Luiz Cesar Bello Fallavena

Diagnosis of skin lesions in condemned or downgraded broiler carcasses — a microscopic and macroscopic study

Eight hundred skin samples from broiler carcasses condemned or downgraded for skin lesions were collected at five processing plants. Histologically, 45.25% were cellulitis, 19.00% were atypical fowlpox, 3.25% were dermal squamous cell carcinoma (DSCC), 17.00% were non-specific dermatitis, 0.5% were focal haemorrhages and 0.25% were haemangiomas. Of the samples, 14.75% were histologically normal. Macroscopically, increased thickening of the skin was a frequent finding occurring in all the skin diseases, as well as skin discoloration, dark nodules in feather follicles and crusts. Skin scratches were associated with all of the diseases, except DSCC. Crater-like ulcers occurred in DSCC and fowlpox. Cellulitis was more frequent on the abdomen, fowlpox on the dorsum, DSCC in thighs, and non-specific dermatitis on the dorsum, thighs, legs and breast. It was concluded that macroscopic changes are not specific and examinations at slaughterhouses do not allow classification of broiler skin diseases. Histological examination appears to be an important tool to provide more accurate data.

Presence of avipoxvirus DNA in avian dermal squamous cell carcinoma

Dermal squamous cell carcinoma (DSCC; avian keratoacanthoma) is a neoplastic skin lesion of broiler chickens of unknown aetiology. In previous studies, the possibility of the involvement of pox viruses in the cause of DSCC was considered. In this work, a sensitive and specific nested polymerase chain reaction (PCR) protocol was developed that could amplify a 419 base pair DNA fragment of fowlpox virus with a detection limit of less than one infectious unit. Fowlpox virus DNA was always detected in skin samples with fowlpox lesions while it was not detected in samples of unrelated diseases such as cowpox, Mareks disease or infectious laryngotracheitis. Some macroscopically normal skin samples from vaccinated and non-vaccinated birds also produced PCR-positive results, corroborating previous studies on the possibility that a latent or chronic form of fowlpox occurs. Fowlpox virus DNA was consistently detected from DSCC skin lesions, and this finding is discussed.

DERMATITE ESTAFILOCÓCICA EM OVINO NO RIO GRANDE DO SUL

SUMMARY A case of Staphylococcal Dermatitis is presented and discussed. The macroscopic and microscopic lesions found are described as well as the characteristics of Staphylococcus aureus strain isolated.

Listeriose em rebanho de ovinos leiteiros na região serrana do Rio Grande do Sul: relato de caso

Clinical cases of listeriosis in two Lacaune rams, fed silage in a lot, are reported. Histological examination of nervous tissue revealed purulent meningoencephalitis, and L. monocytogenes was detected in nervous tissue by immunohistochemistry procedures. This disease should be suspected when oral lesions are visible in dairy sheep fed low quality silage.

Evaluation of bursal lymphoid depletion: comparison between the conventional histology method and digital lymphocyte depletion evaluation system

Fifty-five bursa of Fabricius (BF) were evaluated by optical microscopy for three different avian histopathologists (H1, H3 and H4) to determine the degree of lymphoid depletion. One histologist evaluated the same slides at two different times (H1 and H2) with four-months interval between the observations. The same BFs were evaluated using the system of Digital Lymphocyte Depletion Evaluation (ADDL), being performed by three differents operators of the system, not histopathologists. The results showed was a significant difference between the histopathologists and between the scores established by the same expert (H1 and H2). However, there were not significant differences between the scores with the ADDL system, obtained using ADDL. The results make clear the fragility of the subjective lymphocyte depletion score classification by the traditional histologic method, while the ADDL system proves to be more appropriated for the assessment of the lymphoid loss in the BF.

Infestação simultânea por Cytodites nudus e Laminosioptes cysticola e seus aspectos patológicos em galinhas de subsistência

The occurrence of Cytodites nudus and Laminosioptes cysticola mites is rare and there is no report of this simultaneous infestation in Brazilian scientific literature. C. nudus is known as the air sacs mite and may cause respiratory signs as well as pneumonia and weight loss when present in large numbers in the host. L. cysticola is found in connective tissue of galliforms and causes formation of small calcified subcutaneous nodules that can be confused with the characteristic nodules found in avian tuberculosis. In this paper are discussed the pathological findings of lesions caused by C. nudus and L. cysticola and their morphological characterization.