Chapter I of IV · Feeding Your Dog

What we feed every puppy and why, the calcium-to-phosphorus rule that matters more than any brand, and how to keep a Lagotto lean with body condition scoring.

This chapter is part of our evidence-based feeding guide for the Lagotto Romagnolo. The two-minute summary, the research library with every study cited, and the questions families ask live on the guide overview.

What We Feed and Why

Every puppy that leaves Northwest Lagotto goes home eating Royal Canin Medium Puppy. That is not a sponsorship. It is a decision I made on my veterinarian’s recommendation eleven years ago and have not had a reason to change.

Royal Canin is one of the oldest pet nutrition companies in the world. They conduct ongoing research. Their product line supports breeders specifically, from D42 prenatal food through mother-and-puppy starter food to size-specific puppy formulas, which means the nutritional profile is calibrated to each stage of development rather than offering a single “puppy food” and hoping it covers everything.

Other brands make strong claims. Some may be excellent. But what matters more than the brand label is whether the company meets the criteria that the World Small Animal Veterinary Association’s Global Nutrition Committee established for evaluating pet food manufacturers. The WSAVA guidelines are the closest thing to an industry standard, and they are deliberately unglamorous: does the company employ a full-time, board-certified veterinary nutritionist (diplomate of the ACVN or ECVCN); do they own and operate their own manufacturing plants rather than contract out; do they conduct AAFCO feeding trials rather than relying solely on formulation; and do they publish research in peer-reviewed journals?

A handful of companies meet all four criteria. Royal Canin, Purina Pro Plan, Hill’s Science Diet, Eukanuba, and Iams are the most commonly cited. Most boutique and “premium” brands do not, not because they are malicious, but because they are small operations without the infrastructure to employ full-time nutritionists or conduct formal feeding trials. When grain-free diet-associated dilated cardiomyopathy began emerging around 2018, almost all of the implicated brands were outside this WSAVA-compliant group. That is a pattern worth paying attention to.

Whatever you feed, it should carry an AAFCO “Growth” or “All Life Stages” statement for puppies, have a correct calcium-to-phosphorus ratio (1.1:1 to 1.4:1), and be grain-inclusive unless your veterinarian has specifically directed otherwise for a medical reason. These three things are non-negotiable. Everything else is preference.

The Protein Myth

There is persistent old advice that high-protein diets cause bone abnormalities in large-breed puppies. This has been debunked, and was debunked decades ago. Nap & Hazewinkel’s 1991 study in the Journal of Nutrition fed Great Dane puppies diets containing 14.6%, 23.1%, or 31.6% protein on a dry matter basis and found no differences in skeletal development attributable to protein. The myth came from an earlier Hedhammar study (1974) that conflated protein with excess calories and calcium. The problem is overfeeding and excess minerals, not protein. When calcium ratios are correct and portions are controlled, protein supports healthy growth.

The Calcium Rule: the Most Important Thing in This Essay

Never Supplement Calcium in Puppies

Puppies under six months cannot regulate intestinal calcium absorption. If you feed excess calcium, the puppy absorbs all of it. Adult dogs can excrete the excess. Puppies cannot. This is the single most important nutritional fact for growing dogs, and it is the one most commonly violated by well-meaning owners.

This is not opinion. It is settled physiology, demonstrated in a series of elegant Dutch studies by Hazewinkel and colleagues at Utrecht University beginning in the late 1980s and continuing through the 2000s. The key paper is Tryfonidou and colleagues’ 2002 study in the Journal of Nutrition, which showed that growing dogs absorbed approximately 53% of dietary calcium through passive, non-regulated mechanisms, meaning the more calcium you feed, the more the puppy absorbs, with no mature feedback system to shut the process down. A follow-up study by Mack and colleagues in 2015 confirmed that adult dogs develop the ability to regulate calcium absorption; puppies do not. This difference is the entire reason puppy food and adult food are formulated differently, and it is the reason why calcium supplementation in puppies causes the specific, irreversible skeletal diseases that every veterinary orthopedic textbook describes: osteochondrosis dissecans, hypertrophic osteodystrophy, angular limb deformities, and contributions to hip and elbow dysplasia.

A complete and balanced puppy food already contains the correct ratio, typically 1.2–1.8% calcium on a dry matter basis, with a calcium-to-phosphorus ratio between 1.1:1 and 1.4:1. This range is backed by the National Research Council’s nutrient requirements and reflected in AAFCO’s nutrient profiles. Böswald and colleagues’ 2019 factorial analysis in PLOS One refined these numbers further and is the most current primary source. Adding calcium on top of a complete food disrupts the ratio and overwhelms a system that has no mechanism to protect itself.

If someone recommends adding calcium to your puppy’s diet, a breeder, a trainer, a website, a neighbor, politely decline. If a website recommends raw meaty bones or bone meal as a “natural” supplement for growing puppies, close the tab. This is one area where the science is settled and the consequences of getting it wrong are permanent.

Ca:P Ratio Checker
Paste the calcium and phosphorus percentages from your food’s guaranteed analysis or nutrient statement to check the ratio.

A note on what the evidence has changed. I have not changed what I feed. Royal Canin Medium Puppy has been our standard for over a decade, on my veterinarian’s original recommendation, and there has not been a reason to move. What has changed is what I tell families about why. When I started, the WSAVA manufacturer criteria were not widely published; I would not have been able to articulate why one brand met a meaningful standard and another did not. When the grain-free DCM signal emerged in 2018, I had to tell families on our list to revisit their own choices. Some had been feeding boutique grain-free brands on the assumption that “more natural” meant “better,” and the evidence had moved against that assumption. The body of evidence on body condition scoring has compounded steadily through the same period and now sits near the top of every nutritional priority I discuss. The food has been stable. The conversation around it has not, and I have updated mine as the literature has updated theirs.

Lean Is Healthy, Body Condition Scoring

The Purina Life Span Study is the single most important piece of canine nutrition research ever conducted. Forty-eight Labrador Retrievers, paired by sex and weight at eight weeks of age. One puppy in each pair was fed 25% less than its sibling for the rest of its life. The study ran until the last dog died at 14.5 years old.

At age two, using the Orthopedic Foundation for Animals scoring method, 7 of the 24 lean-fed dogs had hip dysplasia compared to 16 of 24 in the ad-libitum group, a 57% relative reduction. Using the stricter Swedish scoring method, the gap was wider still: 5 versus 18, a 72% reduction. Across lifespan, the lean-fed dogs lived a median of 13.0 years versus 11.2 years, 1.8 years longer, a 16% extension. Osteoarthritis appeared 1.5 years later. Chronic disease onset was delayed across the board.

Lean is not thin. Lean is healthy. And it is the single most controllable factor in your dog’s joint health and lifespan.

Those numbers come from three papers: Kealy and colleagues’ 1992 paper in the Journal of the American Veterinary Medical Association reporting the hip dysplasia findings at age two, Kealy and colleagues’ 2002 follow-up reporting the lifespan data, and Lawler and colleagues’ 2008 paper in the British Journal of Nutrition synthesising two decades of observations across the cohort. All three are open-access or widely available and every claim above is verifiable at its primary source.

One honest caveat: Labradors are a high-risk breed for hip dysplasia. The absolute effect size of body condition on hip dysplasia in a breed with much lower baseline risk, Lagotti, Border Collies, most terriers, is likely smaller. But the direction of the finding has been replicated across every breed studied. The lifespan and osteoarthritis delays are not breed-specific. A 2019 study by Salt and colleagues using Banfield Pet Hospital records examined over 50,000 dogs across 12 breeds and confirmed that overweight dogs had shorter lifespans. A 2024 retrospective of 4.9 million dogs (Salt et al., Preventive Veterinary Medicine) found that dogs overweight during the growth phase had nearly twice the odds of being overweight as adults (odds ratio 1.85). The Purina study is not a curiosity. It is the closest thing canine nutrition has to settled science.

Your dog should live between a 4 and a 5 on the 9-point body condition scale, what the scale calls “ideal.”

Body Condition Score, 9-Point Scale
1–3
Underweight

Ribs, spine, and hip bones prominently visible. Obvious loss of muscle mass. Requires veterinary assessment.

4–5
Ideal Target

Ribs easily felt without pressing. Visible waist when viewed from above. Abdominal tuck visible from the side. This is where your dog should be, always.

6–7
Overweight

Ribs palpable only with pressure. Waist barely visible. Fat deposits developing over the spine and base of tail.

8–9
Obese

Ribs difficult to feel under heavy fat cover. No waist. Abdominal distension. Significant long-term health risk.

Self-Assessment, Where Is Your Dog?
Answer three questions. I’ll give you a body condition estimate.

The most common feedback I get from families is that they think the puppy looks too thin. Visitors comment. Neighbours comment. If you can feel the ribs easily and see a waist, the puppy is not too thin. It is exactly where it should be. Trust the science on this one. The Purina study is as close to definitive as nutritional research gets, and the twenty years of replication since have only strengthened it.

Questions About Feeding Your Dog?

Nutrition decisions compound over years. If you have a specific question about your own dog, what to feed, when to switch, what supplement to try, how to read a label. I’m happy to answer one. Not a consultation. Not a service. Just a question, answered from eleven years of experience and the peer-reviewed literature this article draws on.

If you’re considering a Lagotto and want to know what we do at Northwest Lagotto, the waitlist and breed pages are the right places to start.

Ask a nutrition question Join our waitlist
MN
Mark Nelson
Breeder · Northwest Lagotto LLC · Lynden, Washington

Eleven years with the Lagotto Romagnolo breed. Northwest Lagotto is a selective, health-tested Lagotto Romagnolo breeding program in Lynden, Washington, operating on a waitlist basis with 1–2 litters per year from Italian championship lines (Il Granaio Dei Malatesta, Gillenias). This essay draws on that experience and on the peer-reviewed veterinary literature cited throughout. When the literature disagrees with common practice, the literature wins.

Nutrition Quick Reference

Feeding amounts by weight and age, how to transition foods safely, supplement guidance, and what to leave out, distilled to a single page.

Download the PDF

Primary Sources, Quick Reference

  1. Kealy RD, Olsson SE, Monti KL, et al. Effects of limited food consumption on the incidence of hip dysplasia in growing dogs. JAVMA 1992;201(6):857–863.
  2. Kealy RD, Lawler DF, Ballam JM, et al. Effects of diet restriction on life span and age-related changes in dogs. JAVMA 2002;220(9):1315–1320.
  3. Lawler DF, Larson BT, Ballam JM, et al. Diet restriction and ageing in the dog: major observations over two decades. Br J Nutr 2008;99(4):793–805.
  4. Tryfonidou MA, van den Broek J, van den Brom WE, Hazewinkel HAW. Intestinal calcium absorption in growing dogs is influenced by calcium intake and age but not by growth rate. J Nutr 2002;132:3363–3368.
  5. Hazewinkel HAW, van den Brom WE, van ’t Klooster AT, et al. Calcium metabolism in Great Dane dogs fed diets with various calcium and phosphorus levels. J Nutr 1991;121(11 Suppl):S99–S106.
  6. Nap RC, Hazewinkel HAW, Voorhout G, et al. Growth and skeletal development in Great Dane pups fed different levels of protein intake. J Nutr 1991;121(11 Suppl):S107–S113.
  7. Salt C, Morris PJ, Wilson D, et al. Association between life span and body condition in neutered client-owned dogs. J Vet Intern Med 2019;33(1):89–99.
  8. Serisier S, Feugier A, Delmotte S, et al. Higher neonatal growth rate and body condition score at 7 months are predictive factors of obesity in adult female Beagle dogs. BMC Vet Res 2013/2017.
  9. Bray EE, Zheng Z, Tolbert MK, et al. Once-daily feeding is associated with better health in companion dogs. GeroScience 2022;44(3):1779–1790.
  10. Association for Pet Obesity Prevention. 2024 State of U.S. Pet Obesity Report.
  11. Roush JK, Cross AR, Renberg WC, et al. Multicenter veterinary practice assessment of the effects of omega-3 fatty acids on osteoarthritis in dogs. JAVMA 2010;236(1):59–66.
  12. Mehler SJ, May LR, King C, et al. A prospective, randomized, double blind, placebo-controlled evaluation of EPA and DHA on clinical signs in dogs with osteoarthritis. Prostaglandins Leukot Essent Fatty Acids 2016;109:1–7.
  13. Fritsch DA, Allen TA, Dodd CE, et al. A multicenter study of the effect of dietary supplementation with fish oil omega-3 fatty acids on carprofen dosage in dogs with osteoarthritis. JAVMA 2010;236(5):535–539.
  14. Kampa N, Kaenkangploo D, Jitpean S, et al. Study of the effectiveness of glucosamine and chondroitin sulfate, marine based fatty acid compounds, and carprofen for hip osteoarthritis. Front Vet Sci 2023;10:1033188.
  15. Gupta RC, Canerdy TD, Lindley J, et al. Comparative therapeutic efficacy and safety of type-II collagen (UC-II), glucosamine and chondroitin in arthritic dogs. J Anim Physiol Anim Nutr 2012;96(5):770–777.
  16. Vandeweerd JM, Coisnon C, Clegg P, et al. Systematic review of efficacy of nutraceuticals to alleviate clinical signs of osteoarthritis. J Vet Intern Med 2012;26(3):448–456.
  17. Freeman LM, Michel KE. Evaluation of raw food diets for dogs. JAVMA 2001;218(5):705–709.
  18. Nemser SM, Doran T, Grabenstein M, et al. Investigation of Listeria, Salmonella, and toxigenic Escherichia coli in various pet foods. Foodborne Pathog Dis 2014;11(9):706–709.
  19. Vecchiato CG, Schwaiger K, Biagi G, Dobenecker B. From nutritional adequacy to hygiene quality: a detailed assessment of commercial raw pet-food. Animals 2022;12(18):2395.
  20. Davies RH, Lawes JR, Wales AD. Raw diets for dogs and cats: a review with particular reference to microbiological hazards. J Small Anim Pract 2019;60(6):329–339.
  21. Owens EJ, LeBlanc NL, Freeman LM, Scollan KF. Comparison of echocardiographic measurements and cardiac biomarkers in healthy dogs eating nontraditional or traditional diets. J Vet Intern Med 2023.
  22. Coppinger LM, Freeman LM, Tyrrell WD Jr, et al. Echocardiographic and electrocardiographic findings in Irish Wolfhounds eating high-pulse or low-pulse diets. J Vet Intern Med 2024;38(3):1300–1304.
  23. Role of Diet as a Predisposing Factor for Dilated Cardiomyopathy in Dogs: A Narrative Review. Veterinary Sciences 2025;12(11):1106.
  24. Mueller RS, Olivry T, Prélaud P. Critically appraised topic on adverse food reactions of companion animals (2): common food allergen sources in dogs and cats. BMC Vet Res 2016;12:9.
  25. WSAVA Global Nutrition Committee Guidelines on Selecting Pet Foods. World Small Animal Veterinary Association.