Pathology in Practice. Poorly productive, osteoblastic osteosarcoma of the left paranasal sinuses in a 1-year-old colt

A 1-year-old 195-kg (429-lb) Quarter Horse colt, procured for resale purposes, was evaluated at the Auburn University Large Animal Teaching Hospital because of continuous bilateral, mucopurulent nasal discharge accompanied by respiratory noise of 6 months’ duration. The respiratory noise had worsened during the week prior to the evaluation. The colt had been treated intermittently with systemic broad-spectrum antimicrobials without a positive response. Clinical and radiographical examination revealed a poorly demarcated sinusitis of the left maxillary and conchofrontal sinuses. Surgical exploration of the involved left paranasal sinuses and histological examination of the mass allowed the diagnosis of a poorly productive, osteoblastic osteosarcoma

Retrospective evaluation of clinical outcome after chemotherapy for lymphoma in 15 equids (1991‐2017)

BackgroundPrognosis associated with lymphoma in horses is poorly characterized, and treatment is often palliative. Long-term outcome after chemotherapy for horses with lymphoma is not well documented.ObjectiveTo report long-term outcome of horses with lymphoma treated with chemotherapy.AnimalsFifteen equids.MethodsRetrospective case series. Medical record search and call for cases on the ACVIM listserv for horses treated with chemotherapy for lymphoma.ResultsFifteen cases with adequate data were identified. Complete remission was achieved in 5 horses (33.3%), partial response was achieved in 9 equids (60%), and stable disease was achieved in 1 horse. Overall response rate was 93.3% (14/15). Overall median survival time was 8 months (range, 1-46 months). Nine horses experienced a total of 14 adverse effects attributable to chemotherapy. Adverse effects were graded according to the Veterinary Cooperative Oncology Group common terminology criteria for adverse events grading system (grade 1 alopecia, n = 2; grade 1 neutropenia, n = 2; grade 1 lymphopenia, n = 3; grade 1 lethargy, n = 1; grade 2 neurotoxicity, n = 1; grade 2 colic, n = 1; grade 1 hypersensitivity, n = 1; grade 2 hypersensitivity, n = 2; grade 5 hypersensitivity, n = 1). Higher grade adverse effects most commonly were associated with doxorubicin administration (n = 4), including 1 horse that died 18 hours post-administration.Conclusions and clinical importanceChemotherapy can be used successfully for treatment of horses with lymphoma. Adverse effects, most commonly mild, occurred in approximately two-thirds of treated horses