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Background: Congenital malformations are anomalies, structural or functional, that occur during the embryonic or fetal phase. There are several causes, one of which is the ingestion of toxic plants. Considering the importance of native toxic plants in the Central Backlands of Ceará state - Brazil, this paper reports cases of congenital malformations in sheep due to ingestion of Mimosa tenuiflora. Cases: Cases of abortion and malformations in sheep, were monitored in a rural property in the municipality of Piquet Carneiro with 20 ruminants (15 sheep and 5 cows) raised on a semi-intensive regime. The animals grazed during the day and were supplemented with corn, having unrestricted access to dam water. On its margins, there was a large amount of jurema preta (Mimosa tenuiflora), which the owner reported that the sheep consumed daily. The owner was unaware of the toxicity of M. tenuiflora but reported that cases of malformations had already occurred on his property some time ago. In an interval of approximately 12 days, 3 sheep miscarriage fetuses with multiple malformations. Malformed fetuses were referred for anatomopathological examination at the Animal Pathology Laboratory of the Veterinary Hospital of Federal University of Campina Grande (UFCG), Campus Patos, Paraíba, Brazil. The fetuses were necropsied and tissue samples of the nervous system and organs from the thoracic and abdominal cavities were collected, fixed in 10% neutral buffered formalin, routinely processed for histopathology, included in paraffin, cut into 3 µm sections and stained with hematoxylin and eosin (HE). At necropsies were observed permanent contracture of the thoracic limb joints (arthrogryposis), particularly at the radio-carpal joints; incomplete medial fusion of the palatal bone, with communication between the oral and nasal cavities (palatoschisis); hypoplasia of the mandibular bone (micrognathia); unilateral hypoplasia of the incisive bone with discontinuity of the upper lip (cheiloschisis); unilateral hypoplasia of the eyeball (microphthalmia); lateral curvature of the cervical spine (scoliosis); and chest deformity characterized by ventral protrusion of the sternum and ribs (Pectus carinatum). At the histopathological evaluation of the tissues, no alterations were observed. Discussion: The diagnosis was based on the epidemiological, clinical, and anatomopathological findings. The semi-intensive management system applied on the property predisposed the sheep to ingestion of M. tenuiflora, which grows abundantly on the property and throughout the Central Backlands of Ceará, Brazil, with a high rate of geographical coverage. Despite that, most rural producers, especially subsistence farmers, are unaware of the toxic and teratogenic properties of the plant. In the northeastern, where there are long periods of drought coupled with forage shortages, poisoning by M. tenuiflora is a common cause of malformation and mortality in lambs. Therefore, it is necessary to adopt preventive measures in herds, such as raising awareness among producers about the toxic potential of some native plants and the practice of producing and supplying silage to animals, so that native toxic plants are not the only food source during the scarcity period. [ABSTRACT FROM AUTHOR]

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 meningoencephalitis, multifocal to coalescing, accentuated, chronic, and associated with numerous pigmented fungi. Fontana-Masson–stained fungi exhibited a strong black color. In cleared and unstained histological slides, brownish pigmentation was observed in the cytoplasm and walls of the fungi. C. bantiana was identifi ed via microbiological cultivation. Discussion: A diagnosis of phaeohyphomycosis caused by C. bantiana was made based on the characteristic morphology of the microscopic lesions and confirmed via isolation in microbiological culture. As numerous species cause phaeohyphomycosis, specific confirmation of the etiologic agent using several diagnostic techniques is necessary. In histopathological examinations, pigmented fungal organisms are easily seen among lesions. However, in some cases, the pigment is not apparent in the tissues. FM staining is necessary to demonstrate the presence of the melanin in fungi. As in most phaeohyphomycosis cases, it was not possible to determine the primary portal of entry. However, the lesion on the right thoracic limb probably favored the penetration of the agent. In addition to cerebral lesions, severe lesions in the hepatic and renal parenchyma were observed, which are characteristic of systemic mycosis. Infection and clinical diseases are usually associated with immunocompromised; here, the gestation period may have had an immunosuppressive effect, favoring the proliferation and dissemination of the agent. It was concluded that phaeohyphomycosis caused by C. bantiana produced severe systemic lesions in the brain and organs of the abdominal cavity. Although uncommon, phaeohyphomycosis caused by Cladophialophora bantiana should be included as a differential diagnosis for other canine diseases that present with similar clinical symptoms. [ABSTRACT FROM AUTHOR]

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 radiatio [ABSTRACT FROM AUTHOR]

Background: Aspergillus spp. are dimorphic fungus widely distributed in the environment, including in soil, dust and decaying vegetation. Clinical signs of aspergillosis in horses including rhinitis, pneumonia, guttural pouch mycosis, keratomycosis, endometritis, abortions and systemic involvement. In addition, horses with a history of enterocolitis may be predisposed to pulmonary or systemic mycotic infection. However, reports about systemic aspergillosis in horses are restricted to infections by A. fumigatus and A. niger. There have been no reports of systemic infection caused by A. flavus in horses or in other domestic species. Thus, the objective of this work was to describe the epidemiological, clinical and pathological aspects of systemic infection by Aspergillus flavus in a mare. Case: A 3-year-old pregnant mare of the Manga Larga, had signs of colic two days prior to admission after grazing in a landfill area to which it had free access. The owner observed remains of plastic bags in the stool. Clinically, there was dehydration, apathy, ocular mucosal congestion, oral cyanosis, reluctance to move, diarrhea, fever, drooling and tachypnea. Due to its clinical condition, the animal was referred to the surgical center for exploratory laparotomy, where compaction in the colon and cecum was verified. Enterotomy and enterolith removal were performed in the small colon region. The mare died after eight days of hospitalization, and necropsy was performed. Macroscopically disseminated lesions were observed in the small colon, stomach, kidneys, lungs, heart and brain. Fragments of tissues from organs in the abdominal and thoracic cavities, as well as from the central nervous system, were collected, fixed in 10% buffered formalin solution, and subsequently routinely processed and stained with hematoxylin and eosin and special histochemical stains to visualize the infectious agent and its morphological characteristics. Samples of lung lesions were submitted to microbiological culture for isolation. Fragments of fungal colonies were conserved in mineral oil for molecular analysis. Histologically, lesions showed acute, necrosuppurative colitis, gastritis, pneumonia, myocarditis, nephritis and meningoencephalitis, associated with vasculitis, thrombosis, infarction and intralesional hyphae that were morphologically compatible with Aspergillus spp. The species A. flavus was identified based on isolation and polymerase chain reaction analysis. Discussion: A diagnosis of systemic aspergillosis caused by Aspergillus flavus was determined by the microscopic examination of lesions associated with characteristic intralesional fungal hyphae and the isolation and identification of the fungal DNA by PCR. A pre-existing disease associated with debilitating factors, including the period of pregnancy, postpartum stress, internment, surgery and the intensive use of antimicrobials and corticosteroids, probably contributed to immunosuppression that favored the proliferation of the infectious agent. Grazing for a long period of time in a place with abundant decomposing organic matter, which is favorable to the proliferation of fungi of the genus Aspergillus, may have been a determining factor leading to the infection in the present case as the animal was likely exposed to an excessive number of spores. It is believed that the fungal microorganisms already present in the gastrointestinal tract invaded the surgery-induced lesions present in the mucosa of the small colon and later disseminated to various organs, including heart, lungs, stomach, kidneys and brain. Aspergillus flavus can cause enteric infection and hematogenous dissemination in horses, triggering lesions in the heart, lungs, stomach, kidneys and brain, which are characteristic of the systemic form of aspergillosis. [ABSTRACT FROM AUTHOR]

Background: Candida spp. are pleomorphic fungi that are commensal inhabitants of the oral, gastrointestinal, upper respiratory and urogenital mucosa of mammals. Candida albicans is described as the most important species. This opportunistic pathogen may produce local or systemic infections in dogs. Local infections have been reported in several tissues and systemic infection is rare in dogs with few reports in the literature describing this presentation. The aim of the present study was to report two cases of cerebral Candida albicans infection in dogs in Brazil. Case: Two cases of cerebral Candida albicans infection in dogs that showed nervous signs are described. In both cases, the brain showed marked asymmetry of the telencephalic hemispheres with multifocal to coalescing yellowish or reddish areas and a partial loss of distinction between gray and white matter. In Case 1, the mediastinal, tracheobronchial and mesenteric lymph nodes, as well as the right kidney and adrenal gland, showed altered architecture due to numerous whitish gray nodules. Histological lesions were characterized by granulomatous (case 1) or pyogranulomatous (case 2) necrotizing meningoencephalitis with intralesional fungal organisms. In case 1, similar granulomatous infiltrate with intralesional fungal organisms was also seen in the lymph nodes, kidney and adrenal gland. In case 2, there was evidence consistent with an underlying infection of canine distemper virus. Were observed lymphoplasmocytic interstitial pneumonia, lymphoid rarefaction in lymph nodes, and viral intracytoplasmic inclusion bodies in the epithelial cells of the stomach and vesical urothelium. In these two cases, the fungal organisms displayed three different morphological patterns. The first pattern was characterized by delicate tubular structures with thin parallel walls that were rarely septate and tended to undulate slightly, and measured approximately 4-20 µm (true hyphae). The second pattern was characterized by chains of elongated yeast, separated by constrictions at septal sites, and measured approximately 4-10 µm (pseudohyphae). The other morphological pattern, which was rarely observed, was characterized by round budding yeast cells that measured 3-4 µm in diameter and were often elongated by the germ tube. Sections were also stained using immunohistochemical antibodies against Candida albicans. The fungi revealed strong immunolabelling of the cytoplasm and wall for Candida albicans. Discussion: The diagnosis was based on the histomorphological and immunohistochemical characteristics of the agent, which were consistent with Candida albicans. In these two cases, immunocompromise appeared to have been an important factor in the progression of the infection. In case 1, the dog was senile and treated with corticosteroids, conditions that could effectively limit innate, humoral and cell-mediated immune response to infection. In case 2, the dog displayed cachexia and was infected by canine distemper virus, evidenced by the presence of viral inclusion bodies. The inflammatory reactions in both cases were characteristic of fungal infections, but were distinct due to differences in the infectious process. In case 1, there was a subacute to chronic progression; while in case 2 neutrophilic infiltrate predominated, suggesting an acute progression. The different morphological patterns of the fungi suggested a pleomorphic fungi and the immunohistochemistry allowed us to identify the infectious agent. In conclusion, opportunistic infections caused by Candida albicans should be considered when diagnosing diseases that affect the central nervous system of dogs, particularly in immunosuppressed animals. [ABSTRACT FROM AUTHOR]

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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, redbrown, 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The eosinophilic granuloma is defined by dense cellular infiltration of eosinophils, macrophages, and mast cells, in addition to collagenolysis foci. Canine eosinophilic granuloma is a rare inflammatory skin disease that affects the oral mucosa. However, the cutaneous eosinophilic granuloma is more evident and can be found in the scrotum, testicles, perineum, and flanks. The etiology of eosinophilic granuloma in dogs is unclear but allergic processes can originate in granulomatous nodules or plaques. Affected dogs may experience itching, swelling, and, occasionally, pain. The histopathological analysis is necessary for a definitive diagnosis. The present case report described a 12-year-old male dog, Poodle, with a history of swelling, itching, and pain in the scrotum. Complete clinical staging was performed through blood count, biochemistry analysis, thoracic radiographs, abdominal ultrasound, and electrocardiogram. The dog was submitted for surgical removal followed by histopathologic evaluation. Eosinophilic granuloma should be included in the differential diagnosis of solitary masses in the scrotal region. [ABSTRACT FROM AUTHOR]