Horse thorax Flashcards
What views are needed for a full radiographic study of the thorax of an adult horse?
Cranioventral
Craniodorsal
Caudoventral
Caudodorsal
Overlapping 14x17 in plate
Which lung/hemithorax is highlight or seen more clearly on an adult horse? radiograph?
The one closest to the plate will be the clearest.
Therefore you may need to shoot from both sides.
The right and left lungs of the horse are divided into what lobes?
Left with a cranial and caudal component
Right with a cranial, caudal and accessory component.
How do the horse lung differ from dogs and cats when it comes to the interlobar fissures?
Horse do not have interlobar fissures
Clinical - horse will not show pleural fissure lines when effusive.
When does radiographic clearance of the lungs of a foal occur after birth?
6 hours
When is the thymus the largest in a foal?
2 months of age and then regresses
What is usually the cause of increased opacity in a recumbent foal?
Atelectasis. Foals become atelectatic very fast.
Is a mild diffuse bronchointerstitial lung pattern normal in an adult horse? What may it be due to?
Yes it has been seen in normal horses.
Like secondary to normal abundant lobulation and connective tissue in the horse OR subclinical peribronchial fibrosis
How to assess the heart of the horse on radiographs?
Same as in dogs and cats
In horses, which age set has bigger hearts when compared to the thorax?
Foals
What should the height of the heart of foals be measured at?
6.6-7.8 x the length of a midthoracic vertebral body
What should the width of a normal foal heart be measured at?
5.6-6.3x the length of a midthoracic vertebral body
What is the modality of choice for pleural disease in a horse?
Ultrasound
CT for foals though this is expensive and too small for adults
Nuclear scintigraphy perfusion and ventilation studies are used for what two diseases?
- Chronic obstructive pulmonary disease
2. Excercise induced pulmonary hemorrhage
Does the type of pulmonary patterns correlate well with histopathologic diagnosis?
No… pathology that is interstitial can be histopathologically alveolar and visa versa.
Abscess formation is noted in what percentage of horses with pneumonia?
10-15%
Does acute or chronic pneumonia have better outcomes in foals?
Chronic.
Multinodular pulmonary fibrosis in horses is associted with what virus?
Equine herpesvirus type 5
Differentials for diffuse nodular pattern in an adult horse?
- Multinodular pulmonary fibrosis
- Eosinophilic pneumonopathy (idiopathic pneumonia vs multisystemic)
- Pulmonary silicosis
Fungal and metastatic diseases are uncommon in horses
When are R. equi radiographic changes most apparent after infection?
3 weeks.
The severity/number of what radiographic changes are negatively associated with prognosis in foals infected with R. equi?
- Severity/extent of alveolar pattern
2. Number of pulmonary/cavitary nodules.
What percentage of foals infected with R. equi have at least one additional extrapulmonary site of infection?
74%
What extrapulmonary sites have been noted in R. equi infections?
- GI
- Abdominal lymph nodes
- Abdominal abscess
- Uveitis
- Synovitis
- Hepatitis
Having extrapulmonary sites of infections with R. equi does what to the prognosis?
Significantly reduces it.
How to localize a pulmonary nodule in a horse?
Take both laterals to see where the lesion is clearer
Pulmonary abscess are most commonly detected in what lung lobes?
Caudodorsal
Pulmonary abscesses are predominantly seen in what age group?
Foal 6 month or younger
Foals with what type of pulmonary pattern distribution have significantly higher mortality rates?
Diffuse or caudodorsal
Inflammatory airway disease and recurrent airway obstruction (RAO) can be distinguished radiographically how?
They can’t
What is the most common radiographic changes with RAO and inflammatory airway disease is?
Nothin… commonly normal radiographs
Radiographs are used for ruling out things.
What is different between recurrent airway obstruction and lower airway disease of other species?
RAO does not normally create pulmonary hypertension due to its intermittent nature
Best modality to evaluate the ribs for fractures in horses?
US and CT
Are radiographs a good indicator of clinical signs in horses with exercis-induced pulmonary hemmorrhage?
No… they can have no rad signs and look like shit, or a ton of rad changes and look fine.
Where are lung changes always seen with exercise-induced pulmonary hemorrhage?
Caudodorsal
Can pleural fluid be seen with exercised induced pulmonary hemorrhage?
Yes
Most common reason for a nodular pattern in a horse?
Abscessation
What is the most common cause of pleural fluid in a horse?
Extension of bacterial pneumonia
Why do horse not create pleural fissure lines with pleural effusion?
Anatomy. Horses lack prominent interlobar fissures.
Approximately how much pleural effusion is needed to be seen on radiographs in a horse?
1-2L
On US, if pleural effusion is just in the ventral thorax how much fluid is present?
0.5L
On US, if pleural effusion is to the point of the shoulder how much fluid is present?
1-2.5L
On US, if pleural effusion is 5-7cm dorsal to the point of the shoudler how much fluid is present?
5L
What is the most common thoracic neoplasia in a horse?
Lymphoma
Tracheal collapse is most common in what breed of horse?
American miniature horses
What percentage of American miniature horses have collapsing trachea?
6%
Aortic-cardiac fistulas are common in?
Stallions
Where in the aorta are most aortic-cardiac fistulas located?
Right aortic sinus
Where is a aortic-cardiac fistula commonly located in the heart?
Right atrium or ventricle
Dissecting the myocardial spetal wall
What nerve is responsible for laryngeal hemiplegia (causing roaring)?
LEFT recurrent laryngeal n which wraps around the aorta
How can enlarged lymph nodes cause roaring?
Left TB ln can cause pressure on the LRL n. causing degeneration.
How many pairs of ribs do horses have?
18 pairs
What is the major coronary artery in a horse?
the right… the dog is opposite
what is the conus arteriosus?
The ouflow portion of the right ventricle that gives rise to the pulmonary trunk.
Presence of comet tail artifacts in the caudodorsal lung on thoracic ultrasound has what sensitivity and specificity for induced pulmonary hemorrhage?
Sensitivity - 85.8%
Specificity - 25.7%
