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Kitten Kitten
Adult 1+ Adult 1+
Mature <br/>Adult 7+
Adult 7+
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Adult 1+ Adult 1+
Mature <br/>Adult 7+
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Grain Free


By Health Conditon

y/d® Feline Thyroid Health - Dry

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

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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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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.

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 Contents

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 052742149714,052742159713,052742159706,052742149707 1497,1597

Rated 5 out of 5 by from Bean's thyroid has returned to a normal range with the y/d diet This product is wonderful. My 17 year old cat was too old and sick for any other thyroid treatments. Oral medication did not work and had to be stopped - it caused intense itching above the eyes that resulted in sore areas. Bean was quickly running out of options. Since Bean has been on the diet (wet and dry food), it is obvious he feels much much better - his coat is shiny again, he has started to play again, and he looks better than most cats his age (per the vet tech at my vet's office). Bean has gained about 6 ounces since the diet. I feed Bean the wet y/d in small portions every 3/4 hours and always keep the dry food out for him. I have my best buddy back again and I am grateful!
Date published: 2013-09-28
Rated 5 out of 5 by from Fast Health Improvement, Great product. Thank you. We are close to week 3 on the y/d diet dry food. My cat is almost 16 years old and was diagnosed with pre- hyperthyroidism. Medications made her sick so we opted the food route. She is responding very well to this diet. Gaining weight back, has boundless amounts of energy and is acting way younger than her years and has stopped vomiting. She likes the food alot. We are grateful because quality of life is very important. Even though it is a little expensive you end of saving money because you are not medicating twice a day which can add up to more cost wise. Hills also has a coupon you can get for this food on there website. Thank you Hills for making a great product.
Date published: 2014-01-31
Rated 4 out of 5 by from 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.
Date published: 2014-01-25
Rated 4 out of 5 by from Thank goodnes for this diet!!! My cat was diagnosed with hyperthyroidism. Before the y/d diet was produced, she had been on the tablets that are commonly prescribed for the condition. Sadly, she was one of those cats that reacted to her medication. She was reacting to the medication in the exact same way that the disease was causing problems. She would vomit and was becoming more anorexic. As soon as y/d became available, my veterinarian immediately switched her onto the diet. All I can say is AMAZING! She has maintained her weight, quit vomiting and eats the diet very well! I am just thrilled to no longer having to medicate her and yet see the definite improvement in her overall well being. She just gets it in her food now!
Date published: 2014-02-28
Rated 5 out of 5 by from KEEPS MY PET ALIVE I am very grateful to have the Y/D Prescription diet for my cat Pickles. He was diagnosed with over active thyroid about 2 yrs ago and did not respond well to oral medication. The y/d formula had just come out and he was one of first cats to try it. He was wasting away and I had no way to help him. He eats the dry everyday with a spoon full of the wet at night. This keeps him from starving to death (literally) There was no way to keep up with his metabolism no matter how much he ate. Thank you for saving Pickles! He has been with us for 13yrs. And I plan on him being around for a long time to come : )
Date published: 2014-04-21
Rated 5 out of 5 by from 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!!!
Date published: 2013-04-03
Rated 4 out of 5 by from Happy cat, happy owner I've been feeding our 14-yr-old dry Y/D exclusively for about 5 weeks, after several weeks mixing it in with her old food. She had been on meds for nearly 4 years and gradually got impossible to pill: wouldn't take Pill Pockets, wouldn't take it in cheese, wouldn't take it separately, etc. I asked the vet about Y/D and we tried it; I worried that she'd miss her treats, but she really seems to love the taste. Bloodwork came back today for both thyroid and kidneys, absolutely normal! I'm thrilled!
Date published: 2013-09-14
Rated 5 out of 5 by from 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.
Date published: 2013-09-10
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