Majid Zakerian - MVSc Graduated of Small Animal Internal Medicine, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
Reza Avizeh - Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
Alireza Ghadiri - Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
Mohammad Razi Jalali - Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
Mehdi Pourmehdi - Department of Food Hygiene, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
Hosein Najafzadeh Varzi - Department of Basic Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran

Objective- The aim of this study was to evaluate the efficacy and safety of senna as an alternative or adjunct to polyethylene glycol (PEG) solution in dogs using colonoscopy and radiography.Design - Experimental study.Animals - ۲۰ adult mongrel healthy dogs.Procedures- Dogs were randomly allocated to receive ۱ of ۴ different bowel preparation regimens including PEG, senna or their combinations in addition with enema before colonoscopy. Radiologist unaware of the method of bowel preparation reviewed the standard radiographs and graded the feces and gas in the colon and rectum, fecal radio-opacity and quality of radiographs on a scale of ۰ to ۳ (۰=inadequate to ۳=excellent). The degree of colonic cleansing was assigned a score of ۱-۴ (۱= clean colon to ۴= excessive fecal material) to each of five regions of the colon. Dogs were examined for any drugs side effects up to two weeks after administration of the laxatives.Results- Anesthesia and colonoscopy were performed without complication in all dogs. PEG was demonstrated to be equal or slightly more effective than senna using colonoscopy and radiography (p˂۰.۰۵). There were no side effects or complications attributable to each laxative agent.Conclusion and Clinical Relevance- Polyethylene glycol lavage solution has been proved to be similarly safe and effective as senna for bowel preparation in dogs. Senna can be used as an alternative or adjunctive medication to potentiate the cathartic action of PEG in dogs.

polyethylene glycol, Senna, Bowel Preparation, colonoscopy, Dog