Platynosomum (Trematoda: Dicrocoeliidae) infection in barn owls (Tyto alba) in Northeastern Brazil.

Platynosomum spp. are parasites that inhabit the gallbladder and bile ducts of various mammals and birds worldwide. Most studies of Platynosomum spp. in birds focus on the observation and morphological characterization of the parasite through parasitological or molecular examinations, with scarce literature describing anatomopathological alterations, mainly histopathological. We report the case of a male barn owl infected with Platynosomum spp.. At necropsy, the barn owl showed dilation with parasites and fibrosis of the intrahepatic bile ducts and gallbladder. Microscopically, it was possible to identify trematodes in the bile ducts associated with a lymphoplasmacytic inflammatory infiltrate. The morphological structures of the worms were described on histopathology and direct examination. The presence of parasitism that is usually cosmopolitan in wild animals represents a risk to the biodiversity of fauna in the region, as well as a warning about the spread and maintenance of the biological cycle of the worm in humans and domestic animals.

Clinical, histopathological, and molecular findings for Mycobacterium avium subspecies paratuberculosis (MAP) in dairy goats under semiarid conditions.

The objective of this study was to report the occurrence of Mycobacterium avium subspecies paratuberculosis (MAP) in dairy goats, via description of their clinical presentation, histopathological findings, and molecular identification of the infectious agent. Screening was performed using IS900 real-time PCR (qPCR) in milk samples from 179 properties in the semiarid of Northeast region of Brazil. Pooled milk samples from all lactating goats from processing plants were submitted to molecular diagnosis. One property had a positive result at qPCR. The production unit which had the positive sample for MAP was located, and an on-site visit to this property was performed to collect individual milk samples, seven of which tested MAP positive by IS900 qPCR. With permission from the owner, two goats (Animal 1 was positive and Animal 2 was negative on first qPCR for MAP) were acquired and euthanized. Animals 1 and 2 had milk and portions of the duodenum, ileum, colon, and mesenteric lymph nodes positive at qPCR for MAP. Animal 1 also had MAP DNA detected in part of the jejunum and cecum. In animal 2, the ileocecal valve tested positive. MAP was not detected in the blood or feces of either animal; however; it was confirmed for the association of clinical findings, histopathology, and qPCR. The gene IS900 from the positive samples were sequenced and showed a 99% similarity with MAP. The MAP was identified for the first time in the goat milk and tissues in the semiarid region of Northeast Brazil.

Nasal leiomyosarcoma in a Quarter Horse / Leiomiossarcoma nasal em equino Quarto de Milha

We described the clinical and anatomopathological findings observed in a case of nasal leiomyosarcoma in a five-year-old male Quarter Mile horse, whose main complaints were decreased sports performance and bilateral purulent nasal discharge. The nodule was observed in the nasal cavity, obstructing the left nostril and associated with purulent drainage. The nodule was of irregular shape and yellow color, measuring 19.4 cm × 6.9 cm × 4.3 cm in size, with coalescent multifocal areas that were brownish, friable, opaque, and fetid. When cut, the surface was compact, grayish-white, and smooth with yellow, friable, irregular multifocal areas, measuring 1-3.2 cm in diameter. Histopathological examination showed spindle-shaped neoplastic cells, which was negative on Masson's trichromic stain. A diagnosis of leiomyosarcoma was established based on the morphotintorial aspects of neoplastic cells and confirmed through immunohistochemistry, with positive immunostaining for antibodies 1A4, HHF35, desmin, and S100. Leiomyosarcoma primarily affects the nasal cavity of horses and should be included in the differential diagnosis of diseases that affect the nasal cavity and cause nasal obstruction associated with dyspnea.

Descreve-se os achados clínicos e anatomopatológicos observados em um caso de leiomiossarcoma nasal em um equino, Quarto de Milha, macho, de cinco anos de idade, com queixa principal de diminuição do rendimento esportivo e secreção nasal purulenta bilateral. Na cavidade nasal, observou-se um nódulo obstruindo a narina esquerda associada à secreção purulenta. O nódulo era de superfície irregular, amarelada, brilhante, fibroelástica, medindo 19,4 x 6,9 x 4,3cm de tamanho, com áreas multifocais a coalescente acastanhadas, friáveis, opacas e fétidas. Ao corte, a superfície era compacta, branco-acinzentada e lisa com áreas multifocais amarelas, friáveis e irregulares, medindo 1-3,2 cm de diâmetro. No exame histopatológico foi observado proliferação de células neoplásicas fusiformes, que foram negativas na coloração de Tricrômico de Masson. O diagnóstico de leiomiossarcoma foi estabelecido com base nos aspectos morfotintoriais das células neoplásicas e confirmado através da imuno-histoquímica, no qual houve imunomarcação positiva para os anticorpos 1A4, HHF35, Desmina e S100. O leiomiossarcoma pode afetar primariamente a cavidade nasal de equinos, devendo ser incluído no diagnóstico diferencial de doenças que afetam a cavidade nasal e que provocam quadros de obstrução nasal associado a dispneia.

Rhinitis in goat by Exserohilum rostratum (Setosphaeria rostrata) / Rinite em caprino por Exserohilum rostratum (Setosphaeria rostrata)

We described a case of rhinitis case caused by Exserohilum rostratum in a 3-year-old, mixed breed, afemale goat, presenting with decreased appetite, dyspnea, and face deformity, with evolution of approximately 2 months. Necropsy revealed an extensive brownish yellow, irregular, ulcerated, and friable focal lesion in the nasal cavity. Purulent secretion drained from the lesion, affecting the nasal vestibule and extending the caudal portion of the dorsal concha, associated with nasal meatus obstruction, destruction of the nasal septum, and nasal bone palatine and vomer. Histologically, the lesion was characterized as rhinitis and pyogranulomatous and necrotizing osteomyelitis (multifocal to coalescent, sharp, and chronic) and associated with a myriad of fungal structures. Morphologically, the hyphae were characterized by thin, slightly tortuous, and rarely septate walls (2-6 µm diameter), multiple chains of individual conidia or in groups (8-10 µm diameter), and pigmented chlamydoconidia (7.5-15 µm diameter). They showed positive results for the special histochemical techniques such as Fontana Masson, methenamine silver nitrate by Grocott, and periodic acid by Schiff. E. rostratum was identified as the causative agent using microbiological isolation associated with molecular identification. Pyrogranulomatous rhinitis caused by E. rostratum in goats is unprecedented, being the first isolation of the agent in animals in Brazil and the first case of nasal phaeohyphomycosis in the goats.

Descreve-se um caso de rinite por Exserohilum rostratum em um caprino, sem raça definida, fêmea, três anos, com diminuição do apetite, dispneia e deformidade facial, com evolução de aproximadamente dois meses. Durante a necropsia, observou-se que na cavidade nasal havia área focal extensa, amarelo acastanhada, irregular, ulcerada e friável, que drenava secreção purulenta acometendo o vestíbulo nasal e estendendo-se da porção caudal da concha dorsal, associada a obstrução do meato nasal, destruição do septo nasal e osso nasal palatino e vômer. Histologicamente, a lesão foi caracterizada como rinite e osteomielite piogranulomatosa e necrosante, multifocal a coalescente, aguda, crônica, associada a uma miríade de estruturas fúngicas. Morfologicamente, as hifas foram caracterizadas por paredes finas, discretamente tortuosas e septadas medindo 2 a 6 µm de diâmetro. Observamos algumas cadeias de conídios ou grupos com 8 a 10 µm de diâmetro e clamidoconídios pigmentados medindo de 7,5 a 15 µm de diâmetro. Foram positivos na histoquímica especial de Fontana Masson, Nitrato de Metenamina de Prata de Grocott e Ácido Periódico de Schiff. O agente foi determinado por meio de isolamento microbiológico associado à identificação molecular. A rinite piogranulomatosa causada por E. rostratum em caprinos é inédita, sendo o primeiro isolamento do agente em animais no Brasil e o primeiro caso de feo-hifomicose nasal na espécie caprina.

Meningoencephalitis secondary to rhinitis caused by Pythium insidiosum in sheep / Meningoencefalite secundária a rinite por Pythium insidiosum em um ovino

A case of meningoencephalitis caused by Pythium insidiosum secondary to rhinitis is reported in a three-year-old crossbred sheep from a herd of 15 animals, raised extensively and with free access to a weir. The animal presented mild dyspnea, blindness, mydriasis, opisthotonos, nystagmus, incoordination, decreased mandibular tone, and spasticity of the pelvic limbs. Macroscopic examination of the nasal cavity showed a blackish-red, irregular, friable mass that bilaterally compromised the nasal septum and the rostral portion of the nasal turbinates. In the brain, there was diffuse thickening of the leptomeninges of the cerebellum and ventral portion of the brainstem characterized by yellowish, granular material associated with vessel hyperemia. On the floor of the fourth ventricle, there was deposition of yellowish, irregular, slightly granular material that protruded towards the obex and displaced the cerebellum dorsolaterally. Microscopically, there were pyogranulomatous, eosinophilic, necrotizing rhinitis and fibrinosuppurative, eosinophilic, necrotizing meningoencephalitis, both associated with thrombosis, vasculitis, and intralesional hyphae. The hyphae were impregnated with silver and presented thin, parallel walls, rarely septate and branched. At immunohistochemistry, the hyphae were immunostained with polyclonal anti-P. insidiosum antibody in fragments of the cerebellum and nasal cavity. The findings showed that P. insidiosum rhinitis can secondarily affect the nervous system of sheep, causing nonspecific neurological clinical signs.

Relata-se um caso de meningoencefalite por Pythium insidiosum secundária a rinite em uma ovelha mestiça, três anos de idade, proveniente de um rebanho de 15 animais, criados extensivamente e com acesso livre a açude. O animal apresentava dispneia leve, cegueira, midríase, opistótono, nistagmo, incoordenação, diminuição do tônus mandibular e espasticidade dos membros pélvicos. O exame macroscópico da cavidade nasal evidenciou uma massa vermelho-escura, irregular, friável, que comprometia bilateralmente o septo nasal e a porção rostral dos cornetos nasais. No encéfalo, havia espessamento difuso das leptomeninges do cerebelo e porção ventral do tronco encefálico caracterizado por material granular amarelado associado à hiperemia dos vasos. No assoalho do quarto ventrículo, havia deposição de material amarelado, irregular, levemente granuloso, que se projetava em direção ao óbex e deslocava o cerebelo dorsolateralmente. Microscopicamente, havia rinite piogranulomatosa, eosinofílica, necrosante e meningoencefalite fibrinossupurativa, eosinofílica, necrosante, ambas associadas à trombose, vasculite e hifas intralesionais. Pela utilização da técnica de GMS as hifas foram impregnadas pela prata e apresentavam paredes finas e paralelas, raramente septadas e ramificadas. Na imuno-histoquímica, houve imunomarcação com o anticorpo policlonal anti-P. insidiosum em fragmentos do cerebelo e cavidade nasal. Os achados evidenciaram que rinite por P. insidiosum pode afetar secundariamente o sistema nervoso de ovinos, causando sinais clínicos neurológicos inespecíficos.

Diseases with neurological manifestations diagnosed in cattle in the hospital routine: a retrospective epidemiological study (2009-2019) / Enfermidades com manifestações neurológicas diagnosticadas em bovinos na rotina hospitalar: estudo epidemiológico retrospectivo (2009-2019)

Abstract Neurological disorders in cattle comprise a group of economically relevant diseases with high occurrence and mortality. In this way, the objective was to carry out an epidemiological study of the diseases with neurological manifestations in cattle admitted (alive or dead) to the Garanhuns Bovine Clinic/Federal Rural University of Pernambuco (CBG/UFRPE) from January 2009 to December 2019. Epidemiological information was collected from the clinical records regarding the age group, rearing system, time of year, and area of origin of the animals. The diseases were grouped into categories according to their origin: toxic or toxi-infectious, viral, traumatic/physical, parasitic, metabolic degenerative, bacterial, neoplastic, and others. A total of 6103 cattle were treated during the study period, of which 604 (10.1%) were diagnosed with diseases that had neurological manifestations. Of these, 331 cases were of single occurrence, and 231 cases occurred as outbreaks in the herd. Death was the outcome in almost 80% of the cases (465/596). The frequencies of the different categories were toxic or toxi-infectious (25.2%), viral (21.5%), traumatic/physical (13.6%), parasitic (9.8%), metabolic (9.3%), degenerative (2.3%), bacterial (2.2%), neoplastic (1.2%), and others (1.2%). It was found that almost half of the animals were older than 24 months (229/475), almost 80% were females, more than 60% were submitted to a semi-intensive to intensive rearing system, and the occurrence of disease was higher during the dry period of the year (363/614). The three most frequent neurological diseases in this study were rabies, trauma, and botulism.

Resumo Os distúrbios neurológicos em bovinos abrangem um grupo de enfermidades economicamente relevantes de elevada ocorrência e mortalidade. Desta forma, objetivou-se realizar um estudo epidemiológico das enfermidades que cursaram com manifestações neurológicas que deram entrada (vivos ou mortos) na Clínica de Bovinos de Garanhuns/Universidade Federal Rural de Pernambuco no período de janeiro de 2009 a dezembro de 2019. Nos prontuários clínicos, foram coletadas informaçõe epidemiológicas referentes ao sexo; a faixa etária; ao sistema de criação, época do ano e a área de procedência dos animais. As doenças foram agrupadas em categorias de acordo com sua origem: tóxica ou toxi-infecciosa, viral, traumática, parasitária, degenerativa, metabólica, bacteriana, neoplásica e outras. Um total de 6103 bovinos foram atendidos no período estudado, dos quais 604 (10,1 %) foram diagnosticados com enfermidades que cursaram com manifestações neurológicas. Destes, 331 casos foram de ocorrência individual, 231 casos cursaram como surtos no rebanho. Quase 80% dos casos (465/596) teve o óbito como desfecho. As frequências das distintas categoria foram tóxica ou toxi-infecciosa (25,2%), viral (21,5%), traumática/física (13,6%), parasitária (9,8%), metabólica (9,3%, degenerativa (2,3%), bacteriana (2,2%), neoplásica (1,2%), outras (1,2%). Verificou-se que quase metade dos animais apresentavam idade superior a 24 meses (229/475), quase 80% eram fêmeas, mais de 60% eram submetidos a um sistema de criação de semi-intensivo a intensivo e a ocorrência foi maior durante o período seco do ano (363/614). As três enfermidades com manifestações neurológicas de maior ocorrência neste estudo foram a raiva, os traumatismos e o botulismo.

Outbreaks of philophthalmiasis in ostriches (Struthio camelus) in Northeast Brazil / Surtos de filoftalmíase em avestruzes (Struthio camelus) no Nordeste do Brasil

This study discusses the epidemiological, clinical, and pathological characteristics of two outbreaks of ocular infection in ostriches (Struthio camelus) caused by the trematode Philophthalmus sp. The outbreaks occurred in the states of Ceará and Rio Grande do Norte in Northeast Brazil. Ostrich farming was categorized as semi-intensive farming with free access to the weir and river. The clinical symptoms for infection included nictitating membrane inflammation, epiphora (tearing), eyelid edema, ocular congestion, eyeball destruction, emaciation, and death, and the infection period ranged from 8 to 16 months. Macroscopically, thickening of the eyelids and conjunctiva were observed, with orange parasites infestation. Histologically, the lesions were characterized as lymphoplasmacytic and heterophilic, multifocal to coalescing, moderate, chronic conjunctivitis associated with hyperplasia and ectasia of the Harderian gland, and numerous parasites. The parasites were oval and flattened with an oral suction cup, acetabulum, and thick cuticle containing spicules. The diagnosis of philophthalmiasis was based on epidemiological, clinical, and pathological findings associated with the morphological characteristics of the parasites present in the conjunctival sacs which were similar to the trematode Philophthalmus sp. Philophthalmiasis can occur in ostriches raised on urban and rural properties in Northeastern Brazil, probably associated with the contact of birds with contaminated water, and is characterized by severe conjunctivitis that can result in the loss of the eyeball and death of the animals.

Descrevem-se as características epidemiológicas, clínicas e patológicas de dois surtos de infecção ocular pelo trematódeo Philophthalmus sp. em avestruzes ocorridos nos estados do Ceará e Rio Grande do Norte no Nordeste do Brasil. As propriedades tinham em comum, a criação semi-intensiva e livre acesso a açude e rio. Os sinais clínicos incluíam protrusão da membrana nictante, lacrimejamento, edema palpebral, congestão ocular, destruição do globo ocular, emagrecimento e morte. A evolução clínica variou de oito a 16 meses. Macroscopicamente, observou-se espessamento das pálpebras e conjuntivas associado a numerosas estruturas parasitárias alaranjadas. No segundo surto, as lesões eram mais graves e consistiam em perda do globo ocular direito e anexos. Histologicamente, as lesões caracterizavam-se por conjuntivite linfoplasmocítica e heterofílica, multifocal a coalescente, moderada, crônica associada a hiperplasia e ectasia da glândula de Harderian e numerosas estruturas parasitárias. Os parasitas eram ovalados, achatados com ventosa oral e acetábulo e cutícula espessa contendo espículas. O diagnóstico de filoftalmíase foi realizado com base nos achados epidemiológicos, clínicos e patológicos associadas as características morfológicas dos parasitas presentes nos sacos conjuntivais compatíveis com o trematódeo Philophthalmus sp. A filoftalmíase pode ocorrer em avestruzes criados em propriedades urbanas e rurais no Nordeste do Brasil, provavelmente associado ao contato das aves com água contaminada e caracteriza-se por quadros de conjuntivite grave que pode resultar com a perda do globo ocular e morte dos animais.

Fungal diseases in dogs and cats in Northeastern Brazil / Doenças fúngicas em cães e gatos no Nordeste do Brasil

In this retrospective study, the clinical and anatomopathological findings of fungal diseases in dogs and cats in Northeastern Brazil are described. During the study period, 6,827 histopathological examinations (4,090 necropsies and 2,737 biopsies) of companion animals were reviewed, and fungal infections were diagnosed in 54 cases. Of these, 32 cases were diagnosed in cats and 22 in dogs. Sporotrichosis was the most prevalent mycosis (19/54), followed by dermatophytosis (9/54), cryptococcosis (8/54), candidiasis (7/54), and phaeohyphomycosis (4/54). Other diseases had two cases each, including aspergillosis, mucormycosis, and histoplasmosis, whereas coccidioidomycosis occurred once. Mycoses were diagnosed through microscopic lesions associated with the histomorphological characteristics of the agent, as evidenced by routine and special histochemical stains. They were occasionally confirmed by immunohistochemistry and microbiological cultivation. This retrospective study showed that despite being uncommon, fungal diseases are important causes of death in dogs and cats in the region, with cats being the most affected species and sporotrichosis being the most prevalent mycosis. Clinical signs were correlated with the portal of entry of the infection associated with localized or disseminated superficial and deep skin lesions or affecting parenchymal organs, especially in systemic infections. Microscopic lesions were mainly characterized by pyogranulomatous inflammation associated with fungal structures. In dogs, mycoses occurred mainly owing to an immunological impairment secondary to canine distemper virus co-infection.

Neste estudo retrospectivo, são descritos os achados clínicos e anatomopatológicos das doenças fúngicas em cães e gatos no Nordeste do Brasil. Durante o período de estudo, foram revisados 6.827 exames histopatológicos (4.090 necropsias e 2.737 biópsias) de animais de companhia e diagnosticados 54 casos de infecções fúngicas. Destes, 32 casos foram diagnosticados em gatos e 22 em cães. A esporotricose foi a micose mais prevalente (19/54), seguida pela dermatofitose (9/54), criptococose (8/54), candidíase (7/54) e feo-hifomicose (4/54). Outras doenças tiveram dois casos cada, incluindo aspergilose, mucormicose e histoplasmose, enquanto a coccidioidomicose ocorreu uma vez. As micoses foram diagnosticadas por meio das lesões microscópicas associadas às características histomorfológicas do agente, evidenciadas pelas colorações de rotina e histoquímicas especiais, e ocasionalmente confirmadas pela imuno-histoquímica e cultivo microbiológico. Esse estudo retrospectivo demonstrou que apesar de incomuns, as doenças fúngicas são importantes causas de morte em cães e gatos da região, sendo os gatos a espécie mais afetada e a esporotricose, a micose mais prevalente. Os sinais clínicos estavam correlacionados com a porta de entrada da infecção, associados a lesões cutâneas localizadas ou disseminadas superficiais e profundas ou afetando órgãos parenquimatosos, especialmente em infecções sistêmicas. As lesões microscópicas eram caracterizadas principalmente por inflamação piogranulomatosa associada a estruturas fúngicas. Nos cães, as micoses ocorreram principalmente devido ao comprometimento imunológico secundária a coinfecção pelo vírus da cinomose canina.

Nasal leiomyosarcoma in a Quarter Horse / Leiomiossarcoma nasal em equino Quarto de Milha

ABSTRACT: We described the clinical and anatomopathological findings observed in a case of nasal leiomyosarcoma in a five-year-old male Quarter Mile horse, whose main complaints were decreased sports performance and bilateral purulent nasal discharge. The nodule was observed in the nasal cavity, obstructing the left nostril and associated with purulent drainage. The nodule was of irregular shape and yellow color, measuring 19.4 cm × 6.9 cm × 4.3 cm in size, with coalescent multifocal areas that were brownish, friable, opaque, and fetid. When cut, the surface was compact, grayish-white, and smooth with yellow, friable, irregular multifocal areas, measuring 1-3.2 cm in diameter. Histopathological examination showed spindle-shaped neoplastic cells, which was negative on Masson's trichromic stain. A diagnosis of leiomyosarcoma was established based on the morphotintorial aspects of neoplastic cells and confirmed through immunohistochemistry, with positive immunostaining for antibodies 1A4, HHF35, desmin, and S100. Leiomyosarcoma primarily affects the nasal cavity of horses and should be included in the differential diagnosis of diseases that affect the nasal cavity and cause nasal obstruction associated with dyspnea.

RESUMO: Descreve-se os achados clínicos e anatomopatológicos observados em um caso de leiomiossarcoma nasal em um equino, Quarto de Milha, macho, de cinco anos de idade, com queixa principal de diminuição do rendimento esportivo e secreção nasal purulenta bilateral. Na cavidade nasal, observou-se um nódulo obstruindo a narina esquerda associada à secreção purulenta. O nódulo era de superfície irregular, amarelada, brilhante, fibroelástica, medindo 19,4 x 6,9 x 4,3cm de tamanho, com áreas multifocais a coalescente acastanhadas, friáveis, opacas e fétidas. Ao corte, a superfície era compacta, branco-acinzentada e lisa com áreas multifocais amarelas, friáveis e irregulares, medindo 1-3,2 cm de diâmetro. No exame histopatológico foi observado proliferação de células neoplásicas fusiformes, que foram negativas na coloração de Tricrômico de Masson. O diagnóstico de leiomiossarcoma foi estabelecido com base nos aspectos morfotintoriais das células neoplásicas e confirmado através da imuno-histoquímica, no qual houve imunomarcação positiva para os anticorpos 1A4, HHF35, Desmina e S100. O leiomiossarcoma pode afetar primariamente a cavidade nasal de equinos, devendo ser incluído no diagnóstico diferencial de doenças que afetam a cavidade nasal e que provocam quadros de obstrução nasal associado a dispneia.

Rhinitis in goat by Exserohilum rostratum (Setosphaeria rostrata) / Rinite em caprino por Exserohilum rostratum (Setosphaeria rostrata)

ABSTRACT: We described a case of rhinitis case caused by Exserohilum rostratum in a 3-year-old, mixed breed, afemale goat, presenting with decreased appetite, dyspnea, and face deformity, with evolution of approximately 2 months. Necropsy revealed an extensive brownish yellow, irregular, ulcerated, and friable focal lesion in the nasal cavity. Purulent secretion drained from the lesion, affecting the nasal vestibule and extending the caudal portion of the dorsal concha, associated with nasal meatus obstruction, destruction of the nasal septum, and nasal bone palatine and vomer. Histologically, the lesion was characterized as rhinitis and pyogranulomatous and necrotizing osteomyelitis (multifocal to coalescent, sharp, and chronic) and associated with a myriad of fungal structures. Morphologically, the hyphae were characterized by thin, slightly tortuous, and rarely septate walls (2-6 μm diameter), multiple chains of individual conidia or in groups (8-10 μm diameter), and pigmented chlamydoconidia (7.5-15 μm diameter). They showed positive results for the special histochemical techniques such as Fontana Masson, methenamine silver nitrate by Grocott, and periodic acid by Schiff. E. rostratum was identified as the causative agent using microbiological isolation associated with molecular identification. Pyrogranulomatous rhinitis caused by E. rostratum in goats is unprecedented, being the first isolation of the agent in animals in Brazil and the first case of nasal phaeohyphomycosis in the goats.

RESUMO: Descreve-se um caso de rinite por Exserohilum rostratum em um caprino, sem raça definida, fêmea, três anos, com diminuição do apetite, dispneia e deformidade facial, com evolução de aproximadamente dois meses. Durante a necropsia, observou-se que na cavidade nasal havia área focal extensa, amarelo acastanhada, irregular, ulcerada e friável, que drenava secreção purulenta acometendo o vestíbulo nasal e estendendo-se da porção caudal da concha dorsal, associada a obstrução do meato nasal, destruição do septo nasal e osso nasal palatino e vômer. Histologicamente, a lesão foi caracterizada como rinite e osteomielite piogranulomatosa e necrosante, multifocal a coalescente, aguda, crônica, associada a uma miríade de estruturas fúngicas. Morfologicamente, as hifas foram caracterizadas por paredes finas, discretamente tortuosas e septadas medindo 2 a 6 μm de diâmetro. Observamos algumas cadeias de conídios ou grupos com 8 a 10 μm de diâmetro e clamidoconídios pigmentados medindo de 7,5 a 15 μm de diâmetro. Foram positivos na histoquímica especial de Fontana Masson, Nitrato de Metenamina de Prata de Grocott e Ácido Periódico de Schiff. O agente foi determinado por meio de isolamento microbiológico associado à identificação molecular. A rinite piogranulomatosa causada por E. rostratum em caprinos é inédita, sendo o primeiro isolamento do agente em animais no Brasil e o primeiro caso de feo-hifomicose nasal na espécie caprina.

Meningoencephalitis secondary to rhinitis caused by Pythium insidiosum in sheep / Meningoencefalite secundária a rinite por Pythium insidiosum em um ovino

ABSTRACT: A case of meningoencephalitis caused by Pythium insidiosum secondary to rhinitis is reported in a three-year-old crossbred sheep from a herd of 15 animals, raised extensively and with free access to a weir. The animal presented mild dyspnea, blindness, mydriasis, opisthotonos, nystagmus, incoordination, decreased mandibular tone, and spasticity of the pelvic limbs. Macroscopic examination of the nasal cavity showed a blackish-red, irregular, friable mass that bilaterally compromised the nasal septum and the rostral portion of the nasal turbinates. In the brain, there was diffuse thickening of the leptomeninges of the cerebellum and ventral portion of the brainstem characterized by yellowish, granular material associated with vessel hyperemia. On the floor of the fourth ventricle, there was deposition of yellowish, irregular, slightly granular material that protruded towards the obex and displaced the cerebellum dorsolaterally. Microscopically, there were pyogranulomatous, eosinophilic, necrotizing rhinitis and fibrinosuppurative, eosinophilic, necrotizing meningoencephalitis, both associated with thrombosis, vasculitis, and intralesional hyphae. The hyphae were impregnated with silver and presented thin, parallel walls, rarely septate and branched. At immunohistochemistry, the hyphae were immunostained with polyclonal anti-P. insidiosum antibody in fragments of the cerebellum and nasal cavity. The findings showed that P. insidiosum rhinitis can secondarily affect the nervous system of sheep, causing nonspecific neurological clinical signs.

RESUMO: Relata-se um caso de meningoencefalite por Pythium insidiosum secundária a rinite em uma ovelha mestiça, três anos de idade, proveniente de um rebanho de 15 animais, criados extensivamente e com acesso livre a açude. O animal apresentava dispneia leve, cegueira, midríase, opistótono, nistagmo, incoordenação, diminuição do tônus mandibular e espasticidade dos membros pélvicos. O exame macroscópico da cavidade nasal evidenciou uma massa vermelho-escura, irregular, friável, que comprometia bilateralmente o septo nasal e a porção rostral dos cornetos nasais. No encéfalo, havia espessamento difuso das leptomeninges do cerebelo e porção ventral do tronco encefálico caracterizado por material granular amarelado associado à hiperemia dos vasos. No assoalho do quarto ventrículo, havia deposição de material amarelado, irregular, levemente granuloso, que se projetava em direção ao óbex e deslocava o cerebelo dorsolateralmente. Microscopicamente, havia rinite piogranulomatosa, eosinofílica, necrosante e meningoencefalite fibrinossupurativa, eosinofílica, necrosante, ambas associadas à trombose, vasculite e hifas intralesionais. Pela utilização da técnica de GMS as hifas foram impregnadas pela prata e apresentavam paredes finas e paralelas, raramente septadas e ramificadas. Na imuno-histoquímica, houve imunomarcação com o anticorpo policlonal anti-P. insidiosum em fragmentos do cerebelo e cavidade nasal. Os achados evidenciaram que rinite por P. insidiosum pode afetar secundariamente o sistema nervoso de ovinos, causando sinais clínicos neurológicos inespecíficos.

Cerebral infarction and thrombotic meningoencephalitis in a calf due to candidiasis / Infarto cerebral e meningoencefalite trombótica em um bezerro devido a candidíase

We described a case of cerebral infarction and thrombotic meningoencephalitis due to candidiasis in a seven-month-old calf. The death occurred three days after the onset of apathy, fever, and the head's lateral deviation to the left. Macroscopic changes in the brain consisted of asymmetry of telencephalic hemispheres; the right hemisphere was enlarged, causing cerebellar herniation. A focally extensive red area was observed on the surface of the right occipital lobe. At cross-sections of the fixed brain, the lesions revealed to be extensive, red-brown, soft or cavitated areas affecting the white and grey matter from the level of the thalamus to the cerebellum and compressing subjacent structures. Histologically, there was acute, coalescent, multifocal necrosupurative meningoencephalitis, associated with vasculitis, congestion, thrombosis, edema, infarction, and intralesional fungal hyphae. The diagnosis of cerebral infarction and thrombotic meningoencephalitis due to candidiasis was made by the pathological changes, the staining and morphological characteristics of the agent, and immunohistochemistry. The cerebral infarction and thrombotic meningoencephalitis in cattle can result from vascular lesions due to infection by Candida sp.; although uncommon, this case demonstrated that candidiasis should be part of a list of differential diagnoses of severe brain injuries in cattle.

Descreve-se um caso de infarto cerebral e meningoencefalite trombótica devido a candidíase em um bezerro de sete meses de idade. A morte ocorreu três dias após o início de apatia, febre e desvio lateral da cabeça para a esquerda. As alterações macroscópicas no cérebro consistiam em assimetria dos hemisférios telencefálicos; o hemisfério direito estava aumentado, causando herniação cerebelar. Uma extensa área vermelha focal foi observada na superfície do lobo occipital direito. Nos cortes transversais do encéfalo fixado, as lesões revelaram áreas extensas, marrom-avermelhadas, moles ou cavitadas, afetando a substância branca e cinzenta desde o nível do tálamo até o cerebelo e comprimindo as estruturas subjacentes. Histologicamente, havia meningoencefalite necrossupurativa multifocal aguda, coalescente, associada a vasculite, congestão, trombose, edema, infarto e hifas fúngicas intralesionais. O diagnóstico de infarto cerebral e meningoencefalite trombótica devido a candidíase foi feito pelas alterações patológicas, coloração e características morfológicas do agente e imuno-histoquímica. O infarto cerebral e meningoencefalite trombótica em bovinos pode resultar de lesões vasculares devido à infecção por Candida sp.; embora incomum, este caso demonstra que a candidíase deve fazer parte de uma lista de diagnósticos diferenciais de lesões cerebrais graves em bovinos.

A Retrospective Study of Pythiosis in Domestic Animals in Northeastern Brazil.

Pythiosis is an endemic disease in northeastern Brazil and we now report the epidemiological, clinical and pathological findings in a retrospective study of naturally occurring cases in domestic animals. From January 1985 to December 2020, the Laboratory of Animal Pathology of the Federal University of Campina Grande examined 13,542 tissue samples from necropsies and biopsies. Among these samples, 306 were diagnosed as pythiosis: 195 cases in horses, 75 in sheep, 19 in dogs, six in mules, four in cattle, three in cats, two in goats, one in a donkey and one in an ostrich. Affected equids had lesions in the skin, mammary glands and nasal cavities. Affected sheep had cutaneous, nasal and digestive lesions while cattle and goats had cutaneous lesions. Carnivores developed lesions, mainly in the alimentary tract, of sufficient severity to cause death or result in euthanasia. The single affected bird had lesions in the alimentary tract and surgical excision resulted in remission. The disease had a long and life-threatening clinical course in most affected species but resolved spontaneously in cattle. Clinical signs were directly related to the location of the lesions, which were invariably characterized by chronic inflammation associated with intralesional hyphae. Veterinary clinicians and pathologists should be familiar with the clinicopathological features of pythiosis and the wide range of susceptible animal species.

Bone and pulmonary metastasis from a mammary adenosquamous carcinoma in a bitch / Metástase óssea e pulmonar de adenocarcinoma escamoso mamário em cadela

Mammary tumors are the most common in bitches, and bone and pulmonary metastases are not well described. Adenosquamous mammary carcinoma is a rare tumor that can be classified as a type of metaplastic tumor. This report describes the clinical and histopathological findings of this atypical presentation of mammary carcinoma in an 11-year-old, spayed, Poodle. Surgery was performed to remove malignant mammary nodules with a provisional diagnosis of carcinoma on cytologic examination. Thirteen months later, the dog returned showing left pelvic limb lameness that had persisted for 6 months prior to the consultation. The patient showed right pelvic limb lameness and a mass in the same limb. Radiographs of the affected limb revealed a pathological fracture in the femoral diaphysis and proliferation of the periosteum. After clinical staging, a left pelvic limb amputation was performed. A diagnosis of grade II adenosquamous mammary carcinoma was made through histopathology and immunohistochemistry. Although uncommon, bone and pulmonary metastases from mammary tumors, such as adenosquamous carcinoma, can be considered differential diagnoses for bony tumors. This report highlights the aggressive nature and significant metastatic potential of the adenosquamous carcinoma.

Os tumores mamários são os mais comuns em cadelas e as metástases ósseas e pulmonares não são bem descritas. O carcinoma mamário adenoescamoso é um tumor raro que pode ser classificado como um tipo de tumor metaplásico. Este relato descreve os achados clínicos e histopatológicos dessa apresentação atípica de carcinoma mamário em um Poodle de 11 anos de idade, castrado. A cirurgia foi realizada para remover nódulos mamários malignos com diagnóstico provisório de carcinoma no exame citológico. Treze meses depois, a cadela retornou apresentando claudicação do membro pélvico esquerdo que persistia por seis meses antes da consulta. O paciente apresentava claudicação do membro pélvico direito e uma massa no mesmo membro. A radiografia do membro afetado revelou fratura patológica na diáfise femoral, proliferação do periósteo e áreas de osteopenia. Após estadiamento clínico, foi realizada amputação do membro pélvico esquerdo. O diagnóstico de carcinoma adenoescamoso mamário grau II foi feito através da histopatologia e imunohistoquímica. Embora incomuns, as metástases ósseas e pulmonares de tumores mamários, como o carcinoma adenoescamoso, podem ser consideradas diagnósticos diferenciais para tumores ósseos. Este relatório destaca a natureza agressiva e significativo potencial metastático do carcinoma adenoescamoso.

Linfoma renal primário em cão / Primary kidney lymphoma in a dog

Background: Lymphoma is a malignant lymphoid tumor originating in the lymph nodes or other solid organs and comprises90% of all hematopoietic tumors in dogs. However, primary kidney lymphoma is rare and is associated with nonspecificclinical signs. Tumor invasion in both kidneys can cause severe clinical signs due to renal failure, complicating the patientstreatment and prognosis. The aim of this case was to report the case of a dog affected by bilateral primary kidney lymphoma. In addition, to characterize the clinical and histopathological presentation due to the intense morphological changes.Case: A 5-year-old male Poodle dog was admitted showing apathy and emesis for 5 days. On physical examination, thedog showed 10% of dehydration, reddish oral mucous membranes, poor body condition (score 1/5), uremic breath, andpain in the kidney area. Complementary tests revealed severe low white blood cells count, high BUN levels, high levels ofpotassium, calcium, and phosphorus (serum biochemistry). Abdominal ultrasound showed bilateral kidney enlargement.Fine needle aspiration of the mass (guided by ultrasound) revealed round cell tumor. Radiographs showed no alterations.The dog died due to his poor condition and necropsy was performed. On post-mortem examination, the kidneys were bothenlarged, pale, and with an irregular subcapsular surface. The histopathological diagnostic was primary renal lymphoma.Immunohistochemical staining revealed that neoplastic cells were strongly positive for anti CD20 and PAX5, while negative for CD3, supporting the diagnosis of B-cell lymphoma.Discussion: The diagnosis was based on clinical, complementary tests, fine needle aspiration, histopathological andimmunohistochemical findings. In dogs, primary kidney tumors are uncommon and usually malignant. The presence ofvomiting, uremic breath, dehydration, weight loss, and erosive and ulcerative lesions on the tongue (uremic glossitis)...(AU)

Linfoma renal primário em cão / Primary kidney lymphoma in a dog

Background: Lymphoma is a malignant lymphoid tumor originating in the lymph nodes or other solid organs and comprises90% of all hematopoietic tumors in dogs. However, primary kidney lymphoma is rare and is associated with nonspecificclinical signs. Tumor invasion in both kidneys can cause severe clinical signs due to renal failure, complicating the patient’streatment and prognosis. The aim of this case was to report the case of a dog affected by bilateral primary kidney lymphoma. In addition, to characterize the clinical and histopathological presentation due to the intense morphological changes.Case: A 5-year-old male Poodle dog was admitted showing apathy and emesis for 5 days. On physical examination, thedog showed 10% of dehydration, reddish oral mucous membranes, poor body condition (score 1/5), uremic breath, andpain in the kidney area. Complementary tests revealed severe low white blood cells count, high BUN levels, high levels ofpotassium, calcium, and phosphorus (serum biochemistry). Abdominal ultrasound showed bilateral kidney enlargement.Fine needle aspiration of the mass (guided by ultrasound) revealed round cell tumor. Radiographs showed no alterations.The dog died due to his poor condition and necropsy was performed. On post-mortem examination, the kidneys were bothenlarged, pale, and with an irregular subcapsular surface. The histopathological diagnostic was primary renal lymphoma.Immunohistochemical staining revealed that neoplastic cells were strongly positive for anti CD20 and PAX5, while negative for CD3, supporting the diagnosis of B-cell lymphoma.Discussion: The diagnosis was based on clinical, complementary tests, fine needle aspiration, histopathological andimmunohistochemical findings. In dogs, primary kidney tumors are uncommon and usually malignant. The presence ofvomiting, uremic breath, dehydration, weight loss, and erosive and ulcerative lesions on the tongue (uremic glossitis)...

Systemic phaeohyphomycosis in a dog caused by Cladophialophora bantiana

Background: Cladophialophora bantiana is a dematiaceous fungus that causes phaeohyphomycosis, a generic term used to describe a variety of unusual mycoses caused by fungi that have melanin in their cell wall. C. bantiana targets the central nervous system, commonly causing localized brain infections that may result in disseminated infections. In Brazil, minimal phaeohyphomycosis data are available, and information about C. bantiana infections in animals, especially canines, is scarce. Thus, the aim of this study was to describe the clinical and pathological aspects of systemic phaeohyphomycosis caused by C. bantiana in a dog. Case: A 1-year-old female Pit Bull presented with weight loss, reduced appetite, and a history of cutaneous lesions on the right thoracic limb; however, clinical evolution was not reported. The bitch had reportedly given birth recently. Physical examination revealed thinness, pale ocular and oral mucosa, submandibular lymph nodes, and enlarged popliteal lymph nodes. The bitch died after convulsive crises during hospitalization. At necropsy, white-yellowish multifocal nodules were observed in the liver and right kidney. The brain featured left cerebral hemisphere asymmetry with blood vessel congestion in the leptomeninges and an irregular brownish focal area on the surface of the right occipital cortex. Cross-sections of the formalin-fi xed brain exhibited compression of the left lateral ventricle and the presence of grayish and friable multifocal areas in the gray matter of the left parietal and right occipital cortices. Fragments of the lesions were collected for histopathological and microbiological examination. Histologically, the lesions were similar, characterized by hepatitis, nephritis, and granulomatous and necrotizing...

Clinical and toxicological findings in nitrate and nitrite poisoning in cattle in Northeastern Brazil / Achados clínicos e toxicológicos na intoxicação por nitrato e nitrito em bovinos no Nordeste do Brasil

We report two outbreaks of nitrate and nitrite poisoning in Paraíba, Northeast Brazil. The first, due to Pennisetum purpureum (elephant grass), and the second, due to P. purpureum and Brachiaria spp. (brachiaria grass), both occurred during a prolonged drought. In the first outbreak, the irrigation of the pastures with wastewater and sewage contributed to nitrate accumulation. The second outbreak occurred in pastures cultivated in the border of a dam, that had been submerged for long time accumulating large amounts of organic matter in the soil. Other probably risk factors for nitrate accumulation included the use of chemical fertilizers and herbicides and burning of the vegetation. In the first outbreak, four calves out of a total of 42 cattle died, and in the second outbreak 49 out of 243 cattle, including adults, yearlings, and a 2-day-old calf died. The clinical signs included dyspnea, cyanosis, ataxia, and falls, leading to death. The presence of nitrates was detected in both outbreaks using the diphenylamine test. Quantitative tests were performed in the second outbreak using a portable nitrate meter, and high nitrate concentrations were found. The characteristic macroscopic findings and absence of microscopic lesions and response to treatment with methylene blue were key to the diagnosis of poisoning by nitrates and nitrites. We conclude that poisoning by nitrates and nitrites in ruminants in the semiarid region of Northeastern Brazil is frequent due to the cultivation of grasses in the border of dams that had been covered by water for long periods or in areas irrigated by wastewater and/or sewage. In addition, the use of a portable measuring device is an effective alternative for the quantification of nitrates in pastures.

Relatamos dois surtos de intoxicação por nitrato e nitrito na Paraíba, Nordeste do Brasil. O primeiro por Pennisetum purpureum (capim-elefante), e o segundo por P. purpureum e Brachiaria spp. (capim braquiária); ambos ocorreram durante uma estiagem prolongada. No primeiro surto, a irrigação das pastagens com água poluída e esgoto contribuiu para o acúmulo de nitrato. O segundo surto ocorreu em pastagens cultivadas na borda de uma barragem, que há muito tempo ficavam submersas, acumulando grande quantidade de matéria orgânica no solo. Outros prováveis fatores de risco para o acúmulo de nitrato incluíram o uso de fertilizantes químicos e herbicidas e a queima da vegetação. No primeiro surto, quatro bezerros de um total de 42 bovinos morreram, e no segundo surto 49 de 243 bovinos, incluindo adultos, jovens de um ano e um bezerro de 2 dias de idade morreram. Os sinais clínicos incluíram dispneia, cianose, ataxia e quedas, levando à morte. A presença de nitratos foi detectada em ambos os surtos pelo teste de difenilamina. Testes quantitativos foram realizados no segundo surto usando um medidor portátil de nitrato, e altas concentrações de nitrato foram encontradas. Os achados macroscópicos característicos e a ausência de lesões microscópicas e a resposta ao tratamento com azul de metileno foram fundamentais para o diagnóstico de intoxicação por nitratos e nitritos. Concluímos que a intoxicação por nitratos e nitritos em ruminantes na região semiárida do Nordeste do Brasil é frequente devido ao cultivo de gramíneas nas bordas de barragens que estiveram cobertas por água por longos períodos ou em áreas irrigadas por água poluída e/ou esgoto. Além disso, o uso de medidor portátil é uma alternativa eficaz para a quantificação de nitratos em pastagens.

Clinical and toxicological findings in nitrate and nitrite poisoning in cattle in Northeastern Brazil / Achados clínicos e toxicológicos na intoxicação por nitrato e nitrito em bovinos no Nordeste do Brasil

We report two outbreaks of nitrate and nitrite poisoning in Paraíba, Northeast Brazil. The first, due to Pennisetum purpureum (elephant grass), and the second, due to P. purpureum and Brachiaria spp. (brachiaria grass), both occurred during a prolonged drought. In the first outbreak, the irrigation of the pastures with wastewater and sewage contributed to nitrate accumulation. The second outbreak occurred in pastures cultivated in the border of a dam, that had been submerged for long time accumulating large amounts of organic matter in the soil. Other probably risk factors for nitrate accumulation included the use of chemical fertilizers and herbicides and burning of the vegetation. In the first outbreak, four calves out of a total of 42 cattle died, and in the second outbreak 49 out of 243 cattle, including adults, yearlings, and a 2-day-old calf died. The clinical signs included dyspnea, cyanosis, ataxia, and falls, leading to death. The presence of nitrates was detected in both outbreaks using the diphenylamine test. Quantitative tests were performed in the second outbreak using a portable nitrate meter, and high nitrate concentrations were found. The characteristic macroscopic findings and absence of microscopic lesions and response to treatment with methylene blue were key to the diagnosis of poisoning by nitrates and nitrites. We conclude that poisoning by nitrates and nitrites in ruminants in the semiarid region of Northeastern Brazil is frequent due to the cultivation of grasses in the border of dams that had been covered by water for long periods or in areas irrigated by wastewater and/or sewage. In addition, the use of a portable measuring device is an effective alternative for the quantification of nitrates in pastures.(AU)

Relatamos dois surtos de intoxicação por nitrato e nitrito na Paraíba, Nordeste do Brasil. O primeiro por Pennisetum purpureum (capim-elefante), e o segundo por P. purpureum e Brachiaria spp. (capim braquiária); ambos ocorreram durante uma estiagem prolongada. No primeiro surto, a irrigação das pastagens com água poluída e esgoto contribuiu para o acúmulo de nitrato. O segundo surto ocorreu em pastagens cultivadas na borda de uma barragem, que há muito tempo ficavam submersas, acumulando grande quantidade de matéria orgânica no solo. Outros prováveis fatores de risco para o acúmulo de nitrato incluíram o uso de fertilizantes químicos e herbicidas e a queima da vegetação. No primeiro surto, quatro bezerros de um total de 42 bovinos morreram, e no segundo surto 49 de 243 bovinos, incluindo adultos, jovens de um ano e um bezerro de 2 dias de idade morreram. Os sinais clínicos incluíram dispneia, cianose, ataxia e quedas, levando à morte. A presença de nitratos foi detectada em ambos os surtos pelo teste de difenilamina. Testes quantitativos foram realizados no segundo surto usando um medidor portátil de nitrato, e altas concentrações de nitrato foram encontradas. Os achados macroscópicos característicos e a ausência de lesões microscópicas e a resposta ao tratamento com azul de metileno foram fundamentais para o diagnóstico de intoxicação por nitratos e nitritos. Concluímos que a intoxicação por nitratos e nitritos em ruminantes na região semiárida do Nordeste do Brasil é frequente devido ao cultivo de gramíneas nas bordas de barragens que estiveram cobertas por água por longos períodos ou em áreas irrigadas por água poluída e/ou esgoto. Além disso, o uso de medidor portátil é uma alternativa eficaz para a quantificação de nitratos em pastagens.(AU)

Melanomas em cães no Sertão do Nordeste do Brasil - epidemiologia, fatores de risco e achados clinicopatológicos / Melanoma in dogs in the backlands of Northeastern Brazil - epidemiology, risk factors and clinicopathological findings

Background: Melanoma is a malignant neoplasm that arises from melanocytes and malanoblasts. It is also more frequently reported in dogs than in other species. They may arise from melanocytes in the skin, on the surfaces of the mucous membranes, and eyes. The aim of this study was to describe the epidemiological aspects, risk factors and clinicopathological findings of melanoma in dogs in the backlands, northeastern Brazil. Materials, Methods & Results: A retrospective study was carried out in all biopsy samples and necropsy examinations of dogs, from January 2003 to December 2021, at the Animal Pathology Laboratory of the Federal University of Campina Grande, Patos, Paraiba, northeastern Brazil. Epidemiological data, clinical signs, and gross lesions were reviewed from the diagnostic laboratory reports. Samples of the skin, lymph nodes, central nervous system and organs of the thoracic and abdominal cavities were fixed in 10% buffered formalin, processed routinely for histopathology, embedded in paraffin wax, cut into 4 µm sections, and stained with hematoxylin and eosin (HE). Histological sections were also submitted to immunohistochemistry with the primary antibody anti-Melan A. Of the 4717 records found, 1158 (24.5%) were diagnosed with neoplasms, of which 48 (4.14%) cases were of melanoma. Of this total, 28 (58.3%) dogs were elderly, 19 (39.6%) were adults, and 1 (2.1%) was young. Mixed breed animals were the most affected (42.6%), followed by the pinscher breed (19.1%). According to the anatomical region, the most affected site was the skin (38/53=71.7%), followed by the oral cavity (12/53=22.65%) and the eyes (3/53=5.7%). Grossly, the skin lesions were characterized by exophytic and usually blackened, sometimes irregular and firm, nodules. At cut, they had a smooth, compact and blackened surface. Lesions in the oral cavity were characterized by blackened, irregular and infiltrating nodules or masses. The ocular lesions were always unilateral and were characterized by an enlarged and diffusely blackened eyeball, with areas of ulceration and subversion of tissue architecture. In 5 animals there was more than one anatomical site affected, totaling 53 lesions. In 9 (17%) cases, metastases were identified, 8 in regional lymph nodes and 1 in the lung. Histopathology showed a densely non-encapsulated, poorly delimited, expansive and infiltrative neoplasm, composed of neoplastic cells arranged in islands or nests and supported by fibrovascular stroma, containing a variable amount of brownish pigment (melanin). Immunohistochemistry showed strong immunostaining of the neoplastic cells in brown by the anti-Melan A antibody. Discussion: The diagnosis of melanoma was established based on epidemiological, clinical, anatomopathological, and immunohistochemical findings. Gender is not a predisposing factor, and although there was no statistically significant relationship, males were more affected. Senescence is a conditioning risk factor. Elderly animals were more affected (P < 0.0001) than adult ones, with OR = 4.38; and young ones (P = 0.0051), with OR = 12.65. Some breeds, especially those with marked skin pigmentation, were more affected, however the most affected ones in this survey were pinscher and poodle. Cutaneous melanoma accounted for almost 72% of cases, contesting recent studies where oral cavity melanoma was more frequent. Therefore, it is believed that the climatic conditions of the backlands sub-region, in northeastern Brazil, associated with the individual characteristics of the dogs, are involved in the development of these neoplasms, since the climate is predominantly dry, with high temperatures throughout the year, with maximums that can reach 40ºC, favoring the exposure to high incidence of ultraviolet radiation.