Hill’s Science Diet Dog Food Review

Available fromPet Circle,  

Toothpaste/Shampoo conglomerate Colgate-Palmolive make hundreds of millions of dollars selling Hill’s Science Diet dog foods made largely of rice and corn. Branding these ingredients with the word “Science” doesn’t necessarily mean they’re right for your dog, it means they’re scientifically formulated (cunningly within guidelines) to a product with the highest profit margin possible. It’s a winning formula from a company who’s done incredibly well with products we use “every day”.

Our previous review was negative, so for this revised edition we’ll focus on a formula aimed at healthy, active adult dogs – Hill’s Science Diet Active Adult. Consider this the best of the bunch, so if this doesn’t stack up, the other Science Diet dog food formulas probably won’t either.

Brands such as Hill’s and Royal Canin are trusted worldwide, especially as they’re often heavily endorsed by vets. There are a number of reasons for this, but they’re not necessarily anything to do with the nutritional aspects of the product itself. If you’re interested in the very clever marketing machine which drives these products then read this post about why vets recommended Hill’s Science & Prescription Diet.

Hill’s Science Diet Dog Food Review

The first ingredient in Hill’s Prescription Diet Active Adult, a product designed to feed an animal which is essentially carnivorous, is… [drum roll]… corn 🤷

Hill's Science Diet Dog Food Review

This is very disappointing, and an immediate insight into how the company makes so much money. Corn is one of the cheapest inclusions we can find in a pet food, and a very cheap way to boost protein levels in the food without using meat. Pet food ingredients are listed in order of percentage, which assures us corn is more significant than any other ingredient, perhaps by a large margin.

The fourth ingredient, surprise surprise, is also corn, labelled in this instance as corn gluten meal (or CGM). The 5th ingredient (Beet Pulp) won’t amount to much of the food, which suggests the first four ingredients are the majority of the product. The corn is potentially 50% of the food, but very likely much more. The food boasts a high protein, and corn happens to be high protein, just not in a form as easily digested by your dog than protein from meat.

The 2nd and 3rd ingredients are more species appropriate, a combination of chicken by-product meal and pork fat. These are better inclusions which make Hill’s Science Diet Active Adult ever so slightly better than other formulas in the range. Sadly it’s still very lacklustre.

Moving on from the four main ingredients we find a long list of vitamins, minerals, oils, preservatives, et al. Dog foods need to meet minimum nutrition guidelines (usually based on AAFCO standards). On many pet foods you find “vitamins and minerals” listed, usually in the form of a pack/powder sourced overseas. With Hill’s Science Diet you can expect better inclusions which have been hand picked to work with the formula, so that’s a small plus point.

Hill's Science Diet Dog Food Review

It’s hard to understand from looking at the ingredients, which to iterate are largely corn, why Hill’s Science Diet has such a glowing reputation. Fortunately for them not many people read the ingredients, and even those who do often fail to understand what they really mean. A dog, whether you class them as carnivore or omnivore, have a dental structure and digestive system geared towards digestion of meat and animal products. This is the reason your dog, like their wolf ancestors, will choose meat if you offer them a choice of meat or corn.

Overall this is one of the better Hill’s Science Diet formulas, but we can’t ignore the significant amount of corn. Many other Hill’s formulas use wheat and rice to keep production costs down, both of which are arguably worse. If you choose to feed a Hill’s Science Diet or Prescription Diet product then make sure you assess the ingredients and decide for yourself if it’s right for your dog.

If you still decide to feed Hill’s Science Diet or Prescription Diet, you’ll find their wet food offerings more species appropriate.

We hope our Hill’s Science Diet dog food review has been enlightening. If it has, please help us by sharing it with others. If you want to know more about why Hill’s and Royal Canin are so heavily endorsed by vets, then read this article.

Where to Buy Hill’s Science Diet

Hill’s Science Diet Dog Food Ingredients (Active Adult)

The ingredients of Hill’s Science Diet Active Adult dry dog food (as of July 2021) are as follows:

Whole Grain Corn, Chicken By-Product Meal, Pork Fat, Corn Gluten Meal, Dried Beet Pulp, Soybean Oil, Chicken Liver Flavor, Lactic Acid, Flaxseed, Egg Product, Potassium Chloride, Iodized Salt, Choline Chloride, vitamins (Vitamin E Supplement, L-Ascorbyl-2-Polyphosphate (source of Vitamin C), Niacin Supplement, Thiamine Mononitrate, Vitamin A Supplement, Calcium Pantothenate, Riboflavin Supplement, Biotin, Vitamin B12 Supplement, Pyridoxine Hydrochloride, Folic Acid, Vitamin D3 Supplement), minerals (Ferrous Sulfate, Zinc Oxide, Copper Sulfate, Manganous Oxide, Calcium Iodate, Sodium Selenite), Mixed Tocopherols for freshness, Natural Flavors, Beta-Carotene.

Hill’s Science Diet Dog Food Guaranteed Analysis (Active Adult)

The guaranteed analysis of Black Hawk Working Dog Beef & Lamb dry dog food (as of July 2021) are as follows:

Crude Fibre1.8%
Carbohydrates33.2% (listed on website)
* May be estimated. Read how to calculate carbohydrates in a pet food.

Hill’s Science Diet Recalls

As a major worldwide brand we can expect numerous recalls, and in perspective the standard of Hill’s products is generally good. They have, however, had some major recalls, the latest being as recent as January 2019 when Hill’s issued a massive worldwide recall of various varieties of canned foods due to toxic levels of vitamin D. The recall was issued for 22 million cans covering both Hill’s Science Diet and Hill’s Prescription Diet wet food products, with numerous alleged reported deaths.

Hill’s were one of the many affected manufacturers who fell victim to the pet food recalls of 2007 which led to numerous pet deaths from vegetable proteins imported from China contaminated with melamine.

Calling Aussie pet lovers – join the mailing list!

6.5 Total Score

  • High protein (but substantially from corn rather than meat).
  • High animal fat.
  • Manufacturing standards should be higher.
  • Heavy use of corn rather than meat.


David D'Angelo

David D'Angelo has worked as a scientist since graduating with a BSc (Hons) in 2000. In addition, David holds a CPD accredited Diploma in Pet Nutrition as well as being CPD accredited VSA (Veterinary Support Assistant). However, his experience and involvement in the pet food industry for 15+ years has given true insight into pet food, formulations, science, research, and pet food marketing. Facebook | LinkedIn | Instagram | Pinterest

  1. The last “Hill’s Diet” ingredients listing I reviewed show that the meat product is their No 1 item. On that basis I’m not sure your review is all that factual now.

  2. Hi, I was wondering whether you could point to any scientific studies in relation to how dogs digest corn and grains?

    • Reply
      Pet Food Reviews (Australia) April 25, 2022 at 9:26 pm

      Hi Daniel, may I ask for what purpose? I can point you in directions of studies but finding credible ones which actually prove a valid point is another matter entirely. For example, a study on the digestibility of various types of grain will offer little context in digestibility of grain over meat, or how much grain a dog can be fed without suffering ill effects.

  3. Thought it was toxic levels of vitamin D not C? especially since literally every recent recall was the D again.

  4. Hill’s doesn’t make this Lamb formula no more, Hills have changed most of their Science diet formula’s & have brought out their new “Youthful Vitatility” Adult 7+ wet & dry for Mature dogs, it’s got everything an ageing dog needs for their brain, joints, bones, muscles, healthy immune system, I’m going to try the wet tin food when Pat Barn gets it, Pet Barn are a bit slow behind the times when new foods come out.. Pet Circle seem to get the new foods first…

  5. Our cat is on the urinary care, we don’t know what else to give her?

    • Hi Emma, is that the dry food? If so it’s an absolute farce – cats with urinary issues shouldn’t be on a dry diet, and you’ll find the bulk of that food is brewers rice when cats, being obligate carnivores, shouldn’t be fed such a diet. Hills know this, they just don’t care.

      The wet variety is much more suitable, although still contains grains. At least it has a better standard of meat and much needed moisture which is vital.

  6. Hi there. Our 11yo labrador died here in Melbourne Australia at end January 2017 from catastrophic liver failure. In August 2016 we put him on hills metabolic & mobility as the vet wanted him to lose some weight and we thought the mobility additives would help with his ageing joints mobility. This food has a very unpleasant strong smell and from time of introduction was the marker point in our dogs rapid health decline. He lost 12kgs in 5 months. He didn’t really like the food but would eat it as (due to guidance by our vet) we were not to feed him anything else. (we did eventually give him small amount of fresh meat and veggies as supplement as we were concerned that he didn’t particularly like the food) Anyway, to continue, our dog became restless and would whine a lot. He began eating a lot of grass and vomiting. Becoming really unwell in January, in fact has jaundice and died with catastrophic liver failure. I mentioned to the vet that our dog has not been his usual self since putting him on the diet. The vet believed this was unrelated, though could not really identify what has happened to our dog. I decided to just check online the ingredients of the hills mix in case there was something which would upset dogs in the contents. I was shocked at how many animals have died with very similar symptoms to our dog. DO NOT FEED YOUR DOGS THIS STUFF! ITS NOT FOOD! ITS A CON AND A WAY OF GETTING CARING PET OWNERS TO BUY AN EXPENSIVE PRODUCT MADE WITH CRAP INGREDIENTS. I did not do due diligence on the ingredients of this product and our poor dog paid the price. Yes he was raging but he was a very well dog apart from mild stiffness and being a little overweight which we could have managed another way. Sorry Sunny Jim RIP

    • Our young dog died after being put on Hills science dry dog biscuits
      She was tested and liver was effected badly. She also had unusually high vitamin e levels

  7. Hi guys,
    So after reading this I’m feeling pretty silly knowing I buy hills science optimum nutrition especially since they dropped 3kg off it now to a 12kg bag (same price of course!!).
    I feel pretty ignorant not looking at the fine print.
    So we saved our dog from the rspca, she was three years old and weighed 13kg, she is now 4 and a healthy musclely 27kg.
    Haven’t had any health problems, she is all muscle and has a shiny coat. after reading this I’m looking to change to blackhawk as it represents better value for money and sounds as though it would be better for her, would you recommend slowly weigning her off hills and onto blackhawk to not upset her stomach, though she is pretty damn tough.(swallowed a battery and passed it) or just doing a straight swap??
    She is a am staff x kelpie.

    • When a dog has been eating a single brand of food for a length of time it’s always best to transition gradually. There might be some temporary diarrhea but this should subside within a week. If it doesn’t then something in the new food may not be agreeing with her (actually diarrhea seems common with Black Hawk). Staffie’s are also the most prone to allergies, particularly grain allergies.

      She sounds like a touch cookie!

      • Thank you for the reply, she has been fine on hills in terms of health, the vet said she is in good health considering her past life, but said no more weight as she has too much muscle for her kelpie frame.
        Yeah she certainly is, was covered in fleas and ticks and could see her ribs when we got her, but shes in good health now and is pretty damn spoilt!!.

    • It’s quiet a difference in ingredients regardless of her iron stomach I would do a slow swap over a week if she seems to tolerate it well during that week I guess you can try cold turkey.

      Someone in petbarn yesterday was holding a massive bag of Royal, I asked mum to tell me the price and she said $140 and I was like holy cow, you can buy Blackhawk on pet circle for like $80 when its on special which is quiet often. what a waste of money, if only more people knew.

      Indeed they have been reducing bag sizes but keeping or increasing prices, it seems so far that it’s mostly the most successful brands doing it, but even those smaller ones have been known to do it, I wish they were just more open about it, it doesn’t affect me but I read a lot of comments and I don’t agree with making people angry on such a scale just because you can’t explain the reason.

      I think you should also interest yourself in rotation to change your dog to a new food every month or every 3 months, to keep her digestion working properly and so that she doesn’t have the potential to gain an allergy from the same food all the time and other reasons as well, if you do try this not the same meat protein either change it up, from chicken to turkey to fish to duck you get the idea.
      There’s a few good foods with similar price ranges to Blackhawk.

      • Thank you for the reply, we are going to get a bag of blackhawk this weekend as we still have a bit of hills left and will change up the flavours every few months 🙂

  8. Thank you for the reviews!
    I started my pup out on Royal Canin Junior, and after 6 months she started getting bad diarrhea. The Vet suggested going to the Sensitive Digestion one, so I did. 6 months later, same thing. A few people I know had fed their Border Collies Pedigree with no issues(Chicken and Rice), she did a year and a half on that, and now she has the diarrhea again. The pet store I always go to suggested Hills Science Diet, the Vet she sees suggested Science Diet(as they are linked to the pet store I assume?) and a seperate pet store that only sells Science Diet and Black Hawk are saying feed her Black Hawk Grain-Free.

    I am so confused and feeling ripped off having bought the Hills Science Diet Sensitive Stomach variety.. which looks no different to pedigree out of the bag.

    I am currently giving her(for dinner) 140g of Science Diet, approx. 150g chicken breast(from the deli) and 1 half a dental stick with dinner. Havent noticed any diarrhea lately, but don’t want it coming back.

    • Reply
      Pet Food Reviews (Australia) February 13, 2016 at 10:20 am

      Hi Rachel, dogs can develop an intolerance if fed the same food for a long period, which seems to be the case here. I recommend rotating foods, perhaps from our best rated list – https://www.petfoodreviews.com.au/dry-dog-food/best-dry-dog-food/

      • so should I not feed the Science Diet and go with Black Hawk this time around? I feel like I have to add extra meats and things to Hills SD to make up for its low protein, which is quite costly. I think the Pet Store only recommend SD cos they make more off it than they do Blawk Hawk and therefore dont stock it.
        Also woke up today to find my Border Collie hasnt touched the Science Diet I put in her bowl last night, she just ate the chicken and dental stick… so I dont think she likes it much… and dont know whether to keep going to force her into it or just stop giving it to her and change foods before the bag runs out

        • Pet Food Reviews (Australia) February 16, 2016 at 10:44 am

          Hi Rachel, the choice is ultimately up to you. We rate Science Diet at 2 stars, and Black Hawk as 4 to 5 stars. Science Diet Sensitive Stomach is a food with the main ingredient being Brewers Rice, a known waste product – this is what your vet’s recommending you feed your dog. Veterinary courses don’t go into much depth on pet nutrition, and it’s governed by manufacturers such as Hills (Science Diet), Eukanuba, et al. For the price you pay for Science Diet there are many other foods of a similar price or less, and read far better from an ingredients and guaranteed analysis standpoint. Science Diet is very expensive in comparison, especially given the ingredients.

        • That settles that then, Black Hawk Grain Free it is from now on. Shes doing well on SD but if she can be better on Blawk Hawk I would rather that. Its easier for me to get and better value for money from the look of it. Thanks so much Pet Food Reviews 🙂

  9. I have a 7yr old burmilla that developed kidney disease after having calicivirus he has been recommended renal food by my regular vet and raw organic paws by my holistic vet what do you recommend I feed him on for a longer life? Thanks confused maree

    • My 11yo doberman has kidney failure.She was constantly at the vet with constant itching, ear, eye and skin infections.Being a nurse, I suspected uremic pruitis with the itching. Off my own back, I commenced the Hills KD diet. The itching improved almost overnight. No more infections so no regular A/Bs. She now has drinks and wees more but the itching has gone.Obviously she was having a build up of toxins and her kidneys were struggling.The altered components in the food have helped her immensely. We have bought a little time and she is happy enough, I have ceased all other meds like heartworm & flea contro. Its expensive but I have seen results immediately and I think she is worth it.

      • Reply
        Pet Food Reviews (Australia) April 14, 2016 at 4:44 pm

        Hi Tracey, the itching could’ve been an allergic reaction to an ingredient in the previous food. What were you feeding prior to the Hills?

    • Reply
      Pet Food Reviews (Australia) January 5, 2016 at 1:56 pm

      Hi Maree,

      With renal failure your best option is to feed wet food rather than dry as the moisture is vital. Ensure your dog has plenty of water. The common belief is renal diets should be low protein/low phosphorous, but there’s very little evidence protein has a negative effect. Low phosphorous foods aid comfort, and Hills k/d is one of the lowest phosphorous foods available.

      It depends on the severity of your dog’s kidney issues, but definitely look into wet or fresh diets. I’d opt for the advice of your holistic vet over your regular vet. If you choose to feed dry then I recommend a food with a decent amount of meat, such as chicken or turkey.

  10. Meat meal products are also highly contaminated with heavy metals. They use bones and organ meats from a carcass which is where heavy metals accumulate. One particular study that pulled 10 common dog foods off a USA shelf and found 8 had way too high levels of fluoride. Dont buy any product with a meat “meal” ingredient. You would not feed your child a hot-dog everyday and expect them to live well would you? This is all this food is, hot-dog meat with loads of white carbs, ie the bun, and a few vitamins chucked in to say it is balanced. And as for the “animal fat” ingredient – what animal is this from as in USA it is legal for this to come from any slaughter house, animal shelter or sale yard! As a vet I say dont buy this stuff and thanks for the great reviews.

  11. Leonie & Freda there’s also “Meals For Mutts” Salmon & Sardines Brown Rice & Veggies, Australian Made, the fat is only 10% fat & the protein is low 20% if your dog gets pain with his Pancreatitis/stomach, I’ve noticed when my boy eats a low fat kibble & the protein is higher then 26% my boy gets his pain right side, when he eats a lower fat & lower protein he doesn’t have his pain right side, I’m trying the Earthborn Holistic Ocean Fusion at the moment the fat is 12% & the protein is 22% the Ocean Fusion has the least ingredients, no peas, no tomato pomace, no rice, & no probiotics & Patch is doing really well he seems to do well on fish kibbles, he also suffers with skin problems…..

  12. Hi,
    I have my dogs eating Hills Science Diet for sensitive stomachs because my Neapolitan has the smelliest bum when she isn’t on this food. If Hills is so unhealthy; what would you recommend. She was on Blackhawk which had them both looking amazing but we needed a gas mask to watch TV with her in the same room? Does Canidae have anything in their range?

    Thank you.

    • Reply
      Pet Food Reviews (Australia) April 15, 2015 at 11:41 am

      Hi Leoni, a few people have had issues with Black Hawk and wind (see the Black Hawk review comments).

      Yes, you could try Canidae, perhaps even their grain free range which is fairly limited ingredient. See how it goes.

  13. Thankyou so much for doing all this reviewing ~ its SO helpful. Our dog needs low fat as he gets pancreatitis. Hills Science G/I has been recommended but now I’m feeling very unsure about this being the best … can you help me?
    Thanks so much

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