Abstract OBJECTIVE To analyze the readability of discharge summaries distributed to owners of pets newly diagnosed with cancer. SAMPLE 118 discharge summaries provided to pet owners following initial consultation. PROCEDURES A database search identified records of new patients that had been presented to the North Carolina State Veterinary Hospital medical oncology service between June 2017 and January 2019. Owner-directed portions of the summaries provided at the time of discharge were copied and pasted into a document and stripped of all identifying information. Readability of summaries was assessed with the use of 2 previously established readability calculators: the Flesch-Kincaid Grade Level (FKGL) and Flesch Reading Ease (FRE) tests. RESULTS Mean ± SD FKGL was 11.9 ± 1.1 (median, 11.9; range, 8.6 to 15.5; target ≤ 6), and the mean ± SD FRE score was 43 ± 5.9 (median, 42.7; range, 25.5 to 58.1; target ≥ 60). There were no significant differences in FKGL or FRE scores among discharge summaries for patients with the 4 most common tumor types diagnosed or the described treatment options. Ninety-three percent (110/118) of summaries were scored as difficult or very difficult to read. CLINICAL RELEVANCE Owner-directed written information regarding a diagnosis of cancer at a single teaching hospital exceeded readability levels recommended by the American Medical Association and NIH and was above the average reading level of most US adults. Efforts to improve readability are an important component of promoting relationship-centered care and may improve owner compliance and patient outcomes.