Trial of induction of pilonidal sinus disease in a rat model

Introduction Pilonidal sinus disease is a common suppurative perianal condition.  The aim of this trial is to create an animal model of pilonidal sinus disease to study and compare the mechanism of action of numerous medications. Methods Ten adult Sprague-Dawley rats were enrolled in the study. They were separately housed in polypropylene cages.  They were fed normal chow.  The rats were anesthetized with Ketamine and Xylazine (At a ratio of 3:1) through intramuscular injection into their proximal thigh. The back of each rat was shaved, and a sample of the hair rat was obtained and labeled. After clearing the back of the animal, a vertical 1 cm incision was inflicted upon the dorsal side of each rat with a blade 15’ and a tuft of hair composed of at least 20 fibers was embedded in the wound, later the wound was closed by 4.0 proline suture material in a simple interrupted fashion.  The rats were followed for a period of 4 weeks.  Results Macroscopically, the rats showed 0.5x0.5 cm nodules at the side of the injury at the 5th week.  As there was no draining sinus, the picture in this form cannot be regarded as a typical pilonidal sinus, it was more consistent with a foreign body granuloma.  No pilonidal sinus could be reported. Conclusion Rat is not a suitable animal for the induction of pilonidal sinus disease.