Cat Food Labels: A Can of Confusion

A Can of Confusion for Special Needs Cats

Photo of Cat Eating Nutritious Canned Food
Cat Eating Nutritious Canned Food. photo © Getty / Michael Bodmann

A few years ago, we almost lost Bubba to uremic poisoning. There was very little warning; one minute he was fine, the next, he was lethargic and weakened. I say this with a twinge of guilt, because when I am home working during the day, aside from feeding and watering and an occasional pet when I happen to pass him, Bubba and I do not have much interaction. But the minute Asa's car pulls into the drive, Bubba is at the door.

Asa has learned to keep his hands free when arriving home, because the minute he opens the door, he has an armload of a cat.

Anyway, this particular day, they enjoyed their 20 minutes or so of interaction, and then we ate dinner.

After dinner, Asa looked for Bubba and found him on the bed, nearly unconscious. He could barely meow, and the 3rd eyelid was a clue that something was seriously wrong. Fortunately, that was a Wednesday, the day our veterinarian is open in the evening. We made a rush trip to Brentwood, about 10 miles from our home.

The veterinarian told us gently that Bubba was a very sick kitty, and that he needed to stay there for a few days. The next time we saw him, he looked disheveled, weak and very ill, but very glad to see us. A catheter revealed bloody urine coming from his stressed kidneys. A plastic cone around his head prevented him from yanking the catheter out. We visited him every day for five days, until he was well enough to come home, complete with a new diet.

Low ash and magnesium. Forever. Dr. Schnittker told us that even a small meal of "regular" food could put him into uremic poisoning again.

In Bubba's case, as with many cats, the cause at that time thought to be a high concentration of magnesium, which formed crystals, then stones, which completely blocked his urethra.

Low magnesium and ash content in cat foods seems to be among the keys to maintaining urinary tract health in cats, particularly males, although today it is believed that urinary acid of the cat is more important.

Shannon had a similar problem a few years later, and we were fortunate to catch the symptoms early enough that antibiotics cured the symptoms. Since Shannon was "dentally challenged", he could not properly chew dry food, and was fed mostly the canned variety.

Which leads to the focus of this feature: Why aren't standards more clearly set for cat foods? At that time we fed them both Friskies Special Diet, both canned and dry, for several years. However, in comparing labels, the ash content in Friskies Senior cat food is actually lower in some varieties. Friskies Senior cat food neglects to list the magnesium content on the label, however, upon looking inside the label as instructed, we are advised that it contains "increased levels of B-complex vitamins and trace minerals." Since magnesium is a trace mineral, this information does give cause to wonder.

In fact, to the average consumer, the analysis of ingredients in various cat foods advertised to maintain urinary tract health can be quite confusing.

A small comparison sampling of the percentage of ash and magnesium content in "grocery store brands" of cat foods, as provided by the manufacturers, follows: (All foods were dry packaged.)

Friskies Special Diet: Ash 6.5 | Magnesium, .085
Purina Cat Chow Special Care Formula: Ash 6.2 | Magnesium .08
Iams Senior Formula For Cats: Ash 6.75 | Magnesium .099
Sensible Choice Chicken Meal & Rice Adult Cat Food Ash 5.5 | Magnesium .09

The Association of American Feed Control apparently sets standards for cat food nutrient profiles for maintenance foods, but to date, there appears to be no similar standards set out for "urinary tract health" food label claims. I wrote its Chairman, Dr. Robert Beine, to inquire whether similar standards exist for cat food which claims to promote urinary tract health in 1997, and I am still awaiting a response.

For more information, a most excellent discussion of Wording of Pet Food Labels is provided by Ohio State University School of Veterinary Medicine.

Although their standards seem to differ, all cat food manufacturers agree that it is important to provide kitty with plenty of fresh clean water, a diet low in ash and magnesium and regular veterinary visits. Since this article was first written, thinking has changed a bit, and the new emphasis is on the pH of cats' urine, and a number of cat foods have been developed which claim to promote urinary tract health. Above all, know your cat. Observe his elimination habits and his eating habits. Make it a practice to examine his abdomen regularly for signs of swelling and/or pain. Watch for signs of lethargy-- that third eyelid is a giveaway. If he exhibits signs of FLUTD, don't hesitate-- get him to a vet immediately. Don't take chances with the life of your best friend!