PATHOLOGY - Sudden Death in Youngstock Cattle Flashcards
What are the differential diagnoses for sudden death in cattle?
Anthrax
Clostridium chauvoei
Clostridium sordelli
Electrocution (inc. lighting strikes)
Ruminal bloat
White muscle disease
Acute trauma
Plant toxicity
Why is investigating sudden death in livestock so crucial to one health?
Investigating sudden death in livestock is crucial as sudden death can be caused by anthrax which is both a notifiable and zoonotic disease.
Which disease is caused by clostridium chauvoei?
Blackleg
What are the characteristics of clostridium chauvoei?
Large, gram positive, anaerobic rod
What is the pathogenesis of blackleg?
Blackleg is an infectious, non-contagious disease caused by clostridium chauvoei. Animals ingest the bacterial spores when grazing. The spores penetrate the intestinal wall, enter the bloodstream and travel to the skeletal muscle where they will remain dormant. Following an event that causes anaerobic conditions within the tissue (such as bruising or damage to the muscle), the bacterial spores will germinate, multiply and produce protease toxins resulting in muscle necrosis and haemorrhage
Which signalment is typically affected by blackleg?
Animals between 6 months to 2 years old, tend to be in good body condition but have muscle trauma (this is a key indicator)
Why might heifers be at increased risk of blackleg?
Heifers are at increased risk of blackleg due to bullying behaviours
Which factors are typically associated with increased incidence of blackleg?
Permanent pasture
Soil disturbance
Wet weather
Within 4 weeks of turnout
Remember permanent pasture is pasture that has been layed down but not ploughed for years
Why does soil disturbance and wet weather increase the prevelance of blackleg?
Erosion of the soild due to disturbance or flooding can increase the exposure of grazing livestock to soil-borne bacterial spores (such as clostrida AND anthrax)
What is the most common clinical presentation of blackleg?
Sudden death
What are the potential clinical signs of blackleg if the animal presents alive (rare)?
Severe depression
Anorexia
Pyrexia (usually severe, more than 41°C)
Tachycardia (due to pain)
Tachypnoea (due to pain)
Ruminal stasis
Lameness
Hot, painful, swollen muscles
Convulsions (due to toxicaemia)
How can you diagnose blackleg?
Post mortem (PM)
What are the typical post mortem (PM) findings for blackleg?
Necrotic/congested/blackened muscle
Subcutaneous oedema
Subcutaneous emphysema
Distinctive sour odour
How can you treat blackleg?
Penicillin (preferably IV)
Analgesia
Supportive care
How can you prevent blackleg?
Clostrial vaccinations
Remember clostridial vaccines are two doses
What are the typical post mortem (PM) findings for clostridium sordelli?
Abomasitis
Oedema and emphysema in the abomasal wall
If there is sudden death but no sign of blackleg, check the abomasum
What should you be aware of when broaching a potential electrocution case?
Be careful of any stray voltage that could cause you harm
What is the key indicator of sudden death due to electrocution?
Livestock are in close proximity to a source of electricity or these was history of a lightning storm
What are the typical post mortem findings for electrocution?
Singe marks
Congestion
Ingesta in the mouth
Normal rumen content
How can ruminal bloat cause sudden death?
Ruminal bloat can cause compression of the diaphragm resulting in severe respiratory distress and death
What causes white muscle disease?
Which muscle disease is caused by selenium and/or vitamin E deficiency
What is the pathogenesis of white muscle disease?
White muscle disease is caused by selenium and/or vitamin E deficiency, both of which are crucial for the production of the antioxidant glutathione peroxidase which neutralises free radicals in the muscle tissue. Without this antioxidant, the free radicals (i.e. lactic acid) will cause oxidative damage to the muscle tissue, especially muscle associated with high metabolic activity such as the heart and skeletal muscle (particularly in the limbs). The damage to the cardiac muscle results in sudden death
What is the typical clinical presentation of white muscle disease?
Sudden death
Severe lameness
Why is white muscle disease associated with turnout?
White muscle disease is associated with turnout because animals grazing on selenium and vitamin E deficient pastures are at risk of developing the disease. Furthermore, when animals are turned out they will exercise more, increasing metabolic demand, free radical production and thus muscle damage
Usually seen within 4 weeks of turnout
How can you treat white muscle disease?
Injectable selenium and vitamin E
Which plant toxicities can cause sudden death?
Yew
Rhododendron
