Cat food scam?

Factual Questions
1

After a couple of hours at PetsMart, I have the sinking feeling that I’m the victim of an elaborate scam to take my money based on emotional feelings for my cat (or, more precisely, my wife’s emotional feelings for her cat).

First, the history…

We have a cat who was had problems with struvite crystals in his urine. After cleaning him out, the vet put him on Hill’s Prescription Diet c/d-s . He’s been on that for a couple years with no more crystal problems.

He then started developing constipation issues. The vet switched him to Hill’s Prescription Diet w/d , after carefully explaining to me that magnesium was the cause of the struvite crystals, and showing me the w/d had the same amount of magnesium.

The w/d seems to have helped the constipation only slightly. The vet ended up also giving the cat stool softeners, which seemed to have had more of an effect. We’ve been feeding him the w/d and giving him stool softeners from time to time for several months with no crystal or constipation problems.

Now, the problems…

  1. Having to go to the vet to get the cat food is an inconvenience. Not just in having to go to the vet’s office, but also the hours the office is open.

  2. The price of the food is ridculously expensive. About $40 per 20lb bag.

  3. We have six other cats and have been unsuccessful in attempts to feed them different things separately, which means they all get this prescription food.

And today’s issue…

  1. After comparing content on the bags of the different brands of cat food at Petsmart, I’m not sure the prescription food is all that different from some of the other “urinary health” foods.

More details…

Late yesterday (Saturday), I discovered that we didn’t have as much cat food left as I thought. Too late to get any from the vet until Monday. Can’t really expect them to not eat until then. So I went to Petsmart and ended up buying
Hill’s Science Diet Hairball Control Light Adult. This was very close to the content levels of the w/d. It’s also about $12 cheaper per bag (and we go through two bags a month). I also looked at:

Friskie’s Special Diet ($30 per bag cheaper)

and

Purina One Special Care ($26 cheaper per bag)

C/d has .08% magnesium.
W/d has .075% magnesium.
Hairball light has .073% magnesium.
Friskies has .085% magnesium.
Purina Special Care has .08% magnesium.

Friskies and Purina don’t have the extra fiber, but, like I said, I’m not convinced the extra fiber is helping anything anyway.

My mind looks that the magnesium content of the c/d and thinks anything equal to or less than should be fine (Purina). It also tells me the .005% difference between the c/d and the friskies can’t be enough to cause problems. Regular cat foods have .12% magnesium or more, if they even bother to list on the label how much they have.

Talking to the vet about this previously has gotten responses along the lines of “Don’t you think your cat is worth it?” And the bottom line is, if this prescription food is the only thing I can feed my cat to keep him healthy, I will continue to feed him this food as long as he lives. However, I can’t help feeling I’m being, well, taken advantage of, I guess.
And now for the big question!

Is there really any reason for me to not buy the Friskies or Purina brands and save myself $50 - $60 a month over the prescription food price?

I think I’ve already decided to stick with the Hairball Control Light, so I guess my actual savings might be more like $30 - $40 a month if I went to the others. I’ll probably call Hill’s tomorrow and see what they say about the difference between their own products.

If anyone has any expertise on cat food, I’d appreciate any advice.

2

About 10 years ago, one of my cats had severe urinary tract blockage, though no constipation. The vet put him, and my other cat, on Hill’s. Shortly thereafter, Friskies came out with the Special Diet, and both cats have been eating it (both canned and dry) ever since, with no problem.

And the best thing is that Friskies is sometimes on sale at one of the local supermarkets, so I can stock up. I don’t think Hill’s is ever on sale, anywhere.

3

I can’t advise you about the first problem, but I can tell you what my vet has me do for my cat’s constipation.

I bought unflavored psyllium fiber at a health food store. This is what metamucil is made of. I put 1/8 teaspoon in a little canned food, and feed it to her.

This has done wonders. If she has more trouble than ususal, I just give her a second serving of canned food with fiber later in the day.

4

I can’t help with the cat food question, but definately do make the call to Hill’s just to see what they say.

I had a problem with a human baby (mine) and some formula. We were supplementing with a very expensive Nutramigen brand for a protien problem. Looking at labels and calling the companies was a big help. I learned alot and managed to survive the baby’s babyhood, too.

(Breast is definately best for human babies, but I lost almost 16 gallons {yes, gallons} of breast milk when my freezer died.)

5

Curious about your question, I asked my wife, the Veterinarian. Instead of explaining it to me, she typed a response:

The obvious problem with your initial reasoning is that you can pick up different foods, look at the label, read percentages and think you are comparing apples to apples. In order to compare apples to apples you must compare foods on a dry weight basis. To do this you have do some calculations. You know the net weight of the bag and the % moisture. Now figure out the actual weight of food. The percentages on the guarenteed analysis are listed on an “as fed” basis. You have to convert them to dry weight basis. After you do this you can have meaningful percentages of different minerals and nutrients in order to compare foods. Until you do that, you can’t look at:

and compare these numbers.

If you are looking at foods within a specific format (ie all the foods on your list are dry foods) you might be able to make some relative judgements but you really can’t compare foods until you compare the actual foods, not the food plus its water.

But as if this weren’t complicated enough, it gets worse. The struvite/magnesium relationship seemed to hold true in the eighties. Then in the late eighties, urinary pH complicated the issue (ie a cat can eat plenty of magnesium as long as the urinary pH is appropriately acidified.) Diets were reformulated all over the place. Now the disease formerly known as “FUS” has been renamed and rethought again. We know that normal cats produce struvite crystals with the same frequency as symptomatic cats. So the syndrome is not all about crystals like we thought. We still don’t know about this syndrome. Currently it looks like a special neurologic sensitivity to stress is what sets the symptomatic cats apart from the non-symptomatic cats and this disease has not really been of a nutritional basis since the mass reformulation of foods 10 years ago or so.

So what you do you feed a cat taking in all the current information? Here’s what we think:

  1. If the cat makes crystals but doesn’t have symptoms, then he’s probably normal and you can feed him whatever you want.

  2. If he’s had symptoms then you do best feeding a canned food diet as the extra water helps keep his urine dilute.

If your original question is: why do these foods seem to have the similar guarenteed analyses yet have such a different cost to the consumer. the answer is a long story about how these foods are different and you can’t really appreciate the differences via the information that is on the bag (ie guar. analysis on an as fed basis, list of ingredients listed with most prevalent first etc.) These are very complicated foods.

If your original question is: what can I feed my cat who has a history of struvite crystals, hopefully I covered it.

  1. Feed him the same thing every day since symptomatic cats are especially sensitive to changes in their routine and they prefer to eat the same food and never change. Changing food leads to symptoms.

  2. Should you use a traditional diet like CD-s? CD-s has been THE therapeutic diet for cats with lower urinary disease for decades. It is hard to go wrong with it. It’s also hard to argue against what empirically works in a syndrome that is a puzzle wrapped in an enigma etc.

Again, the above from a practicing vet.

As for myself, I looked at a Hill’s explanation for what is in their W/D food, and according to them, “this low fat, high fiber formula helps avoid excesses of magnesium and phosphorus while providing a normal acid urine pH to help reduce the risk of struvite urolithiasis in obese-prone and overweight patients. Obesity is a risk factor for struvite crystalluria or urolithiasis to maintain a healthy weight while minimizing struvite risk factors.”

This is a quote from the Prescription Diet Feline W/D fact sheet that my wife’s animal hospital provides for her clients. Your vet should have similar information sheets for all of the Hill’s diets they sell.

It seems to me there is more to it than just the amount of magnesium. They mostly talk about weight issues, but then W/D is their Weight Diet. Actually, I can’t seem to find a fact sheet for C/D-s, but the fact sheet for Feline S/D says it is for cats with struvite stones and crystal dissolution. “Feline S/D contains low levels of magnesium and phosporus and promotes formation of a more acid pH. The high caloric density helps control intake and urinary excretion of these minerals. High sodium helps to increase urine volume with a salt induced diuresis. More acid urine also pH also increases solubility of struvite crystals and uroliths to minimize urolith formation.”

It goes on to say that “after the initial feeding period (two to three months), Feline C/D-s or Feline W/D may be used to avoid recurrence of FLUTD.”

If you are asking what food in particular is best for your cat, that is far different than asking if the idea of higher priced prescription diets are a scam. If they are, they have fooled most veterinarians around the country. Even given that there must be some veterinarians who would sell anything if it were profitable, I think that most vets actrually care about the well-being of their patients and Hill’s (and Purina and Iams) would have a hard time selling all the prescription-based foods that are sold primarily through vet hospitals for health reasons if they weren’t scientifically valid or didn’t produce results.

6

richardb Thanks to you and your wife for the detailed response.

I want to make it clear that I don’t think the vet is doing anything other than playing it safe. What we’re feeding the cat is working, so he doesn’t want us to change.

The conversation with Hill’s was a little interesting. At first, all they would do is tell me to do what the vet says. They also confirmed the comment about comparing the dry matter weight. Their web site lists the target urinary pH of the c/d-s and w/d foods at 6.2 - 6.4, but doesn’t list anything for the Hairball Control Light. Another call told me that all Hill’s Science Diet products have that same target urinary pH of 6.2 - 6.4.

Fortunately, Hill’s is kind enough to provide dry matter % breakdowns on their web site. Unfortunately, I am apparently no longer bright enough to be able to do the math myself, because I can’t come up with the same numbers Hill’s has. Hill’s doesn’t provide moisture information on their web site. The bag of Hairball Control Light I bought says 11% moisture and is a 17.5lb bag.

After looking at all the percentages, the ingredients, and talking to Hill’s, I think I’m comparing at least the two Hill’s products properly (w/d and Hairball Control Light). While they may not be exactly the same formula, they’re very, very close.

Now, the Friskies and Purina Special Care products (Purina also has a Pro Care brand food, but the link to it on their web site is broken) are a little harder for me at the moment. Neither web site lists urinary pH levels. I don’t remember seeing anything other than “low urinary pH” on the bags. The moisture content for both is 10%. So, even though my math no longer functions, I would guess that if both have the same moisture content, and I’m comparing the same weights (16lb bags), comparing the guaranteed analysis between the two products is a valid comparison. That still doesn’t help me comparing against the Hill’s products, but I’ll figure the math out eventually.

So, it looks like I’m due for another trip to Petsmart to read more packages, this time with hopefully a little better understanding of what I’m reading. I may also call the Purina people and ask for more details on Friskies, Special Care, and Pro Plan.

If I analyzed my own food this much, I’d either starve to death trying to figure out what to eat, or get grossed out and lose my appetite once I found out what was in my food.

7

My wife could probably shed a bit more light on this issue, but she’s asleep. I don’t always get to check these boards as often as I like, so it was just lucky when she happened to be there when I read your OP.

My guess is that for any food you can buy in a grocery store, there is no where near the kind of scientific analysis done that prescription foods have. They put on the label what they are required to by law, and perhaps what they need to in order to be competitive with other brands. They certainly do not have a bunch of veterinarians and nutritionists trying to develop foods for health reasons. They probably couldn’t tell you the “urinary pH levels” if you paid them.

Although I’m not personally familliar with Purina’s Pro Plan, I would guess they do have the same sort of scientific analysis and formulations that Hill’s has available (after all, a food designed for medical benefits would need that).

I’m afraid I’m not going to be much more help (I was primarily just providing my opinion that Hill’s Prescription Diets are not just a “big scam”), but if you would like a little more information on pet food, my wife writes quite a few pet health articles for her hospital (and the public at large), and has a series of articles on how pet food is made, including how to read the label and the manufacturing process:

The Pet Nutrition Corner

Unfortunately, the pages on Feline Struvite Stones are not yet done, but if info on Canine Struvite Stones would be any help (and since I am not a vet I don’t know if it is or not), you can also check out:

Bladder Stones Information Center