Endoscopy of the Respiratory Tract

Patrick Lecoindre, DVM, Dip ECVIM(CA)
St Priest, France

 

RHINOSCOPY

Diagnosis of nasal disease is complicated by the similarity of signs and the non specificity of the symptoms of most nasal diseases and by inaccessibility of the nasal cavity. It's often necessary to use complementary exams. Rhinoscopy gives access to the nasal cavity for the examination of the mucosal surface, for the biopsy of mucosa and suspects lesions, for therapeutic procedures in some cases. Previous reports have shown that effective rhinoscopy is essential for differential diagnosis of nasal diseases . But this exam alone cannot be relied on to provide a diagnosis for every case and must be included in a protocol that associates history, physical examination and other exams: radiographs, culture, histopathology, fungal serology, allergy screening. The aim of this conference si to present after define indications of rhinoscopy, different abnormal aspects of the nasal cavity, in the nasal diseases that we have observed in an important study of about 324 cases in dogs and cats.

Indications

The most common indication for rhinoscopy is the chronic unresolved diseases that have not responded to a symptomatic treatment and in which a diagnosis has not been established.

Table 1.

Common clinical signs observed in 324 cases of nasal diseases

Frequency

Nasal discharge

Epistaxis

Sneezing

Difficult or noisy breathing

coughing

Ulceration of the rhinarium

Facial swelling or distortion

Facial or nasal pain or sensitivity

Reverse sneezing

Exophtalmy, visual dyssymmetry

Lethargy, poor appetite, weight loss

Dental diseases

125

36

18

75

17

18

4

4

13

8

19

12
The symptoms associated with nasal diseases are listed in table I. The duration of the problem was from 6 to 7 month for the majority of cases. Persistent severe sneezing, important nasal discharge, epistaxis are the most common signs observed in this series. The nasal discharge is often mucoïd, mucopurulent or hemopurulent at the time of the rhinoscopy (73%). This discharge is often (82%) bilateral but in 68% of cases the history show a discharge, first unilateral then becoming bilateral. Epistaxis (11%) is a frequent sign observed. Then can either be spontaneous or complicate a chronic discharge. Snoring, sometimes complicated by inspiratory dyspnea expressing an important obstruction of the nasal cavities are observed in 23% of cases. The reverse sneezing is a sign observed in 4% of cases. Other symptoms are described, ulceration of the rhinarium, facial swelling or distortion, facial or nasal pain or sensitivity, reverse sneezing, exophtalmy, visual dissymmetry.

Table 2.

Nasal diseases diagnosed in 324 cases of rhinoscopy

Frequency %

Neoplasia

Dog (25,6%)

Cat (17,6%)

Nasal foreign body

Dog (12,80%)

Cat (11,76%)

Mycotic rhinitis

Dog (7,31%)

Cat 0

Dental disease

Dog (8,53%)

Cat 0

Rhinitis (allergic, hypertrophic, atrophic, idiopathic)

Dog (23,17%)

Cat (47,05%)

Parasitis

Dog (1,21%)

Cat 0

Congenital abnormalities

Dog 0

Cat (23,52%)

Polyps

Dog (2,43%)

Cat 0

Traumatism of nasal

Dog (1,82%)

Non identify lesions

Dog (4,26%)

Normal aspect

Dog (5,48%)

Cat 0
The primary abnormalities found in the nasal cavity include neoplasia, nasal foreign body, inflammation of the mucosa (rhinitis), mycotic infection, rhinitis secondary to dental diseases. In the cases of mycotic rhinitis, it's frequent to see mucopurulent exudation, turbinate destruction, mucosal inflammation or ulceration. A variable quantity of fungal material may be found. The location of tumour varies but most often it is found in the distal nasal cavity and one can see a nasal mass during the examination of the nasopharynx. Their color, shape and consistency are highly variable. A variety of nasal foreign body have been found, including foxtails, blade of grass, sticks, rocks, pine needles. If foreign bodies are found, they can be removed under endoscopic visualization using foreign body removal forceps. Dental disease can cause unilateral or bilateral rhinitis. Periapical abscess or severe gingivitis associated with bone erosion can be responsible for oral nasal fistula. Diffuse bilateral mucoid or mucopurulent exudate, hyperhemic mucosa with variable roughening and friability are often associated with inflammation of the nasal cavity. Rhinoscopy cannot differentiate allergic rhinitis, idiopathic or bacterial rhinitis and it's necessary to make biopsies for histologic examinations.

TRACHEO-BRONCHOSCOPY

Today, respiratory endoscopy has become an important diagnostic technique in the practice of high-quality veterinary medicine. Bronchoscopy has allowed to understand the physiopathology of respiratory diseases in dogs and cats and has made easier the diagnosis and treatment of many respiratory disorders. Supplementing the X-ray examination, the respiratory endoscopy gives a totally reliable diagnosis.

Indications

They are many indications for a tracheobronchoscopy. The two main indications are the acute cough for which an inhalated foreign body is the suspected cause, or the chronic cough that has an unknown cause or does not respond to standard therapy. Unexplained lung infiltrate, unexplained abnormal breathing pattern, staging of chronic bronchitis, diagnosis and staging of pulmonary neoplasia, are other important indications for using this technique. This technique can confirm functional disorders (tracheal collapse) difficult to bring to light with usual techniques of exploration. Bronchoscopy is a technique that can reveal the nature, vascularity, extent and distribution of inflammatory infectious or infiltrative lesions of the pulmonary tract.

When there are indirect signs such as an abnormal production of mucus, presence of pus or blood, the endoscopic examination enables to make complementary investigations, sometimes determining as cytologic evaluation, bronchoalveolar lavage, biopsy. An endoscopy may have been decided after the observation of abnormal x-ray pictures, for which the etiology was not precise enough. In this case a bronchoalveolar lavage (BAL) is an examine which, for a first step determines the cellular profile of a pulmonary area so as to give a better description of an alveolitis (inflammation of the alveolar area). Doing a BAL is based upon the principle that the cells in the alveolar lumen reflect the cells of the pulmonary interstitium. The histocytology of this lavage will make it possible to describe a luminal alveolitis, to confirm a tumoral process, an allergic etiology, a chronic inflammation, a bacterial infection.

Patrick Lecoindre, DVM, Dip ECVIM(CA)
St Priest, France