# Assessment of Stress in Dogs Under Cancer Therapy via Faecal Cortisol Metabolite Analysis: A Pilot Study

## TL;DR

This study found that cancer therapy in dogs does not increase their stress levels, based on analysis of stress hormone metabolites in their feces.

## Contribution

The study is the first to use faecal cortisol metabolites to assess stress in dogs undergoing cancer therapy, providing ethical guidance for treatment decisions.

## Key findings

- Stress levels in dogs undergoing cancer therapy were not significantly higher than in healthy dogs.
- Cancer therapy did not increase stress levels in dogs at specific time points during treatment.
- The results suggest that stress should not be a reason to exclude dogs from cancer treatment.

## Abstract

The aim of this study was to investigate whether dogs receiving cancer therapy are exposed to additional stress due to their treatment. Thus, faeces from dogs were collected before and during therapy from their owners at home to avoid the stress of visiting the veterinarian at the clinic. Stress hormone metabolites were then measured from the faecal samples. This long-established method has proven to be reliable for non-invasively evaluating stress levels. Our results indicate that tumour therapy did not add to the stress levels of dogs suffering from cancer. This finding could help owners in their decision-making on whether to attempt cancer therapy for their companion dogs.

Stress reactions play an important role in animals’ ability to cope with various situations. Glucocorticoids are measured as a stress parameter, and analysis of their faecal metabolites has proven to be a good method for evaluating long term stress. We hypothesised that dogs suffering from cancer would have a higher stress level during cancer therapy, which would be reflected in higher levels of faecal cortisol metabolites (FCMs). Faeces were collected from 40 dogs receiving radiation or chemotherapy before and during the treatment, and from 53 healthy dogs, who served as a control group. FCMs were extracted and quantified by a cortisol enzyme immunoassay. The results showed that the stress levels were not significantly higher in the cancer patients before therapy compared to those in the control group. Additionally, there were no significant differences in the FCM concentrations of dogs at specific time points during chemotherapy or radiotherapy. Therefore, suspected stress should not be a criterion to exclude animals from cancer treatment. Such a treatment seems ethically justifiable if it is expected to provide benefits and improvement in the quality of life for patients.