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y/d® Feline Thyroid Health - Dry

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Hill's® Prescription Diet®
y/d® Feline Thyroid Health

Prescription Diet y/d is the safe, effective and easy way to manage thyroid health. Clinically proven nutrition to restore thyroid health in 3 weeks.

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100% Guarantee We're confident your pet will enjoy Hill's® Prescription Diet® foods. We're so confident that we offer a 100% money-back guarantee.*

Prescription Diet Foods are made in our own U.S. facilities with ingredients from North America, Europe, Australia and New Zealand, which exceed industry standards for purity and nutrient content.

* 100% Satisfaction Guarantee - if you are unsatisfied for any reason, return the unused portion to the place of purchase for a full refund or replacement.

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Key Benefits

Easy. Effective. Safe.
Clinically proven nutrition to restore thyroid health
Improves thyroid health in 3 weeks* (when fed as the sole source of nutrition)
Complete daily nutrition with a taste your cat will love

Additional Info

Additional benefits for overall health
Supports kidney health with controlled phosphorus and low sodium
Helps maintain bladder health with controlled mineral levels
Promotes heart health with essential nutrients like taurine and carnitine
Promotes healthy skin and a luxurious hair coat with high levels of omega-3 and -6 fatty acids

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.

Feeding Guide

Daily Feeding Guide:

Important Feeding Information

  • These amounts are a starting point only. Your cat may need less or more food to maintain proper weight. Adjust as needed. If you are unsure, ask your veterinarian.
  • With your veterinarian's approval, mix increasing amounts of your cat's new food with decreasing amounts of the old food over a 7-day period.
  • Prescription Diet formulas are available in a wide variety of dry foods and treats for your cat's unique needs, and canned foods with delicious flavors your cat will love. Supplementation with other foods or treats is unnecessary and may decrease the effectiveness of the food. When using with canned food, decrease the amount of dry food to avoid overfeeding.
  • Keep fresh water available at all times!
  • For best results, have your veterinarian monitor your cat's condition.
  • To prevent suffocation, keep this plastic bag out of the reach of pets and children.

Feeding transition

Adult maintenance

Weight of CatAmount per Day
6 lb (2,7 kg) 1/4 cup (30 g) - 3/8 cup (45 g)
10 lb (4,5 kg) 3/8 cup (45 g) - 5/8 cup (80 g)
14 lb (6,4 kg) 1/2 cup (65 g) - 3/4 cup (95 g)
18 lb (8,2 kg) 2/3 cup (85 g) - 7/8 cup (110 g)
Use only as directed by your veterinarian.
Animal feeding tests using AAFCO procedures substantiate that Prescription Diet® y/d® Feline Thyroid Health provides complete and balanced nutrition for maintenance of adult cats.

Average Nutrient and Caloric Content

Dry 4147 kcal/kg (517 kcal/cup)

Dry Matter1
Carbohydrate (NFE)28.6
Crude Fiber3.1
Carnitine651 ppm
Iodine0.2 mg/kg


1The nutrient in the product after moisture is removed. It is used to make direct comparisons of nutrient profiles of products with differing moisture contents.
An eight fluid oz. measuring cup of y/d® Feline Thyroid Health contains 4.4 oz. by weight.


Corn Gluten Meal, Pork Fat, Whole Grain Corn, Soybean Mill Run, Dried Egg Product, L-Lysine, Chicken Liver Flavor, Potassium Citrate, Lactic Acid, Dicalcium Phosphate, vitamins (L-Ascorbyl-2-Polyphosphate (source of vitamin C), Vitamin E Supplement, Niacin Supplement, Thiamine Mononitrate, Vitamin A Supplement, Calcium Pantothenate, Riboflavin Supplement, Biotin, Vitamin B12 Supplement, Pyridoxine Hydrochloride, Folic Acid, Vitamin D3 Supplement), Fish Oil, Choline Chloride, Calcium Carbonate, Calcium Sulfate, DL-Methionine, Taurine, Vitamin E Supplement, L-Tryptophan, Natural Flavor, minerals (Ferrous Sulfate, Zinc Oxide, Copper Sulfate, Manganous Sulfate), L-Carnitine, Mixed Tocopherols for freshness, Phosphoric Acid, Beta-Carotene, Natural Flavors.

y/d® Feline Thyroid Health - Dry yd 052742149707,052742159706 1497,1597

Hill's® Prescription Diet® y/d® Feline Thyroid Health 4.6 5 104 104
I'm a believer My 16 year old Molly showed slightly abnormal thyroid and kidney functions on a recent blood test. The vet suggested y/d. He told me this food would be good for both conditions. I was a little skeptical- my cat would only eat one kind of dry cat food previous to this. I started mixing in a little of the dry y/d with her regular food. After a couple of weeks she was eating the y/d without her old food mixed in! An unexpected benefit of the diet change- Molly had been throwing up fairly often- I thought she was trying to pass a hair ball, except there was rarely any hair. After switching to the y/d, she stopped thowing up! Whether that was due to an improvement in her thyroid/ liver function with the new food or just the quality of the new food I can't be sure, but it works!! I'm a believer!!! April 2, 2013
Expensive but worth it My neighbors domesticated a feral cat and then moved away. The cat kept returning to the neighborhood from about 15 miles away (4 times) so I adopted him or maybe the reverse. Amazing solid black cat, Rex -- not sure of his age but he's no spring kitten. Took him to the vet for a checkup and discovered hyperthyroidism. Didn't like the 3 options the vet gave me for managing the malady so with google's help I discovered Hill's Y/D. I asked the vet why he didn't suggest it and he said cats won't eat the stuff but if I wanted to try it he would give me a free sample. P.S. My cat loved it right from the get go, has been on it for a year and a half and has maintained his weight, shiny coat and high normal thyroid readings. The vet is amazed and cites my cat as his first success story with Y/D. May 17, 2014
Excellent results!!!! My 13+ yr old male cat Jeter was losing weight and seemed to be drinking a lot of water. Toward the end of August I noticed a slight head twitch like a seizure from time to time. I immediately took him to the Vet who was pretty sure from an exam that he had an enlarged thyroid. We did an entire blood work up including the thyroid. The thyroid came back elevated at 9.1 while all other bloodwork was normal. The Vet suggested we try the y/d diet only for 6-7 weeks then recheck the thyroid. Jeter prefers the dry food but eats a couple of teaspoons of wet food mixed with water per day. He eats between 1/2 - 2/3 cup of dry food per day. At his top weight he was 19.6 lbs. His weight in August was 13.6. He was initially tested on August 21st. He was retested on October 16th. WITH THE Y/D FOOD ONLY - his reading is now 2.3 which is within the normal range of .8 - 4.2. We were thrilled!!!!! He has more energy and there are no head twitches. He lost 2 ounces but we are hopeful he will put on a pound or so. He eats ONLY THIS FOOD. The Vet wants a retest in 6 months but expects the reading to come down further. I couldn't be more pleased and would HIGHLY recommend this food for any senior cat with thyroid issues!!!! October 31, 2012
Best remedy for my cat Zoe Ann is a fifteen year old calico that was recently diagnosed with hyperthyroidism. We tried medication, but it made her liver angry and she became lethargic, stopped eating and lost weight on it. My vet prescribed the Hill's Yd food. She transitioned from her junk food easily to the Yd and is now eating it solely. She loves the dry food but not so much the canned. To help her eat more, I use a blender and whip up a frappe with the canned food and use a syringe 3-4 time daily. She loves it and sticks out her tongue eagerly for it. It works because at the vet's her weight increased and her T-serum level dropped from 4.5 to 3.5. She looks good and has a nice coat, is happier and sleeps well. She is still drinking a lot of water, but overall I am hoping the next checkup is even better. Thank you Hill's January 22, 2014
It works...but so expensive! PROS: My cat lost alot of weight and was miserable. Thyroid level was 23 and within 4 weeks of being on this food his Thyroid level dropped to 6- so it is almost back to normal. He is happier and gaining weight. He has more energy and his fur looks shiny and healthy. He took to the taste of it immediately with no problems. I also utilize the can version in the AM to supplement the Dry. CONS: Cost. This food is mega expensive. I am not sure that I will even be able to afford to keep my cat on it due to the cost which is very disheartening because it works. September 9, 2013
My sweet 16 yr old Maine Coon has become Hyperthyroid After Willie Woo's bloodwork, the vet said lets try this food first to see if we can avoid pills everyday. ( I'm sure you know how hard it is to give a cat a pill) He was starving all the time, crying and wondering all around the house like he was lost or in pain but after one day on this food, he has settled down and now about a month later, much better. I am waiting for him to gain back some weight and he should be good to go. He also eats some of the canned y/d too. The y/d dry food is so expensive though and on a fixed income, its a real concern. Especially because I have a dog on meds with a heart condition and 2 other aging cats. I am still glad to see my big boy feeling better. January 24, 2014
Amazing food that changed my cats health! By simply changing the food that 8 year old Lexie eats, her body seems completely healthy again. She likes the food and seems to be thriving. It's been 3 months so far, and all is well. I will continue feeding her this diet. August 28, 2014
Life Saver My sweet Little baby developed an over active thyroid and lost a considerable amount of weight , the vet started her on meds and as it would be she is the 1% of felines that can not tolerate this medication. Her vet then placed her on the y/d dry and wet food , she loved it , in fact both my girls loved it ( my other baby gets feed a little something alone too ! ) She gained weight and it helped level her out some , y/d saved my Furbabies life , it doesn't get better than that !! February 4, 2014
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