Neoplasmas encefálicos em cães idosos / Brain Neoplasms in Elderly Dogs

Acta Scientiae Veterinariae, 2019. 47(Suppl 1): 384

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Carolina da Fonseca Sapin, Cristina Gevehr Fernandes, Márcia de Oliveira Nobre & Fabiane Borelli Grecco

Background: The prevalence of intracranial neoplasms in dogs represents 2.1 to 4.0% of the cases. Brain tumors may be primary or metastatic. The objective of this study was to describe two cases of intra encephalic neoplasia in elderly dogs received for necropsy by the Veterinary Oncology Service in the Federal University of Pelotas. 

Cases: 

Case 1: A 12-year-old female canine, without breed and medium size, was received for necropsy. The animal has had behavioral changes. Macroscopic examination of the encephalus revealed asymmetry and congestion. The organs were collected and fixed in 10% formalin. In the brain cleavage we noticed an extensive brown-gray mass with reddish areas, expansive, moderately demarcated, soft to cut and discrete hydrocephalus. Serial fragments of the brain and fragments of the organs were sent for processing. The slides were stained with the hematoxylin and eosin technique for histopathological analysis. At the microscopic examination, cuboidal cells were observed in the encephalus sometimes in acinar arrangements, of extensive and very limited pattern, diagnosed as ependymoma. Case 2: It is a 15-year-old, female Poodle dog, with several tumors. During necropsy multiple subcutaneous nodules, mesentery, intestinal serosa, stomach and liver were noticed. At the cut these were firm and whitish. No macroscopic changes were observed in the other organs. Fragments of organs and brain were collected and a serial section of the encephalus was performed for further processing and histological analysis. In the histopathological analysis the masses were constituted by proliferation of sometimes rounded cells, elongated, with rounded nuclei and eosinophilic cytoplasm, allowing the diagnosis of mesothelioma. The same cell pattern was observed in other organs. In the frontal cortex of the encephalus there were small foci of cells similar to those observed in the mesentery, as well as metastatic emboli in the meningeal and encephalic vessels, characterizing the diagnosis of metastatic mesothelioma. 

Discussion: Neoplasms of the central nervous system may be primary or metastatic. The ependymoma observed in case 1 was only diagnosed after visualization of the encephalic mass during necropsy, pointing to the importance of postmortem examination. Brain neoplasms in dogs occur with a frequency and variety similar to that of humans. Most of these are found in older dogs, and 95% of those affected are over five years of age. One situation that may occur in ependymomas is the development of obstructive hydrocephalus by the expansion of the neoplasm into the ventricular system. The animal studied in case 1 presented behavioral changes for weeks before death, and at necropsy ventricular dilation was evidenced, suggesting that hydrocephalus had occurred and the behavioral changes due to tumor localization. Metastatic brain neoplasms occur due to the hematogenous spread of many tumors. The species in which the metastatic neoplasms are most commonly described is the canine. Metastases of mesotheliomas in the central nervous system are rare, which reinforces the need for a thorough postmortem examination, as evidenced in the second case of this study, since the animal did not manifest clinically signs of neurological involvement and the metastasis was only identified microscopically by serial cuts of the encephalon. It can be concluded that detailed, systematic and serial post-mortem examination of the central nervous system should be part of the diagnostic routine even if no clinical neurological signs are evident. The reports presented here are of importance since they are considered rare diagnoses of primary and metastatic brain tumors.

Neuropathic pain and prognosis of a dog submitted to limb amputation after diagnosis of soft tissue sarcoma - case report

Arq. Bras. Med. Vet. Zootec., v.71, n.4, p.1116-1120, 2019

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M.G.P.A. Ferreira , A.V. Antunes , A.L. Pascoli , T.L. Nazaret  , A.P. Gering , N.P. Reis Filho , M.T. Costa , A.B. Nardi

Neuropathic pain occurs when there is a lesion or a dysfunction of the nervous system. Humans and veterinary patients may develop neuropathic pain, but in veterinary it is not often reported probably because of its mistaken diagnosis. A canine patient was admitted to the Veterinary Hospital of UNESPJaboticabal-SP, Brazil with a nodule on the left thoracic limb. The nodule was surgically removed, and histopathological analysis demonstrated the tumor was a soft tissue sarcoma (STS) and the margins were not clean. Based on the patient’s health condition and the lack of suitable equipment, the next procedure was limb amputation. The patient received analgesic medication in the post-surgery period; nevertheless, clinical signs of neuropathic pain were present, such as compulsive licking and other behavioral disorders. Medications were administered for forty days, but clinical signs ceased only when replaced with a tryciclic antidepressant drug, Amitriptyline. Therapeutic management of the patient in this report can be considered effective, since five years after the end of the treatment there was no recurrence or presence of metastasis. 

Dor neuropática e prognóstico de um cão submetido à amputação de membro após diagnóstico de sarcoma de tecidos moles - relato de caso

A dor neuropática ocorre quando há uma lesão ou disfunção do sistema nervoso. Tanto pacientes humanos quanto veterinários podem desenvolver a dor neuropática, mas na medicina veterinária ela é pouco relatada provavelmente por não ser corretamente diagnosticada. Um paciente canino foi atendido no Hospital Veterinário da Unesp-Jaboticabal, SP, Brasil, com um nódulo em membro torácico esquerdo. O nódulo foi removido cirurgicamente, e o exame histopatológico evidenciou a presença de sarcoma de tecidos moles (STM) e de margens comprometidas. Baseando-se nas condições de saúde do paciente e na ausência de equipamentos adequados, o próximo procedimento foi a amputação do membro. No pós-cirúrgico, o animal recebeu medicações analgésicas, todavia, mesmo assim, apresentava sinais de dor neuropática, como lambedura compulsiva e outros distúrbios comportamentais. O tratamento para dor aguda se estendeu por 40 dias; no entanto, os sinais clínicos cessaram apenas quando os analgésicos comuns foram substituídos por um medicamento antidepressivo tricíclico, a amitriptilina. O manejo terapêutico do paciente do presente relato pode ser considerado satisfatório, uma vez que, após cinco anos do término do tratamento, não houve recidiva nem presença de metástase. 

Encefalite parasitária em cadela

Acta Scientiae Veterinariae, 2019. 47(Suppl 1): 431.

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Lygia Silva Galeno , Brenda Lurian do Nascimento Medeiros , Sávio Matheus Reis de Carvalho , Vanessa Brígida Pinheiro Rodrigues, Pablo Martins Veloso de Sousa , Joanna Jéssica Sousa Albuquerque , Bruno Martins Araújo & Francisco Lima Silva

Background: Encephalitis is common in most inflammatory and infectious diseases of the central nervous system, and bacterial and viral pathogens, protozoa, fungi, and erythematous parasites are recognized as etiological agents. Clinical signs vary according to the anatomical location and severity of the inflammation. Some parasites may undergo aberrant migration into the brain of dogs and cats, which is are considered a rare clinical phenomenon. This case report describes the occurrence of parasitic encephalitis in a mixed breed bitch about 4 year-old. 

Case: A mixed breed bitch, about 4 year-old, rescued from the street with weakness of the pelvic limbs, was treated at the Veterinary Hospital of the Federal University of Piauí - UFPI. After A clinical and neurological examination, the patient was hospitalized for diagnosis, treatment, confirmation and follow-up of her clinical evolution. Complementary tests were performed to evaluate her general condition, given her unknown history because she was a rescue dog. Complete blood count (CBC), hemoparasite screening, biochemical function (urea, creatinine, ALT, alkaline phosphatase, total protein, albumin and globulin), abdominal and pelvic ultrasound, serological and parasitological tests for leishmaniasis, distemper antigen and ehrlichiosis antibody detection tests were performed, and cerebrospinal fluid (CSF) was collected for analysis. The CBC revealed normocytic hypochromic anemia and thrombocytopenia. Biochemical functions were within normal limits, except for alanine aminotransferase (ALT), which was slightly low. The ultrasound examination showed splenomegaly. The canine distemper, ehrlichiosis and leishmaniasis tests were negative. The results of the CSF analysis revealed the presence of spherical structures compatible with parasitic cysts, suggestive of Echinococcus granulosus. After the laboratory diagnosis of parasitic encephalitis, the animal was treated with prednisolone, albendazole, praziquantel and doxycycline. Three days after starting treatment for parasitic encephalitis, the patient presented significant clinical improvement, began to feed again and to move around.

Discussion: The presence of parasitic cysts in cerebrospinal fluid is uncommon; however, encephalitis due to aberrant parasite migration has been described in dogs and cats. The migration and growth of the parasite causes extensive damage to the neural parenchyma. The clinical signs of worm encephalitis tend to show acute to super-acute onset, and the definitive diagnosis depends on the identification of the parasitic agent in the patient’s brain. This type of diagnosis has so far been performed only during necropsy. In the case reported here, parasitic cysts were identified in CSF, thus confirming and formulating a definitive diagnosis. It is rare to find microorganisms and tumor cells in samples of cerebrospinal fluid; however, if this occurs, a definitive diagnosis can be formulated. The use of cerebrospinal fluid is therefore an important diagnostic tool when other imaging tests such as tomography and magnetic resonance provide limited access. Praziquantel and Albendazole are recommended for the treatment of Echinococcus, prednisolone is recommended for cases of encephalitis, and prophylactic antibiotic therapy is used to prevent secondary bacterial meningoencephalitis. The recommended treatment was efficient for this patient, and could be adopted to treat other dogs with parasitic encephalitis. The main forms of prevention in dogs are periodic worming, and the ingestion of only processed or cooked foods and treated water.