Bovine Ketosis (Acetonaemia)

Question 1

bovine ketosis takes how long to develop? What is its common sign?

Answer 1

• 2-4 d to dvlp, rapid reduction in milking

Question 2

bovine ketosis is a dz of

Answer 2

lactating cows

Question 3

characteristics of bovine ketosis

Answer 3

• marked fall in milk yld
• rapid wt loss
• selective inappetence
• ketonaemia
• ketonuria
• positive milk test

Question 4

Clinical ketosis is an

Answer 4

iceberg problem

Question 5

Clin morbidity

Answer 5

1-5%

Question 6

clin mortality

Answer 6

• low
• Self-limiting subclin infections

Question 7

Occurrence of ketosis reflects

Answer 7

pathogenesis

Question 8

Type I ketosis

Answer 8

• 4-6 wks post-calving
• peak lactation but demand too high to keep up

Question 9

Type II ketosis

Answer 9

• 1st 2-3 wks post-calving
• overconditioned prior to calving
• not managed appropriately prior to lactation

Question 10

Explain normal energy balance in ruminants

Answer 10

Question 11

Explain ketogenesis in ruminants

Answer 11

Question 12

What is the limiting step of ketogenesis in ruminants

Answer 12

• propionate - slows/stops TCA activating alternative pathway that is less efficient

Question 13

Energy balance in Ruminants

Answer 13

• v. little diet carbs absorbed as hexose
• rely on gluconeogenesis to generate glucose from precursors
• most important precursor: propionate -> proportion depends on diet

Question 14

ketosis in ruminants

Answer 14

• primary ketosis = Type I/II
• secondary ketosis = assoc’d w/ a primary illness
• Alimentary ketosis = butyric acid changed to BHB due to poorly fermented silage
• Starvation ketosis (uncommon) - no access to feed
• Ketosis due to specific nutritional def (Cobalt)

Question 15

Risk Factors

Answer 15

• Age? 1st lactation and older at highest risk
• BCS at calving - overconditioned
• Dry period length > 60 d
• XS protein in prod’n ration
• ‘bidirectional’ association w/ other metabolic/prod’n/transition dz’s (milk fever, RFM, lameness, hypoMg)

Question 16

Ketosis predisposes to…

Answer 16

RFM

Question 17

Subclin ketosis

Answer 17

• cows in NEB in early lactation
• Ketonuria present, NO obvious dullness
• reduced milk yld
• reduced lvls of milk protein
• increased incidence of endometritis (immunocompetence mediated)
• infertility

Question 18

Primary ketosis types

Answer 18

• Dull wasting form (main presentation)
• nervous form

Question 19

Dull wasting form presentation

Answer 19

• decreased milk yld over 2-3d
• selective inappetence
• marked wt loss
• decreased ruminal-reticular activity
• heart sounds prominent on rumen auscultation in PLF
• ketones on breath/in milk

Question 20

DDx to dull wasting form

Answer 20

• indigestion
• LDA/RDA/fatty liver syndrome
• traumatic reticuloperitonitis
• pyelonephritis
• DM

Question 21

Nervous form signs

Answer 21

• XS licking everything
• rapid compulsive chomping/chewing
• hyperaesthesia, twitching
• behavioural changes
• startle easily

Question 22

Nervous form DDx

Answer 22

• Stage 1 hypoCa
• Subacute HypoMg
• BSE
• Rabies
• Pruritic conditions

Question 23

Clin path signs

Answer 23

• Ketonaemia
• ketonuria (BHB, acetone, acetoacetic acid)
• milk ketones (not super sensitive)
• Hypoglycaemia
• +/- increased NEFAs

Question 24

Primary ketosis txt

Answer 24

• Replacement therapy: 400 ml 50% glucose IV
• Glucose precursors: propylene glycol PO 225 g BID for 2 d, then 110g/d SID for 2d
• corticosteroids (controversial - gluconeogenic & repartitioning effect) + IV glucose
• B vitamins - Cobalt/Vit B12

Question 25

Control

Answer 25

* BCS mgmt * dry period manipulation * transition cow mgmt * OAD milking