10/11/2023
❤️❤️Brachycephalism❤️❤️
🌸The images to the side show a CT slice through the middle of the head of a non-brachycephalic dog (A) and a brachycephalic dog (B).
🌸uncoloured CT scans “white” is the bones of the skull and upper neck. Grey is the so called “soft tissue” which includes the structures of the nose, palate, tongue, larynx and brain. The black is air.
🌸Purple - A common feature of brachycephalic dogs is that the skull base (purple) is short because it stopped growing prematurely. The consequence is that the cranium is shorter.
🌸Red arrows - in response, the developing brachycephalic puppy adapts by making the skull taller and consequently the top of the head becomes rounder and domed (bright red arrows).
🌹The eyes are more toward the centre of the “face” and appear larger because of a combination of shallow eye sockets and less eyelid coverage.
🌸Dark red - The muzzle is shorter and the nose that is more “button like” (dark red) lies between and just below the eyes.
🌸Blue outline - A reduction in the frontal sinus means that dog has “broad flat forehead” again like baby. Finally the ears are smaller and/ or floppy.
❤️❤️This change in head shape (conformation) has >>>>>dire consequences for the brachycephalic dog.
The soft tissues (the grey areas) do not follow the bone structure and the same amount of tissue found in non-brachycephalic dogs fills and obstructs the airway.
In the bottom panel C and D, compare the tissue (grey area) around the nasal passage (yellow).
This dog cannot, or has severely restricted, breathing through its nose. Consequently, the dog must open its mouth to breathe but even that airway is obstructed by a tongue (green) and soft palate (pink) that is compressed to fill the reduced space.
The soft palate pushes back on the larynx (orange) further obstructing the airway.
