Metabolic dx of sheep Flashcards
Describe the timelines of the conditions we are going to discuss
What is ‘Milk Fever’?
Hypo calcaemia
When do we see hypoCa?
- Most commonly BEFORE lambing in heavily pregnant ewe
- Inc in need of Ca from ewe
What causes inc Ca rq?
- Bone development of lamb
- Ca storage in lamb for further bone development
- Greatest demand bc mineralization in lamb 1-3 wk prepartum
- Ewe metabolizes 20% of her bone Ca in pregnancy and lactation
Reduction in digestion of Ca -> de rumen capacity
What are the risk factors to HypoCa?
- Older animals >3rd parity
- Pregnancy with multiple foetuses
- Other diseases causing reduced feed intakes
- Management that reduces feed intakeshousing ewes/movement of ewes 1-3 weeks prepartum
- Feed low in calcium- lush growing grass, cereals
- Feed high in oxalates like beets precipitate with calcium making it unavailable
- Inadequate replenishment of calcium in recovery from lactation
CLS of HypoCa?
- Rapid deterioration
- Ataxia
- Weakness
- Muscle tremors
- Recumbency
- ruminal stasis and bloat
- Salivation
- TachyP & tachy C w/ dec sounds
- Delay in parturition or dystocia due to uterus inertia
Death 48-72h
Diagnosis of HypoCa?
- History
CLS - Serum Ca levels
Post M = aqueosu humour - Serum Ca <2mmol/L (normal 2.8-3.2)
Tx for hypoCa?
- 20ml 40% IV admin of calcium borogluconate
- Admin slow (monitor HR & reduce poss arrythmias
- S/C admin of Ca
Oral supp?
Prognosis?
- Immediate, rapid resp to IV tx
- Simple early-stage dx recover well
- Often linked with hypoMg/ preg tox
- Recumbency ass w/ poor pg
Prevention?
**- Sufficient provision of Ca in diet **
- Minerals mixed in cereal based diets
- Provide concentrate pellet incl Ca
- Supp of Ca for animals on pastures with lush rapid grass growth
- Avoid feeds high in oxalates ex: beets
- Supp animals >3rd parity
- Lick supp
- Reduce husbandry practices that reduce feed intakes
- Handling & mov 1-3m prepartum
- Limited trough space in housed animals (15m/ewe forage , 45cm conc)
What is ‘grass taggers’?
Hypomagnesaemia
Role of Mg?
Viral for skeleton & muscle function , enzyme and nervous system function
Sheep cannot store it meaning they rq constant supply & need even more during lactation
What is hypoMg usually secondary to?
- Dec in feed intake (bad wether, transport)
what is rumen absorption of Mg affected by?
high potassium and nitrogen intakes/ low sodium phosphorous intakes -> pastures fertilised with nitrogen (poultry manure)
What other cause to hypoMg?
Lush grass pastures can cause mtabolic alkalosis which can dec availability of Ca & Mg
T/F HypoMg dx progression is rapid?
true
Describe the signs in order of progression
- Hyper-sensitivity
- Ataxia
- Twitching
- Recumbency
- Nystagmus
- Rapid pounding heart
- Seizures
- Salivation
- Leg paddling
- Severe tremors
- Death
Dx hypoMG?
- Based on history and clinical signs
- Treatment response
- Diagnosis needs to be rapid to ensure rapid treatment
- True emergency
- Low serum Mg levels/ Low Mg in vitreous humour sample-post mortem
Tx for hypoMg
- Sedation
- Mg sulphate - should not be given IV alone
- Ca & Mg together 8:1 ratio Ca/ Mg IV bolus
- Subcut Mg Sulfate
- increases blood Mg levels over 6-12 hrs
- Provide dietay intake to prevent relapse
Prevention of hypoMg?
- High risk = late preg & lactation -> supp
- Soluble mg salts added to water
- Concentrate feed high in Mg
- High concentrate boluses lasts 4-8 weeks
Describe Pregnancy Toxaemia?
- Pregnancy- late gestation
- Inadequate nutritiion -> energy density & reduce capacity of rumen
What does pregnancy tox cause?
Hypoglycaemic encephalopathy
concurrent hypoCa & fatty liver is common
Risk factors to twin lamb dx?
- Poor condition ewes
- Over-conditioned ewes
- Twin pregnancy
- Ewes on fast growing wet pasture
- Suden extreme weather
Describe pathogenesis of pregnancy tox?
