milk fever (hypocalcaemia) in cows

Question 1

what is a bull calf

Answer 1

male calf

Question 2

‘Fr/H’ meaning?

Answer 2

Friesian Holstein (typical dairy cow)

Question 3

‘neoplastic’

Answer 3

categorised by abnormal growth of cells/tumour (within disease) - benign or malignant

Question 4

degenerative meaning

Answer 4

worsen/onset with age

Question 5

‘idiopathic’ disease meaning

Answer 5

unknown cause

Question 6

‘vascular’ disease meaning

Answer 6

to do with blood vessels

Question 7

acronym for categorising diseases:

Answer 7

DAMNIT V

Question 8

categorising disease: the different categories (DAMNIT V)

Answer 8

Degenerative –

Anomalous -

Metabolic –

Nutritional –

Infection and/or inflammation –

Traumatic –

Vascular -

Question 9

technical term for milk fever

Answer 9

hypocalcaemia

Question 10

which type of cow is most likely to get milk fever

Answer 10

recently calved dairy cows (most common cause of recumbency)

Question 11

what causes the lack of Ca?

Answer 11

large quantities of Ca diverted to udders for milk production

Question 12

where does hypocalcaemia fall in ‘DAMNIT V’ acronym?

Answer 12

Metabolic

Question 13

why does hypocalcaemia cause recumbency?

Answer 13

prevents (due to no Ca) sliding filament theory:

• lack of Ca
• Ca not able to bind to troponin
• no conformational change in troponin shape
• so tropomyosin remains covering/on myosin binding sites on actin
• = no actinomyosin cross bridges formed
• not able to contract

Question 14

why may issues that seem nutritional (e.g. hypocalcaemia) may in fact be metabolic issue

Answer 14

• sufficient nutrients may be in feed
• but nutrients not absorbed by body/desired areas

Question 15

clinical signs

Answer 15

1. Struggling to move - recumbency
2. Weakness
3. Tuck head into flanks, “s-bend” (especially after just having given birth)
4. Stiff dry faeces
5. Dry muzzle
6. Retained foetal membranes
7. Lack of rumen contractions
   Weak heart sounds

Question 16

diagnosis of milk fever: 2

Answer 16

• Clinical signs (physical examination)
• Clinical pathology (results from samples collected and analysed in lab)

Question 17

why tubes for sampling contain a vacuum:

Answer 17

• To get blood out without air entering.
• Faster – safer
• One-handed – easier to control the tail and be aware.
• Tail vein similar size to jugular vein in a dog.

Question 18

3 reasons why needle-stick injuries are important:

Answer 18

“Needle-stick injuries” = serious
* Disease – HIV, hepatitis
* Can be fatal
Potential faecal contamination from underneath tail

Question 19

treatment:
- Infusing Ca salts into cow
- Best route = I/V (fastest?)
- Bottle of Ca also administered S/C
Administer slowly (bottle 5-10 mins) - why? Rapid can interfere w cardiac rhythm = death

Answer 19

• Infusing Ca salts into cow
• Best route = I/V (fastest?)
• Bottle of Ca also administered S/C
• Administer slowly (bottle 5-10 mins) - why? Rapid can interfere w cardiac rhythm = death

Question 20

Ca solutions (percentages)

Answer 20

20% S/C

40% I/V

Question 21

how to reduce risk of air embolism:

Answer 21

hold bottle upside down at all times (raising/lowering = rate of flow)

Question 22

valve when administering medication:

Answer 22

flutter

Question 23

needle/gauge side

Answer 23

14 or 16G

Question 24

Milk fever as reason for death of CALVES - why?

Answer 24

• Low Ca levels interfere w contraction of uterus (cows ability to strain)
  
  • = delay in calving
  • = death of calf
    = stillborn