Ocular Lesions in Red-Tailed Hawks ( Buteo jamaicensis) With Naturally Acquired West Nile Disease.

Ocular lesions are common in red-tailed hawks with West Nile (WN) disease. These lesions consist of pectenitis, choroidal or retinal inflammation, or retinal necrosis, but detailed investigation of the ocular lesions is lacking. Postmortem examination of the eyes of 16 red-tailed hawks with naturally acquired WN disease and 3 red-tailed hawks without WN disease was performed using histopathology, immunohistochemistry for West Nile virus (WNV) antigen, glial fibrillary acid protein, cleaved caspase-3, and the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling method. Retinal lesions were classified as type I or type II lesions. Type I lesions were characterized by lymphoplasmacytic infiltrates in the subjacent choroid with degeneration limited to the outer retina (type Ia lesion) or with degeneration and necrosis of the outer retina or outer and inner retina (type Ib lesion) while retinal collapse, atrophy, and scarring were hallmarks of type II lesions. Type II retinal lesions were associated with a more pronounced choroiditis. Although not statistically significant, WNV antigen tended to be present in larger quantity in type Ib lesions. Type I lesions are considered acute while type II lesions are chronic. The development of retinal lesions was associated with the presence of an inflammatory infiltrate in the choroid. A breakdown of the blood-retina barrier is suspected to be the main route of infection of the retina. Within the retina, virus appeared to spread via both neuronal and Müller cell processes.

Disseminated toxoplasmosis in magpie geese (Anseranas semipalmata) with large numbers of tissue cysts in livers.

Fatal disseminated Toxoplasma gondii infection was diagnosed in 2 captive magpie geese (Anseranas semipalmata) from a zoo in Texas. Both geese died suddenly, without apparent clinical signs. Lesions associated with T. gondii tachyzoites were seen in lungs, pancreas, liver, adrenals, bursa of Fabricius, spleen, brain, and kidneys. Toxoplasmic pneumonia and hepatitis were considered to be the primary cause of death. An unusual feature was the presence of numerous tissue cysts in hepatocytes of both geese. The diagnosis was confirmed immunohistochemically. Antibodies to T. gondii were found in 2 of 11 other geese from the zoo examined using the modified agglutination test. This is the first report of T. gondii infection in magpie geese (Anseranas semipalmata).

Lymphocytic gastritis--prospective study of its relationship with varioliform gastritis.

Lymphocytic gastritis is a new histopathological entity characterised by a dense lymphocytic infiltration of surface and pit gastric epithelium. Previous retrospective work has suggested that lymphocytic gastritis is related to an endoscopic form of gastropathy comprising enlarged folds, nodules and erosions, commonly denoted as varioliform gastritis. In the present prospective study, the relationship is clearly shown; nearly 82% (54/66) of the varioliform gastritis observed in four different endoscopy units correspond histologically to lymphocytic gastritis. The correlation is even better if cases showing strictly antral localisation are excluded (53/55) - that is, more than 96%. The histological concept of lymphocytic gastritis seems, however, to extend beyond varioliform gastritis as of 67 cases of lymphocytic gastritis diagnosed during the period under study, one third had no particular endoscopic expression.