Health problems & treatment protocols
There is a range of animal health and welfare problems caused by exaggerated physical features. Below is a list of common problems and treatment protocols.
Brachycephalic Obstructive Airway Syndrome (BOAS)
This is a direct result of selection for exaggerated features, resulting in stenotic nares, elongated soft palate, and everted laryngeal saccules. Clinical signs vary in severity and are usually evident from a young age. Veterinary treatments will range from medical management of acute episodes (O2, cooling, corcticosteroids) through to surgeries to reduce airway obstruction more permanently to make the dogs more comfortable. Without early intervention clinical signs tend to worsen over time due to the effects of chronic negative airway pressure which exacerbates airway obstruction; for example, tracheal collapse may occur.
Secondary health problems caused by breathing distress and brachycephalic anatomy include chronic sleep deprivation, heat stress, and heat stroke, and exercise intolerance.
Breeding advice will include:
- strongly recommending desexing of dogs with clinical signs, in particular, those that have required surgical correction
- focusing on prevention by breeding away from exaggerated features that cause breathing distress using judicious outcrossing programs to restore these breeds to a phenotype that is fit for life.
Intervertebral Disc Disease (IVDD)
Chondrodysplastic breeds such as the Dachshund, Corgi, and Bassett are predisposed to IVDD, due to selection for short limbs and associated cartilage development defects. They are thus at an increased risk of disc herniation which may occur at a relatively young age and at several sites. Clinical signs range through varying degrees of pain, loss of proprioception, paresis, and paralysis, and vary with the location of the lesion(s).
As the mode of inheritance is not understood, the best breeding advice is to not breed from affected individuals or those with affected close relatives.
Brachycephalic Ocular Syndrome
Also known as Exposure Keratopathy Syndrome, this is a combination of disorders including protrusion of the eyeball (exophthalmos), inability to close the eyelids (lagophthalmos) and abnormally large eyelid openings (macroblepharon). Entropion may also be present. This is a direct result of selection for bulging, large eyes and excessive facial skin folds. Signs of chronic irritation through to ulceration may be evident, and medical as well as surgical correction is commonly required.
Breeding away from the exaggerated features which cause this group of eye defects, selecting for a more normal head shape and eye anatomy, and desexing of affected individuals should be recommended.
Skin Fold Dermatitis
Skin fold dermatitis and associated pyoderma occur on the face, body, and legs of breeds selected for excessive skin wrinkle, such as the Shar Pei. It is also a side effect of the head shape in brachycephalic breeds because the facial skin is in relative excess over the shortened muzzle and structures underneath. Pugs are also prone to this in the folds on their abnormally short and twisted tails. The condition requires ongoing medical management and in many cases, surgical removal of excessive folds.
Breeding advice includes choosing dogs with few or no wrinkles for breeding and altering the brachycephalic conformation to result in normal anatomic structure.