An 8 week old MI DSH presented to the veterinarian for respiratory difficulty. He was the runt of the litter and the mother stopped feeding him, so he had been bottle fed. On physical examination he was found to be tachypneic with marked abdominal effort when breathing. He was underweight, although he was eating well and BAR.
Orthogonal radiographs of the thorax and abdomen were obtained to investigate for the cause of respiratory distress.
On first inspection of the lateral radiograph, the impression is that the image is badly rotated leading to superimposition of the vertebral column with the lungs. However, upon closer inspection, the vertebrae are well-aligned and there is marked vertebral lordosis (ventral bowing) leading to narrowing of the thoracic height (see annotated image).
Similar clinical signs and some of these radiographic changes can be seen with a more common congenital anomaly - pectus excavatum. Here is a radiographic example in a different kitten of about the same age. Here you’ll note that the sternum deviates dorsally, leading to similar narrowing of the thoracic height while the vertebral column is normal. On the VD radiograph, the apex of the heart is also shifted (to the left in this case). Both of these conditions are managed with external thoracic splint application; consider surgical referral in these cases. The cited article discusses this procedure.