Prescription Diets For Pets: How Hill’s Prescription Diet Can Help

Husky dog being offered a bowl of dog food indoors.

If your dog or cat is showing changes in appetite, weight, bathroom habits, or energy, start with your veterinarian. After an exam and testing, your vet may recommend a prescription diet for pets. These therapeutic foods are formulated to support specific health needs as part of your veterinarian’s care plan.

Quick shop: Explore Hill’s Prescription Diet for dogs and cats at PetSmart.

At a glance

What it is: Vet recommended nutrition formulated to support defined health needs.
How it works in your plan: Feed exclusively unless your veterinarian says otherwise.
Why it matters: Targeted nutrients can support urinary, digestive, kidney, weight, and mobility needs.
Next step: If concerning changes last more than a day or two, schedule a vet exam.

Spot the signs that merit a vet visit

Call your veterinarian if you see patterns that persist or any sudden concerning change.

Urinary health: more frequent trips, straining, accidents, strong odor, pink-tinged urine, or litter box avoidance.
Digestive comfort: repeated vomiting, loose stools, gas or bloating after meals, skipping meals, or picky eating.
Kidney support cues: drinking and urinating more, weight loss despite eating, low energy, or a dull coat.
Weight and mobility: gradual weight gain, stiffness after rest, hesitation on stairs, or shorter walks. If these patterns last beyond a day or two, book an exam.

What your vet will do

Your veterinarian will review history, perform a physical exam, and may order lab work or imaging. Once your vet has enough information to set goals, they may add a dog prescription diet or cat prescription diet to support those goals.

What a prescription diet is, and what it is not

A prescription diet is a therapeutic pet food your veterinarian recommends after an exam and testing. It uses targeted nutrient profiles, controlled minerals, and carefully selected ingredients to support your pet’s health needs. You need a valid authorization from your veterinarian to purchase.

Good to know:

A prescription diet supports your veterinarian’s plan. It is not a cure.
Feed only the prescribed food and approved treats. Mixing with regular food often dilutes the intended nutrient profile.
Rechecks matter. Your vet will adjust servings or format as your pet’s needs change.

How veterinarians use therapeutic nutrition

Your veterinarian matches the nutrient profile to a specific health goal, then monitors progress over time.

Urinary support: controlled minerals and a targeted nutrient profile to support bladder and urinary health.
Digestive support: highly digestible nutrition with tailored fiber to support stool quality and comfortable digestion.
Kidney support: controlled phosphorus with carefully balanced nutrients to support kidney health.
Weight and mobility support: calorie structure designed to support healthy weight, plus nutrients to support joint comfort.

Consistency matters. Feed the prescribed diet exclusively unless your veterinarian gives other instructions.

Featured Hill’s Prescription Diet options

Your veterinarian will confirm the exact recipe, format, and daily amount.

Hill’s Prescription Diet c/d Multicare Urinary Care

Formulated with controlled minerals and a targeted nutrient profile to support urinary health in dogs and cats your veterinarian identifies as needing bladder support.

Hill’s Prescription Diet i/d Digestive Care

Highly digestible nutrition with tailored fiber to support stool quality and digestive comfort for pets with sensitive stomachs.

Hill’s Prescription Diet k/d Kidney Care

Carefully balanced nutrition with controlled phosphorus to support kidney health as part of your veterinarian’s plan.

Hill’s Prescription Diet Metabolic + Mobility

Designed to support healthy weight while also supporting joint comfort and daily activity. Your veterinarian may adjust portions, formats, or the specific formula as your pet’s needs change.

How to get started at PetSmart

Shop in store or online. Have your veterinarian’s authorization ready. If you do not have it on hand, PetSmart will guide you through the process at checkout. Choose the pickup or delivery option that fits your routine. Many areas offer Free In-Store Pickup, Free Curbside Pickup, and Same-Day Delivery. Autoship helps you stay on schedule. Once you have your vet’s recommendation, plan a slow transition. Transitioning the right way Most pets do best with a gradual change over 7 to 10 days unless your veterinarian directs an immediate switch.

Days 1 to 3: 75% current food, 25% new food
Days 4 to 6: 50% current food, 50% new food
Days 7 to 10: 25% current food, 75% new food
Day 11 and beyond: 100% new food

If your pet has a sensitive stomach, extend each step a few extra days.

For detailed guidance, read Safely changing your dog’s diet. If food reactions are part of the conversation, see Allergies and your dog’s food.

When it’s time to switch foods

Daily feeding playbook Keep execution simple and consistent.

Measure every meal. Use a standard cup or kitchen scale.
Feed on a schedule. Consistent timing supports digestion and makes tracking easier.
Limit extras. Ask your vet which treats fit the plan and how many to offer.
Hydrate. Keep fresh water available at all times, especially for urinary and kidney support.
Track changes. Note appetite, stool quality, activity, and weight, and share updates at rechecks.
One bowl per pet. Feed separately so the right pet gets the right food.

Dogs

Many dogs do well with a mix of wet and dry within the same prescription family if your veterinarian approves. For weight plans, measure for your dog’s target weight unless your veterinarian advises otherwise. Bring water on longer walks and avoid large treats that displace daily calories.

Cats

Water intake matters. Try a fountain, multiple water stations, and wet food options if your vet approves them. Keep litter boxes clean and accessible so you can monitor changes. Make feeding areas calm and quiet to support acceptance of new diets.

Rechecks and when to call sooner

Plan follow-up visits as scheduled. Your veterinarian may adjust serving amounts, switch formats, or recommend a different formula as your pet’s needs evolve. Call sooner if you see any return of urinary signs, repeated vomiting, ongoing diarrhea, major appetite changes, sudden lethargy, or any concerning new behavior.

FAQs

What is the difference between regular food and a prescription diet for pets?

Regular food is complete and balanced for healthy dogs and cats.

Hill’s Prescription Diet formulas are therapeutic. They use targeted nutrients to support defined health needs under your veterinarian’s guidance and require authorization.

Can I mix prescription food with my pet’s current food?

Only if your veterinarian says it is appropriate. Mixing usually dilutes the intended nutrient profile and can reduce the benefits your vet is aiming for, especially with urinary, kidney, and digestive formulas. If your veterinarian approves mixing during transition, keep it time limited and stay within the same prescription line.

How long will my pet need a prescription diet?

It depends on your pet’s needs. Some pets use a therapeutic diet short term. Others benefit long term. Your veterinarian will set milestones for weight, stool quality, comfort, energy, and lab values when applicable.

What if my pet refuses the new food?

Slow the transition. Offer smaller, more frequent meals. Warm the food slightly. Mix wet and dry formats from the same prescription line for texture and aroma. Keep the feeding area quiet. If acceptance does not improve, ask your veterinarian about flavor alternatives within Hill’s Prescription Diet.

Are treats allowed on a prescription plan?

Yes, within limits. Your veterinarian can suggest treat options and daily amounts that fit the plan. Keep treats small and count them toward daily calories.

Can puppies or kittens use prescription diets?

Some therapeutic formulas are not intended for growing pets. Your veterinarian will choose age appropriate options or a different plan for puppies and kittens.

How will I know it is working?

Track daily notes on appetite, energy, bathroom habits, and comfort. Some pets show changes within days. Others need several weeks. Your veterinarian will interpret progress at follow-ups and adjust the plan.

Shop Hill’s Prescription Diet at PetSmart

Hill’s Prescription Diet for dogs and cats
In store and online with veterinarian authorization
Free In-Store Pickup, Free Curbside Pickup, and Same-Day Delivery in many areas
Autoship for easy reorders

Information in this article is not intended to diagnose, treat, or cure your pet and is not a substitute for veterinary care. Always follow your veterinarian’s advice and use prescription diets only with a valid authorization.