Sudden death in Companion Animals

Question 1

How is sudden death defined?

Answer 1

• sudden death by definition means a death by natural causes, excluding severe acute trauma, stabbing, gunshot, toxicity etc
• Was fine a few moments ago, now dead (<60 min)

Question 2

What are the acute death systems?

Answer 2

• Cardiac/cardiovascular
• CNS (CVA and seizures)
• Respiratory

Question 3

What are the sudden death systems?

Answer 3

• Gastrointestinal
• Coagulation

Question 4

Will failure of an organ system or acute loss of function always lead to death?

Answer 4

• If left untreated, failure of any organ system is likely to eventually result in death, but acute loss of function does not always mean acute death

Question 5

How is acute/peracute death defined?

Answer 5

Was fine a few moments ago, now dead (<60 minutes)

Question 6

What are the main causes of acute death in dogs and cats?

Answer 6

• Cardiovascular (~30%, varying aetiologies, dogs and cats)
• Gastrointestinal (~20%, GDV, viral enteritis, intestinal torsion)
• Toxicity (~12%, various)
• Trauma (~10%)
• Respiratory
• CNS (CVA)

Question 7

What are bouts of synocope a warning sign of?

Answer 7

Acute cardiac death

Question 8

What is an atioventricular block?

Answer 8

• Disorder of transmission of electrical impulses from the atria to the ventricles via the atrioventricular node

Question 9

What are the three degrees of atrioventricular blocks?

Answer 9

• 1st: Delay of conduction, but consistent delay
• 2nd: Progressive slowing then reset
• 3rd: Complete loss of conduction

Question 10

What are the treatment options for an atrioventricular block?

Answer 10

Pacemaker, can be controlled with drugs in the short term but they show little effect

Question 11

What is sick sinus syndrome?

Answer 11

• acute, intermittent arrhythmia that can lead to sudden death
• Sinus arrhythmias / bradycardia
• Periods of sinus arrest
• Paroxysmal supraventricular tachycardia / alternating bradycardia
• Often associated with syncopal episodes, may be misinterpreted as seizures

Question 12

How is sick sinus syndrome treated?

Answer 12

Pacemaker implantion

Question 13

Is mesenteric torsion a potential cause of sudden death? What is it?

Answer 13

• Yes it is a cause of sudden death
• Rotation of intestines, spleen etc around the mesenteric root
• Typically preceded by GIT signs

Question 14

What are some other GIT causes of sudden death?

Answer 14

• Gastric dilation and volvulus (GDV)
• Severe acute enteritis (Volume loss and venous sequestration reduces cardiac output)

Question 15

What is the treatment options for mesenteric torsion?

Answer 15

• Euthanasia
• Even with surgery, it is usually terminal

Question 16

What are some causes of actue volume loss or cardiac failure? Give some specific examples

Answer 16

• Acute bleeding from intraabdominal tumour - haemangiosarcoma in spleen or liver
• acute bleeding into pericardial space (cardiac tamponade, haemangiosarcoma)

Question 17

Between cadiovascular failure and gastrointentnal causes of sudden death, which is more likely to have a better outcome?

Answer 17

• The cardiovascular failure mechanisms are more likely to cause death before presentation to a veterinarian - collapse to death within minutes
• The gastrointestinal accidents are potentially treatable if recognised and treated early and aggressively - NOTE: Bloating in dogs is an ASAP problem