Successful correction of flat-chested kitten syndrome in two littermate kittens.

Case summary Two 18-day-old domestic shorthair kittens presented with dyspnoea, mild cyanosis, heart murmur, lung pattern, abnormal crawling and a marked dorsoventral flattening of the thorax. Deformity of the thoracic wall without pectus excavatum was diagnosed. Cardboard corsets tailored to each kitten were applied. This gave immediate respiratory relief, easing distress and pain. After 10 days, clinical and radiographic monitoring revealed normalisation of the shape of the chest wall with an improvement in general condition. At 6 months of age, clinical examination showed normal growth and development of both kittens, with a normal thoracic profile and shape also seen on radiographs. Relevance and novel information Data about flat-chested kitten syndrome and its aetiopathogenesis, treatment and outcome are scarce, but there is significant experience among breeders that is shared through online communities. High mortality rates are reported. The use of a cardboard splint appears to be novel in the published literature; in this case report, it proved to be a rapid and easy solution. For this reason, cardboard splints could be considered as a first approach for the clinical management of flat-chested kitten syndrome.