Protecting short-term intravascular ear catheters in healthy rabbits

Researchers may place a catheter in the ear vessel of a rabbit for a short period of time in order to collect repeated blood samples without extensive restraint of the animal. Maintaining such a catheter in a healthy rabbit can be challenging, as the animal may scratch at the ear, removing the catheter or forming a large hematoma that might impede blood sampling. The authors developed a technique for protecting the indwelling catheter by cutting a section of moleskin to the same shape as the ear and gluing it to the surface of the ear and the catheter. They applied this technique to collect multiple blood samples during 12-h periods from nine rabbits in a pharmacokinetics study. Catheters remained patent in five rabbits for 12 h, in two rabbits for 8 h, in one rabbit for 6 h and in one rabbit for 4 h. This technique allowed for collection of repeated blood samples and prevented the rabbits from interfering with the catheter while allowing them to move freely during the sampling period.