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MIS: Home > Exotics > Small mammal > Upper respiratory endoscopy
Small mammal
Upper respiratory endoscopy
In all cases general anesthesia greatly facilitates endoscopic examination and therefore the veterinarian must ensure that the patient has been stabilized and can be safely anaesthetized.
For rhinoscopy procedures the animal is orally intubated, but for endoscopic evaluation of the glottis and trachea, nasal intubation is often preferred.
In addition, supplemental oxygen and isoflurane/sevoflurane can be delivered via an anesthetic line connected to a sheath port.
For detailed buccal examinations, naso-intubation or endotracheal intubation can be used depending upon the size of the animal and space within the oral cavity.
Respiratory and cardiovascular monitoring is essential and can include pulse oximetry, capnography, and blood gases.
Clinicians should guard against hypoventilation and hypothermia of small, anesthetized mammals.
Depending upon animal size, a 2.7mm telescope, 1.9mm telescope, or 1.0mm semi-rigid endoscope can be used to examine of nasal passages and turbinates of most rabbits. Examination of the nasal turbinates can be extremely useful for the characterization of rhinitis and the collection of tissue biopsies and microbiological samples, which are essential to accurately attribute pathogenicity to a particular organism. Many different bacterial and fungal organisms cultured from nasal swabs or, worse still, nasal discharges may simply represent commensal or environmental contaminants.
With the head and neck held in full extension, the larynx can be approached via a buccal approach, however, the rabbit glottis is not usually visible as (being a nasal breather) the epiglottis is engaged over the soft palate.
Gently pushing the scope up against the soft palate will cause the epiglottis to fall ventrally revealing the glottis and the obvious cuniform processes.
Entry through the glottis permits the examination of the trachea, which in rabbits looks hyperemic.
This intense red coloration is simply due to the brightly colored smooth muscle that encloses the trachea. The pale dorsal ligament of the trachea is obvious.
The trachea divides into two primary bronchi and very quickly subdivides into secondary bronchi. A rigid scope can, with care, be inserted down to the level of the bifurcation and the primary and secondary bronchi can often be seen.
For larger rabbits small diameter bronchoscopes may be required. Respiratory exudates are not infrequently encountered and may be sampled through the endoscope operating channel.
Endoscopic examination of the nasal chambers in an anesthetized rabbit.
Normal nasal turbinates in a rabbit.
Grossly abnormal nasal chamber in a rabbit with nasal mycobacteriosis.
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