Diphtheric aspergillosis tracheitis is an uncommon syndrome described in human pathology, usually associated with immunosuppression in the affected individuals. Interestingly, no comparative/equivalent cases were found in domestic animals. This report describes the pathological and mycological findings associated with diphtheric aspergillosis tracheitis in an immunocompromised calf. The main pathological findings were diphtheric tracheitis and rhinitis, and necrotizing ruminitis associated with intralesional septate, acute branching fungal hyphae consistent with Aspergillus spp. Mycological culture and isolation confirmed the fungal hyphae as A. fumigatus due to characteristic features. Immunohistochemistry (IHC) assays identified intralesional antigens of bovine viral diarrhea virus (BVDV) and malignant catarrhal fever virus (MCFV) at the trachea and small intestine; IHC detected intralesional antigens of bovine alphaherpesvirus 1 (BoHV-1) only at the trachea. These findings confirmed the simultaneous occurrence of A. fumigatus with concomitant infections due to BVDV, MCFV, and BoHV-1 in this calf. Since ovine gammaherpesvirus-2 (OvHV-2) is the cause of MCF in Brail, it is likely that the intralesional MCFV antigens identified were those of OvHV-2. In this case, disseminated aspergillosis was probably associated with the undeveloped immunological status of the calf that was further impaired due to the combined immunodepressive effects of BVDV and BoHV-1 infections. Although BVDV and BoHV-1 are infectious disease pathogens frequently associated with the development of bovine respiratory disease (BRD) in feedlot and dairy cattle, the identification of intralesional OvHV-2-like antigens in several parts of the lungs suggest that this MCFV also played a role in the BRD-associated lesions identified in this calf.

Background: Calf diarrhea remains one of the main diseases affecting the cattle industry. Persistence of this significant problem is associated with the complexity of factors that may be involved (infectious, environmental). An accurate diagnosis is essential for confirming the cause and helping clinicians and cattle producers to apply appropriate strategies in a timely manner. This report describes the histological changes according to the degree of salmonellosis severity, which is a contagious infectious disease caused by Salmonella enterica subsp. enterica, a Gram-negative bacterium, in two beef calves in northern Paraná State, southern Brazil. Cases: Two 90-day-old crossbred Angus and Nellore calves from a beef farm in northern Paraná State were referred to a Veterinary Hospital. Animal 1- developed acute clinical signs (enteritis, ataxia, and muscle rigidity) and died the day after the signs began. Gross findings included heavy and non-collapsed lungs, pulmonary oedema, hepatomegaly, enteritis, and severe diffuse typhlitis. Microscopic analysis revealed severe diffuse necrotic enteritis, typhlitis, severe diffuse interstitial pneumonia, moderate centrilobular hepatic necrosis, mild multifocal nephritis, and severe spleen and lymph node necrosis. Paratyphoid nodules were evidenced on the liver, spleen, and mesenteric lymph nodes. Animal 2- presented apathy, green fibrinous diarrhea, and died three days after the onset of clinical signs. The macroscopic examination showed moderate diffuse enteritis and hepatosplenomegaly. At the microscopic examination, many paratyphoid nodules were observed on the liver, spleen, kidneys, and Peyer's patches, which were associated with intralesional and intravascular bacilli. Additional findings included severe diffuse fibrinous necrotic enteritis with intralesional bacilli, diffuse interstitial pneumonia, multifocal splenic necrosis, lymphoid depletion, and moderate multifocal to coalescent lymphocytic nephritis. Histological Gram staining was performed on selected samples, revealing intralesional Gram-negative bacilli in the liver and intestine. Thus, liver and intestine fragments were used for the microbiological examination. Microbiological culture, isolation and biochemical tests identified the genus Salmonella spp. Then, the colonies were subjected to serological tests for serovar identification, according to ISO/TR 6579-3, which determined the serovar Dublin. After identifying the disease etiological agent, the outbreak was controlled by appropriate antibiotic therapy combined with the correction of sanitary measures.Discussion: Enteritis is a frequent disease in calves, posing a diagnostic challenge in identifying the etiological agent. In the present case, the histological, microbiological, and serological results confirmed a disseminated Salmonella spp. infection. The microscopic findings, such as interstitial pneumonia, fibrinous necrotic enteritis markedly in ileum and paratyphoid nodules in various organs, are the most common aspects of the disease. However, fibrinous cholecystitis, which is considered pathognomonic for salmonellosis, was not observed in this study. Therefore, the absence of such a lesion should not exclude the disease in sick animals. A microscopic injury score was used to determine lesion severity by assigning values from 1 to 4, wherein: 1 = no apparent lesions, 2 = mild lesions, 3 = moderate lesions, and 4 = severe lesions. Both calves were scored as 4. Multiple predisposing factors for the condition were identified in this farm such as different age animals in the same paddock and no specific paddock for sick animals, given that the infectious agent remains in feces, saliva, and nasal discharge. The serovar Dublin induces several clinical signs such as septicemic, respiratory, and enteric manifestations, making a clinical diagnosis a challenge. Keywords: dysbiosis, calf diarrhea, infection, paratyphoid nodules, septicemia.Descritores: disbiose, diarreia neonatal, infecção, nódulos paratifoides, septicemia.Título:  Salmonelose em bezerros pelo sorovar Dublin no estado do Paraná, Brasil - aspectos clínico-patológicos

O rabdomiossarcoma botrióide é uma variante do rabdomiossarcoma embrionário e tem origem nas células musculares estriadas, ou precursores destas células, por isso podem se iniciar em partes do corpo com ausência de músculo estriado, como o trato urogenital. Geralmente, os cães acometidos são jovens até dois anos e as massas neoplásicas têm aspecto de cacho de uva. O objetivo do presente relato foi descrever um caso de rabdomiossarcoma botrióide em um cão, American Pittbull Terrier, de 16 meses que apresentou uma massa no interior da vesícula urinária, posteriormente diagnosticada através de exame histopatológico e imunoistoquímico. A massa era multilobulada, firme, rósea a vermelha com áreas multifocais de necrose e estava aderida na mucosa da região mais cranial da vesícula urinária emitindo ramificações disseminadas em direção ao trígono vesical. Microscopicamente, a neoplasia é constituída por duas populações celulares entremeadas a uma matriz mixóide, uma composta por células pequenas e redondas, com citoplasma escasso e núcleo basofílico hipercorado e a outra por células alongadas, com citoplasma eosinofílico e núcleo paracentral, ambas as populações celulares possuíam pleomorfismo moderado e 2 figuras de mitose por campo (400 x). Densidade celular aumentada foi observada abaixo do epitélio vesical. A combinação de exames complementares foi conclusiva para o diagnóstico da neoplasia.