RESUMEN
The aim of this study is to report the case of a 4-month-old Beagle dog diagnosed with Musladin-Lueke syndrome. The dog appeared to walk on the digits ("tiptoes") with all limbs during ambulation and rigid extension of the carpus, elbow, tarsus, and knee joints during ambulation. Thickening of the fur and auricular cartilage, reduction in radiocarpal, and tibiotarsal joint amplitude, macrocephaly, and lateralized eyes were noticed on physical examination. Echocardiography showed reduced mobility and altered (tortuous) valve morphology. Bilateral abdominal cryptorchidism was confirmed by ultrasonography. Musladin-Lueke syndrome was the presumptive diagnosis, based on the clinical signs presented. The diagnosis was confirmed after DNA testing performed by serial collection of saliva. This is the first paper that describes unprecedented cardiac and reproductive changes of Musladin-Lueke syndrome in which the dog was followed for 2 years, presenting a good quality of life.