Pectus carinatum in a dog.

Background: The deformities of the anterior chest wall are universally designated as pectus deformities. Two types of deformities are known, pectus excavatum and pectus carinatum. Pectus excavatum is a dorsal ventral narrowing of the chest, also known as ‘funnel chest’, while pectus carinatum is a ventral protrusion of the sternum, also known as ‘pigeon breast’. Both are diseases seen in children and adolescents, however, they are considered rare in small animals, especially pectus carinatum. Thus, the aim of this study is to report a case of pectus carinatum in a Shih-tzu puppy dog. Case: A male canine Shih-tzu, 2 months-old, was present at the veterinary hospital. The owner reported that in the fi rst days of life, the animal felt diffi culty breathing when she took him in her lap, and still noticed abnormal increase of the thoracic region. The patient was from a litter of eight pups, without consanguinity, and the parents showed no congenital abnormality. During the interview, it was reported that the patient was eating and drinking water normally, and presented an active temperament. Moreover, he had one dose of vaccine and a dose of anthelminthic. On clinical examination, all physiological parameters were normal. However, during palpation, it was observed swelling in the ventral thoracic region. For that, we suspected pectus carinatum. Chest radiograph was requested and revealed marked ventral protrusion of the distal part of the sternum. Discussion: The diagnosis of pectus carinatum is basically clinical and relatively simple, since there is a good physical examination and ratifi cation by imaging tests. However, their identifi cation requires observation and palpation, as may go unnoticed in asymptomatic and long haired animals. Moreover, this rare disease is not known by many professionals and therefore, at a fi rst moment, it is not included in the differential diagnosis of dyspnea. In many cases, the deformity is progressive growth, and can or cannot be accompanied by cardiac and respiratory signals. Although pectus excavatum, the most frequently type of disease observed in small animals, can often cause severe dyspnea, pectus carinatum can present an asymptomatic animal or can cause a transient respiratory distress. The patient in this report had no cardiac or respiratory signs at query time. It is likely that the reported animal had developed idiopathic deformity, since the animal had a good general condition and had no anatomical deformities elsewhere. Surgery for pectus carinatum is the fi rst choice in humans. But more recently, some authors have proposed successfully conservative treatments using orthotics that provides a ventral-dorsal continuous compression of the sternum, especially in individuals at an early age. Compressive orthosis with velcro or snaps on the sides have been described as effective conservative treatment options for children with fl exible types of pectus carinatum. Placing compressive bandage was suggested in the chest region during the growth period for the dog. However, as the animal was uncomfortable with the bandage, its use was discontinued within a few days by the owner. The puppy was accompanied by three months more, remaining during this time with active temperament, and discrete gradual improvement in respiratory status. The dyspnea was observed only when the dog was subjected to longer walks, intense activities or when positioned in dorsal recumbency.