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Hill's PRESCRIPTION DIET y/d Cat Food is a complete dietetic pet food for reduction of iodine levels in feed in cases of hyperthyroidism in adult cats. This food contains a restricted level of iodine.

To support your cat's thyroid health


Thyroid Care




Adult, Senior



Satisfaction guarantee

For quality, consistency and taste, or your money back

Hill's Prescription Diet y/d Dry Cat Food is an easy and convenient way to reduce the iodine levels in food for cats with hyperthyroidism. For best results, consistent long term feeding of this product is critical for efficacy of the product benefits. Dry and canned formulas can be mixed or fed concurrently.

How it works:

Limited iodine Reduced phosphorus and sodium with omega-3 fatty acids from fish oil High levels of L-carnitine

How it helps:

Supports thyroid health Supports kidney and heart health Helps maintain lean muscle mass S+OXSHIELD: Formulated to promote a urinary environment that reduces the risk of developing struvite & calcium oxalate crystals

Additional info:

Please consult your veterinarian for further information on how our Prescription Diet foods can help your cat to continue to enjoy a happy and active life.

Formulated to help

reduce the risk of struvite & calcium oxalate crystals

Made in the USA
with global ingredients you can trust

Proud to have helped
13 million shelter pets
find a forever home & counting


COMPOSITION: Vegetable protein extracts, cereals, oils and fats, eggs and egg derivatives, minerals, meat and animal derivatives, seeds.


ANALYTICAL CONSTITUENTS: Protein 33.5%, Fat content 22.0%, Crude fibre 0.93%, Omega-3 fatty acids 0.9%, Crude ash 6.1%, Calcium 0.86%, Phosphorus 0.64%, Sodium 0.23%, Potassium 0.86%, Magnesium 0.08%; per kg: Vitamin A 9,014IU, Vitamin D3 783IU, Vitamin E 600mg, Vitamin C 110mg, Beta-carotene 1.5mg, Total Iodine 0.18mg, L-carnitine 561mg.


ADDITIVES PER KG: Nutritional additives: 3b103 (Iron) 97.0mg, 3b405 (Copper) 9.6mg, 3b503 (Manganese) 10.0mg, 3b603 (Zinc) 167mg, with natural antioxidant.

Adult maintenance Mixed Feeding Guide

Weight of Cat - kgs Amount per Day - 156 g cans Amount per Day - grams
2 0.5 + 10 g
3 0.5 + 25 g
4 1 + 10 g
5 1 + 20 g
6 1 + 30 g
7+ 1 + 7 g per kg

Adult maintenance

Weight of Cat - kgs Amount per Day - grams
2 35
3 45
4 55
5 65
6 75
7+ 11 per kg

IMPORTANT: Because iodine intake from other food sources – treats, another pets food, flavoured medicines, etc. – can compromise the effectiveness of low-iodine nutrition, it is critical that you follow your veterinarian's feeding instructions carefully and feed only Prescription Diet y/d. Ask your veterinarian for specific feeding instructions for your pet. Daily Feeding Recommendations are only a guide and a place to start. Grams are the most accurate form of measurement; cups are estimated from grams. For best results: – Gradually transition to this new food for 7 days or more. – Exclusively feed the recommended Prescription Diet dry and wet foods. – Keep fresh water available at all times. – Have your veterinarian monitor your pet's condition. – To prevent suffocation, keep the packaging out of the reach of pets & children.



Days 1-2

Days 3-4

Days 5-6

Day 7

Days 1-2

Days 3-4

Days 5-6

Day 7

Days 1-2

Days 3-4

Days 5-6

Day 7

4177 kcal/kg (418 kcal/100g)

Nutrient As Fed2
Protein 33.5 %
Fat 22 %
Carbohydrate / NFE 31.9 %
Crude Fiber 0.9 %
Calcium 0.86 %
Phosphorus 0.64 %
Potassium 0.86 %
Sodium 0.23 %
Magnesium 0.082 %
Taurine 0.21 %
Vitamin C 113 ppm
Vitamin E 596 IU/kg
Total Omega-3 FA 0.92 %
Total Omega-6 FA 3.53 %
Carnitine 561.2 ppm


1The displayed analytical values may differ slightly from the values shown on the package. Both values meet product specifications.

Prescription Diet

Groundbreaking nutrition that can save the lives of sick pets and comfort the people who care for them.

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