Clinical Trial

Mitigating diarrhoea in dogs under chemotherapy

Disease of interest

Lymphoma, and other cancers


Diarrhoea is one of the most common side effects of chemotherapy in dogs, and can significantly impact the quality of life of dogs undergoing chemotherapy treatments. Based on our previous research, it is estimated that about 30-40% of dogs receiving vincristine or doxorubicin will develop diarrhoea. In humans, it has been found that gut bacteria can re-activate chemotherapy drugs, inducing gastrointestinal damage and consequently diarrhoea. Recent data suggest that aspartame, an artificial sweetener, appears to be promising in preventing gut bacteria to reactivate chemotherapy drugs.

Purpose of the study

To provide preliminary data to evaluate the potential benefit of aspartame for the prevention of chemotherapy-induced diarrhoea in dogs


Eligibility criteria

Inclusion criteria:

  1. Dog diagnosed with cancer not involving the gastrointestinal tract
  2. Dog undergoing chemotherapy including vincristine and doxorubicin (single-agent or CHOP-based protocol)

Exclusion criteria:

  1. Diarrhoea noted within 2 weeks prior to enrollment
  2. History of chronic diarrhoea
  3. Known gastrointestinal tract cancer involvement
  4. Dog with the MDR1 mutation
  5. Severe pre-existing comorbidity

Study Protocol

  • Your dog should receive a first dose of vincristine or doxorubicin chemotherapy before starting and will be randomised into one of four study groups (3 groups will receive different schedules of aspartame, 1 group will not and serve as a placebo/control group)
  • Your dog will participate for only one or two doses of chemotherapy at the beginning of their protocol (vincristine or doxorubicin)
  • A stool sample will be collected before and after chemotherapy for further analysis, to look for markers of gut damage

Owners responsibilties

  • Administer aspartame (powder) orally to your dog at home, for a maximum of 3 days.
  • Complete a medical diary.
  • Collect two samples of your dog’s stools, one the day before the chemotherapy treatment and one at day 3.

Financial support

  • This project has been awarded by a grant which covers all costs related to the study, including aspartame powder and faecal analysis.
  • The standard chemotherapy treatments will be at the charge of the owner.

Do you have any questions?

For questions regarding the clinical trial, please email with the subject “Clinical trial – Aspartame”.

Clinical trial overview

Species or breeds of interest


Closing date

June 30, 2023

Clinical trial documents

Clinical trial links