Homemade Dog Diets: DAP Study Finds Supplements Are Essential for Health

Dog Aging Project Research Finds 94% Of Meals Nutritionally Incomplete

Summary

Home-prepared diets for dogs are often created with the very best intentions – more control, fresher ingredients, fewer “mystery” additives. But new research from the Dog Aging Project, published in the American Journal of Veterinary Research in November 2025, shows a stark reality:

Of 1,726 homemade dog diets reported by owners, only 6% were potentially nutritionally complete according to established AAFCO standards.PubMed

In other words, 94% of homemade diets were missing at least one essential nutrient, often more. This is not an isolated finding – it simply confirms what smaller studies have been telling us for over a decade: when owners formulate their own recipes without proper veterinary nutrition support and targeted supplementation, nutritional gaps are the rule, not the exception. AMVA Publications

This article unpacks:

• What the Dog Aging Project study actually did and found
• Why homemade diets so often miss the nutritional mark
• Which nutrients are most commonly low or excessive
• The potential health risks of long-term imbalance
• Why proper supplements are non-negotiable for homemade diets
• How a broad-spectrum formulation like Balance+ can help provide the missing safety net – alongside a properly formulated recipe

Key Takeaways

• The Dog Aging Project study evaluated 1,726 home-prepared dog diets reported by owners. Only 6% met nutrient targets for adult maintenance; 94% were incomplete.
• Diets were diverse – typically 9–10 ingredients including meat, organs, vegetables, fruits, grains, nuts, seeds and oils – but variety of ingredients did not guarantee balance.
• These findings mirror earlier work on published home-prepared recipes: in a 2013 JAVMA study, 95% of 200 recipes failed at least one NRC/AAFCO nutrient recommendation; only 5 recipes (2.5%) were fully adequate, and all 5 were written by vets.
• Common issues include too little calcium and vitamin D, low trace minerals (zinc, copper, iodine, selenium), inconsistent vitamin E and essential fatty acids, and occasionally excesses (e.g. vitamin A, some minerals) that can also be harmful.Today’s Veterinary Practice
• Long-term feeding of unbalanced diets has been linked to serious clinical problems such as nutritional secondary hyperparathyroidism, osteopenia, fractures, taurine-deficiency cardiomyopathy and thiamine deficiency in case reports.Today’s Veterinary Practice
• Homemade diets can be safe and effective – but only when:
  • They are formulated or approved by a veterinary nutritionist
  • They use a proper vitamin–mineral supplement specifically designed to achieve complete and balanced nutrition
• Broad-spectrum formulations like Bonza Balance+ (Balance+) are an important part of this strategy: they provide carefully calibrated vitamins, chelated minerals, taurine, carnitine, methionine and other co-factors, plus joint, gut and immune support – filling the gaps that typical “meat and veg” bowls simply cannot cover on their own.

Table of Contents

Summary
Key Takeaways

Introduction

• Why homemade diets are so popular
• The nutritional risk that sits behind the good intentions

What Did the Dog Aging Project Study Do?

• Who was involved?
• How were diets assessed?

Key Findings: 1,726 Homemade Diets Under the Microscope

• Ingredient diversity
• The “6% complete” headline
• How this compares with earlier studies

Why Are So Many Homemade Diets Nutritionally Incomplete?

• The “fresh is best” misconception
• Where owners – and online recipes – go wrong

Which Nutrients Are Most Commonly Missing (or Excessive)?

• Macro-minerals (calcium, phosphorus) and vitamin D
• Trace minerals (zinc, copper, iodine, selenium)
• Fat-soluble vitamins A and E
• B-vitamins, essential fats and taurine

Health Risks of Long-Term Imbalance

• Bones, joints and skeletal development
• Heart and muscle function
• Immune health, nerves and brain

The Role of Veterinary Nutritionists and Formulation Tools

• Why expert recipe design matters
• How tools like Balance It are used in studies and in practice

Where Supplements Fit In

• Premixes vs “general multivitamins”
• Why products like Balance+ are critical for homemade feeding

FAQs: Homemade Diets and Supplements

Conclusion

• Homemade with love – and with science
• Why we recommend a supplement like Balance+ for dogs on home-prepared diets

Introduction

Why homemade diets are so popular

More and more guardians are turning to home-prepared diets because they want:

• More control over ingredients and sourcing
• Fewer perceived “additives” or “fillers”
• To use human-grade or “fresh” foods
• To tailor diets to allergies and intolerances or ethical preferences

The intention is excellent. But dogs are not small humans. They have their own species-specific nutrient requirements, and those requirements are much harder to meet consistently in a home kitchen than most owners realise.PMC+1

The hidden risk

The Dog Aging Project study makes one point very clear:

Good intentions and fresh ingredients do not automatically equal balanced nutrition.

Without expert formulation and the right supplement, most homemade diets fall short somewhere – sometimes mildly, sometimes dramatically.

What Did the Dog Aging Project Study Do?

Who was involved?

• The study used data from the Dog Aging Project (DAP) – a large longitudinal study following tens of thousands of companion dogs in real homes.
• Researchers analysed diet information from owners whose dogs were receiving home-prepared food – cooked, raw, or a mix with commercial diets.

How were diets assessed?

• Owners described their dog’s home-prepared diet in detail via survey (ingredients and preparation methods).
• Researchers entered these recipes into Balance It, a formulation and analysis tool that checks diets against AAFCO adult maintenance nutrient profiles.Texas A&M University
• Diets were then classified as “potentially complete” or “likely incomplete” based on whether all essential nutrients met AAFCO minimums.

Key Findings: 1,726 Homemade Diets Under the Microscope

Ingredient diversity

The study paints a vivid picture of how people actually feed at home:

• 1,726 home-prepared diets analysed
• Diets commonly included:
  • Meat & organs – present in ~90%
  • Vegetables – ~65%
  • Fruits, grains, nuts, seeds, added oils – variable
• The median number of ingredients per diet was roughly 9–10, not “just chicken and rice”.
• Almost half of owners (45%) were already adding some kind of commercial food, topper or base mix alongside their home-prepared portion.

So these were not simplistic recipes – but they were still nutritionally unreliable.

Only 6% complete – 94% incomplete

When diets were assessed against AAFCO:

• Only 6% of the 1,726 home-prepared diets were deemed potentially complete for adult maintenance.
• That means 94% failed to supply at least one essential nutrient at the required level.

The authors concluded that home-prepared diets, as actually fed, are highly variable and few are nutritionally complete, potentially posing health risks over time.

How does this compare with earlier work?

This is not a one-off outlier; it’s remarkably consistent with previous studies:

• Stockman et al., 2013 (JAVMA) examined 200 published recipes for adult dogs. Only 5 recipes met all NRC requirements; 95% were deficient in at least one essential nutrient.PubMed
• Pedrinelli et al., 2017 evaluated 80 home-prepared dog diets published in Portuguese; again, the majority were significantly unbalanced.ResearchGate
• A DVM360 review summarised multiple studies and concluded that most home-prepared recipes, including many written by vets, are nutritionally inadequate without additional supplementation.DVM360

The Dog Aging Project data simply confirm, on a much larger scale, what we already suspected: nutrient imbalance is the norm in owner-formulated diets.

Why Are So Many Homemade Diets Nutritionally Incomplete?

The “fresh is best” misconception

Many owners assume that:

• If a diet contains fresh meat, vegetables and “superfoods”,
• It looks colourful and “healthy”,
• And the dog is bright, active and has a shiny coat,

…then the diet must be adequate.

Unfortunately, dogs can appear outwardly healthy for months or years while underlying deficiencies slowly develop. Bones, organs and nervous tissue can compensate for a long time – until they can’t.

Where recipes typically go wrong

Common issues include:

• Human-style plating – plenty of meat and veg, not enough bone-equivalent calcium or added mineral mix
• Over-reliance on muscle meat with minimal organ content or mineral supplementation
• Assuming “a bit of everything” covers all bases
• Using recipes from books, blogs or social media that are not formulated to FEDIAF/NRC/AAFCO standards
• Not using a proper vitamin–mineral premix at the correct dose for the dog’s bodyweight

Even recipes originally created by professionals can be problematic if:

• Owners substitute ingredients (e.g. trading liver for more mince)
• They don’t add the specified supplement, or
• They mis-measure or “guestimate” quantities.

Which Nutrients Are Most Commonly Missing (or Excessive)?

The Dog Aging Project paper itself highlights completeness as a binary, rather than listing every nutrient deficit in public summaries. But earlier work shows clear patterns.

1. Macro-minerals and vitamin D

• Calcium is frequently too low, especially in meat-based recipes without sufficient bone or a calcium supplement.
• Calcium:phosphorus ratios are often skewed, favouring phosphorus (from meat) and under-supplying calcium.
• Vitamin D is commonly insufficient.

This combination is a classic set-up for nutritional secondary hyperparathyroidism, osteopenia and fractures.

2. Trace minerals

Analyses of home-prepared recipes frequently show:

• Low zinc and copper
• Inadequate iodine (unless a specific iodine or seaweed source is added carefully)
• Suboptimal selenium

These are vital for:

• Skin and coat
• Immune function
• Thyroid health
• Antioxidant defence and muscle function

3. Fat-soluble vitamins A and E

• Vitamin A may be too low (bone/organ-poor recipes) or too high (excess liver).
• Vitamin E, a key antioxidant, is often under-supplied unless specific oils and/or supplements are included.

4. B-vitamins, taurine and essential fats

• B-vitamins can be short, especially if diets are cooked and no specific B-complex is added.
• Taurine and L-carnitine may be marginal or low in some home diets and certain breeds, contributing to dilated cardiomyopathy (DCM) in susceptible dogs if other factors also align.Today’s Veterinary Practice
• Essential fatty acids, particularly EPA/DHA omega-3s, often fall below levels we’d like to see for joint, cognitive and cardiovascular support unless specific marine or algal sources are added.PMC

Health Risks of Long-Term Imbalance

Short-term feeding of an unbalanced diet is unlikely to cause obvious harm. The concern is chronic, cumulative exposure – months to years.

Documented problems associated with poorly balanced home-prepared diets include:Today’s Veterinary Practice

• Skeletal disease and fractures – nutritional secondary hyperparathyroidism, osteopenia and pathological fractures from low calcium and vitamin D
• Poor growth in puppies – stunting, limb deformities, joint issues from incorrect calcium:phosphorus ratios and energy/protein balance
• Cardiac disease – taurine-deficiency and associated DCM in predisposed animals
• Neurological signs – thiamine deficiency causing seizures, ataxia, vestibular signs
• Poor skin and coat quality, recurrent infections, delayed wound healing due to trace mineral and essential fatty acid deficiency

These are not theoretical risks; they are real clinical cases documented in the literature. The Dog Aging Project study doesn’t track individual outcomes yet, but it tells us a large proportion of dogs are being fed in a way that puts them at unnecessary nutritional risk.

The Role of Veterinary Nutritionists and Formulation Tools

The Dog Aging Project authors are very clear in their clinical relevance statement:

• Vets should thoroughly examine the details of any home-prepared diet reported by owners.
• Owners should be directed to board-certified veterinary nutritionists for recipe formulation or review.
• Tools like Balance It and professional software are invaluable for checking whether a recipe actually meets FEDIAF/NRC/AAFCO nutrient profiles.

In practice, a safe home diet usually involves three pillars:

1. A professionally formulated recipe tailored to the dog’s size, age, health, and energy needs
2. The correct use of a vitamin–mineral supplement or premix at the exact dose specified for that recipe
3. Ongoing veterinary monitoring (body condition, growth, bloods where appropriate)

Where Supplements Fit In

Premixes vs general multivitamins

For home-prepared diets, not all supplements are equal.

• A general multivitamin designed for dogs on complete commercial food may not provide enough calcium, trace minerals or vitamin D to bring an unbalanced home diet up to spec.
• A GOOD home-prepared plan relies on a proper vitamin–mineral premix designed to achieve complete and balanced nutrition when used at the right dose.

The Dog Aging Project study also notes that many owners were already adding commercial bases or toppers, but still only 6% of diets were “complete”. This suggests:

Simply adding “a bit of something commercial” isn’t enough. The supplement or base needs to be specifically formulated to fill the exact gaps left by the home ingredients.

Why products like Balance+ are critical for homemade feeding

A formulation like Bonza Balance+ (Balance+) is designed to act as that nutritional safety net, particularly for owners who:

• Want to prepare at least part of their dog’s diet at home
• Are concerned about long-term micronutrient adequacy
• Would like additional health support (joint, gut, immune, liver, antioxidant, cognitive) on top

Balance+ provides, per weight-adjusted daily dose:

• A comprehensive vitamin spectrum (A, D3, E, C and full B-complex)
• Chelated trace minerals (zinc, copper, iron, manganese) plus iodine and selenium
• Calcium support alongside the rest of the diet
• Taurine, L-carnitine, DL-methionine, cysteine and leucine – important for heart, liver, muscle and immune function
• Additional functional ingredients: joint actives (glucosamine, chondroitin, MSM, HA), synbiotics and postbiotics for the gut, milk thistle and antioxidants for the liver, and algal omega-3 DHA for brain and eye health

Used alongside a properly formulated recipe, Balance+ addresses exactly the kind of micronutrient gaps highlighted in the Dog Aging Project and earlier studies, while simultaneously supporting multiple organ systems.

FAQs: Homemade Diets and Supplements

1. If I use a recipe from a reputable website, do I still need a supplement?
Almost always yes. In published recipe analyses, even many vet-authored recipes were incomplete without the specified supplement.

2. Can I “fix” an unbalanced homemade diet just by adding Balance+ or another premix?
A good supplement can correct micronutrient gaps, but it can’t fully fix major errors in macronutrient balance (calories, protein, fat, calcium:phosphorus) or inappropriate ingredient choices. The underlying recipe still needs to be sound.

3. Is it safer to feed a complete commercial food and just add fresh toppers?
For many guardians, yes. A complete commercial diet plus a moderate amount of fresh toppers is usually lower risk than a completely homemade diet with no professional input – especially if you also use a well-designed supplement.

4. How do I know if my current home diet is balanced?
The only honest answer is:

• Have the recipe professionally reviewed (by a veterinary nutritionist), and/or
• Run it through a validated formulation tool that checks against FEDIAF/NRC/AAFCO targets.

Conclusion: Homemade with Love – and with Science

The Dog Aging Project’s analysis of 1,726 home-prepared diets sends a clear message:

Homemade diets are not automatically healthier. Without proper formulation and supplementation, they are very often incomplete – 94% of the time in this study.

That doesn’t mean homemade feeding is wrong. It means that love and effort in the kitchen must be matched by nutritional rigour.

For guardians who wish to home-prepare:

1. Start with a recipe formulated or approved by a veterinary nutritionist.
2. Use a purpose-designed vitamin–mineral supplement or premix exactly as directed.
3. Work with your vet to monitor your dog’s health over time.

In that context, a broad-spectrum supplement like Bonza Balance+ becomes more than “a nice extra”. It is an important part of making homemade feeding safe and sustainable:

• Providing the critical vitamins, minerals, amino acids and co-factors that typical home ingredients lack
• Supporting joints, gut, liver, immune system, skin and brain at the same time
• Helping to ensure that the diet you prepare with so much care is not just fresh and appealing, but also balanced, complete and protective for your dog’s long-term health.