SOURCES AND LIMITS
Keep the method beside the number.
These sources support the factual explanation. They did not review or endorse Longview, its illustrations or its invented-data board.
McMillan et al.: Longevity of companion dog breeds
Primary UK survival study, February 2024. 584,734 records, including alive and deceased dogs. Estimated median survival is not an individual forecast.
Read the source ↗Author Correction: Figure 3 caption
April 2024 correction: the Miniature Dachshund caption is 14.0, not 12.2. We do not reproduce a breed ranking.
Read the source ↗Teng et al.: Life tables for UK companion dogs
Primary RVC/NTU study, April 2022. Hypothetical cohort life tables from 30,563 confirmed deaths in a primary-care sampling frame. Its age-zero mean is not the later median.
Read the source ↗AAHA: Defining the senior patient
Professional senior-care guideline. Life-stage definitions are not a formula for an individual death date.
Read the source ↗AAHA: Understanding the senior life stage
Owner education on individual care and changes as pets age. No guaranteed lifespan extension is adopted.
Read the source ↗AAHA: Discussing a senior pet's quality of life
Owner education supporting a veterinary conversation. No quality-of-life score, treatment claim or end-of-life decision rule is copied.
Read the source ↗Scientific American: Size, face shape and lifespan
Independent science reporting, February 2024. Not an independent replication of the study or a review of this website.
Read the source ↗Why the headline numbers are not pooled
The 2022 study reports life expectancy at age zero from a hypothetical cohort life table. The 2024 study estimates median survival using alive and deceased records from multiple sources. Different quantities, populations and methods are not repaired by averaging the two results.
What the tool contributes
Middle & Spread uses original invented values, with its arithmetic visible in a table. It illustrates how summaries conceal a distribution. It is not new longevity evidence, a breed comparison, a replication or a medical assessment.
What stays out
No drug, supplement, neutering or treatment is claimed to add years. No quality-of-life scale or end-of-life decision rule is offered. Source checking is editorial work, not clinical review.