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M.N. Novilla

Publications and source records attributed to M.N. Novilla.

14 recordsLinked to original sources

Parental development of Eimerian coccidia in sandhill and whooping cranes

In contrast with isosporoid species of coccidia that have established extraintestinal phases of development, the eimeriids, except for a few species, generally have been considered inhabitants of the intestinal tract. Eimeria infection in sandhill cranes ( Grus canadensis ) and whooping cranes ( G. americana ) may result in disseminated visceral coccidiosis. Nodules were observed in the oral cavity of 33% (n = 95) of the G. canadensis at the Patuxent Wildlife Research Center (PWRC) in Laurel, MD. Necropsy of six of the afflicted cranes revealed granulomatous nodules in many tissues and organs. Histologic studies disclosed protozoan organisms morphologically resembling schizonts in the granulomas, and endogenous stages of coccidia were present in the intestines of four birds. Fecalysis of three of four sandhill cranes yielded oocysts of E. reichenowi and E. gruis. Only E. reichenowi -type oocysts were recovered from a dead whooping crane sample. Domestic broiler chicks each intubated with about 1 times 10 6 pooled sporulated oocysts of E. reichenowi and E. gruis were not infected. Exposure of six incubator-hatched and hand-reared sandhill crane chicks to oocysts artificially (two chicks) and naturally (four chicks) resulted in typical infection of intestinal epithelium with invasion of subepithelial tissues extending to the muscular layer and widespread extraintestinal development. Asexual and sexual stages occurred primarily in macrophages in the liver, spleen, heart, and lung. In the lung, oocysts were found in bronchial exudate and epithelial lining cells. Six of ten G. canadensis chicks, one adult G. americana , and three of five G. americana chicks that died naturally at PWRC had disseminated visceral coccidiosis.

Journal of Protozoology↗

Pulmonary lesions in disseminated visceral coccidiosis of sandhill and whooping cranes

Fifty cranes, consisting of 46 sandhill (Grus canadensis) and four whooping cranes (Grus americana), were studied. Eighteen sandhill cranes and the four whooping cranes were naturally infected with disseminated visceral coccidiosis (DVC). The remaining sandhill cranes were chicks experimentally infected with oocysts of Eimeria reichenowi and/or E. gruis; five chicks served as controls. There were no clinical signs attributed to respiratory infection. Necropsy of naturally infected adult birds revealed nodules in many organs, including the lung, air sacs, trachea and nares. Artificially infected sandhill cranes and the whooping crane chicks that died from DVC had congestion and consolidated areas in the lung with frothy fluid in the airways. Grossly visible nodules were observed from 10 days postinoculation. Granulomatous pneumonia and tracheitis were observed with light microscopy. Lesions were associated with merogonic and gametogonic stages of eimerian coccidia. Granulomas and granulomatous foci contained parasitized large mononuclear cells. Merogonic stages were seen in lymphoid cells by ultrastructural examination. Oocysts were observed in the trachea and bronchial mucosa and admixed with exudate in the airways, indicating that crane eimerians can complete their life cycle at these sites. Of the few eimeriid coccidia that have extraintestinal stages of development in birds and mammals, only the species in cranes complete their life cycle in both the digestive and respiratory tracts.

Journal of Wildlife Diseases↗

Disseminated visceral coccidiosis in sandhill cranes

Disseminated visceral coccidiosis (DVC) caused by Eimeria spp was first recognized as a disease entity in captive sandhill cranes (Grus canadensis) and whooping cranes (G americana) at the Patuxent Wildlife Research Center. Because cranes produced at the Center are reintroduced to the wild to augment wild populations, studies involving both experimentally induced and natural infections were initiated to determine the potential or actual occurrence of DVC in wild Gruidae. Nine sandhill cranes dosed orally with eimerian oocysts of wild origin developed lesions characteristic of DVC. Extraintestinal granulomas associated with developing schizonts were found in 6 birds. Similar lesions were observed in wild sandhill cranes throughout parts of midwestern United States, Alaska, and Saskatchewan. These studies revealed the wide geographic distribution and the high frequency of occurrence of DVC in wild cranes.

Journal of the American Veterinary Medical Associa↗

Metastatic, papillary cystadenocarcinoma of the mammary gland in a black-footed ferret

A simple, papillary cystic adenocarcinoma of the mammary gland with metastases to the internal iliac and mesenteric lymph nodes, liver, and spleen was observed in a 12 to 13 year old female black-footed ferret (Mustela nigripes). Histologically, the tumor was aggressive, and lymphatic invasion was found. Attempts at virus isolation were negative. Other findings were bilateral infarcts in the kidneys, apparently resulting in acute renal shutdown and death, multiple thrombi in the right atrium, aortic arteriosclerosis, and focal interstitial pneumonia.

Journal of Wildlife Diseases↗

Disseminated visceral coccidiosis in whooping cranes

Three 13- to 18-day-old whooping cranes (Grus americana) and a 9-year-old whooping crane died in outdoor pens at the Patuxent Wildlife Research Center. The deaths were associated with an overwhelming systemic infection by an intracellular protozoan parasite, which resulted in enteritis, granulomatous bronchopneumonia, hepatitis, splenitis, and myocarditis. The clinical, histopathologic, and electron microscopic findings were similar to those in sandhill cranes (Grus canadensis) at the Patuxent Center found to be infected with Eimeria reichenowi and E gruis. Since these eimerian species also parasitize wild whooping cranes, this parasite might be an important pathogenic agent for this species.

Journal of the American Veterinary Medical Associa↗

Diet-related die-off of captive black-crowned night herons

Several species of herons, which are top-level consumers in aquatic food chains, have experienced population declines in certain areas o f their normal range (7,13) -- areas in which elevated levels of various environmental pollutants are known to occur. (6) To determine the effects of environmental contaminants on the Ardeidae, a colony of black-crowned night herons (Nycticorax nycticorax) was established in 1972 at the Patuxent Wildlife Research Center. The night heron was selected as the model species because of its widespread occurrence and its ability to survive and reproduce in captivity. Birds for the colony were obtained from either the New York Zoological Park and Dallas Zoo or were wild-caught along the Maryland and Virginia coasts in 1972, 1973, and 1975. This report describes a die-off in the colony following a change in the origina of their food source. The data suggest that the mortality was diet-related, most likely caused by vitamin E deficiency. Excessive dietary thiaminase may have resulted in concurrent thiamine deficiency, but evidence for this is equivocal.

American Association of Zoo Veterinarians, Annual ↗

Disseminated granulomas caused by an unidentified protozoan in sandhill cranes

Oral granulomas were observed in 31 (33%) of 95 captive sandhill cranes (Grus canadensis) at the Patuxent Wildlife Research Center. Necropsy of six of the afflicted cranes revealed granulomatous nodules throughout many of their organ systems. Intracellular protozoan organisms morphologically resembling schizogonic stages were observed within the granulomas by light and electron microscopy. Sexual and asexual stages of coccidia were seen in sections of the intestines of 4 of 5 cranes examined microscopically, and Eimerian oocysts were seen in fecal flotation specimens from 3 of 4 birds.

Journal of the American Veterinary Medical Associa↗

Diabetes mellitus in a black-footed ferret

Diabetes mellitus was tentatively diagnosed in a black-footed ferret with polyuria, polydipsia, polyphagia, dehydration, and weight loss. Laboratory findings (marked hyperglycemia (724 mg/100 ml), glycosuria, and ketonuria) and the subsequent favorable response to insulin therapy confirmed the diagnosis. Although lesions were not observed in the pancreas, gross and histologic findings concomitant with diabetes mellitus included arteriosclerosis, with calcification of the aorta and other major vessels; mild necrotizing hepatitis; and mild proliferative glomerulonephritis. A perineal adenocarcinoma, with metastasis to an internal iliac lymph node, was an incidental finding. Special stains demonstrated adequate numbers of beta cell granules in the islets of Langerhans. Thus, the diabetes was apparently due to a lack of release of the synthesized insulin or to diminished effectiveness of the secreted insulin.

Journal of the American Veterinary Medical Associa↗

Fatal vaccine-induced canine distemper virus infection in black-footed ferrets

Four black-footed ferrets that were live-trapped in South Dakota and transported to the Patuxent Wildlife Research Center died within 21 days after vaccination with modified live canine distemper virus. Immunofluorescence, European ferret inoculation, virus isolation attempts, and serum-neutralization tests indicated insufficient attenuation of the vaccine for this species.

Journal of the American Veterinary Medical Associa↗