Anti-Leishmania spp. antibody detection in domestic cats from a visceral leishmaniasis transmission area.

Feline leishmanial infection is reported worldwide, but the epidemiological role of domestic cats in the leishmaniasis cycle remains unclear, and cats might act as cryptic reservoir hosts in endemic areas with no feline leishmaniosis cases. Considering that, a serological screening for anti-Leishmania spp. antibodies was performed by indirect immunofluorescence antibody test (IFAT) in 389 necropsied cats' serum samples from a new visceral leishmaniasis transmission area with no feline leishmanial infection reported to unveil if the cats are being exposed to the parasite. The overall seroprevalence for Leishmania spp. was 11.05% (43/389). No association was found between sex, neutering status, age group, breed, coat length, feline immunodeficiency virus (FIV) infection, and Leishmania spp. antibody detection. A positive association was found with coat color (cats within the orange spectrum with white [particolor]) (OR = 2.47, CI 95% 1 - 6.13, P = 0.044) and a negative association (OR = 0.38, CI 95% 0.18 - 0.79, P = 0.01) between feline leukemia virus (FeLV) infection and IFAT positivity for Leishmania spp. Therefore, it is concluded that the seroprevalence found was greater than 10%, indicating contact of the protozoan with cats in the region served.

Dynamics of Leishmania spp. infection in dogs from an unaffected region in transition to a visceral leishmaniasis transmission area, Rio Grande do Sul, Brazil.

In Brazil, visceral leishmaniasis (VL) has been expanding and urbanizing, mainly in non-endemic areas such as the State of Rio Grande do Sul. Considering that infected dogs are the main reservoirs of VL in urban areas, the present study aimed to evaluate the propagation of canine visceral leishmaniasis (CVL) infection from an unaffected region in transition to a VL transmission area. For this, 1159 and 1087 samples of canine serum from 2015 and 2021, respectively, were analyzed, using the indirect immunofluorescence test. In addition, necropsy reports between 2007 and 2021 were evaluated. The results showed a prevalence of anti-Leishmania spp. antibodies of 7.5% in the samples from 2015, while in 2021 samples, it was 23.5%, with an incidence of 0.4 cases per 100 dogs. It is noteworthy that in 2007, there was no record of CVL as the cause of death in the pathological reports, and in 2021, 41 diagnoses were made with the protozoan being a determinant of the death of the animal. These values indicate an increasing trend in the prevalence and incidence coefficients of CVL. The results of this study allowed us to verify the spread of the disease from an unaffected region to a transmission area of the agent, as well as provide subsidies for health authorities to implement improvements in the CVL control program in the municipality, to mitigate the emergence of human cases of the disease.

Intracranial epidermoid cyst in a cat / Cisto epidermoide intracraniano em um gato

ABSTRACT: Epidermoid cysts, also known as epidermal and keratin cysts, or congenital cholesteatomas are benign congenital non-neoplastic tumors, rarely observed in the brain of humans and some animal species (dogs, horses, mice, and rats). Histologically, they are composed of laminated, concentrically arranged keratin surrounded by a thin layer of stratified squamous epithelium. We describe a case of intracranial epidermoid cyst in a 6-year-old mixed-breed male cat in southern Brazil. The patient presented central vestibular syndrome. Given the poor prognosis and the fact that it belonged to a shelter with many dogs and cats, the owner requested euthanasia, and a thorough post-mortem examination was conducted immediately after death. The definitive diagnosis was based on histopathological findings. To the best of our knowledge, this is the first report of an intracranial epidermoid cyst in a cat.

RESUMO: Cisto epidermoide, também denominado cisto epidermal, cisto de queratina ou colesteatoma congênito é um tumor não neoplásico, benigno e congênito raramente encontrado no encéfalo de humanos e de algumas poucas espécies animais (cães, equinos, camundongos e ratos). Histologicamente, esse tumor é composto por queratina laminada concentricamente arranjada e circundada por uma fina parede de epitélio escamoso estratificado. Descreve-se um caso de cisto epidermoide intracraniano em um gato, macho, sem raça definida, de seis anos de idade, no sul do Brasil. O paciente foi encaminhado para atendimento veterinário por apresentar sinais de síndrome vestibular central. Devido ao mau prognóstico e por pertencer a um abrigo com muitos cães e gatos, o proprietário optou pela eutanásia e o paciente foi encaminhado para a realização de necropsia. O diagnóstico definitivo foi baseado nos achados histopatológicos. Pelo conhecimento dos autores, este é o primeiro relato de um cisto epidermoide intracraniano em um gato.

Histologic Evaluation of Palmar Digital Nerves after Perineural Injection of 2% Ammonium Chloride in Miniature Horses.

Neurolytic compounds are widely used by equine practitioners for the management of lameness, mostly related to the foot. The present study aimed to evaluate the neurotoxicity of 2% ammonium chloride (2% AC) applied adjacent to the palmar digital nerves in six miniature horses. The 2% AC and 0.9% saline solution were randomly injected into three and one palmar digital nerve of each horse, respectively. Nerve samples were collected by neurectomy performed under general anesthesia at 5, 12, 19, 35, 47, and 62 days after treatment, with one horse per day of surgery. The inflammatory reaction to perineural injection was evaluated by an increase of pastern superficial skin temperature through thermography 24 hours after treatments. Histological lesions were classified as absent, mild, moderate, and severe Wallerian degeneration. An increase of 2.43 ± 0.79°C and 1.69 ± 0.55°C was observed in the 2% AC and control groups, respectively (P > .05). Moreover, histologic lesions were observed after perineural injection of 2% AC (severe, n = 5/18; moderate, n = 4/18; mild, n = 5/18; and absent, n = 4/18) and saline solution (moderate, n = 3/6; mild, n = 1/6; and absent, n = 2/6) (P = .46). The 2% AC demonstrated to be as safe as 0.9% saline solution, producing mild to severe Wallerian degeneration for up to 62 days after injection with no interference in further neurectomy.

Renal intravascular lymphoma in a dog / Linfoma intravascular renal em um cão

ABSTRACT: A 10-year-old male large mixed breed dog was presented with skin ulcers and fracture on the right hind limb caused by vehicle collision. Given required limb amputation, and as being a shelter senior dog, euthanasia was requested by the owner and a complete post-mortem examination was conducted immediately after death. Gross changes were consistent with marked bilateral nephromegaly. Histopathological examination of the kidneys revealed round cells filling blood vessels. Immunohistochemically, the round cells were positive for CD3 antibody. Based on these findings, in absence of involvement of the bone marrow and peripheral blood, and inexistence of primary extravascular masses, the tumor was classified as T-cell intravascular lymphoma. To the author's knowledge, this is the first report describing intravascular lymphoma involving the kidneys alone in a dog.

RESUMO: Um canino, macho, de 10 anos, sem raça definida (SRD), e grande porte, chegou para atendimento apresentando fratura em membro pélvico direito devido a atropelamento por veículo automotivo. Adicionalmente, foram observadas úlceras cutâneas ao nível da fratura. Devido à necessidade de amputação do membro e, por ser um cão idoso, o proprietário optou pela eutanásia, realizando-se necropsia imediatamente após a morte do paciente. Os achados macroscópicos foram consistentes com acentuada nefromegalia bilateral. A avaliação histopatológica dos rins revelou células redondas neoplásicas obliterando vasos sanguíneos. Imunohistoquimicamente, essas células foram positivas para CD3. Baseando-se nos achados histopatológicos, na ausência de envolvimento da medula óssea e do sangue periférico e, na inexistência de massas primárias extravasculares, o tumor foi classificado como linfoma intravascular de células T. Possivelmente, este é o primeiro relato de linfoma intravascular envolvendo unicamente os rins de um cão.

Ancillary techniques on the evaluation of canine cutaneous mast cell tumors from Brazil / Técnicas auxiliares avaliação de mastocitomas cutâneos caninos do Brasil

ABSTRACT: The use of histologic classification by a 2-tier grading system only, immunohistochemistry (IHC) for KIT and Ki-67 and polymerase chain reaction (PCR) for internal tandem duplications (ITD) on exon 11 has improved the prognostication of canine cutaneous mast cell tumors (CCMTs) particularly in the United States. However, these techniques are not commonly used in most Brazilian laboratories. Likewise, no studies, to date, have investigated the occurrence of ITD in CCMTs from the country. Thus, this study tested the 2-tier grading system, the immunohistochemistry for KIT and Ki-67 and the PCR for exon 11 in a group of Brazilian CCMTs with the goal of investigating the applicability of these tests in a Brazilian laboratory. Of the 39 CCMTs, 69.2% (27/39) were identified as low-grade and 30.8% (12/39) as high-grade by a 2-tier grading system. All tumors had a KIT expression pattern II, and 30.6% (11/36) had a high growth fraction (Ki-67). PCR amplification was successful in four of the 11 tumors examined. Two of these (50%) were positive for ITD. This study highlights the importance of using auxiliary techniques in the CCMT evaluation, identifies limitations and confirms the applicability of these methods on a routine diagnostic basis in Brazil. Our results will help to improve the prognostication of CCMTs in Brazilian diagnostic laboratories, encouraging the use of supplementary methods.

RESUMO: O uso de classificação histológica por um novo sistema de graduação que utiliza apenas duas categorias, imuno-histoquímica (IHQ) para KIT e Ki-67 e reação de polimerase em cadeia (PCR) para mutações (duplicações internas) no éxon 11 tem melhorado a avaliação do prognóstico de mastocitomas cutâneos caninos (MCCs), particularmente nos Estados Unidos. No entanto, essas técnicas são ainda pouco utilizadas em laboratórios brasileiros e, até então, nenhum estudo investigou a prevalência de duplicações internas (DIs) em MCCs do país. Este estudo testou o novo sistema de graduação histológica de duas categorias, a imuno-histoquímica para KIT e Ki-67 e o PCR para exon 11 em um grupo de MCCs brasileiros, com o objetivo de investigar a aplicabilidade desses métodos em um laboratório brasileiro. De 39 MCCs, 69,2% foram identificados como sendo de baixo grau e 30,8% como de alto grau. Todos tiveram um padrão II de expressão de KIT, e 30,6% (11/36) tiveram uma alta contagem para Ki-67. A amplificação foi bem-sucedida em quatro dos 11 tumores examinados. Dois destes (50%) foram positivos para DIs. Este estudo ressaltou a importância do uso de técnicas auxiliares na avaliação de MCCs, identificou limitações e confirmou a aplicabilidade desses métodos em uma rotina de diagnósticos no Brasil. Esses resultados irão auxiliar na melhor avaliação prognóstica dos MCCs em laboratórios brasileiros, encorajando o uso de métodos suplementares neste processo.