Animal Feeding Needle…Over The Teeth, Past The Gums, Look Out Stomach, Here It Comes
Posted on Mar 19, 2012 by SolomonScientific
A veterinarian came to Solomon Scientific almost ten years ago requesting plastic animal feeding needles. He stated that the Popper stainless steel needles (now owned by Cadence) were good tubes for gavage. However, he preferred a disposable plastic tube to reduce the labor costs of cleaning, packaging, and sterilizing reusable products. Additionally, he preferred to obviate the potential for cross-contamination of body fluid material between animals and inadvertent delivery of previous study test articles.
We started our product development using Teflon (PTFE) tubing. However, we observed that it was very difficult to bond a female luer and soft tip to the Teflon tube—PTFE is notoriously difficult to bond to. The rubber tips too easily delaminated from the Teflon tube, and the force required to detach the tube from the luer was not sufficiently high. We opted to employ polypropylene tubing for several reasons. First, it is the same material as plastic syringes thereby providing a homogeneous fluid path which is inert to virtually all compounds instilled into the stomach of rats, mice, and other rodents. Second, polypropylene is easy to mold. As such, a female luer can be molded directly to the tube yielding a permanent chemical bond between tube and luer without the use of organic solvents and adhesives. Lastly, the rubber tip can be molded directly to the polypropylene tube and attach more rigorously than it did to a Teflon tube.
The next challenge during development was to engineer sizes for the variety of species and ages commonly used in oral gavage (gastric lavage) studies. Solomon developed the 20 gauge animal feeding needle for juvenile rats. However, this size proved too large for many mice, and certainly for juvenile mice. A 22 gauge product proved difficult to construct due to the very small tube size, but a slightly thicker tubing wall allowed for effective molding of the luer to the 22 gauge tube. As such, the company offers gavage tubes for use in animals ranging from juvenile mice, to rats, hamsters, guinea pigs, and adult rabbits.
These gavage dosing tubes are provided sterile. The female luer is color coded by gauge, and a soft rubber tip reduces the risk of inadvertent placement down the trachea and minimizes trauma during insertion. The risk of perforation is reduced through use of the flexible plastic tube and its soft, rounded tip. For direct infusion, Solomon also manufactures intragastric catheters for rats, dogs, rabbits, and monkeys (nonhuman primates).