Equine respiratory diagnostics

Question 1

Upper airways of horses, includde: (6)

Answer 1

nasal cavity,
paranasal sinuses,
guttural pouches,
nasopharynx,
larynx,
trachea

horses are obligate nasal breathers because of their long soft palate completely separating nasal and oral cavities in the region of the nasophraynx.

Question 2

how many pairs of ribs in horses

Answer 2

18

Question 3

name the lobes of the lungs on the left side in horses

Answer 3

cranial and caudal lobes

Question 4

name the lobes of the lungs on the right side in horses

Answer 4

cranial, caudal and accessory lobes

right lung is slightly bigger than left.

Question 5

Sources of Epistaxis to consider (3)

Answer 5

• Nasal passages
• Guttural pouches
• Lungs

Question 6

Describe Percussion of paranasal sinuses

Answer 6

• Frontal sinus
• Rostral and caudal maxillary sinuses
• Any pain
• Dull sound

Question 7

Normal RR of an adult horse, resting

Answer 7

8-12 (16) x min

Easier to observe than to listen
* Nostrils, thoracic wall and abdominal muscles barely move

Question 8

Normal respiration type in horses

Answer 8

costoabdominal

Abnormal respiratory pattern is abdominal
* Expiration requires effort, abdominal muscles contract visibly („heave line“)

Question 9

Increased sound on inspiration, problem where

Answer 9

upper airways; nasal passages or larynx

Question 10

Increased sound on expiration, problem where

Answer 10

lower airways: trachea or bronchi

Note: Normal sounds in the caudal trachea (bronchial sounds)
* Soft sounds, resemble blowing
* In the early phase of inspiration and expiration

Question 11

Normal sounds in the lungs are

Answer 11

bronchovesicular/ vesicular

• Barely audible
• Normally stronger during inspiration
• Stronger on the right side
• Fat horses – almost inaudible
• Well heard in foals and thin horses

Question 12

Wheezes on expiration often indicate what pathology?

Answer 12

severe equine asthma

Question 13

Wheezes on inspiration often indicate what pathology? (4)

Answer 13

atelectasis,
consolidation,
interstitial pneumonia,
fibrosis

Question 14

Stridor (intensive, harsh vibrating wheeze) often indicates what pathology? (2)

Answer 14

obstruction in the upper airways,
tracheal
collapse

Question 15

Explain the use of a Rebreathing bag.

Answer 15

During auscultation, a rebreathing bag allows for the build-up of carbon dioxide stimulating the horse to take deeper breaths which makes evaluating their lung sounds easier.

• Medium-sized trash bag
• Rectal glove will do for a small horse
• Can just close the nostrils for 30-60 sec
• Auscultate with the bag on and after taking off

Question 16

Why use percussion of the lungs?

Answer 16

To find areas without any air
* Fluid or consolidation
* Dull sound
* Pain

Percussion is a little old fashioned now, ultrasound is more favored.

Question 17

Why use percussion of the paranasal sinuses?

Answer 17

• Check if fluid-filled
• May be painful

Question 18

What are my options for airway imaging? (3)

Answer 18

• Endoscopy
• Radiographs (head?, neck?, thoracic cavity?)
• Ultrasound

Question 19

Airway samples: (5)

Answer 19

• Swabs (viruses, bacteria, fungi)
• Sinus or guttural pouch flush
• Transtracheal aspirate (TTA)
• Thoracocentesis
• Broncho-alveolar lavage (BAL)

Question 20

equine acute phase proteins

Answer 20

• Fibrinogen
• Serum amyloid A

Question 21

Describe Lung ultrasound:

Answer 21

• Air in the lungs will not let ultrasound waves to pass
• Penetration up to 10 cm (7.5 – 10 MHz), > 15 cm (2.5 – 3.5 MHz)
• Easy to do
• Minimally invasive

Question 22

Arterial blood gas allow the assessment of

Answer 22

lung function

• Evaluation of O2 and CO2 exchange
• Severe acute respiratory distress or diffuse lung disease
• Severe chronic respiratory disease