Milk Fever!!

Question 1

hypocalcemia signalment

Answer 1

older dairy cows with dystocia

Question 2

hypocalcemia physiology

Answer 2

1. recumbency: calcium required for muscles to work
2. immune- suppression: leukocytes need calcium as important enzyme co-factor
3. decreased smooth muscle activity: at a Ca of 7, reduced uterine and abomasal activity by 30%, at a Ca of 5 reduced by 70%
4. Reduced DMI: hard to eat if weak or sick

Question 3

hypocalcemia presentation and dx

Answer 3

clinical presentation is a cow in recumbency with muscle paresis within 48 hours of calving or parturition. Dz is based on clinical signs

Question 4

hypocalcemia tx and prevention

Answer 4

Tx with calcium IV and PO, the IV will help for 6 hours but oral will help long term

prevent with dietary cation anionic difference diet

Question 5

hypocalcemia causes __ in bovine while it causes tetany in muscles in canines

Answer 5

flaccid paralysis with a low to normal temperature

Question 6

what can hypocalcemia cause in horses?

Answer 6

synchronous diaphragmatic flutter thumps horse hiccups for every heartbeat

Question 7

what can hypocalcemia cause in small ruminants?

Answer 7

parturient paresis - last few weeks of gestation, often concurrent with pregnancy toxemia (ketosis)

Question 8

hypercalcemia is __ in large animals

Answer 8

uncommon

Question 9

tx of hypophosphatemia

Answer 9

oral supplementation of phosphate, reformulate the diet

Question 10

causes of hypophosphatemia in all LA

Answer 10

starving/chronic wasting dz

Question 11

causes of hypophosphatemia in ruminants

Answer 11

periparturient transient hypophosphatemia
- high yield diary cows -> increased loss in colostrum at calving -> decreased feed intake around calving -> decreased GI motility due to hypocalcemia
- tx with PO monosodium diphosphate

post parturient hemoglobinuria
post-renal azotemia due to urolithiasis

Question 12

causes of hypophosphatemia in equine

Answer 12

chronic renal failure (increases calcium from decreased renal excretion, decreased phosphate)

Question 13

hyperphosphatemia in ruminants v equine

Answer 13

ruminants: dehydration

equine: nutritional secondary to hyperparathyroidism “Big head/Big brain disease”

Question 14

magnesium is not controlled by __

Answer 14

any hormone

Question 15

hypomagnesium signalment

Answer 15

beef on lush, immature grass pasture or those in the winter only eating grass hay

Question 16

hypomagnesium physiology

Answer 16

• magnesium is absorbed from the rumen/reticulum and large intestine
• increases with decreased blood pH and ionophores in the diet
• decreases with increased K+, decreased Na+, increased pH

milk, bile, gastric juices and saliva all req mg in ruminants

Question 17

hypomagnesium presentation and dx

Answer 17

• muscle fasiculations
• ataxia
• recumbency
• tetany
• seizures and other neuro signs
• death
• tachycardia
• tachypnea
• fever

Question 18

hypomagnesium treatment

Answer 18

• IV Mg or Mg enema if paddling/aggressive
• oral supplementation of the whole herd

must do both to prevent recurrence, IV Mg only fixes the problem for about 6 hours

Question 19

hypomagnesium prevention

Answer 19

• High magnesium mineral to cows when in lush pasture
• good energy supplementation at all times
• regular mineral supplementation at all times

Question 20

synchronous diaphragmatic flutter in horses

Answer 20

caused by electrolyte/mineral imbalances (hypocalcemia and hypomagnesmia) which made the phrenic nerve depolarize with the adjacent myocardial contraction (hiccup every heartbeat)

Question 21

phosphate metabolism and regulation in ruminants

Answer 21

• lots of phosphate is excreted into saliva, which is then reswallowed and reabsorbed
• phosphate is lost/excreted into milk, urine and feces