Page 92 - BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery, 2nd Edition

Chapter 6 · Brachycephalic airway disease

make cardiac auscultation difficult, which nonetheless
Authors’ comment needs to be performed meticulously to rule out concurrent
VetBooks.ir It is essential that the veterinary profession starts to useful for recognition of obstructing structures in the
cardiac disease such as pulmonic stenosis.
Diagnostic imaging of the head, neck and chest is
radically influence brachycephalic dog breeding.
Brachy cephalic diseases are purely human-made.
Veterinary surgeons (veterinarians), as the guardians
to detect secondary aspiration pneumonia or pulmonary
of animal health and welfare, should play a much more pharynx and larynx, tracheal hypoplasia (Figure 6.1), and
active role in the public discussion. Kennel clubs and oedema. The tracheal diameter can be measured at the
their scientific advisers are faced with the real thoracic inlet and expressed as a percentage of the thoracic
challenge of rescuing these old breeds. Although inlet diameter. In bulldogs, the tracheal diameter is a mean
there have been minor efforts, breed standards have of 12.7% of the thoracic inlet, compared with 20% in non-
to be revised rigorously, based solely on animal brachycephalic breeds (Harvey, 1982c). In some patients, a
health, not on appearance. Additional nose length will hiatal hernia can be identified. Radio graphy is limited in its
definitely not spoil the unique character of these dogs. ability to provide information on the degree of narrowing
Social awareness is increasing, and politicians and the of pharyngeal and laryngeal dimensions and associated
media are increasingly aware of the negative impact pharyngitis and laryngitis, and it does not allow a proper
that selective breeding for exaggerated features has evaluation of the nasal passages (aberrant conchae) and
had on the welfare of pedigree breeds (Rooney, 2009; nasopharyngeal dia m eter. Pharyngeal fluoroscopy may be a
Rooney and Sargan, 2010; Palmer, 2012). Obviously, useful diagnostic test for assessment of the degree of naso-
individual dogs suffering from this syndrome are pharyngeal collapse in brachycephalic patients (Rubin et al.,
patients that require expert veterinary treatment, and 2015). Computed tomography (CT) imaging is recom-
many conservative, medical and surgical options are mended in brachycephalic animals to allow assessment of
available to improve breathing, which will be all of the anatomical abnormalities using a single modality.
discussed in this chapter. The treatment of all other This allows a much more accurate evaluation of the bony
brachycephaly-related diseases and abnormalities is abnormalities and measurements of airway diameter, with
beyond the scope of this chapter. assessment of the presence of nasopharyngeal turbinates
and potential concurrent middle ear disease, also related to
brachycephaly (Figure 6.2) (Grand and Bureau, 2011;
Grosso et al., 2015; Kaye et al., 2015; Heidenreich et al.,
2016; Oechtering et al., 2016a; Rutherford et al., 2017; Mielke
Diagnosis et al., 2017).
Direct inspection of the pharynx and larynx with a laryn-
The diagnosis of BAD is very straightforward and based goscope is the most important diagnostic procedure for
on the combination of a brachycephalic dog breed and the subjective assessment of pharyngeal and laryngeal
obstructive upper airway signs alone. Taking a full history, dimensions, the length of the soft palate and the degree of
performing a complete and multi-organ-system physical eversion of tonsils and mucosa of the lateral ventricles, and
examination, and appropriate advanced imaging followed for evaluation of laryngeal collapse (Figures 6.3 and 6.4).
by endoscopic assessment are all mandatory to assess With flexible or rigid endoscopes the nasal passages and
the severity of disease and thus inform the options for nasopharyngeal area can be completely inspected, and
management. evaluated for aberrant turbinates and increased mucosal
A full history of clinical signs should be taken, prefer- contact points and protrusion of turbinates into the naso-
ably based on a structured standardized questionnaire pharynx (Figure 6.5). Endoscopic evaluation of the trachea
(Roedler et al., 2013; Pohl et al., 2016) so that the clinician helps in differenti ating true tracheal hypoplasia from diffuse
can assess the presence and severity of clinical signs tracheal mucosal swelling and allows samples to be taken
associated not only with the airway obstruction but for cytological evaluation and culture in patients suspected
with other brachycephaly-related conditions as well. Nasal of having aspiration pneumonia (Figure 6.6).
stertor indicates obstruction of airflow through the
nasal passages, snoring is typically associated with (naso)
pharyngeal disease, whereas laryngeal stridor (‘g’-sound
or sawing sound) is associated with laryngeal disease.
Coughing, gagging, retching, regurgitation, vomiting and
flatulence are frequently present as well, and may indicate
significant aerophagia, or secondary or concurrent lower
airway or gastrointestinal disease. Hearing loss often
goes unrecognized by the owner, but scratching at the
ears, head shaking, discharge and aural pain may be
present. Epiphora, rubbing the face and ocular abnormal-
ities may have been observed by the owner, as well as
conformational orthopaedic and/or neurological abnor-
malities. A detailed description of all concurrent possible
brachycephaly-related abnormalities is beyond the scope
of this chapter, which will focus on the airways.
Physical examination findings are usually unremarkable
except for the possible audible stridor and the obvious
brachycephalic conformation of the animal. In addition,
most patients demonstrate some degree of stenosis of the
nares, and increased referred respiratory noises are Lateral thoracic radiograph demonstrating a hypoplastic
frequently heard upon thoracic auscultation. These noises 6.1 trachea in a 13-week-old Boston Terrier.

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