Epistaxis in cattle

Question 1

CVCS is a common cause of what clinical signs?

Answer 1

• severe, bilateral epistaxis in cattle

Question 2

Ddx for epistaxis in cattle

Answer 2

Common:
- Caudal vena cava syndrome (CVCS) (substantial and bilateral epistaxis)
- Embolic pneumonia (related to CVCS) (substantial and bilateral epistaxis)
- Trauma (typically unilateral epistaxis)
- Pulmonary abscesses (bilateral epistaxis)
- Thrombocytopaenia (bilateral epistaxis, will be other signs of a bleeding disorder e.g. petechiae)
- Pulmonary haemorrhage (bilateral epistaxis)

Less common, more sporadic or localised ddx:
- Bracken toxicity (causes a coagulopathy and often presents as bilateral epistaxis)
- Rodenticide toxicity
- Nasal foreign body (unilateral epistaxis)
- Miscellaneous coagulopathies (bilateral epistaxis)

Very rare conditions:
- Bovine neonatal pancytopaenia (this isn’t an appropriate ddx for adult cattle as animals with BNP aren’t likely to survive to adulthood)
- Nasal mass (unilateral epistaxis)
- Aspergillosis
- Inherited bovine thrombopathia of Simmental cattle

Question 3

Risk factors for CVCS

Answer 3

• Age – CVCS is rare in animals < 1yr old
• Diet – CVCS is more commonly seen in animals fed high grain or concentrate diet. The recent(ish) change from grass to a diet including barley is also a risk factor.
• Subacute ruminal acidosis (SARA) (scour and tail swishing)

Question 4

Pathogenesis of CVCS

Answer 4

• Subacute ruminal acidosis leads to rumenitis
• This facilitates bacterial translocation from the rumen into the blood stream
• Bacteria that enter the hepatic portal system disseminate to the liver and result in hepatic abscessation
• If there is hepatic abscessation near the caudal vena cava, the vena cava can become eroded and a septic thrombus forms
• Emboli may break away and travel to the lungs, resulting in an embolic pneumonia
• Endocarditismay also occasionally occur
• Pulmonary aneurysms commonly develop following embolic spread to the lungs
• Rupture of pulmonary aneurysms causes epistaxis +/- haemoptysis
• If the aneurysms are small, there may be several mild to moderate episodes of epistaxis
• However, rupture of a large aneurysm can result in fatal haemorrhage and the animal may present as a sudden death

Question 5

Prognosis & tx of CVCS

Answer 5

• Poor prognosis
• Treatment is usually unrewarding
• Euthanasia is usually recommended

Question 6

How does haemoptysis present with CVCS

Answer 6

• melena as blood is being swallowed and digested

Question 7

Diagnosis of CVCS

Answer 7

• Diagnosis of CVCS can be difficult, esp in the early stages of the disease where clinical signs and biochemistry/haematology are non-specific
• Imaging can be helpful and radiography, ultrasonography and endoscopy have all been described
• The CVC can be imaged in the liver from the 11th and 12th intercostal spaces on the right side
• The normal CVC should appear triangular in this ^ image