Sources

Every figure on this site comes from one of the references below. Each entry says exactly what we take from it, so you can check our work rather than take our word for it. If a source and this site ever disagree, the source is right and we have a bug. Please tell us.

Clinical guideline

AAFCO calorie content statement

Association of American Feed Control Officials. Calories, Understanding Pet Food.

What we use it for: The requirement that dog food labels carry a Calorie Content statement in kilocalories per kilogram on an as-fed basis, which is why our cost calculator asks you to read the energy density off your own bag instead of assuming one.

Clinical guideline

AAFCO Dog Food Nutrient Profiles

Association of American Feed Control Officials. Dog and Cat Food Nutrient Profiles, growth and reproduction.

What we use it for: The calcium ceiling for large-breed puppy foods, about 4.5 g per 1,000 kcal, and the "complete and balanced for growth" statement that tells you a food is formulated for puppies at all.

Clinical guideline

AAHA Canine Life Stage Guidelines

American Animal Hospital Association. AAHA Canine Life Stage Guidelines.

What we use it for: Life-stage definitions and the size-dependent onset of senior status, which is why our age tools do not use a single conversion for every dog.

Clinical guideline

AAHA Canine Vaccination Guidelines

American Animal Hospital Association. 2022 AAHA Canine Vaccination Guidelines (2024 update).

What we use it for: Core vaccination timing: series beginning at 6 to 8 weeks, repeated every 2 to 4 weeks until after 16 weeks, rabies as a single dose at 12 to 16 weeks, and a booster one year later.

Breed standard

AKC breed standards

American Kennel Club. Official Breed Standards.

What we use it for: Published adult height and weight ranges used to sanity-check breed-specific predictions. We are not affiliated with or endorsed by the AKC.

Clinical guideline

CAPC Parasite Control Guidelines

Companion Animal Parasite Council. Guidelines for the diagnosis, treatment and control of internal parasites in dogs.

What we use it for: Deworming schedule timing: treatment at 2, 4, 6 and 8 weeks, then monthly to six months, then quarterly, plus the recommendation of at least four faecal examinations in the first year. We publish the timing only, never a dose.

Peer-reviewed study

Correction to Salt et al. 2017

Correction: Growth standard charts for monitoring bodyweight in dogs of different sizes. PLOS ONE. 2024;19(11):e0314711.

What we use it for: Cited for completeness. The 2024 correction amended only the data-availability statement; no growth parameters or conclusions changed.
DOI: 10.1371/journal.pone.0314711

Breed standard

FCI Cane Corso standard 2023

Federation Cynologique Internationale. FCI-Standard No. 343: Cane Corso (Italian Cane Corso). Official valid standard published 25 September 2023.

What we use it for: The Cane Corso adult weight ranges of 45 to 50 kg for males and 40 to 45 kg for females, and height ranges of 64 to 68 cm and 60 to 64 cm respectively.

Veterinary reference

Merck Veterinary Manual

Merck Veterinary Manual. Nutritional Requirements of Small Animals. Management and Nutrition.

What we use it for: The resting energy requirement formulas (RER = 70 x kg^0.75, and the linear RER = 30 x kg + 70 valid for 2 to 45 kg), and the growth multipliers of 3 x RER under four months and 2 x RER over four months.

Veterinary reference

Merck Veterinary Manual, breeding management

Merck Veterinary Manual. Breeding Management of Bitches. Management and Nutrition, Management of Reproduction in Dogs and Cats.

What we use it for: Parturition 64 to 66 days after the LH peak, due dates 56 to 58 days after the first day of cytological diestrus, and ovulation occurring 2 to 3 days after the LH peak — which is how we derive the 61 to 64 day window measured from ovulation.

Veterinary reference

Merck Veterinary Manual, labor and delivery

Merck Veterinary Manual. Labor, Delivery, and Postpartum Care in Bitches and Queens. Management and Nutrition, Management of Reproduction in Dogs and Cats.

What we use it for: Stage I labor lasting 12 to 24 hours, stage II efforts that should not last more than 1 to 2 hours between puppies with typical intervals of 30 to 60 minutes and delivery completed in about 7 to 9 hours, and stage III as delivery of the placenta.

Veterinary reference

Merck Veterinary Manual, pregnancy determination

Merck Veterinary Manual. Pregnancy Determination in Dogs and Cats. Management and Nutrition, Management of Reproduction in Dogs and Cats.

What we use it for: When a pregnancy can actually be confirmed: relaxin assay after 22 to 27 days, ultrasonography best at 25 to 35 days with false negatives before 21 days, and fetal skeletons not visible on radiography until about day 42 to 45, prominent by day 47 to 48.

Veterinary reference

Merck Veterinary Manual, whelping

Merck Veterinary Manual. Whelping and Queening in Bitches and Queens. Management and Nutrition, Management of Reproduction in Dogs and Cats.

What we use it for: The three gestation lengths our due date calculator counts from: 56 to 58 days from the first day of diestrus, 64 to 66 days from the LH surge or the initial rise in progesterone above baseline, and 58 to 72 days from the first mating. Also the pre-whelping temperature drop to a mean of 37.1 C, range 36.7 to 37.8 C, 8 to 24 hours before whelping.

Peer-reviewed study

Salt et al. 2017

Salt C, Morris PJ, German AJ, Wilson D, Lund EM, Cole TJ, Butterwick RF. Growth standard charts for monitoring bodyweight in dogs of different sizes. PLOS ONE. 2017;12(9):e0182064.

What we use it for: The five adult-bodyweight size categories, the sex-specific centile curves from 12 weeks to 2 years, and the centile positions our growth calculator reports.
DOI: 10.1371/journal.pone.0182064
Licence: Creative Commons Attribution 4.0

Institutional resource

Synchrony 2025 Lifetime of Care Study

Synchrony. 2025 Pet Lifetime of Care Study. Survey of 4,861 US pet owners conducted 31 January to 22 February 2025.

What we use it for: The only recent, methodologically described total we cite for what a dog costs: $22,125 to $60,602 over a 15 year lifetime, up 11.65% from 2022, against owners own estimates of about $8,200. We use it as a sanity-check band for a finished budget, never as a default price, and the division by 15 years is ours rather than the study's.

Veterinary reference

VCA Animal Hospitals, teething

VCA Animal Hospitals. Teeth, Teething and Chewing in Puppies.

What we use it for: Deciduous and permanent tooth counts and eruption timings: 28 baby teeth in by 6 to 8 weeks, up to 42 adult teeth erupting between roughly 3 and 7 months.

Institutional resource

WALTHAM Puppy Growth Charts

WALTHAM Petcare Science Institute. Puppy Growth Charts.

What we use it for: The clinical presentation of the Salt et al. centile curves as ten charts (five size categories by two sexes), and their intended use in practice.

Peer-reviewed study

Wang et al. 2020

Wang T, Ma J, Hogan AN, Fong S, et al. Quantitative Translation of Dog-to-Human Aging by Conserved Remodeling of the DNA Methylome. Cell Systems. 2020;11(2):176-185.e6.

What we use it for: The epigenetic dog-age conversion, human age = 16 x ln(dog age) + 31, derived from DNA methylation in 104 Labrador Retrievers compared with 320 humans.
DOI: 10.1016/j.cels.2020.06.006

Clinical guideline

WSAVA Global Nutrition Guidelines

World Small Animal Veterinary Association. Global Nutrition Guidelines.

What we use it for: Nutritional assessment as a routine part of every veterinary examination, and the principle that a calculated energy requirement is a starting point to be adjusted against body condition rather than a prescription.

Reuse and attribution

Some of the data we build on is openly licensed. Where a source carries a Creative Commons Attribution licence, that licence travels with the data: if you reuse our tables, credit the original authors as well as this site. Full terms are on our terms page.

What is not here

We do not cite content farms, AI-generated pet blogs, or retailer marketing pages as evidence for a number. If a figure is widely repeated online but we cannot trace it to a primary source, we either leave it out or label it clearly as a rule of thumb rather than a finding. There is more on the thinking behind the site on the about page. Our methodology page explains how each calculator applies these sources.