There is a scientific study published online on the nature.com website which concludes that there may be a link between fish flavoured (fish-based) foods and chronic kidney disease (CKD) but the link is tenuous. It is however worth flagging so cat owners know about it. More work needs to be done.
My understanding is that the study says the following:
- Domestic cats are fed more fish-based foods that dogs
- Fish-based foods have a higher arsenic content although this is primarily non-toxic arsenic
- Arsenic in tissues and urine is present in higher amounts in cats compared to dogs.
- The arsenic content is a pro-oxidant metallic element which lowers the concentration of antioxidant minerals such as copper and zinc and minerals which protect the kidney such as rubidium and strontium.
- As I understand it this lowering of antioxidant minerals can lead to chronic interstitial nephritis (CIN) which is the most common renal lesion and a cause of chronic kidney disease.
- CIN was present in 51% of cats compared to 15% of dogs. CIN is absent in Scottish wildcats.
That is an essential breakdown. It is very technical and a potential warning to cat guardians, no more.
If you are so predisposed i.e. scientifically minded, you can read the study by clicking on this link (sometimes links to other website break and if that has happened I apologise but I have no control over it). I don’t want to write extensively about this study because it is very technically and I am liable to make a mistake.