AbstractBackgroundSudden acquired retinal degeneration syndrome (SARDS) is a common cause of irreversible blindness in dogs. It bears clinical resemblance to hypercortisolism, which can be associated with hypercoagulability. The role of hypercoagulability in dogs with SARDS is unknown.ObjectiveDetermine hemostatic profiles in dogs with SARDS.AnimalsProspective pilot study: Dogs with a history of SARDS (n = 12). Prospective case‐control study: Dogs with recent onset of SARDS (n = 7) and age‐, breed‐, and sex‐matched controls (n = 7).MethodsProspective pilot study: We performed thromboelastography (TEG). Prospective case‐control study: Dogs had CBC, serum biochemistry, urinalysis, TEG, fibrinogen concentration, antithrombin activity, D‐dimers, thrombin‐antithrombin complexes, and optical platelet aggregometry performed.ResultsProspective pilot study: 9/12 dogs with a history of SARDS were hypercoagulable with increased TEG G value and 2/3 had hyperfibrinogenemia. Case‐control study: All dogs with SARDS and 5/7 controls were hypercoagulable based on TEG G value. Dogs with SARDS had significantly higher G values (median, 12.7 kdynes/s; range, 11.2‐25.4; P = .04) and plasma fibrinogen concentration (median, 463 mg/dL; range, 391‐680; P < .001) compared to controls.Conclusions and Clinical ImportanceHypercoagulability was common in both dogs with SARDS and controls, but dogs with SARDS were significantly more hypercoagulable on TEG. The role of hypercoagulability in the pathogenesis of SARDS remains to be determined.