<p>PRISMA-ScR flow diagram of study selection.</p>

The immature platelet fraction (IPF(and related immature or reticulated platelet parameters, has been suggested as a non-invasive alternative for assessing megakaryocytic activity. However, a comprehensive assessment of the depth and balance of evidence across the two most prevalent companion animal species has not been conducted previously.</p> <p>Objective</p><p>Aim of this scoping review was: (1) to map and classify primary studies that report on IPF or reticulated platelets in the context of thrombopoietic activity or bone-marrow activity in dogs and/or cats, (2) to classify the subjects, assays, reference criteria, clinical information, findings etc; and (3) to highlight principal evidence gaps and identify if the evidence generated is adequate and comparable for the systematic review or for a future meta-analysis.</p> <p>Methods</p><p>Following the Population-Concept-Context (PCC) framework and the PRISMA Extension for Scoping Reviews (PRISMA-ScR guidelines, an exhaustive search was conducted in PubMed/MEDLINE, Web of Science, Scopus, and CAB Abstracts.

The parameters of immature and reticulated platelets have been examined in relation to bone marrow and platelet status. Records were reviewed to ensure eligibility, and a standard data sheet was used to extract data.</p> <p>Results</p><p>Of 35 records identified, 10 met the eligibility criteria. Nine of the ten included studies reported data only in dogs; a single retrospective study reported data in both dogs and cats, and no study addressed cats exclusively.