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Hill's Prescription Diet y/d Thyroid Care with Cat Food

  • Dry » 1.5kg Bag £16.49
  • Dry » 5kg Bag £44.50
  • Wet » 24 x 156g Cans £38.99

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£16.49 to £44.50

Hills Y/D available from VIoVet

Hill's y/d is the first and only clinically proven nutrition that is specially formulated to help support your cat's thyroid health. The y/d diet carefully restricts the levels of iodine to help support thyroid function, particularly in cats with hyperthyroidism, whilst providing a complete daily nutrition with a taste your cat will love.

Additional benefits for overall health

Hills y/d diet also provides extra benefits in addition thyroid health, including:

-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 Hills Y/D.

Hills 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 Cat Amount of Hills Y/D 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)



Liver, pork, chicken, maize, rice, animal fat, vitamins, digest, cellulose, minerals, trace-elements, fish oil, L-carnitine.


Maize gluten meal, maize, animal fat, dried whole egg, flaxseed, L-lysine, digest, minerals, fish oil, dl_methionine, L-carnitine, rice, taurine, vitamins and trace-elements.



Average Nutritional Contents

As Fed Dry Matter kcal/100g
Beta-carotene 0.6 mg/kg 2.1 mg/kg 0.05 mg
Calcium 0.25 % 0.86 % 192 mg
Carbohydrate (NFE) 9.1 % 31.4 % 7 g
Fat 7.5 % 25.9 % 5.8 g
Fibre (crude) 0.9 % 3.1 % 0.7 g
Iodine 0.04 mg/kg 0.14 mg/kg 3 ug
L-Carnitine 188 mg/kg 648 mg/kg 14 mg
Magnesium 0.02 % 0.07 % 15 mg
Moisture 71 % 54.5 g
Omega-3 fatty acids 0.19 % 4.61 % 150 mg
Omega-6 fatty acids 1.34 % 0.66 % 1030 mg
Phosphorus 0.17 % 0.59 % 131 mg
Potassium 0.25 % 0.86 % 192 mg
Protein 9.9 % 34.1 % 7.6 g
Sodium 0.07 % 0.24 % 54 mg
Taurine 722 mg/kg 2490 mg/kg 55 mg
Vitamin A10] 18756 IU/kg 64675 IU/kg 1440 IU
Vitamin C[sup:10] 12 mg/kg 41 mg/kg 0.9 mg
Vitamin D[sup:10] 237 IU/kg 818 IU/kg 18 IU
Vitamin E[sup:10] 215 mg/kg 741 mg/kg 17 mg

Metabolisable Energy

As Fed Dry Matter
kcal/100 g 130.3 449.1
kJ/100 g 545 1879


Average Nutritional Contents

As Fed Dry Matter kcal/100g
Beta-carotene 1.5 mg/kg 1.6 mg/kg 0.04 mg
Calcium 0.8 % 0.85 % 189.13 mg
Carbohydrate (NFE) 32 % 34.04 % 7.57 g
Fat 23.4 % 24.89 % 5.53 g
Fibre (crude) 1 % 1.06 % 236.41 mg
Iodine 0.18 mg/kg 0.19 mg/kg 4 ug
L-Carnitine 500 mg/kg 531.91 mg/kg 11.82 mg
Magnesium 0.07 % 0.07 % 16.55 mg
Moisture 6 % 1.42 g
Omega-3 fatty acids 1.01 % 1.07 % 238.77 mg
Omega-6 fatty acids 3.63 % 3.86 % 858.16 mg
Phosphorus 0.57 % 0.61 % 134.75 mg
Potassium 0.85 % 0.9 % 200.95 mg
Protein 32 % 34.04 % 7.57 g
Sodium 0.24 % 0.26 % 56.74 mg
Taurine 1974 mg/kg 2100 mg/kg 46.67 mg
Vitamin A10] 13623 IU/kg 14492.5 IU/kg 322.06 IU
Vitamin C[sup:10] 110 mg/kg 117.02 mg/kg 2.6 mg
Vitamin D[sup:10] 1316 IU/kg 1400 IU/kg 31.11 IU
Vitamin E[sup:10] 610 mg/kg 648.94 mg/kg 14.42 mg

Metabolisable Energy

As Fed Dry Matter
kcal/100 g 423.1 450.1
kJ/100 g 1770 1883

Signs of feline hyperthyroidism

Signs of Feline HyperthyroidismTransitioning from Anti-Thyroid Medication to Hills Y/D Feline

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Reviews of Hill's Prescription Diet y/d Thyroid Care with Cat Food

Read our customers' reviews of Hill's Prescription Diet y/d Thyroid Care with Cat Food

Questions & Answers for Hill's Prescription Diet y/d Thyroid Care with Cat Food

Below are some recent questions we've received regarding Hill's Prescription Diet y/d Thyroid Care with Cat Food, including answers from our team.

Ask Your Own Question

Y/d wet or dry?

2nd May 2016
  • VioVet Customer Since: May 2016
  • From: CHANNEL ISLANDS, United Kingdom

My cat normally eats dry food and has been recommended the y/d diet by our vet. Can she continue just eating the dry food or does it have to be mixed with the wet food?

  • Non-Executive Director

You can choose wet or dry, or a combination of the two, it will be fine as far as her hyperthyroid treatment is concerned. The main issue with this diet is that it tastaes a bit boring to cats, so they tend to go off it after a while. Using both wet and dry can help to provide interest, so I would recommend that is what you do. It is important that she does not eat any other type of food at all.

Hills y/d variety

16th Sep 2014

My cat has a thoroid problem & won't rejects Felimazole tablets in any form.
Q1. Does the y/d only come in one variety (which my cat doesn't like) - are there any other varieties.
Q2. Is there any way of making it taste like Chicken or Beef?

  • Non-Executive Director

There is only one form of y/d diet and it is true that lots of cats do not enjoy it. Adding anything significant to it to improve the flavour will probably prevent it from being fully effective, so I would not recommend that. If hunger will encourage your cat to eat it then you will have to work on that, but this is a problem for many cat owners.

Is y/d ok for multicat households?

31st Aug 2013
kay barnett

i can't find anywhere, whether it is OK for prescription y/d to be fed to other healthy cats within the household, or must it ONLY be fed to the cat diagnosed with hyperthyroidism?

  • Non-Executive Director

This diet is safe for other cats to eat, but ideally they should get some other foods as well. A hyperthyroid cat should not be allowed to eat anything else at all. The y/d diet is not especially tasty, so your other cats would probably prefer other food anyway. You have to make sure you do not offer any other foods when the hyperthyroid cat is present, or that one will not want to eat the prescription food either. If you can cope with the hassle of organising the feeding, the y/d dose seem to be very effective.