Duchene's muscular dystrophy is a lethal childhood myopathy X-linked that occurs after a mutation on dystrophin gene which is responsible for protein synthesis with the same name. This protein has a fundamental importance for muscle functional and structural integrity. The dystrophin-glycoprotein complex is responsible for connecting the actin cytoskeleton of myofibers to the extracellular matrix and muscle contraction. Some homologues forms of this myopathy have been indentified in several species like dogs, cats, mice, fish and invertebrates. In dogs the spontaneous dystrophin gene mutations have been indentified in several breeds: the Golden Retriever, the Rottweiler, the German short-haired pointer and Beagle. In Golden Retriever the muscular dystrophy (GRMD) is most extensively studied and best characterized. The GRMD shows muscle changes similar to human models and have more muscle mass if compared with others species used for this disease studies. A French Bulldog, 8 months old, was received at clinical facilities of Veterinary Teaching Hospital of São Paulo University with apathy, muscle weakness, dysphagia, regurgitation and dyspnoea. After physical examination moderate dehydration, reduced weight, gait abnormality and limbs severe muscle atrophy were observed. Therefore cervical resistance during the manipulation and an important increase of lingual muscle mass was also detected. The hematological and biochemical exams showed elevated serum creatinine kinase -CK (6710,5). Thorax radiography showed irregularity and caudal positions of diaphragm muscle. The muscular biopsy was performed under general anesthetic procedure. The histopathological exam of biceps muscle samples showed groups of degenerating and basophilic regeneration fibers. These changes are characteristics of muscular dystrophy. The dog was euthanized due to the poor prognosis. During the necropsies it was observed diaphragm changes equal to that found in GRMD. Mores muscle fragments were collected and the immunohistochemical and Western Blot tests were performed by Genome Group and confirmed lack of dystrophin protein is muscle samples. That is to the best of our knowledge the first confirmed case of muscular dystrophy in a French bulldog in the literature.