Lymphoma comprises approximately 25 percent of all canine cancers. Up to 40 percent of these cases are caused by T lymphocytes, known as peripheral T cell lymphoma (PTCL). The vast majority of lymphoma cases cannot be addressed with surgery and instead warrant chemotherapy. The standard of care chemotherapy protocol for lymphoma is abbreviated CHOP, which stands for the 4 drugs involved. Generally, dogs with PTCL treated with CHOP chemotherapy tend to experience shorter remission durations and overall survival than dogs with diffuse large B cell lymphoma (DLBCL). When treated with CHOP chemotherapy, PTCL dogs have a median survival time of 4-9 months, while DLBCL dogs have a median survival time of 11-13 months.

Previous studies have questioned whether other, non-CHOP protocols may be better suited for dogs with PTCL in hopes of increasing remission and survival times. One protocol that has been repeatedly investigated is LOPP chemotherapy. This protocol uses two of the same drugs as CHOP and two that are different. Recent studies have demonstrated that dogs with PTCL treated with LOPP can experience survival times closer to 11-17 months. While these findings are promising, none of these investigations have had a control arm of dogs receiving CHOP chemotherapy.

The purpose of this study is to provide a direct comparison between the outcomes for dogs with peripheral T cell lymphoma (PTCL) treated with CHOP or LOPP chemotherapy. The findings of this study could help veterinarians understand if one protocol is truly superior to the other for dogs with PTCL. In this study, canine participants will be randomly selected to receive either CHOP or LOPP chemotherapy. At each visit, their lymph node size, blood work, and overall wellbeing will be assessed. Both protocols involve treatments every 7-14 days and take 4-6 months to complete. Following protocol completion, study participants will return once monthly to assess remission status.

Specific Aims

  1. To determine if remission rate and duration differ in dogs with naïve PTCL treated with CHOP or LOPP chemotherapy
  2. To determine mutational profiles of canine PTCL that may serve as prognostic or therapeutic biomarkers.


Dogs with non-indolent PTCL that are naïve to treatment will be enrolled. Dogs will be randomly assigned to receive LOPP or CHOP chemotherapy. Every visit will consist of a physical examination, blood sample collection, and/or chemotherapy administration. Lymph node cytology samples will be collected for genomic analysis and post hoc analysis will be performed at study completion.


Currently, veterinary medical oncologists choose CHOP or LOPP for their PTCL patients based on their professional experience. While there are several publications on the use of LOPP chemotherapy in dogs with PTCL, all are retrospective and lack a control arm (receiving CHOP chemotherapy).