Ewe Periparturient Diseases Flashcards
List periparturient diseases of the ewe
Hypomagnesaemia
Pregnancy toxaemia
Hypocalcaemia
Describe the aetiology of pregnancy toxaemia
Caused by inadequate energy intake, excessive energy usage
Rumen size decreases due to increased uterine size and energy demand increases due to foetal requirements.
Insulin levels and sensitivity are altered, ability to metabolise ketones in late pregnancy decreases
Occurs from 4 weeks before to lambing
Describe the clinical disease of pregnancy toxaemia
Primary disease = hypoglycaemic encephalopathy which is initially reversible. Later this is compounded by hyperketonaemia and ketoacidosis.
What are the clinical signs of pregnancy toxaemia?
Inappetant Dull Weak Lethargic Blin, incoordination, head tilit, head pressing, star gazing, tremor/convulsions Depression Recumbency Death
What biochemical changes would be expected in pregnancy toxaemia?
Low glucose (3) High urea Low calcium High liver enymes Low insulin High growth hormone
How is pregnancy toxaemia treated?
IV glucose Glucogenic precursors - propylene glycol into rumen IV Ca FT Treat any concurrent disease Remove/abort/caesar lambs
How can pregnancy toxaemia be prevented?
Group ewes according to litter size and BCS, metabolic profiling
How does subclinical pregnancy toxaemia present?
Low lamb birthweight and vitality
Decreased mothering ability
Decreased colostrum quality
Describe the aetiology of hypocalcaemia
Demand exceeds supply, increased demand for foetal bone development
Decreased feed intake
Associated with stress
Occurs 4 wks before to 1 week after lambing
What are the clinical signs of hypocalcaemia?
Early - staggering, weakness, tremors, sluggish PLR, tachycardia
Late - tachypnoea, recumbency, death
How is hypocalcaemia treated?
IV Ca
Subcut Mg
May need repeat tx
How can hypocalcaemia be prevented?
Avoid stress late in gestation, adequate dietary Ca, supplement if only feeding root crops and cereals.
Describe the aetiology of hypomagnesaemia
Lack of available Mg and absence of readily mobilised Mg store due to ineffective homeostatic mechanisms (+/- hypocalcaemia)
Seen in peak lactation and from 2 wks prior to lambing to 6 weeks post.
What are the risk factors for hypomagnesaemia?
High patassium in grass
Rapidy growing grass (decreases gut transit time)
Cold/wet/stressful weather
Lactating ewes with twins
What are the clinical signs of hypomagnesaemia?
Sudden death Anxiety Hyperaesthesia Tachycardia Unsteady, staggering Blindness, nystagmus Recumbency +/- paddling Opisthotonus Hypersalivation
