Dr. Lisa Pierson has done a more thorough job than I could ever hope to summarizing the causes and management of feline cystitis, urethral obstruction, and urinary tract Infection issues.
Excerpt from Dr. Lisa Pierson on Urinary Tract Health
If I could have the reader of this webpage take away just one word from this discussion, it would be "water". If your cat is on a properly hydrated diet of 100% canned food - and no dry food - you stand a very good chance of never needing to read this webpage.
Always keep in mind that water flowing through the urinary tract system is the most important factor in keeping it healthy.
Note that I said "water" - not "crystals" or "urine pH" - or any of the expensive prescription diets often recommended by veterinarians.
A cat's normal prey is ~70% water. Canned food is ~78% water. Dry food is ~5-10% water. Cats have a low thirst drive and do not make up the deficit at the water bowl. They are designed to get water with their food.
Cats on canned food have been shown to consume at least double the amount of water (from food and water bowl) when compared to a dry food-fed cat.
This results in approximately double the amount of urine flowing through the bladder.
Think of canned food as not only a proper diet for an obligate carnivore, in general (see Feeding Your Cat: Know the Basics of Feline Nutrition), but also understand that it is the healthiest way to keep your cat's bladder flushed out and 'happy'.
If you do not want to read this entire webpage, please at least scroll down to see Opie's pictures. Opie is a very sweet, (previously dry food-fed) cat that suffered tremendously when his urethra became blocked in July 2008. He has been fine since his blockage and will always be maintained on canned food.
It makes absolutely no sense to feed dry food to any cat - especially one with urinary tract problems.
If your cat is a 'dry food addict', please see Tips for Transitioning Dry Food Addicts to Canned Food. All cats can be switched to canned food if the caregiver is patient enough.
Please note that when you change your cat's diet to canned food, the litter box will need to be cleaned more frequently.
It is also very important to make sure that you have enough large litter boxes with CLEAN clumping (scoopable) litter placed in easily accessible locations in your home so that your cat will not 'hold his/her urine' for any reason.
Litter boxes should always be scooped at least twice daily.
See The Litter Box From Your Cat's Point of View. This webpage discusses the importance of providing clean litter boxes with an inviting litter.
(republished with permission of Dr. Lisa Pierson, www.catinfo.org.)
The full text of Dr. Pierson's article on urinary tract issues is available on her web page.
by Eunsoo Lee