Ondansetron for the treatment of nausea in dogs with vestibular syndrome
Vestibular system disorders are a common presentation in everyday clinical practice. Nausea is a complex multi-dimensional sensation and a common clinical sign in dogs with vestibular syndrome. It is difficult to evaluate and often associated with the urge to vomit; however, it is not necessarily associated with the result of vomiting. Nausea is more difficult to control with drugs than vomit, and dogs that are not vomiting can be nauseated.
Approved medications for nausea and vomit in veterinary medicine are the neurokinin-1 receptor antagonist maropitant and the dopamine D2 receptor antagonist metoclopramide. However, studies have shown that these drugs do not have a clinically relevant effect against nausea compared to placebo.
5-HT3 receptor antagonists, such as ondansetron, can eliminate both nausea and vomit. In humans and animals, ondansetron has been proven to successfully treat chemotherapy related nausea and vomiting and showed clear advantages over antidopaminergic drugs, antihistamines, neurokinin-1-receptor antagonists and anticholinergics.
This recent study provides preliminary evidence of the potential benefit of ondansetron in the treatment of nausea in dogs with vestibular syndrome. In the study, all dogs initially showed signs of nausea of which only 31% showed vomitus. The intensity of nausea was significantly reduced in all dogs 2 hours after ondansetron administration. The clinical signs observed that improved were salivation, licking, restlessness and lethargy.
There is the need to raise awareness in veterinary medicine for the difference between a drug’s antiemetic and/or antinausea effects.
This was the first study to provide results on the efficacy of ondansetron as a treatment for nausea in dogs with vestibular disease. In future studies, the measurement of a controlled biomarker, such as arginine or vasopressin, would enhance the interpretation of the results and potentiate the improvement of canine welfare in veterinary medicine.
Barash, NR, Lashnits, E, Kern, ZT, Tolbert, MK, Lunn, KF, Outcomes of esophageal and gastric bone foreign bodies in dogs, 2022, Journal of Veterinary Internal Medicine, 36:500–507.
