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Iams ProActive Health Mature Adult Large Breed Dog Food Review

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You can find detailed information about Iams Dog Food, made by Procter & Gamble (P&G), in our main Iams Dog Food review. There you will also find information about how the food is made, recalls, and their quality control.

Iams produces a tremendous range of products for all ages, sizes of dogs, and dogs with different health needs. They emphasize nutrition in their foods but many people who look at ingredients will balk at the corn and other grains used in them. Some of their foods are popular grocery store brands and others can be found in pet stores or bought online. The veterinary formulas have to be purchased through veterinarians.

Eukanuba is the sister company of Iams. Ingredients in the two foods can differ and Eukanuba is generally sold online or in pet stores but the two companies rely on the same nutritional research.

Compare To The Best Selling Mature Dog Food This Month


Ingredients In Iams ProActive Health Adult Active Maturity Large Breed

Corn Meal, Chicken By-Product Meal (Natural source of Glucosamine), Ground Whole Grain Sorghum, Chicken, Ground Whole Grain Barley, Dried Beet Pulp, Chicken Fat (preserved with mixed Tocopherols, a source of Vitamin E), Dried Egg Product, Chicken Flavor, Brewers Dried Yeast, Potassium Chloride, Salt, Sodium Hexametaphosphate, Calcium Carbonate, Caramel, Flax Meal, Fructooligosaccharides, Minerals (Ferrous Sulfate, Zinc Oxide, Manganese Sulfate, Copper Sulfate, Manganous Oxide, Potassium Iodide, Cobalt Carbonate), Choline Chloride, Vitamin E Supplement, DL-Methionine, Dried Chicken Cartilage (Natural source of Glucosamine), Vitamins (Ascorbic Acid, Vitamin A Acetate, Calcium Pantothenate, Biotin, Thiamine Mononitrate (source of vitamin B1), Vitamin B12 Supplement, Niacin, Riboflavin Supplement (source of vitamin B2), Inositol, Pyridoxine Hydrochloride (source of vitamin B6), Vitamin D3 Supplement, Folic Acid), L-Lysine Monohydrochloride, L-Tryptophan, Beta-Carotene, L-Carnitine, Citric Acid, Rosemary Extract


Top 5 Ingredients Breakdown

The first five ingredients in this food are: Corn Meal, Chicken By-Product Meal (Natural source of Glucosamine), Ground Whole Grain Sorghum, Chicken, andGround Whole Grain Barley. As you can tell from looking at these first five ingredients, this food contains a lot of grain products, including corn as the first ingredient. It does contain some good meat protein from the chicken and chicken by-product meal. Overall, lots of carbs and some good meat protein and and protein from plants, so it looks like it meets the manufacturer’s claims. But we can’t yet tell if this is a good food for mature large breed dogs.

According to Iams:

This Iams ProActive Health formula has PreBiotics that work inside the digestive tract to promote healthy digestion and strong defenses. Healthy inside. Healthy outside.

Designed for dogs ages 5+ and 50+ lbs, Iams Active Maturity contains an exclusive antioxidant blend with Vitamin E and Beta-Carotene to help boost your large breed dog’s immune system response to healthy adult levels.

Natural sources of Glucosamine promote healthy joints. Easy-to-chew Iams Daily Dental Care™ reduces tartar buildup by up to 50%.* Protein sourced from chicken and egg helps build strong, firm muscles while seven essential nutrients nourish the heart.

Vet recommended, this premium dog food is 100% complete and balanced, with no fillers or artificial preservatives. 100% Satisfaction Guaranteed* Learn why Iams is so confident about our quality..

*as tested in an Iams Adult Formula

Recommended For: Adult Dogs (over 50 lbs) – 5 years and older

We normally raise questions about dog foods that say they reduce tartar but in the case of this food it actually contains an ingredient – Sodium Hexametaphosphate – that has been proven to reduce tartar when it coats dog food (read more). You can also help keep your dog’s teeth clean and healthy by giving him dental chews and treats that have been approved by the Veterinary Oral Health Council (VOHC) or a similar organization.

We don’t have a problem with most of the claims made by Iams here but we do note a couple of things that raise questions.

1. We’re not sure how the “exclusive antioxidant blend with Vitamin E and Beta-Carotene” helps boost your large breed dog’s immune system response to healthy adult levels.


2. We would like Iams to provide more information about the “seven essential nutrients [that] nourish the heart.”

Feeding Older Large Breed Dogs

Feeding older large breed dogs can be tricky. It can already be difficult to know how to feed a mature dog but when you are dealing with a large breed mature dog, even more factors have to be considered. Large breed dogs, in particular, are subject to more health problems if they are allowed to become overweight or obese. They are especially subject to joint trouble and musculoskeletal problems as they age – even more so if they are overweight. For this reason, most large breed dog foods will have fewer calories than other dogs foods in an attempt to try to keep large breed dogs slim.

Mature dogs in general can also be subject to joint problems and trouble with arthritis as they get older. Again, if they are overweight or obese, these problems can be magnified. Some foods for mature dogs will try to keep calories very low so mature dogs will still very lean. However, many mature dogs continue to need the same amount of calories as adult dogs for a long time. Or they can need even more calories in some cases if they begin losing weight.

You can see that a dog food designed for mature large breed dogs could have some conflicts. We suggest looking for a mature large breed dog food with a moderate amount of calories, plenty of protein, and enough fat so your dog won’t feel hungry again too soon. This applies to mature large breed dogs who are fit or just a little overweight. If your dog is at an ideal weight, you should continue feeding his normal adult dog food as long as you can. Even though he may be chronologically a “senior” dog, if his body is still in prime condition, there is no need to change his diet until he starts showing definite signs of aging. If you dog is definitely overweight, you can consider a mature adult dog food and adjust the amounts you feed or look at good weight control dog foods for senior dogs. If you have a mature adult breed dog who is losing too much weight, especially if the weight loss is rapid, take a trip to the vet. Your vet can tell you if your dog has an illness that needs attention.

Compare To The Best Selling Mature Dog Food This Month

Extra Large & Giant Breed Dogs

Keep in mind that extra large and giant breed dogs usually have a shorter lifespan than medium and small dogs. This means that “mature” can begin for some of these breeds at a much earlier age than it does for other dogs. For instance, a Whippet or Chihuahua often lives well into their late teens. Senior years for these dogs might not start until they are 12-13 years of age. But the senior years for an Irish Wolfhound might start when the dog is 5 years old because they often only live until they are around 9 years old. So, if you have a very large breed dog, keep an eye on him so you can tell when he might start needing to change foods to a mature dog food.

Dental Care For Older Dogs

One thing that’s often overlooked with mature dogs is their dental care but it can be vital to their continued good health. It’s not unusual for an older dog to refuse food and start to lose weight. Owners often assume this means that their dog isn’t hungry and has lost interest in life. They might even make the decision to have their dog put to sleep. In actuality, many older dogs refuse to eat because they have a bad tooth or some other dental problem and they can’t eat without pain. If your dog stops eating or only eats a few bites when you offer him food, the first thing you need to do is take him to the vet and ask the vet to check your dog’s teeth. It could save your dog’s life. Having a rotten tooth removed is a relatively easy surgery and it often means that your dog will be home eating dinner in no time. You should have your mature dog with you for many more years.

In case you’re wondering, one of the top signs of a dog with dental problems is extra bad breath so if your dog has breath like something died in his mouth, take him to the vet for a check-up. Brush your dog’s teeth regularly throughout his life and you can avoid some of these issues but it’s still a good idea to have your vet check your dog’s teeth regularly.

If your older dog is showing less interest in his food and his teeth are fine, you can try warming his food, adding a little warm water to make a gravy, or putting something yummy on top of his kibble (like some canned food) to make it more appealing. Most older dogs start to have some of their senses dull as they get older so they can’t smell or taste things as well as they did when they were younger. Just make the food a little tastier for your dog and he should go back to eating it.

Top 5 Ingredients Breakdown

The first ingredient is corn meal. It’s usually not a good sign to see a grain as the first ingredient in a dog food. According to one source, there are 27 different corn or corn-derived products listed in the AAFCO manual that are all by-products of the various corn milling operations which make human food products. The company says that corn meal is used in their food as a high quality source of carbohydrates for energy (read more). We are uncertain about the nutritional information for the corn meal used in dog food. Assuming that it is similar to corn meal sold for human cooking, then it has about 10 percent protein, 14 percent fat, and 76 carbohydrates. However, we’re not sure if this is the same as the corn meal that’s used in dog food. If you have additional information about corn meal in dog food, please let us know.

Chicken by-product meal is the second ingredient in this food and chicken is the fourth ingredient. Together, this indicates that the food probably contains a reasonable amount of chicken protein. Chicken is about 80 percent protein and it’s a good source of Vitamin B6 and Phosphorus, and a very good source of Niacin and Selenium. Chicken is more desirable than chicken by-products. Obviously the chicken would appear lower in the list if the moisture were removed but the chicken by-product meal already has most of the moisture removed so it contains a lot of protein. AAFCO defines chicken by-product meal as: consists of the ground, rendered, clean parts of the carcass of slaughtered chicken, such as necks, feet, undeveloped eggs and intestines, exclusive of feathers, except in such amounts as might occur unavoidable in good processing practice.” There are some good parts in chicken by-products and chicken meal supplies concentrated animal protein, but it’s a mix and it’s not the same high quality protein as chicken meat. However, it should be noted that it’s definitely chicken. It’s not by-products from some unknown animal. So, it might not be chicken breast but it’s not so bad. Many people who feed raw like to give their dogs chicken necks and other parts that would be called “chicken by-products.” As mentioned, chicken by-product meal is a good source of glucosamine which is good for the joints and is often used for older dogs and large breed dogs with arthritis.

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The third ingredient is ground whole grain sorghum. While sorghum is currently touted as having a lot of health benefits for humans, such as being gluten-free and helping with some health issues (which haven’t been proven), it’s usually associated with livestock feed. Sorghum is about 3 percent protein, 8 percent fat, and 89 percent carbohydrates. It contains some B vitamins and a few assorted minerals, but not large quantities of anything, although it does have a lot of omega-6 fatty acid. One species of sorghum is the source of sorghum molasses. Other kinds of sorghum are used for grass/fodder and grains for animals.

The fourth ingredient is chicken, which is covered with chicken by-product meal. It provides more meat protein in the food which is a plus.

The fifth ingredient is “Ground Whole Grain Barley – more carbohydrates. Barley is about 90 percent carbohydrates, 3 percent fat, and 7 percent protein. It’s a good source of dietary fiber and Manganese. Whole grain barley is considered to be a good grain for regulating the body’s blood sugar.

Overall, these ingredients seem to meet the company’s claims about the food. They provide protein from plants (especially corn) and from meat (chicken by-product meal and chicken). We like the fact that the food contains chicken as well as the chicken by-product meal. However, there are lots of carbs here. We note the presence of the natural glucosamine which is good for joints for both mature and large breed dogs. The first five ingredients look like a reasonable start to the food, though it’s too early to tell if the food has all of the ingredients claimed that will make it good for mature large breed dogs.

Additional Ingredients of Interest

The food also contains dried beet pulp. There are some misconceptions about beet pulp, probably because of the name. Dried beet pulp is a natural, fermentable source of fiber. It is a wonderful addition to dog food to help move fecal matter along in the intestines, for one reason because it soaks up a lot of moisture and keeps things moving. It also acts as a pre-biotic to help good bacteria grow in the gut. Dried beet pulp is not a source of sugar for dogs. It does not make dogs hyper. The sugar has already been removed. “Despite being a byproduct of sugar beet processing, beet pulp itself is low in sugar and other non-structural carbohydrates, but high in energy and fiber. Among other nutrients, it contains 10 percent protein, 0.8 percent calcium and 0.5 percent phosphorus” (read more on Wikipedia). We particularly like to see dried beet pulp featured prominently (sixth ingredient) in a food for older dogs who can start to have some problems with digestion.

The food also contains chicken fat (preserved with mixed Tocopherols, a source of Vitamin E). Chicken fat is a good named fat which is good for dogs. Mixed tocopherols are a form of vitamin E and they act as natural preservatives to keep the fat from spoiling. Chicken fat is also a good source of Omega-6 fatty acid and glucosamine which can be good for joint problems in older dogs such as arthritis

The food also contains chicken flavor. This ingredient probably contains little nutritional value but it’s better than “natural flavors” which are sometimes added to dog foods and which often feature monosodium glutamate (MSG).

Dried egg product is a good source of animal protein. Eggs offer high bioavailability for mammals like dogs.

The food also contains flax meal. Flax meal is a good source of omega-3 and omega-6 fatty acid but it’s also a phytoestrogen and it can cause hormonal problems for dogs, especially for unspayed female dogs. If you are a dog breeder, you should be careful about feeding a food with heavy concentrations of this ingredient to a puppy.

Brewers dried yeast (not to be confused with brewers rice) is a yeast that is leftover from making beer (Saccharomyces cerevisiae) and it has a lot of nutritional uses. It provides biotin and B complex vitamins, as well as protein. It’s considered to be very good for your dog’s skin and coat, for example. Many people add brewers yeast to their dog’s diet as a supplement to discourage fleas. It supports the nervous system and helps keep the skin, hair, eyes, and liver healthy. It’s a source of the antioxidant nutrient selenium.

The food contains the natural sweetener Fructooligosaccharides which is 30 to 50 percent as sweet as other commercial sweeteners/syrups. It is usually derived from fruits and vegetables but it can come from grains and cereals. Dogs don’t really need sugar added to their diet. However, fructooligosaccharides (FOS for short) has some other benefits. It’s becoming popular as a prebiotic, for example, helping to increase gastrointestinal health. According to some sources, it may also help prevent yeast infections. According to some studies, FOS, together with inulin (which is not present in this particular dog food) promotes the absorption of calcium in animals (and in people). The microflora in the lower gut is able to ferment FOS which leads to a reduced pH. Since calcium is more soluble in acidic conditions, the intestines are better able to digest foods that contain calcium and transfer it to the bloodstream. FOS can also be considered a small dietary fiber with a low caloric value.

We also note the presence of inositol in the food. Inositol is a component of the B vitamin complex. It can be found in plant and animal tissue and it is necessary for the growth of yeasts and other fungi. It’s especially important as a part of a phospholipid found in the brain.

The food also contains the compound L-carnitine. L-carnitine comes from the amino acids lysine and methionine. It helps the body turn fat into energy, among other things. L-Lysine is an essential amino acid. It’s a necessary building block for all protein in the body. L-Lysine plays a major role in calcium absorption; building muscle protein; recovering from surgery or sports injuries; and the body’s production of hormones, enzymes, and antibodies.

We also note the presence of dried chicken cartilage (Natural source of glucosamine). The cartilage is, indeed, a natural source of glucosamine. (There are other natural sources of glucosamines such as the exoskeletans of crustaceans and, commercially from the fermentation of some grains.) It’s naturally present in animal bones and bone marrow. Many owners say that glucosamine helps with joint problems such as arthritis. There have been clinical studies of glucosamine but the results have been mixed.

Sodium Hexametaphosphate is a very interesting ingredient in the food. It’s not usually found in pet foods. It’s added to pet food to help remove tartar buildup and there is research to support its effectiveness (read more here).

L-Tryptophan is an amino acid that acts as a building block for protein biosynthesis in the body. According to one source it can help relieve pain. It is not a very common ingredient in pet food though it is found in some dog foods. It can also be bought as a supplement for dogs that need calming. Tryptophan is the ingredient that people often associate with with drowsiness after eating turkey though this effect is actually exaggerated. Tryptophan is found in many foods, including chocolate, eggs, some cheeses, milk, other meats, and some fruits and vegetables.

Rosemary extract is an antioxidant that acts as a natural preservative. It’s a common ingredient in many dog foods but if your dog is prone to seizures you will probably want to look for foods that do not contain rosemary since this ingredient has been linked to them. The food also contains citric acid which is used as an antioxidant and natural preservative.

Beta carotene is a carotenoid that usually comes from various foods such as fruits, vegetables, and whole grains. It’s a red, orange, or yellow pigment – you’re probably familiar with it in carrots. It provides lots of vitamin A and it’s an antioxidant so it can act as a natural preservative. Beta carotene has many suggested benefits. One of them is improving physical strength and health in the elderly. We don’t know if this would also apply to mature dogs or not.

The food also has caramel which can refer to coloring or flavor. In either case, it’s not something that your dog needs. Finally, the food contains the essential fatty acid Methionine. Methionine is related to aging and there are ongoing studies about how it affects people and animals. However, it usually seems to be added to dog food because it can keep dog urine from leaving burned patches in the grass.

Most of these ingredients are found in other Iams ProHealth dog foods as well though the percentages may be different.

Guaranteed Analysis

Crude Protein minimum ….. 24.0%
Crude Fat minimum ….. 10.0%
Crude Fat maximum ….. 12.5%
Crude Fiber maximum ….. 5.0%
Moisture maximum ….. 10.0%
Vitamin E minimum ….. 140 IU/kg
Beta-Carotene minimum ….. 10 mg/kg*
L-Carnitine minimum ….. 30 mg/kg*
Omega-6 Fatty Acids minimum ….. 2.0%*
Omega-3 Fatty Acids minimum ….. 0.13%*
Glucosamine minimum ….. 350 mg/kg*

*Not recognized as an essential nutrient by the AAFCO Dog Food Nutrient Profiles.

Calories Content

293.34 calories per 8 oz cup – we note that there are approximately 40 calories per cup fewer calories in this food for mature large breed dogs than in Iams ProActive Health Adult Active Maturity Large Breed dog food. That’s a lot of calories in a dog food.

Nutritional Adequacy Statement

Iams ProActive Health Active Maturity Large Breed is formulated to meet the nutritional levels established by the AAFCO Dog Food Nutrient Profiles for Maintenance.

Dry Matter Basis

On a dry matter basis, this food contains 26.7 percent protein and 11.1 percent fat. Fiber makes up 5.6 percent of the food. The food contains 47.8 percent carbohydrates. These figures are identical to Iams ProActive Health Mature.


Once again, we don’t like to see corn as the first ingredient in any dog food. However, we do like a lot of the ingredients in this food for mature large breed dogs. We also like the protein and fiber percentages. It would be nice if the fat percentage was a little higher but we understand that many companies work on the assumption that older dogs are chubby. The carb percentage is a little high but not as high as some foods. We note that this food has fewer calories per cup than Iam ProActive Health Mature Dog Food. So, same basic percentages but fewer calories. We would recommend this mature large breed food if your dog is a little overweight. If your mature large breed dog is still very active and fit, we suggest you continue feeding him his normal adult food. We would not feed this food to a mature large breed dog that is already thin.

Iams ProActive Health Mature Adult Large Breed Dog Food has received our 4 paw rating.


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