Canine Embryonic Atlas : The dog is a great companion animal and researchers and clinicians alike want to help produce healthy dogs, and particularly healthy puppies. Unfortunately, we know very little about the genetic control of canine embryonic development or the timing of organ development. As a result, we do not actually know at what ages the canine embryo is likely to be detrimentally affected, for example, by common therapeutic drugs that might be administered during pregnancy. One of the purposes of producing the Canine Atlas is to provide accurate information about the normal developmental events that occur during canine gestation and when they occur. With such information, we can identify which genes and gene pathways are important for the development of major organs and the critical periods during gestation that these genes must act. This is of critical importance if we are to understand which mutations are causing deleterious and lethal disorders in dogs. The Canine Atlas consists of a collection of pages with photographs, tables, and text describing the data. A general text search function will enable pages to be quickly located. The sections are broken down by: Stages : A photo gallery showing development of several organs at each Canis familiaris developmental stage (CfS) is found in the Stage Pages. Organs : A photo gallery showing organ development through all developmental stages available is found in the Organ Pages. These are viewed by organ: Whole embryo, Forelimb & Hindlimb, Heart, Lungs, Head, Eye, Liver, Kidney, and Urogenital System. Tables : Classification criteria for each CfS are in two tables : Quick Reference Comparison Table and Comprehensive Comparison Table of Stages, in the TABLES section. The Comprehensive Comparison Table compares text of the CfS criteria to those for the mouse (Theiler Stages, TS) and the human (Carnegie Stages, CS), based on published information (see References). The Quick Reference Comparison Table is designed for quick correlation of CfS, TS, and CS, and does not contain text explaining classification criteria. For quick reference, this table can also be accessed by clicking the “Species Comparison Table” in the upper right corner from all Stage and Organ pages. ----- The Canine Embryonic Atlas (Canine Atlas) was developed by Dr. Vicki Meyers-Wallen, a faculty member at the Baker Institute for Animal Health. When Dr. Meyers-Wallen first began her research career in the 1980’s, she had no expectations of creating a canine atlas, but ended up doing so as a necessary tool for her research on abnormal reproductive tract development in dogs. [...] The correct attribution text is: Canine Embryonic Atlas, Baker Institute for Animal Health, Cornell University, https://www2.vet.cornell.edu/canine-atlas