Methodology & Editorial Policy

Last updated: 19 April 2026

CritterCalcs exists to make published veterinary science accessible through accurate, tested calculator tools. This page explains how calculators are built, where the data comes from, how clinical content is reviewed, and what you can do to verify the claims made on this site.

How our calculators are built

Every calculator on CritterCalcs follows a structured development process. The formula that powers each tool is sourced from a specific published veterinary reference — not from unattributed web sources, not generated by AI, and not derived from unverified material.

The sources used across CritterCalcs include:

• Plumb's Veterinary Drug Handbook (9th edition) — the standard North American veterinary drug reference, used for dog and cat medication dose ranges
• BSAVA Small Animal Formulary — the standard UK veterinary drug reference, published by the British Small Animal Veterinary Association
• Merck Veterinary Manual — a comprehensive veterinary reference covering toxicology, pharmacology, and clinical medicine
• ASPCA Animal Poison Control Center — published toxicology data on common substances toxic to pets
• WSAVA Global Nutrition Committee guidelines — nutrition formulas including resting energy requirement (RER) and maintenance energy requirement (MER)
• WALTHAM Petcare Science Institute — peer-reviewed puppy and kitten growth curve data from published studies
• AKC and Kennel Club breed standards — weight ranges, height data, and breed characteristics for 234 recognised dog breeds
• CFA and TICA breed standards — profiles for 61 recognised cat breeds
• AAFP feline life stage guidelines — age-based health and nutrition recommendations for cats

Once the source is identified, the formula is implemented in code and tested against known values from the source material. In plain language: the same calculation described in the published source is run through the tool, and the output is verified to produce the same result. Every worked example on a calculator page uses inputs that have been run through the actual calculation code, with all intermediate and final values verified to match the narrative.

How clinical content is reviewed

Ivana Pintar, MRCVS (RCVS registration number 7218452), reviews all health-related content on CritterCalcs. She is a practising veterinary surgeon with nine years of clinical experience, registered with the Royal College of Veterinary Surgeons since 2017. Her registration is publicly verifiable on the RCVS register.

Her review covers:

• Dosage ranges: Verifying that dose ranges match the cited formulary source and are clinically appropriate for the target species
• Toxicity thresholds: Confirming that severity band cutoffs (mild, moderate, severe, emergency) align with published toxicology data
• Severity classifications: Ensuring that urgency ratings and recommended actions are clinically sound
• Contraindications and warnings: Checking that species-specific risks, drug interactions, and safety warnings are complete
• Health recommendations: Verifying that educational content, caveats, and guidance are clinically accurate
• Species-specific considerations: Confirming that dog and cat calculators reflect the genuine metabolic and physiological differences between species

“Reviewed” does not mean rubber-stamped. It means the formula implementation has been checked against the published source, the dosage ranges have been assessed for clinical appropriateness, and the caveats and warnings have been evaluated for adequacy. This is the same standard applied in veterinary publishing: does the tool accurately reflect the cited evidence, and are the limitations clearly stated?

Pages that pass vet review display her name and RCVS registration number. Pages flagged as requiring veterinary review cannot be published without clinical sign-off.

Our data sources

The databases powering CritterCalcs are compiled from official standards and published veterinary research:

• Breed database: 234 dog breeds from AKC breed standards and 61 cat breeds from CFA and TICA standards. Each entry includes weight ranges, life expectancy, activity baseline, and source citation.
• Growth curves: Puppy and kitten growth curve data sourced from WALTHAM Petcare Science Institute peer-reviewed published studies.
• Medication database:25 dog medications and 18 cat medications, with dose ranges from Plumb's Veterinary Drug Handbook and the BSAVA Small Animal Formulary. Dog and cat medication lists are maintained separately, reflecting the significant metabolic differences between species — cats lack key glucuronidation pathways that dogs rely on, making many dog-safe drugs toxic to cats.
• Toxicity database: Thresholds for chocolate (theobromine by chocolate type), xylitol, grapes and raisins, onions and garlic, lily toxicity in cats, and macadamia nuts. Values sourced from the Merck Veterinary Manual and ASPCA Animal Poison Control Center data.

Every database entry cites its specific source. Where sources differ — for example, when Plumb's and BSAVA recommend slightly different dose ranges for the same drug — the variation is noted and the presented range covers both recommendations.

What we test

278 automated tests run before any change is published to the live site. If any test fails, the change does not ship.

• Formula accuracy tests: At least one primary scenario per calculator with all results verified against the published source, plus edge case and boundary tests
• Worked example verification:Every worked example's inputs are run through the calculator code, and all intermediate and final values are compared programmatically
• Content quality checks:Automated detection of vague, generic, or formulaic language patterns that do not meet the site's editorial standards
• Link integrity: Every internal link on every page is verified automatically — no broken links, no orphan pages
• Schema validation: JSON-LD structured data is validated for correct types, required fields, and valid URLs on every page
• Data completeness: Every calculator entry is checked for required fields, source citations, valid dates, unique FAQ questions, and minimum internal link counts

In plain language: the same rigour applied to clinical content is applied to the technical infrastructure. A broken link or a missing source citation is treated with the same seriousness as a formula error.

Our limitations

These tools provide general guidance based on published veterinary protocols. They do not replace veterinary examinations or diagnoses.

Individual animals vary. A 35 kg Labrador and a 35 kg Staffordshire Bull Terrier may need different approaches despite weighing the same. Breed, age, existing health conditions, concurrent medications, and individual metabolism all affect how a pet responds to medication, food, or exercise recommendations.

CritterCalcs updates its sources periodically, but veterinary science evolves. Drug recommendations change, new research refines toxicity thresholds, and breed health profiles are updated as new data is published. When guidelines change, the relevant calculators and educational content are updated and the revision is noted.

When in doubt about any calculator result, consult your veterinarian. These tools are designed to inform conversations with your vet, not to replace them.

How to verify our claims

Transparency is a core principle of this site.

• Verify the vet reviewer:Ivana Pintar's RCVS registration is publicly searchable on the RCVS register
• Verify the sources:Each calculator page cites its specific formula source. The references listed above — Plumb's, BSAVA, Merck, ASPCA, WSAVA, WALTHAM — are all established veterinary references available to professionals and the public
• Check the calculations: Every calculator displays its formula source and methodology. The worked examples show exact inputs and outputs, so the calculations can be verified independently
• Report errors: If you find an error in any calculation, dosage range, toxicity threshold, or educational content, email hello@crittercalcs.com. Corrections to clinical content are prioritised and investigated within 48 hours

Trust is earned through verifiability, not assertions.

Editorial independence

CritterCalcs is independently developed and not sponsored by any pharmaceutical company, pet food brand, or veterinary product manufacturer. Calculator formulas are based solely on published veterinary science, not commercial interests. If advertising is displayed on the site, it does not influence the content, formulas, or recommendations in any calculator.