10. Metabolic diseases in ruminants Flashcards
Metabolic diseases in cattle?
Milk fever
downer cow syndrome
Grass tetany
Metabolic osteopathies
rickets
osteomalacia
osteoporosis/osteopenia
osteodystrophia finrosa
spastic paresis
Occurence of milk fever?
Occurrence
- high producing, adult dairy cows (mainly in 5-10 years of age)
- Immediately after calving (1-3 days)
Cause of Milk fever?
Cause
- Increased neuro-muscular irritability (hypocalcaemia, hypophosphatemia)
- Simultaneous hypermagnesemia (rarely normo- or hypomagnesemia)
Pathogenesis of milk fever?
Pathogenesis
- Relative/absolute hypoparathyroidism
- Loss of mobilizable Ca-stores in bones (age)
- Decreased Ca- absorption from GI tract
- Increased Ca-excretion with decreased Mg-excretion in milk
Clinical signs of milk fever?
Clinical signs
• Sternal, later on lateral recumbency, (tetany), opisthotonos, coma
Frequent consequences of milk fever?
Frequent consequence –
• ‘Downer cow’ syndrome (remember the George formula)
§ Introductory phase: semi-comatose state. Sitting like a frog
Diagnosis of milk fever?
Diagnosis:
- Ca-test (whole blood) – semi-quantitative test
- Sulkowitch probe
§ Composition
§ Hypothesis
§ Normocalcemic cow excretes calcium via urine, precipitating in the presence of oxalic acid,
hypocalcaemia cow excretes Ca (hypocalciuric), therefore less/no precipitation is present
§ Procedure of the Sulkowitch test
§ Equal volume urine and reagent mixed, after 3 min - the amount of precipitate is evaluated
§ Evaluation:
§ -/+ (no Ca/hypocalciuric = most probable hypocalcaemia)
§ - ++ (normocalciuria, hypocalcaemia rare)
§ - +++ (normo/hypercalciuria, hypocalcaemia can be excluded)
Measurement of blood Ca?
Measurement of Blood Ca
- Total vs ionised calcium (tCa vs iCa)
- Total calcium fractions in the sera:
o Ionised Ca
o Albumin binded Ca
o Other proteins binded Ca
o Anion complex binded Ca
• Effecting of the fractions:
o Blood pH
o Blood albumin concentration
o Other proteins in blood
• The ratio of the ionised Ca changes 3-5% compared to total Ca as days going on after calving in the first 5
days
Course of treatment?
Course
• regularly good response to Ca-therapy (except: atypical forms, downer cow syndrome) calcium paste system
(300g): 2-6hours give CaCl2 61% and MgCl2 2% or 5-7hours Ca-propionates 88%
Treatment of milk fever?
Treatment
• Ca-borogluconate 25% solution IV and SC 100-120 ml/100kg IV SLOWLY also Surcalce, tetanus and primalen
is used to treat!
• Calcium paste system (300G)
Prevention of milk fever?
Prevention
- P-rich, Ca-poor diet before calving, vit D3 injection, 1 million unit IM before calving
- This condition rarely occurs in sheep (before lambing) and in goats (after parturition)
- Avoid Paravenous Ca-infusion, it causes (para)-phlebitis, severe tissue necrosis
o Recovery after 2 weeks, affected jugular vein is necrotized and lost
Downer cow syndrome info?
Atypical milk fever: downer cow syndrome
- Always there is a primary cause
- Animals staying recumbent after 24 hours of the calving
- Cattle do not stand out long lasting recumbency well
- After a short time degenerative alterations occur in the musculoskeletal system
- Secondary musculoskeletal disorders can cause long lasting recumbency
Pathogenesis of downer cow?
Pathogenesis
- Long-term lateral recumbency > muscle compression, ischemia, hypoxia, necrosis, (inflammation) –
- Compression of the nerves as well (N. ischiadicus, N. peroneus)
- Repeated efforts to get up > rupture of muscles, hematoma
Occurence and incidence of downer cow?
Occurrence
- Usually periparturient
- But anywhere in lactation
Incidence
- 2-5% of the herd
- 20% around calving time
Definition of downer cow?
Definition
- Primarily disorder of (hind) limb muscles (extensors)
- Due to their ischemia myodegeneration, necrosis develops.
- Ischemia is caused by permanent compression
- Similar myodegeneration occurs in human after long-term strangulation of the limbs (tourniquet-paralysis)
