Background: Peripheral nodal B-cell lymphomas (PNBCL) represent the most common presentation of lymphomas in dogs. Multiagent CHOP (C = cyclophosphamide, H = hydroxydaunorubicin [Doxorubicin], O = Oncovin, P = prednisolone)-based chemotherapy protocols have been widely accepted as gold standard 1st-line treatment. CHOP-25 and CHOP-19 are most commonly prescribed but have never been directly compared. Objectives: Our primary aim was to compare outcomes of dogs diagnosed with PNBCL, treated using a 1st-line CHOP-19 or CHOP-25 protocol. A secondary objective was to determine the impact of protocol-related variables on outcomes. Animals: Five hundred two dogs from 16 European oncology referral centers. One hundred fifty-five dogs were treated with CHOP-19 and 347 dogs with CHOP-25. Methods: Retrospective, multicentric cohort study of dogs diagnosed with PNBCL between 2014 and 2021. Results: The 6-month, 1-year, and median progression-free survival (PFS) were 56.5% (95% confidence interval [CI], 49.2-65.0), 14.1% (95% CI, 9.4-21.0), and 196 days (95% CI, 176-233) with CHOP-19; and 56.4% (95% CI, 51.4-61.9), 17% (95% CI, 13.4-21.6), and 209 days (95% CI, 187-224) with CHOP-25. The 1-year, 2-year and median overall survival (OS) were 36.9% (95% CI, 29.7-46.0), 13.5% (95% CI, 8.6-21.1), and 302 days (95% CI, 249-338) with CHOP-19; and 42.8% (95% CI, 37.7-48.7), 15.4% (95% CI, 11.7-20.4), and 321 days (95% CI, 293-357) with CHOP-25. No significant difference in PFS and OS was found between the 2 protocols. Conclusions and Clinical Importance: Our study confirmed similar outcomes for dogs with PNBCL treated with 1st-line CHOP-19 or CHOP-25. Both protocols therefore could be used as a standard of care in future trials.

Canine inflammatory mammary carcinoma (IMC) is an aggressive and rare type of mammary gland cancer in dogs where vascular endothelial growth factor and cyclooxigenase-2 overexpression usually occur, which contribute to its invasive and angiogenic nature. This study aimed to evaluate the efficacy and safety of a combined treatment regimen of toceranib phosphate and carprofen in dogs with measurable IMC. Fifteen female dogs with histopathologically confirmed IMC were included, undergoing a regimen of toceranib (2.4–2.75 mg/kg PO, three times weekly) and carprofen (4.4 mg/kg/24 h PO). Initial evaluations included physical exams, tumor measurements, complete blood count, biochemistry, urinalysis, three view thoracic radiographs, and abdominal ultrasound. Follow-up assessments of physical condition and quality of life (QOL) were conducted bi-weekly, with tumor response evaluations monthly, using RECIST v1.0 criteria. While no complete or partial responses were observed, 60% of the dogs maintained stable disease, with a median progression-free survival of 76 days and an overall survival of 90 days. Notably, 60% of the dogs showed clinical benefit through improved QOL and disease stabilization. The treatment was well-tolerated, with only grade I/II toxicities reported. Despite limited biological activity against the cancer, this protocol may enhance QOL in dogs with IMC, offering a valuable palliative option.

Background: Listeriosis is a severe foodborne infection caused by Listeria monocytogenes, an important foodborne pathogen of animals and humans. Listeriosis is a rare disease in cats. Objective: To describe the clinical, diagnostic imaging, histological, and microbiological features of L. monocytogenes-associated mesenteric lymphadenitis in a cat. Animals: Listeria monocytogenes-associated mesenteric lymphadenitis was confirmed in a cat by histology and microbiology. Results: Two distinct isolates of L. monocytogenes were cultured from the affected mesenteric lymph node and whole genome sequencing was performed. Conclusion and Clinical Importance: This report should alert veterinary clinicians and microbiologists to the syndrome, which may have implications for health and food safety in animals and humans.