Background

Reported response rates of transitional cell carcinoma (TCC) in dogs to piroxicam in combination with either mitoxantrone or carboplatin are similar; however, it is unknown whether either drug might provide superior duration of response.

Hypothesis/objectives

To determine if the progression-free interval (PFI) of dogs with TCC treated with mitoxantrone and piroxicam was different than that of dogs receiving carboplatin and piroxicam. The hypothesis was that the efficacy of mitoxantrone is no different from carboplatin.

Animals

Fifty dogs with TCC without azotemia.

Methods

Prospective open-label phase III randomized study. Either mitoxantrone or carboplatin was administered every 3 weeks concurrently with piroxicam with restaging at 6-week intervals. Twenty-four dogs received carboplatin and 26 received mitoxantrone.

Results

Response was not different between groups (P = .56). None of the dogs showed complete response. In the mitoxantrone group, there were 2 (8%) partial responses (PR) and 18 (69%) dogs with stable disease (SD). In the carboplatin group, there were 3 PR (13%) and 13 (54%) dogs with SD. The PFI was not significantly different between groups (mitoxantrone = 106 days; carboplatin = 73.5 days; P = .62; hazard ratio 0.86; 95% confidence interval 0.47-1.56). Dogs with prostatic involvement experienced a shorter survival (median, 109 days) compared to dogs with urethral, trigonal, or apically located tumors; this difference was significant (median 300, 190, and 645 days, respectively; P = .005).

Conclusions and clinical importance

This study did not detect a different in outcome in dogs with TCC treated with either mitoxantrone or carboplatin in combination with piroxicam.

Objectives

To estimate prevalence of exposure to environmental tobacco smoke and other environmental toxins in dogs with primary lung tumours and to analyse association between exposure and lung tumour development.

Materials and methods

In this case-control study, an owner survey was developed to collect data on patient characteristics, general health care and environmental exposures. Dogs diagnosed with primary lung carcinomas formed the Case group. Dogs diagnosed with mast cell tumours served as Control Group 1 and dogs diagnosed with neurologic disease served as Control Group 2. Associations between diagnosis of primary lung tumour and patient and environmental exposure variables were analysed using bivariate and multivariate statistical methods.

Results

A total of 1178 owner surveys were mailed and 470 surveys were returned and included in statistical analysis, including 135 Cases, 169 dogs in Control Group 1 and 166 dogs in Control Group 2. An association between exposure to second-hand smoke and prevalence of primary lung cancer was not identified in this study.

Clinical significance

Second-hand smoke is associated with primary lung cancer in people but a definitive association has not been found in dogs. The results of this study suggest that tobacco smoke exposure may not be associated with primary lung cancer development in dogs but study limitations may have precluded detection of an association.

CHOP-based (cyclophosphamide, doxorubicin, vinca alkaloid, prednisolone) chemotherapy protocols are often recommended for treatment of feline lymphoma. While maintenance-free CHOP-based protocols have been published and readily used in dogs, there is limited literature regarding similar maintenance-free protocols in cats. The purpose of this study was to describe the outcome of cats with intermediate- to high-grade lymphoma that were prescribed a modified 25-week University of Wisconsin-Madison (UW-25) chemotherapy protocol. A secondary objective was examination of potential prognostic factors. One hundred and nineteen cats from five institutions treated with a UW-25-based protocol were included. The Kaplan-Meier median progression-free interval (PFI) and survival time (MST) were 56 and 97 (range 2-2019) days, respectively. Cats assessed as having a complete response (CR) to therapy had significantly longer PFI and MST than those with partial or no response (PFI 205 versus 54 versus 21 days, respectively, P < 0.0001 and MST 318 versus 85 versus 27 days, respectively, P < 0.0001).