Diseases and Conditions of the Avian Respiratory System

Question 1

Acute presentation of avian respiratory distress?

Answer 1

Acute Presentation – (Owner’s reason for presentation)

• Dyspnoea with open mouth breathing
• Whole body effort in inspiration or expiration
• Exaggerated ‘tail bobbing’
• Acute change in vocalisation noise
• Wheeze, squeak, rasp, gurgle etc
• Glottis, trachea, syrinx
• Bottom of the cage and gasping

These cases usually represent emergencies

Question 2

Chronic presentation?

Answer 2

Chronic Presentation (Can fulminate for many years with subtle clinical changes. Often seen when bird presented for other reasons)

• Sinusitis (often with conjunctivitis)
• Soft swellings
• Hard ‘abscesses’
• Chronic airsaculitis
• Rhinitis – (nasal discharge)
• Oculanasal discharge
• Stained/matted feathers around the nares
• Sneezing
• Dyspnoea – (+/- above and weight loss)

Question 3

Normal respiratory effort in the bird should?

Answer 3

Should not be noticeable

• The mouth should remain closed
• An increase in abdominal effort or head movement may be recognised in association with increased respiration following exercise but this should return to normal within minutes of ceasing activity

The avian patient should be observed from a distance to evaluate:

• Subtle changes in posture, wing position
• Respiratory rate and respiratory pattern that may
  indicate an abnormality (tail-bobbing)

Question 4

URT signs?

Answer 4

−Change in voice

− Sneezing

− Periorbital swellings - Sinus swelling

− Rhinorrhoea

− Plugged nares - Nasal granuloma

− Exercise intolerance

− Head-shaking

− Mucopurulent nasal discharge

− Inflamed swollen cere

− Stretching the neck - Yawning

− Epiphora

− Open-mouthed breathing – Dyspnoea – but not stressful

Question 5

LRT signs?

Answer 5

−Dyspnoea – with distress

− Open-mouthed breathing

− Tail-bobbing

− Loss of voice

− Change in vocalization

− Laboured respiration

− Exercise intolerance

− Coughing

− Sounds on auscultation

− Depression

Question 6

Non-respiratory disease with respiratory signs?

Answer 6

− Presence of other system signs or lesions

− Abdominal swelling

Differential

•Ascites

− Liver and renal disease, Neoplasia

•Malnutrition

− Obesity, Goitre

• Neoplasia
• Systemic viral disease

− Paramyx, Herpes, Reovirus

• Cardiac disease
• Egg related peritonitis

Question 7

Discuss the nasal cavity?

Answer 7

Nares

−The nasal cavity serves to filter inhaled particles which are trapped in mucous and swept into the choana by cilia

−They then pass into the oropharynx and are swallowed

•Disruption (malnutrition – immunosuppression) will lead to malfunction of this system

−The nasal cavity is connected to the infraorbital sinus by an extremely small passage

• ~0.5mm in most parrots
• Barely visible in Amazons
• Larger in African Greys

−Easily plugged by dry mucous or caseous debris

Question 8

Discuss rhinitis?

Answer 8

Clinical Signs

• Unilateral or bilateral
• Occluded nares
• Rhinorrhoea – inflammatory exudate

− Mucous

− Purulent

• Sneezing +/- discharge
• A growth or change in size of the nasal opening

− Chronic inflammation - Rhinolith

− Knemidocoptes

• Crusted soiled feathers around the nares
• Grooves in the maxilla

Do not mistake the operculum for a foreign body

Question 9

What is wrong here?

Answer 9

Rhinolith

Question 10

What are the clinical diagnostics for rhinitis?

Answer 10

−Cytology of nasal discharge (flush)

− Culture and sensitivity of rostral choana

• Culture of nares yields mainly contaminates
• Normal choanal flora + Gm+ve

−Lacto, Streps, Staph epidermidis, Corynebact

•Potential pathogens = Gm –ve

−Staph aureus (inc MRSA), Staph spp, Fungus

•Special pathogens

−Chlamydophila, Mycoplasma

Question 11

Therapy for rhinitis?

Answer 11

−Parental antibiotics (C&S)

•Caution should be used in treating chronic, mild cases of rhinitis with repeated courses of different antibiotics as this can lead to immune system depression and predispose the bird to more sever systemic illness (Aspergillosis)

−Nasal flushes and intranasal antibiotics

• Ophthalmic solutions
• F10

−Nebulisation

• Various
• F10

Question 12

Discuss clinical anatomy of the sinuses?

Answer 12

• In mammals, the sinuses are contained within the bones of the skull
• By contrast, avian sinuses are restricted laterally by the skin and subcutaneous tissues of the face

− And therefore have the capacity to expand

•The sinuses have simple mucous glands and are lined by stratified squamous and ciliated columnar epithelium

Question 13

What clinical considerations are there for the sinuses?

Answer 13

−The numerous pockets and extensions of the nasal system make sinus infections difficult to treat

−The interconnection of the nasal cavity, infraorbital sinuses and the porous calvaria creates a situation in which inflammatory reactions in the sinus or nasal passages can involve most of the anatomic structures of the head

−With severe chronic sinusitis, the accumulation of caseous necrotic debris can cause destruction of the nares, nasal cavity, operculum and nasal conchae

Question 14

What will the clinical exam for sinusitis yield?

Answer 14

−Periocular swelling and reddening

− Distended sinus may soft, tense or firm

− +/- nasal discharge

− Sunken eye – chronic sinusitis in macaws

Chronic problems in Amazons and Af Greys

Question 15

What can cause sinusitis and how is it diagnosed?

Answer 15

Causes

− Same organisms as with rhinitis

− Hypovitaminosis A

• Hyperkeratosis
• Squamous metaplasia

Diagnosis

• Appropriate wash
• Culture and sensitivity

Question 16

What is the therapy for sinusitis?

Answer 16

−Isolate any causative organisms and treat
accordingly

• Sinus flush
• Surgical removal of ‘abscesses’

− Correct the underlying malnutrition

− Look at environmental humidity (S Am species)

Question 17

What is the clinical anatomy of Glottis, Trachea and Syrinx?

Answer 17

−The trachea consists of complete cartilaginous rings in most avian species

−DO NOT INFLATE A CUFFED ET TUBE!!

−The tracheal rings can calcify with age

−The anterior trachea can be wider than the lower trachea (Macaw)

−The length, configuration and anatomic position of the trachea vary widely among genera

•E.g. The whooping crane has a trachea that extends to the cloaca, where it doubles back and returns to the thoracic inlet before connecting to the syrinx

Question 18

How do birds produce sound?

Answer 18

−Most psittacine birds have a tracheobronchial-type syrinx in which the last of the tracheal rings fuse into a syringeal box, which joins to the first of the bronchial rings

−The shape of the syrinx and the sound it emits are controlled

• By the bronchial muscles that attach to the syrinx
• The first bronchial rings
• The bronchotracheal muscles, which extend from the bronchus to the trachea.

−Sounds are believed to be produced in the syrinx by the turbulent flow of expelled air that is forced through syringeal membranes, which form slots

−The pitch of the sound is also controlled by

•The length of the trachea and whether the air sacs are inflated or flattened. A long trachea and inflated air sacs produce a loud, booming, low-frequency sound

Question 19

How should sound be considered clinically?

Answer 19

A change of sound – Alteration in air turbulence

−Pathology involving the syrinx is best diagnosed and treated when signs of disease are first recognised

−If a bird stops talking or has a voice change it should be evaluated immediately for lesions developing in the perisyringeal area (frequently Aspergillosis)

−Progressive changes recognised clinically as dyspnoea, coughing or tracheal discharge are more difficult to successfully resolve

−The trachea and primary bronchi contain goblet cells and are lined with pseudostratified, ciliated, columnar epithelium. The syringeal mucosa contains bistratified squamous or columnar epithelium that is subject to squamous metaplasia and granuloma formation

Question 20

Aetiology of sound changes?

Answer 20

−Fungal - Aspergillosis

− Bacterial - Chlamydophila

− Parasitic

• Syngamus trachea (gape worms) – See Parasite notes
• Sternostoma tracheacolum

− Viral

• Amazon tracheitis virus
• Pox
• Herpes

− Malnutrition

• Granuloma
• Metaplasia

− Fumes and toxins

− Acute obstruction

Question 21

For causes of sound change how should they be treated?

Answer 21

Diagnosis

− Tracheal wash

− Auscultation

− Endoscopy

− Transillumination (tracheal mites)

Treatment

− Nebulisation

− IvermeCtin (mites and worms)

− Fenbendazol (worms)

•For obstruction – placement of an air sac tube

Question 22

What is the clinical anatomy of lungs and air sacs?

Answer 22

−All air sacs are thin-walled and lack vascularity.

−The air sacs of a normal bird are completely transparent (appear similar to clear plastic wrap)

−Any alteration in transparency should be considered abnormal (Endoscopy)

−The presence of blood vessels in the air sacs may be an indication of early inflammation

−Air sac lesions that are localized and do not alter the flow of air in or out of the air sacs may not cause clinical changes

The double-pass airflow make lungs and air sacs twice as likely to encounter disease

Question 23

What is the diagnosis and aetiology of air sac and lung disease?

Answer 23

Diagnosis and Aetiology

−Presenting sign - dyspnoea

−All of the previously mentioned agents

−Granuloma formation

−Asthmas and Allergies

Question 24

Discuss auscultation diagnostic techniques?

Answer 24

• The sinuses, trachea, lung, thoracic air sacs and abdominal air sacs can be auscultated using a paediatric stethoscope
• Audible sounds on inspiration generally correlate with upper respiratory tract disease …
• …while sounds on expiration are more commonly associated with lower respiratory tract diseases
• Because air moves through the lungs continuously and the air capillaries do not collapse and expand to the same degree as alveoli, a “smacking” sound characteristic of pneumonia in mammals does not occur in birds
• Air sac pathology is best detected by placing the stethoscope on the lateral or dorsal wall

Question 25

Audible sounds on inspiration generally correlate with?

Answer 25

upper respiratory tract disease

Question 26

sounds on expiration are more commonly associated with?

Answer 26

lower respiratory tract diseases

Question 27

Discuss endoscopy in birds?

Answer 27

Endoscopy

−A 1.9 mm will reach the syrinx of a 200gm bird; a 1.7 mm a cockatiel

−Laparoscopic – biopsy, surgical removal

−Tracheal – wash/biopsy

Question 28

Discuss radiography in avian respiratory disease?

Answer 28

−Air sac lines in air saculitis (Not generalised opacity)

−Soft tissue masses

Question 29

Discuss samples that can be taken for diagnostic techniques in birds?

Answer 29

• Blood profile
• Culture and Cytology

−Sinus wash

−Choanal swab

ØRostral not Caudal (Limited due to oral contaminants

−Tracheal wash

−Endoscopic sample

Question 30

Discuss aspergillosis infection?

Answer 30

−Ubiquitous environmental organism

−Will colonise birds

• Waterfowl, Penguins, Raptors and Parrots

−Primary sites

• Skin
• Beak and sinus
• Respiratory system

−Peracute allergic

−Acute

−Chronic granuloma formation (Immune status?)

ØObstructive – dyspnoea – syringeal

ØNon–obstructive – air sac/lungs

Question 31

How is aspergillosis diagnosed and treated?

Answer 31

Diagnosis

• CBC – Marked leucocytosis ( can be 100,000)
• Radiography
• Endoscopy
• Serology?
• (Post mortem)

Treatment = Prevention

•Antifungals

−Itraconizole; Amphotericin B

•Nebulisation

−Antifungals/F10

• Supportive treatment
• Surgical removal
• Nutrition and immune stimulants

Question 32

Discuss myocplasma?

Answer 32

Specific Respiratory Disease

•Mycoplasma

−Species affected – All

•Poultry, Pigeons, Raptors, Passerines, Psittacines

−Potential high commercial loss

−Vertical egg transmission

−Latent infection

−Symptoms

• Rhinitis, sinusitis, conjunctivitis
• Bubbles in conjunctiva
• Mucopurulent sinus swellings
• Dyspnoea

Question 34

How to diagnose and treat mycoplasma?

Answer 34

Mycoplasma

−Diagnosis

•Culture not easy as mycoplasma spp unstable

−Treatment

• Oral abs
• Eye ointment
• Sinus flushing

Question 35

Discuss fumes and toxins and respiratory disease in avians?

Answer 35

Teflon poisoning

•Presenting signs

−DEAD birds

−Acute respiratory dyspnoea

ØDD history

ØCooking (especially in caravans)

Source

−Overheated pans and some heat lamps

Treatment

−Oxygen

−Bronchial dilators by nebulisation

−?Dexamethasone?

Passive smoking - cotinine levels in blood

Question 36

Discuss aerosol therapy?

Answer 36

Aerosol therapy

−Humidification

•Increase the RH and improve the efficiency of the mucociliary blanket

−Vaporization

−Nebulisation

• Indicated in birds exhibiting any respiratory tract problems (and other systems)
• Used to augment systemic therapy
• Help maintain proper hydration of the respiratory epithelium
• Break up necrotic debris

Question 37

How to perform a nasal flush?

Answer 37

• Assemble equipment before restraining bird
• Sterility important
• Warm saline (39C)
• 10ml -35ml syringe
• Use metal gavage tube or rubber bung to get closer apposition (see photo)
• Wrap bird ‘mummy-like’ in towel head pointing down
• Flush each sinus
• Collect fluid as it appears from hard palate
• Centrifuge – cytology and culture
• Treat with appropriate medication – 2x daily for 10 days +/- . Leave 4 days post treatment re-culture

Question 38

How to do a sinus flush?

Answer 38

Sinus Flush - Diagnostics and Treatment

−Similar protocol to nasal flush

−Insert needle into infraorbital sinus between nares and eye

−Insert small amount of fluid

−Ensure that the globe of the eye does not bulge!!

−Slowly insert more fluid and complete wash/treatment

Question 39

When is an air sac tube indicted?

Answer 39

• As an immediate ‘life-saving’ procedure
• To relieve acute obstructive dyspnoea

−Granuloma

−Seed aspiration

•NOT for restrictive respiration (1st consideration O2/Centisis)

−Chronic URT

−Air saculitis

−Non-respiratory orientated disease

•To allow tracheal/oral surgery (FB removal)

Question 40

Discuss air sac tube placement?

Answer 40

• Variously sized tubes (ET or similar) with placed suture stays are used
• The diameter of the tube should be the approximate diameter of the patient’s trachea
• Under anaesthesia, the patient is placed in right lateral recumbency with the dorsal leg pulled caudally
• The caudal edge of the eighth (last) rib is palpated and the skin over this site is surgically prepped.
• A small skin incision is made behind the eighth rib
• Using mosquito forceps, the muscle wall is bluntly dissected and the body wall is penetrated
• The tube is placed into the hole and sutured in place
• To check if the tube is properly seated, place a down feather over the tube opening. The feather should move with each breath
• Care must be taken to avoid iatrogenic organ damage caused by pushing the tube in too far.

Maintenance of the tube is important to ensure a patent airway

Question 41

Discuss Tracheal foreign body removal?

Answer 41

Tracheal foreign body removal- Very difficult

−Anaesthetise bird

−Place air sac tube

−Visualise with endoscope

−Insert ET or similar through glottis

−Attach syringe and exert suction - hope to ‘suck’ seed

−Alternatively – ‘push’ through syrinx into abdomen and retrieve later

The same approach can be tried with granulomas

−Endoscopically guided in larger birds

Question 42

Discuss Nebulisation?

Answer 42

•Deliver antimicrobial agents to the upper respiratory tract and portions of the lower respiratory tract

−Mucolytics

−Tylosin (local rather than absorbed)

−Amphotericin B

−Itraconizole

−F10 (1:250)

• Depending on the agents delivered, nebulisation can be used two, three to four times per day for 10 to 20 minutes for each session
• Therapy should be continued for three days after all clinical signs have been resolved

Question 43

What is subcutaneous emphysema?

Answer 43

−Due to damage to any air sac system but most common with damage to the cervicocephalic, abdominal or caudal thoracic air sacs

−In addition, the cervicocephalic air sac may distend as a result of rhinitis, which causes occlusion of the nasal passage or damage to the outflow tracts

−The resulting lesion looks clinically like subcutaneous emphysema as the air sacs progressively inflate with each successive expiration

−When the air is removed with a needle, the sac will deflate but will typically re-inflate with subsequent respiratory cycles.

−If the problem persists, long-term management can be achieved by inserting a Teflon stent in the dorsal wall of the air sac that allows air to escape.

−In some cases, the damage to the sac will repair itself and the stent can be removed. In other cases, the stent must remain in place permanently

Question 44

What is sunken eye sinitis?

Answer 44

−The pathogenesis of this lesion is unclear

−A syndrome characterized by periorbital depression

−Has been described as a sequel to sinusitis in macaws, conures and emus

−Progressive collapse of the epithelium into the infraorbital sinus around the eye is typical

−Gram-negative organisms have been isolated from the infraorbital sinuses and choana of affected birds.

Question 45

What is choanal atresia?

Answer 45

−Congenital condition of chicks (Af Grey)

−Bilateral sero-mucoid nasal discharge

Correct by surgery

Question 46

Look at this?

Answer 46

Question 47

Look at this?

Answer 47