Kidney stones are immensely painful to us and our feline friends. They can also lead to kidney infections and block the flow of urine from the kidneys to the bladder. Sometimes, surgical intervention is required.

Similar to the stents that are used to open up clogged arteries in the heart, a urinary stent may be inserted into ureter, the tube that connects the kidneys to the bladder. This allows for urine to once again pass.

However, surgeons (and veterinary surgeons!) are observing that calcium-based crystals are building up on the stents which stops them from working properly and leads to more pain. But here’s the catch – stents in cats do not accumulate as much encrustation as the human stents.

What feline characteristics stop the stents from encrusting as much? Can these characteristics help to prevent encrustation in human stents? Differences in the cat diet and physiology, compared to humans, produce differences in the chemical composition of the urine.

Bioengineers, led by Prof Martin Knight here at SEMS, investigated whether this difference in chemical composition was responsible for the better performance of cat stents. The Bioengineers, in collaboration with clinicians and vets, discovered that it is not the difference in the chemical composition of the cat urine that reduces stent encrustation in cats. Instead they concluded that it is differences in the organic macromolecules and proteins that are present in urine.

So, before you start eating cat food, wait for the further research which is being conducted to determine the specific proteins responsible. The next step in this research may lead to cats helping us live more painless lives!

Shafat M, Rajakumar K, Syme H et al. (2013). Stent encrustation in feline and human artificial urine: does the low molecular weight composition account for the difference? Urolithiasis