Many years ago, a wise old beef farmer bought an old veterinary textbook from an antiques shop…
The farmer fed a lot of bread waste to his herd and had a lot of larger (250kg plus) bullocks with severe bloat due to the plastic wrappers being eaten. These wrappers ended up balling up and preventing proper rumination. The current trocar and cannulas (red devils) are very good for short term relief of bloat but need constant supervision to prevent blocking and are prone to the plate part being chewed by other cattle. The farmer called us out to see a couple of sick calves which were in fact two large, very blown, bullocks. He proceeded to produce his book and request that we carry out the technique that he’d read about.
The book did indeed have some idiot proof pictures of a technique called “fenestration”, from the French for ‘window’.
The technique is very simple and involves some local anaesthetic, cutting a 5-6cm hole out of the skin over the site that you would trocarise, then bluntly pushing through the muscle layers down to the peritoneum.
Gently cutting through the peritoneum, the idea is to grab the bloated rumen. My advice is to wear goggles, as there is a limit as to how much rumen contents you want in your eyes. Two big stitches hold the rumen to the skin, then we cut properly into the rumen and stitch the rumen edges over the muscle onto the skin. This takes a bit of time as it involves a lot of single stitches.
Once completed there is now a semi-permanent “hole” or “window” into the rumen. Because the touching parts are the inside of the rumen wall, they won’t heal together. The bluntly dissected muscle layers act as part sphincter so the hole semi-closes but opens to allow gas out.
After-care is minimal, although the area below the blow hole can be quite stained with rumen contents, and the animal should get to a useful size for slaughter.
It’s an excellent salvage technique for larger beef animals where the cause of bloat isn’t obvious.
As always, if you have any questions you can contact the team!