Clinical and Pathological Findings of Necrotizing Meningoencephalitis in a Maltese Dog

Brazilian Journal of Veterinary Pathology, Vol. 6, n. 1 - March 2013, p.31-36

http://www.abpv.vet.br/upload/documentos/DOWNLOAD-FULL-ARTICLE-09-20881_2013_4_5_17_11.pdf

Rodrigo M. Couto, Silvia A. França, Marina A. Rios, Isabel R. Rosado, Paula M. Costa, Roselene Ecco - UFMG

Abstract: A 2-year-old, intact female Maltese dog was presented to the veterinarian with a history of acute neurological signs. On neurological examination the dog showed deficit of mental status (apathy and depression), seizures, constant howling, head turn and compulsive circling to the right side and falls to the left side. The treatment protocol using prednisolone (for seizures remission) and cyclosporine (initiated in the chronic stage) did not stop the progression of the disease and euthanasia was elected 65 days later. Necropsy revealed mild cerebral asymmetry, and in the frontal (more affected) parietal and occipital lobes of the right hemisphere there were friable, depressed and yellowish areas characterizing malacia. The left contralateral frontal lobe was edematous and slightly yellowish. At histopathology, the lesions were characterized by marked, multifocal to coalescing necrotizing meningoencephalitis, characterized by focally extensive areas of malacia, especially in the cortex of the frontal and right parietal lobes. Extension of lesions to white matter was observed only in the caudal region of the right frontal lobe. Plasma cells and lymphocytes infiltration was observed around vessels, leptomeninges and in the neuroparenchyma. In addition, the non-cavitation areas were also characterized by neuropil vacuolization, neuronal necrosis, neuronophagia, astroglyosis with various gemistocytes, endothelial hyperplasia and hypertrophy. The immunohistochemical analysis showed predominance of CD3 positive T lymphocytes in proportion to CD79 positive cells. Clinical signs, character and distribution of neurological lesions were compatible with necrotizing meningoencephalitis (NME). This condition, initially reported only in Pugs, currently affects other breeds and attention should be given to the differential diagnosis with other neuropathies in dogs.

Aspectos epidemiológicos, clínicos e anatomopatológicos da infecção por Gurltia paralysans em gatos

Pesq. Vet. Bras. 33(3):363-371, março 2013 
 http://www.pvb.com.br/pdf_artigos/13-04-2013_17-08Vet%201395_3097%20PA.pdf

Monique Togni,  Welden Panziera, Tatiana M. Souza,  José C. Oliveira Filho, lexandre Mazzanti,  Claudio S.L. Barros  e Rafael A. Fighera

Abstract: In the last 20 years, an unknown neurological disease affected cat populations in the  Western Border Region of the State of Rio Grande do Sul, Brazil. The onset of the disease  was characterized by tail paralysis, followed by progressive paraparesis in the pelvic limbs,  difficulty in ambulation and proprioceptive ataxia. After long prolonged clinical courses  (12-24 months), when then affected cats became severely paraparetic and start to develop pressure sores do to decubitus, they were destroyed by the owners. At necropsy there  were variable degrees of skeletal muscle atrophy of the pelvic muscles and some degree of  reddening of the meninges at the level of T10-L7, due to the presence of a myriad of small  blood vessels, as a typical varicose lesion that resembled a vascular hamartoma. Histologically, such lesions consisted of distension of the subarachnoid space due to a collection of  dilated, blood-filled, tortuous blood vessels the lumina of which were  occasionally partially  or completely occluded by thrombi. Those varices were randomly surrounded by a lymphocytic or granulomatous inflammatory infiltrate with small foci of mature eosinophils. 

In the lumina of these varicose venules cross and longitudinal sections of nematode parasites could be observed. Based on the morphology of these parasites, in their anatomical  localization (meningeal blood vessels) and in the species (cat) affected the nematode was  identified as Gurltia paralysans. This paper describes detailed aspects of the epidemiology,  clinical disease and pathology of this intriguing feline myelopathy and the definitive diagnosis of the condition: Feline crural parasitic paraplegia, a disease first described in Chile  in the 1930’s and now, for the first time, in Brazil.

Resumo: Nos últimos 20 anos, uma doença neurológica  desconhecida acometeu populações de gatos da Região da  Campanha do RS e tornou-se um desafio diagnóstico para os  veterinários locais. Os gatos afetados desenvolviam inicialmente paralisia da cauda, seguida de paraparesia progressiva nos membros pélvicos, alteração da marcha, posição  plantígrada e ataxia proprioceptiva. Após longos períodos  de evolução clínica (12-24 meses), quando se tornavam  marcadamente paraparéticos e começavam a apresentar  escaras de decúbito, eram sacrificados pelos proprietários.  Na necropsia, demonstravam graus variados de atrofia dos  músculos pélvicos e algum grau de avermelhamento das  meninges entre T10 e L7, devido à presença de miríades de pequenos vasos sanguíneos, uma típica lesão varicosa,  semelhante a um hamartoma vascular. Histologicamente,  tais lesões consistiam de distensão do espaço subaracnóideo por vasos sanguíneos dilatados e tortuosos, repletos de  sangue e, ocasionalmente, de trombos, que ocluíam parcial  ou totalmente seus lúmens. Essas varizes venulares eram  aleatoriamente circundadas por infiltrado inflamatório  granulomatoso ou linfocítico com pequenos focos de eosinófilos maduros. No lúmen das vênulas varicosas havia secções transversais e longitudinais de parasitos. Com base na morfologia desses parasitos, em sua localização anatômica  (vasos sanguíneos meníngeos) e na espécie afetada (gato),  o nematódeo foi identificado como Gurltia paralysans. O  objetivo desse trabalho é apresentar em detalhes os aspectos epidemiológicos, clínicos e anatomopatológicos dessa  intrigante mielopatia de gatos e estabelecer definitivamente seu diagnóstico definitivo: paraplegia crural parasitária  felina, uma doença descoberta no Chile, na década de 1930,  e agora, pela primeira vez, descrita no Brasil.