 1 to 29), and was negatively correlated with the body weight/curved carapace length ratio (rs = -0.8; P = 0.001). The red blood cell count in turtles with fibropapilloma was lower than in non-fibropapilloma turtles captured and examined at the same time (P = 0.001). The prevalence of fibropapilloma in turtles captured near densely populated, industrial regions (26.3%) was greater than in turtles from sparsely populated areas (17.7%). CONCLUSION: Fibropapillomatosis in green sea turtles in Indonesia is of moderate occurrence: young mature turtles (curved carapace length = 85 cm) are most frequently affected. Fibropapilloma adversely affects health of turtles. Fluke infestation seems not to be a causal factor, but viral infection, perhaps with concurrent stress of environmental origin, seems likely.

Efficacy of praziquantel in the treatment of green sea turtles with spontaneous infection of cardiovascular flukes.

OBJECTIVE: To assess the efficacy of praziquantel as a treatment for cardiovascular flukes in turtles. PROCEDURE: Six green sea turtles (Chelonia mydas) spontaneously infected with cardiovascular flukes (Digenea: Spirorchiidae) were treated orally with praziquantel, and necropsied 3 or 7 days later to look for flukes in the heart and major blood vessels. Six similar animals were maintained as untreated controls. RESULTS: Absence of flukes in treated, but not control turtles, indicated that a one day course of treatment at a dose rate of 3 x 50 mg/kg body weight is effective. CONCLUSION: This result should be of value for preventing disease in wild caught green turtles introduced into farms or aquaria.

Relationship of blood corticosterone, immunoglobulin and haematological values in young crocodiles (Crocodylus porosus) to water temperature, clutch of origin and body weight.

OBJECTIVE: To examine whether sub-optimal temperature induced stress and immunosuppression in farmed saltwater crocodile (Crocodylus porosus) hatchlings. DESIGN: A clinico-pathological study. ANIMALS: A total of 140 hatchlings were used. PROCEDURE: Body weight and length, plasma corticosterone and immunoglobulin concentrations and total and differential white blood cell counts were measured in 140 hatchlings from five clutches divided between five water temperature treatment groups. Initially all groups were housed at 32 degrees C for 10 weeks, then two groups (L, LC) were changed to low temperature (28 degrees C) and two groups (H, HC) to high temperature (36 degrees C), while one group (C) remained at 32 degrees C. The LC and HC groups were maintained at these temperatures for 10 days, after which the water temperature of both groups was returned to 32 degrees C. Blood samples were collected twice (at 6 and 9 weeks of age) before the initial temperature change, and at 10 days and 4 weeks after the initial temperature change (at 11.5 and 14 weeks of age). RESULTS: Except for an increase in plasma corticosterone in the HC group and a decrease in the L group when the temperature change was first introduced, changes in plasma corticosterone were not significant. There were no significant changes in immunoglobulin concentrations. There were, however, significant decreases in the total white cell and lymphocyte counts in the LC group after the temperature was decreased to 28 degrees C, and an increase in these counts after water temperature was returned to 32 degrees C. Clutch of origin had significant effects on body weight and length gains, and there were negative relationships between body weight and corticosterone concentrations and between body weight and immunoglobulin concentrations. CONCLUSIONS: As haematological changes indicative of stress were not associated with significant changes in serum corticosterone, immunosuppression in young crocodiles may be independent of the hypothalamic-pituitary-adrenal cortical axis.

Pathology of mucormycosis of cane toads in Australia.

The gross and microscopic pathology of a fungal septicaemia caused by the zygomycete. Mucor amphibiorum in 27 free-ranging cane toads, Bufo marinus, in Australia is described. Seven of the 27 toads had clinical signs of illness when discovered and five of these seven were moribund. Multiple granulomas were found in many organs, and in massive infections granulomas tended to coalesce. Liver, spleen, kidneys, urinary bladder, heart and lung were most commonly involved, but granulomas also occurred in subcutaneous lymph spaces, skin, gastro-intestinal tract, voluntary muscle, bone, cranial cavity and the oral cavity. Single lesions appeared grossly as a lemon coloured nodule < or = 5 mm in diameter. Histologically, the primary lesion was a granuloma composed of multinucleate giant cells, macrophages, occasional lymphocytes and eosinophils surrounding the distinctive sphaerules of M. amphibiorum. Fibroblasts occurred in greater numbers at the periphery and collagen formed a dense fibrous capsule around some nodules. A less common lesion resembled a microabscess and consisted of mononuclear cells, neutrophils and eosinophils surrounded by macrophages. Many of the centrally placed mixed inflammatory cells appeared necrotic. This reaction appeared to be more acute. Both types of lesions sometimes occurred concurrently, but the latter was less common. The pattern of lesions and natural history of M. amphibiorum suggested that ingestion of contaminated soil may have been the route of infection.

The immunopathology of unilateral vasectomy in the ram.

This study investigated the relationship between the local (spermatic granuloma) and systemic events after unilateral vasectomy in six rams. Spermatic microgranulomas were first observed at 4 weeks post vasectomy (PV), at which time lymphocytes, chiefly CD4+ (helper/inducer) cells, were incorporated into the periphery of the phagocytic wall. Although plasma cells accumulated around blood vessels near these early granulomas, they were not incorporated into them. All sectioned vas deferens contained additional microscopic spermatic granulomas away from the point of sectioning, as did one-third of cauda epididymides on the vasectomised side. There were significant (P < 0.001) increases in T-lymphocytes, especially CD4 cells and plasma cells (chiefly IgG-containing) within the granulomas at each successive PV interval. Concurrent enzyme-linked immunosorbent assay indicated initial presence of IgG and IgM antisperm antibody in serum between 2 and 4 weeks PV. There were significant increases of IgG (P < 0.01) and IgM (P < 0.001) throughout the experiment but IgA antisperm antibody was negligible.

Major histocompatibility complex antigens in normal, acanthotic and neoplastic ovine skin: an association been tumor invasiveness and low level MHC class I expression.

The distribution and density of ovine MHC class I and class II antigens in normal, acanthotic and malignantly transformed ovine skin was investigated using monoclonal antibodies and an immunoperoxidase technique. The subjects were sheep that had been exposed to high levels of sunlight for more than 6 years. The expression of MHC class II antigens in the plasma membrane of cells within the normal epidermis was restricted to basally located dendritic and mononuclear cells. Normal keratinocytes did not express MHC class II antigens. However, we observed low levels of intracellular MHC class II expression in both acanthotic and neoplastic keratinocytes. Expression of MHC class I antigens was variable in normal and acanthotic epithelium; it was usually present, but of low intensity in very early ovine squamous cell carcinoma and was increased in small, but morphologically typical, tumors. Tumors originating on the nose, which are more invasive than those on the ear, were found to express significantly less MHC class I (P < 0.05). Thus, an association between tumor invasiveness and low level expression of MHC class I was apparent. This may have diagnostic value and highlights a mechanism by which neoplastic cells may evade immune surveillance by T cells.

Diseases in young farmed crocodiles in Irian Jaya.

Thirty-eight young crocodiles that were emaciated and were euthanased or were found dead on 12 farms in Irian Jaya were examined post mortem. Major diseases were coccidiosis (nine crocodiles), pentastomiasis (four), visceral gout (two) and bacterial pneumonia and septicaemia (two). Other diseases and infections were steatitis, fungal pneumonia, gastric capillariasis, haemogregarine infection, ascariasis, filarioid infection and the presence of flukes in the intestine, kidney and blood. Multiple parasitism due to the collection of hatchlings in the wild was considered the primary cause of the ill-thrift and death of the crocodiles.

The distribution of lymphocyte subpopulations in normal and acanthotic ovine skin.

The prevalence and distribution of lymphocyte subpopulations in normal and acanthotic ovine skin were investigated using monoclonal antibody immunocytochemistry. CD8+ cells were predominant in the epidermis of both normal and acanthotic skin, but were CD8+ cells, CD4+ cells and T19+ cells infrequent in normal epidermis. Within the dermis of normal skin, there were significantly greater numbers of CD4+ and T19+ cells situated around the superficial dermal vessels than in any other region examined. The majority of the CD8+ cells adjoined vessels, but the proportion that did not was greater for CD8+ than for CD4+ or T19+ cells. The CD4+ and CD8+ subsets were represented equally in adnexa. T cells were of memory phenotype. B cells and naive T cells, both of which express the CD45RA antigen, were rarely seen and tended to be associated with vessels in both normal and acanthotic skin. None of the T19+ cells (which are gamma delta+) resembled the dendritic gamma delta cells seen in murine epidermis. Acanthotic skin was strikingly different to normal skin. There was a greater abundance of T cells, particularly CD4+ cells, in acanthotic epidermis and the numbers of CD8+ and T19+ cells, and to a greater extent CD4+ cells, were greater at the dermal-epidermal junction. There were more CD4+ and CD8+ cells in the superficial dermal stroma of acanthotic skin. Within the dermis of acanthotic skin, T cells were concentrated near vessels but the apportioning of T cells between stromal/adnexal and vessel-associated sites differed from normal. Such observations suggest that migration away from perivascular sites and into the stroma may be controlled separately for subregions of skin and for each T cell subset. The role of this altered nonrandom migration of T cells in skin chronically exposed to ultra violet radiation is uncertain.