Summary: 2-year-old, intact female, a Golden Retriever Dog was presented with the signs of respiratory distress, exercise intolerance, and muscular weakness. A high-grade systolic murmur was auscultated over the tricuspid valvular area. Thoracic radiographs showed an enlarged D-shape heart and free fluid (chylothorax) in the pleural space. ECG revealed small QRS complexes. Doppler echocardiography disclosed severe tricuspid insufficiency with moderate pulmonary hypertension, and tricuspid leaflets also were displaced down into the right ventricle, substantiating Ebstein's anomaly. Five-weeks after the medical therapy, patient died at home. The owner of the patient refused the necropsy. This is the first case report of tricuspid dysplasia and Ebstein's anomaly along with chylothorax in dogs.Key words: Chylothorax, Ebstein's anomaly, tricuspid valve dysplasia, dog Golden Retriever ırkı bir köpekte Ebstein's anomalisi ilişkili şilotoraksÖzet: 2 yaşında, kısırlaştırılmamış, dişi Golden Retriever köpek solunum güçlüğü, egzersiz intoleransı ve kas zaafiyeti bulguları ile kliniklerimize sunuldu. Triküspit kapak alanında yüksek derece sistolik kalp üfürümü oskülte edildi. Torasik radyografide; D-şeklinde kalp büyümesi ve plöyral alanda serbest sıvı (şilotoraks) belirlendi. EKG'de küçük QRS kompleksleri gözlendi. Doppler ekokardiyografide orta dereceli sistolik pulmoner hipertansiyon, ciddi triküspid kapak yetmezliği ve Ebstein anomalisi olarak tanımlanan triküspit kapağın sağ ventriküle doğru yer değiştirmesi saptandı. Beş hafta medikal tedaviden sonra hasta, evinde hayatını kaybetti. Hasta sahibi nekropsiyi reddetti. Bu rapor köpeklerde Ebstein anomalisi, triküspit displazi ve şilotoraksın birlikte seyrettiği ilk olgu rapordur. Anahtar sözcükler: Şilotoraks, Ebstein anomalisi, triküspit kapak displazisi, köpek.Tricuspid valve dysplasia (TVD) is a congenital malformation of the tricuspid valve (TV), chordae tendineae, or papillary muscles, resulting in TV insufficiency (29). The basal attachments of TV are ventrally displaced into the right ventricle (RV) resulting in a further malformation named Ebstein's anomaly (14,22).Chylothorax a triglyceride (TG) and cholesterol (Chol) rich fluid is an infrequent cause of pleural effusion (10). There is limited information on chylothorax relating with heart diseases in human (1, 7) and animals (9). Although only two dogs with chylothorax associated with congenital cardiac disorders of TVD (9, 25) have been described, chylothorax due to Ebstein's anomaly in dogs has not been reported yet. Thus, we reported here, for the first time, Ebstein's anomaly as well as its possible mechanism(s) associated with chylothorax in a dog.The dog (2-year-old, intact female, Golden Retriever, 24.5 kg) was presented to the private clinic with the signs of exercise intolerance and respiratory distress. The prevention of heartworm was complete. Despite the treatment, dog was worsened, and referred to the small animal clinic (Veterinary Faculty, Uludag University, Bursa) with the similar symptoms. Hear...