If you have a dog with kidney issues, you probably know about oxalates.
Oxalates are naturally occurring substances in many foods, including numerous vegetables. People who have dogs with kidney stones, crystals or kidney failure are often advised to stay away from oxalate-rich foods including some otherwise healthy vegetables like spinach (seen here), chard, Brussels sprouts and beets.
I recently read a study on vegetable cooking methods on oxalate content. A team of researchers analyzed nine different vegetables to see if cooking methods had any effect on oxalate content. Turns out, a great deal of oxalates actually boil out into the cooking water. So, according to their findings, pouring off the cooking water means pouring off a lot of the oxalates.
Most of the time, I recommend saving the cooking water because some vitamins boil out too. But in the case of dogs with kidney issues, boiling oxalate-containing vegetables and tossing the water can mean hope for including at least small amounts of nutrient-rich vegetables that are otherwise off the list. You can look at the study abstract here: https://www.ncbi.nlm.nih.gov/pubmed/15826055
If you’re not comfortable serving any amounts of these vegetables to your kidney-compromised furbaby, no problem. There are seemingly endless vegetables out there to enjoy. As with us, vegetables offer your dog dramatically protective benefits against cancer, inflammation and more. Basically every dog food batch I make, every recipe I create includes at least one type of vegetable, usually more than one.