Cohort profile of the first 2,000 canine enrolees in the Mars Petcare Biobank: demographic, hematologic and serum biochemistry results from March 2022 to December 2024

Abstract Background The MARS PETCARE BIOBANK™ (MPB) is a study recruiting pets visiting Mars Veterinary Health hospitals in the USA over a ten-year period, with the aim of analysing longitudinal data from thousands of otherwise healthy dogs and cats at their first presentation to identify novel and actionable pet health insights​. The present study summarises the baseline demographic, haematologic, and serum biochemistry data recorded for the first 2000 dogs enroled in the MPB study between March 2022 and December 2024 and considers how representative they are of the general population in the United States. Results The median enrolment age was 3.0 years (0.5–10.0 yrs). The population was 52% male and 48% female with approximately 84% of the population having undergone neutering by their initial study visit. The median enrolment body weight was 20.0 kg (2.5 – 71.5 kg) and the median body condition score was 5/9 (range 3–7). One hundred and twenty eight breeds were represented and 47% of the population were described as mixed breed. The median values for all serum biochemistry and complete blood count parameters were within the applicable reference interval. For certain analytes including serum glucose, amylase, cholesterol, phosphorus, creatine phosphokinase, precision pancreatic lipase, platelet count, haematocrit, and haemoglobin more than 5% of dogs had results outside the reference intervals. On review only 0.25% of dogs were subsequently excluded from continuing the MPB study because the results were considered of clinical significance. Conclusions The MPB aims to enable research to deliver insights applicable to the general dog population accessing primary veterinary care in the USA, and recruits accordingly. These data suggest that the first 2,000 dogs recruited in the MPB are comparable in demographics to other studies of the US population. The number of blood test results falling outside of reference intervals (up to 17% depending on analyte), for dogs deemed by veterinarians to be healthy in the context of the clinical history and examination, raises questions around the definition of health and how reference intervals are used. Data gathered during the study is expected to provide valuable information to studies pertaining to genetic, metagenomic, metabolic, dietary, and environmental risk factors associated with early signals of transition to various common diseases.