Immunohistochemical evidence of canine morbillivirus (canine distemper) infection in coatis (Nasua nasua) from Southern Brazil.

The pathological and immunohistochemical (IHC) findings associated with infection due to canine morbilivírus (canine distemper virus, CDV) are described in coatis (Nasua nasua). Tissue fragments of coatis (n = 13) that died at the Bela Vista Sanctuary, Paraná, Southern Brazil, were routinely processed for histopathology to identify the main histopathologic patterns as compared to that of the domestic dog. Selected formalin-fixed paraffin-embedded (FFPE) tissue fragments of the lungs, liver, urinary bladder and small intestine were used in IHC assays designed to identify the antigens of CDV, canine adenovirus (CAdV-1 and CAdV-2) and canine parvovirus type 2 (CPV-2). The main histopathologic patterns identified were interstitial pneumonia (n = 9), interstitial nephritis (n = 6), atrophic enteritis (n = 4) and ballooning degeneration of the uroepithelium (n = 3). Positive immunolabelling for intralesional antigens of CDV was identified in the lung with interstitial pneumonia (n = 3), in the intestine (n = 2) and in the degenerated epithelium of the urinary bladder (n = 2). Antigens of CPV-2, CAdV-1 and CAdV-2 were not identified in any FFPE tissue sections evaluated. These findings indicate that these wild carnivores were infected by a viral disease pathogen common to the domestic dog and develop similar histopathologic findings. Collectively, these findings suggest that these coatis were infected by CDV and can serve as a potential host for this infectious disease pathogen.

Immunohistochemical characterization of cutaneous leishmaniasis in cats from Central-west Brazil.

Feline leishmaniasis (FeL) is an emerging infectious disease of cats caused by Leishmania infantum with global distribution. This study investigated the cause of chronic progressive cutaneous lesions in two cats from Central-west Brazil by using cytological, histopathologic, and immunohistochemical (IHC) analyses. Clinically, both cats had ulcerative cutaneous lesions at the nasal planum and ear resulting in a tentative diagnosis of squamous cell carcinoma (SCC). Moreover, both cats had varying degrees of onychogryphosis. However, cytology revealed chronic inflammatory reactions associated with intralesional amastigotes; histopathology confirmed chronic ulcerative dermatitis associated with intralesional and intracytoplasmic parasitic organisms consistent with amastigotes of Leishmania spp. within histiocytes. The IHC assay demonstrated that the intralesional parasitic structures identified by cytology and histopathology were immunoreactive to antigens of Leishmania spp., confirming the participation of this infectious disease agent in the development of the cutaneous lesions of these cats. The observation of onychogryphosis must be highlighted, since this lesion is frequently observed in dogs with visceral leishmaniasis but is underreported in FeL. Collectively, the pathologic and IHC findings of the chronic cutaneous disease confirmed active infections due to Leishmania spp. in these cats. Additionally, FeL with associated lesions to the ear and nasal planum must be considered as differential diagnosis for SCC in cats.

Disseminated melanized fungal infection due to Cladosporium halotolerans in a dog coinfected with canine adenovirus-1 and canine parvovirus-2.

This report presents the pathologic findings associated with disseminated infection due to Cladosporium halotolerans in a dog that was simultaneously infected with canine adenovirus-1 (CAdV-1) and canine parvovirus-2 (CPV-2). A 12-year-old, mixed breed dog, with a clinical history of neurological manifestations was submitted for routine autopsy due to poor prognosis. The principal pathologic findings were mycotic necrotizing nephritis, hepatitis, and splenitis with embolic dissemination to the brain resulting in mycotic necrotizing meningoencephalitis, ventriculitis, choroid plexitis, and obstructive hydrocephalus associated with intralesional and intravascular septate pigmented fungi. PCR and sequencing of the ITS region of fungi revealed that the intralesional fungal organisms had 82% nucleotide identity with members of the Cladosporium sphaerospermum complex of organisms. However, a PCR assay and sequencing of the beta tubulin gene confirmed that the organism identified in this dog had 100% nucleotide sequence identity with C. halotolerans. Using immunohistochemistry, intralesional antigens of CAdV-1 were identified within the epithelial cells of the liver and lungs; there was positive immunolabeling for CPV-2 antigens in degenerated cardiomyocytes. These findings confirmed the active participation of C. halotolerans in the development of disseminated cladosporiosis in this dog and represent a rare occurrence of concomitant infection with CAdV-1 and CPV-2.