Diffuse large B-cell lymphoma affecting the third eyelid of two young adult FeLV-infected cats.

Lymphoma is one of the most frequently diagnosed tumors in FeLV-infected cats. Extranodal lymphomas include lymphomas in ocular and periocular tissues, such as the third eyelid (TEL), which is an uncommonly diagnosed type of lymphoma in cats. This study aimed to describe the clinicopathological features of lymphoma in the TEL of two FeLV-infected cats. A retrospective study in two anatomic pathology laboratories was performed, and two cases met the inclusion criteria. A 4-year-old, female cat (case 1), positive for FIV gp40 antigen and FeLV gp70 antigen by immunohistochemistry (IHC), and a male cat of 22 months old (case 2), positive both serologically for FeLV p27 antigen and for FeLV gp70 antigen by IHC, were referred to veterinary clinics with unilateral swelling and mass in the TEL, which had rapid growth in case 2. Histological and immunohistochemical analysis established the final diagnosis of diffuse large B-cell lymphoma in both cases. The cat in case 2 died 4 months after the diagnosis, with clinical worsening prior to death. Necropsy was not performed in either case, which precluded the definition of a primary or secondary involvement. However, the ocular lesions were the reason for consultation in both cases and it may have been an initial manifestation of a multicentric disease. Thus, FeLV-infected cats with clinical finding of eyelid swelling or mass formation should have lymphoma as a differential diagnosis, and a complete physical examination should be performed to detect extraocular involvement.

Genotypic characterization of Streptococcus didelphis causative of fatal infection in white-eared opossums.

Streptococcus didelphis was once reported as related to severe infections in opossums. Thus, we present the first comprehensive whole-genome characterization of clinical S. didelphis strains isolated from white-eared opossums (Didelphis albiventris). Long-read whole-genome sequencing was performed using the MinION platform, which allowed the prediction of several genomic features. We observed that S. didelphis genomes harbor a cluster for streptolysin biosynthesis and a conserved genomic island with genes involved in transcriptional regulation (arlR) and transmembrane transport (bcrA). Antimicrobial resistance genes for several drug classes were found, including beta-lactam, which is the main antimicrobial class used in Streptococcus spp. infections; however, no phenotypical resistance was observed. In addition, we predicted the presence of 33 virulence factors in the analyzed genomes. High phylogenetic similarity was observed between clinical and reference strains, yet no clonality was suggested. We also proposed dnaN, gki, pros, and xpt as housekeeping candidates to be used in S. didelphis sequence typing. This is the first whole-genome characterization of S. didelphis, whose data provide important insights into its pathogenicity.

Abortion outbreak in a sheep flock caused by Toxoplasma gondii clonal type III.

Toxoplasma gondii is a major cause of reproductive losses in small ruminants in several countries. We describe here an outbreak of T. gondii-associated abortion in sheep in Southern Brazil. The flock was comprised of 55 adult sheep, and late-term abortions and stillbirths were detected in 15/36 (41.66%) gestating ewes. Serum samples collected from 45 sheep were tested for T. gondii through indirect immunofluorescence assay; IgM and IgG positive results were detected in 44.44% (20/45) and 86.67% (39/45) of the cases, respectively. Four fetuses and two placentas were pathologically evaluated. Gross changes were restricted to fetal membranes and were characterized by multifocal white areas in the cotyledons. Microscopically, these areas corresponded to necrotic foci affecting the chorionic epithelium accompanied by rare cysts of T. gondii. The main histological change in fetal tissues consisted of well-demarked and sparsely distributed necrotic foci in the central nervous system. Tissue samples from all four fetuses and one placenta had positive PCR results for T. gondii. Restriction fragment length polymorphism (RFLP) genotyping using ten markers (SAG1, 5'-3'SAG2, alt.SAG2, SGA3, BTUB, GRA6, c22-8, c29-2, L358, and PK1) was carried out on one sample, and results were consistent with T. gondii clonal type III (ToxoDB-PCR-RFLP genotype #2, TgCpBr4).

Ophthalmopathologic characterization of multicentric or metastatic neoplasms with an extraocular origin in dogs and cats.

OBJECTIVE: To characterize the frequency and distribution of secondary ocular neoplasms in dogs and cats identified during necropsy. METHODS: A retrospective analysis of necropsy records of dogs and cats was conducted, and cases with metastatic/multicentric neoplasms with an extraocular origin, involving the eyes, were selected. RESULTS: From January 2015 to January 2019, we identified a total of 233 dogs and 100 cats with metastatic disease. Of these, 11.6% (27/233) of the dogs and 13% (13/100) of the cats had ocular metastases. Lymphoma was the most common multicentric neoplasm involving the eyes of both species. In dogs, these neoplasms occurred bilaterally, predominantly in the anterior uvea, and were diffuse large B-cell, T-lymphoblastic, peripheral T-cell not otherwise specified, and lymphocytic B-cell lymphomas. In cats, feline leukemia virus (FeLV)-associated T-cell lymphoma was the most common. Mammary carcinoma was the second most common ocular metastatic neoplasm in bitches, with a predominantly unilateral involvement of the uveal tract. In cats, following lymphoma, pulmonary and squamous cell carcinomas were the most common multicentric/metastatic neoplasms of the eyes. Individual cases of cholangiocarcinoma, hemangiosarcoma, and chemodectoma in dogs, as well as mammary gland cribriform carcinoma, salivary gland carcinoma, and histiocytic sarcoma in cats were detected. CONCLUSIONS: The eyes of dogs were mostly affected by lymphoma or mammary gland carcinoma, while those of cats mostly had lymphoma, pulmonary carcinoma, or squamous cell carcinoma as the main metastatic/multicentric neoplasm. To the best of our knowledge, this is the first study to identify intraocular metastatic cholangiocarcinoma and chemodectoma in dogs, aside from identifying salivary gland carcinoma in cats.