# Dog and cat food **URL:** \ **Category:** Cecil's Columns/Staff Reports\ **Created:** [September 23, 2016, 5:53pm UTC](https://boards.straightdope.com/t/dog-and-cat-food/766657 "2016-09-23T17:53:50Z")\ **Posts on this page:** 9\ **Page:** 3
**Author:** ![Crazier\_Catlady](https://avatars.discourse-cdn.com/v4/letter/c/b9e5f3/32.png) [@Crazier\_Catlady](https://boards.straightdope.com/u/Crazier_Catlady)\ **Post date:** [September 28, 2016, 10:27am UTC](https://boards.straightdope.com/t/dog-and-cat-food/766657/41 "2016-09-28T10:27:53Z")
I totally agree that different animals thrive on different brands. For instance I feed my cats Hill’s Y/D because several of them have hyperthyroidism. I know of no other brand that offers a diet for this and most of my cats thrive on this diet which consists mostly of vegetable ingredients. Just one of my cats lost weight on the diet and that’s because he just won’t eat enough of it. I happen to know that hill’s does a lot of research because one of my vets used to work for them. ---
**Author:** ![voltaire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voltaire/32/313_2.png) [@voltaire](https://boards.straightdope.com/u/voltaire)\ **Post date:** [September 28, 2016, 8:36pm UTC](https://boards.straightdope.com/t/dog-and-cat-food/766657/42 "2016-09-28T20:36:57Z")
> [@Crazier\_Catlady](#): > > I totally agree that different animals thrive on different brands. For instance I feed my cats Hill’s Y/D because several of them have hyperthyroidism. I know of no other brand that offers a diet for this and most of my cats thrive on this diet which consists mostly of vegetable ingredients. Just one of my cats lost weight on the diet and that’s because he just won’t eat enough of it. I happen to know that hill’s does a lot of research because one of my vets used to work for them. A few people in this thread could probably benefit from some reading over at [catinfo.org](http://catinfo.org) (particularly those equating cat nutrition to dog/human nutrition), but it would seem to me that none would be more likely to immediately benefit than you (and your cats) by [reading this on feline hypothyroidism and Hill’s Y/D](http://catinfo.org/?link=felinehyperthyroidism). ETA: Also [don’t miss this article](http://www.endocrinevet.info/2011/11/is-protein-content-of-hills-yd-too-low.html) that’s linked there. ---
**Author:** ![voltaire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voltaire/32/313_2.png) [@voltaire](https://boards.straightdope.com/u/voltaire)\ **Post date:** [September 28, 2016, 8:48pm UTC](https://boards.straightdope.com/t/dog-and-cat-food/766657/43 "2016-09-28T20:48:16Z")
Actually this is the link I meant to add in the ETA above, but the other one is very much worth reading, as well. [http://www.endocrinevet.info/2011/09/treating-hyperthyroid-cats-with-iodine.html](http://www.endocrinevet.info/2011/09/treating-hyperthyroid-cats-with-iodine.html) As long as I’m link spamming: [http://www.endocrinevet.info/2011/09/is-hills-yd-nutritious-diet-for.html](http://www.endocrinevet.info/2011/09/is-hills-yd-nutritious-diet-for.html) ---
**Author:** ![Guinastasia](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/guinastasia/32/5751_2.png) [@Guinastasia](https://boards.straightdope.com/u/Guinastasia)\ **Post date:** [September 28, 2016, 11:10pm UTC](https://boards.straightdope.com/t/dog-and-cat-food/766657/44 "2016-09-28T23:10:20Z")
> [@Crazier\_Catlady](#): > > I totally agree that different animals thrive on different brands. For instance I feed my cats Hill’s Y/D because several of them have hyperthyroidism. I know of no other brand that offers a diet for this and most of my cats thrive on this diet which consists mostly of vegetable ingredients. Just one of my cats lost weight on the diet and that’s because he just won’t eat enough of it. I happen to know that hill’s does a lot of research because one of my vets used to work for them. Buff was fine on Hills Light formula, but the “Senior” (which Piper-Grace eats), was far too rich for her – she kept getting UTIs. But Piper-Grace is completely healthy. (When she’s not eating pillow stuffing or whatever). Annie and Luci eat Purina Indoor Advantage. (Maggie will only eat Friskies, and won’t touch dry food. I don’t think it even registers as food for her) ---
**Author:** ![voltaire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voltaire/32/313_2.png) [@voltaire](https://boards.straightdope.com/u/voltaire)\ **Post date:** [September 29, 2016, 12:51am UTC](https://boards.straightdope.com/t/dog-and-cat-food/766657/45 "2016-09-29T00:51:49Z")
> [@Crazier\_Catlady](#): > > I totally agree that different animals thrive on different brands. For instance I feed my cats Hill’s Y/D because several of them have hyperthyroidism. I know of no other brand that offers a diet for this and most of my cats thrive on this diet which consists mostly of vegetable ingredients. Just one of my cats lost weight on the diet and that’s because he just won’t eat enough of it. I happen to know that hill’s does a lot of research because one of my vets used to work for them. Now that I’m home and not on my phone, I just wanted to followup with a better link with some quotes. [This link (and following quotes)](http://www.animalendocrine.com/yd/) belong to the same vet whose blog I linked a few times above, but this is on his actual website, is very well written and actually makes for interesting reading, even for someone who doesn’t have a cat. > [@](#): > > **Is it safe to feed an iodine deficient diet to hyperthyroid cats?** > > In light of our increasing awareness that iodine deficiency likely plays a role in the development of hyperthyroidism in cats, how advisable is it to intentionally feed a dramatically iodine deficient diet to cats that have already developed benign tumors of their thyroid? Will ongoing, severe iodine deficiency accelerate the growth of these benign tumors? Will severe ongoing iodine deficiency accelerate the progression from benign thyroid adenoma to malignant thyroid carcinoma [25]? Currently these questions remain to be answered. Minimally, we know that this diet does nothing to prevent the continued growth of the tumors responsible for hyperthyroidism in cats. Hill’s y/d includes at least two of the dietary factors that appear to contribute to the development of hyperthyroidism including overt iodine deficiency and soy isoflavins that act as goitrogens. > [@](#): > > **Is it safe to feed an iodine deficient diet to cats with normal thyroid function?** > > What about feeding y/d to cats without pre-existing thyroid disease? Many hyperthyroid cats live in multi-cat households. According to Hill’s web site, “Because iodine intake from other food sources — treats, another pet’s food, etc. — can compromise the effectiveness of low-iodine nutrition, it’s critical that you follow your veterinarian’s feeding instructions carefully and feed only y/d” [26]. Consumption of even small amounts of foods containing higher levels of iodine, including essentially all commercially available cat and dog foods and many human foods will negate the effect of y/d. This may pose a real problem to most multi-cat households in which the pet food and water resources are shared. While publicly acknowledging the potential risks of feeding an iodine deficient diet to cats without established thyroid disease, privately Hill’s representatives encourage veterinarians to recommend feeding y/d to all of the cats in multi-cat households as a means of overcoming this problem. They argue that supplementing the cats without hyperthyroidism with small amounts of other foods will overcome the deficiencies of the y/d product. In light of our current knowledge of pervasive iodine deficiencies in many commercially available cat foods, this logic seems flawed. Feeding y/d to every cat in a multi-cat household, just to ensure severe iodine deficiency in a single hyperthyroid cat seems sure to accomplish only one goal, namely increasing the sale of y/d. > > In addition to the issues created by feeding an iodine deficient diet, Hill’s y/d has many other features that make it a poor choice for feeding cats as a species. Cats are after all obligate carnivores and Hill’s y/d is relatively low in protein, high in carbohydrates and relies on large quantities of plant based proteins, all of which make it a poor choice to feed to any cat [7, 27, 28]. The dry variety of y/d utilizes the cheap by-product filler “soybean mill run”. Soy has been shown to contain enzyme inhibitors that impeded normal protein digestion and soy is a known goitrogen suspected as a contributing factor in the development of hyperthyroidism in cats[18, 29-34]. I wanted to highlight those two quotes in particular because the part that confused me about your post is that you begin by saying that different animals thrive on different foods, but then you mention that you feed all your cats a special, expensive prescription diet that is NOT a complete or appropriate diet for a healthy cat. (or any cat, IMHO) ---
**Author:** ![Crazier\_Catlady](https://avatars.discourse-cdn.com/v4/letter/c/b9e5f3/32.png) [@Crazier\_Catlady](https://boards.straightdope.com/u/Crazier_Catlady)\ **Post date:** [September 29, 2016, 6:20am UTC](https://boards.straightdope.com/t/dog-and-cat-food/766657/46 "2016-09-29T06:20:05Z")
I run a small shelter for mostly elderly cats, which means that a lot of them have hyperthyroidism. I started using the Ý/D diet because the price difference with regular food was less than the cost of pills needed to treat the condition. Add to that that our 18 yo cat Flash can’t be forced to take pills. She won’t eat them if you hide them in food and if you try to force them into her throat she starts chewing her lips until they bleed and foam. No way am I going to put her through that twice a day. Strange thing is, she is thriving on the food. When we got her last year, her coat looked messy and her muscles were wasted. Until that time she had been fed a no-grain high end cat food. Now that she’s been on the Y/D diet for more than six months her coat is glossy again and she has visibly regained muscle mass. So excuse me if I’m a bit sceptical about specialists claiming that the diet wil make the cats waste away. Btw, all the other cats are doing just fine on the diet as well, except for Pluk who doesn’t like the taste and so won’t eat it. So he gets different food with pills in a separate room. ---
**Author:** ![voltaire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voltaire/32/313_2.png) [@voltaire](https://boards.straightdope.com/u/voltaire)\ **Post date:** [September 29, 2016, 7:34am UTC](https://boards.straightdope.com/t/dog-and-cat-food/766657/47 "2016-09-29T07:34:29Z")
In context, that makes more sense. In a shelter/rescue/lotsa-cats situation, particularly with elderly cats where surgery or expensive treatments don’t have a favorable cost/risk:benefit ratio considering their lifespan, I guess you do what you can. And clearly, you do a lot more good in that regard than I do. ---
**Author:** ![KarlGrenze](https://avatars.discourse-cdn.com/v4/letter/k/dbc845/32.png) [@KarlGrenze](https://boards.straightdope.com/u/KarlGrenze)\ **Post date:** [September 29, 2016, 9:23am UTC](https://boards.straightdope.com/t/dog-and-cat-food/766657/48 "2016-09-29T09:23:52Z")
[hijack] In general, though, the site you linked doesn’t say the diet is not good or does not work, just that it is not the best treatment option, something I agree with. But I do not like the couple of nitpicks. First, feline thyroid hyperplasias/adenomas DO NOT become malignant. They remain functional benign masses producing tons of thyroid hormones. Similar, in general dogs do not get hyperthyroidism. They get thyroid carcinomas, which do not produce hormones. These things give me pause on the rest of the article, even if I do agree with the general part. [/hijack] ---
**Author:** ![SageGrouse](https://avatars.discourse-cdn.com/v4/letter/s/e47c2d/32.png) [@SageGrouse](https://boards.straightdope.com/u/SageGrouse)\ **Post date:** [September 30, 2016, 1:28am UTC](https://boards.straightdope.com/t/dog-and-cat-food/766657/49 "2016-09-30T01:28:26Z")
I’ll believe that cat food manufacturers have an “all natural” diet when they come out with… First Robin of Spring Feast Grasshopper Surprise! Fillet of Mouse (in Meadow Vole gravy) Fancy Bugs Banquet Songbird Souffle Half-A-Gopher Goulash I’ll believe that dog food manufacturers have an “all natural” diet when I see… Crotch Crunchies Old Tampax Treats Catfood Casserole Fricasse of Frogs Dead Bird Brulee Mighty Power Bars (Fresh from Catbox Kitchens!) Ratatouille (with real rat-flavored tail-snips!) Poo-Poo Platter! [Previous page](https://boards.straightdope.com/t/dog-and-cat-food/766657.md?page=2)