Section 2: Metabolic Diseases of Ruminants: Laminitis (Donovan)

Question 1

Typical PE of cows with laminitis

Answer 1

swelling above coronary band (20%)
thin soles (55%)
white line separation (25%)
wall cracks/erosions (20%)
subsolar abscesses (40%)
secondary trauma to hocks

Question 2

laminitis

Answer 2

diffuse, aseptic inflammation and degeneration of metabolic origin affecting the sensitive laminae of the foot

Question 3

junction b/w corium and horn of hoof is called:

Answer 3

dermal-epidermal junction

Question 4

4 categories of causes for laminitis

Answer 4

1) nutritional
2) environmental
3) animal
4) infectious

Question 5

environmental causes

Answer 5

• excessive solar wear

- excessive wetness

Question 6

what is the weight-bearing surface of cow’s feet?

Answer 6

the WALL

Question 7

animal causes

Answer 7

• inherited factors
• low exercise
• unbalanced weight
• behavioral chars.

Question 8

infectious causes

Answer 8

• endotoxemia

- high fever

Question 9

nutritional causes

Answer 9

• excessive feeding of energy/protein during peripartum
• low dietary fiber
• slug feeding

Question 10

how does feeding lots of soluble CHO cause laminitis? **

Answer 10

rapid ferm. in rumen –> decrease rumen pH –> release of endotoxins and histamine –> vasoconstriction –> laminitis and respiratory signs

Question 11

process of dermal-epidermal jx separation

Answer 11

1) vasoconstriction of corium
2) hypoxia of corium
3) inflammation of corium
4) swelling/hemorrhage in corium

Question 12

acute laminitis clinical signs (uncommon)

Answer 12

-feet sensitivity
-reluctance to move
-arched back
-digital puls
-swelling above coronary band
-sinking of pedal bone
-listless
+/- fever
-decreased milk prod.

Question 13

subclinical laminitis is common!

Answer 13

:)

Question 14

chronic laminitis clinical signs

Answer 14

• abnormal horn growth
• white line sep.
• subsolar absess
• sole ulcer at insertion of flexor tendon (result from pinched corium no longer producing horn) *
• septic arthritis
• 2ary trauma hocks and carpi

Question 15

tx for acute laminitis

Answer 15

rumen buffers, antihistamines, corticosteroids, NSAIDs, comfortable footing, control infections/toxemia

Question 16

tx for chronic laminitis

Answer 16

-get off concrete
-correct foot trimming
-pare out ulcers/abscesses
-block foot
+/- bandage feet, antibiotics, claw amputation
-cull

Question 17

most expensive disease of cows

Answer 17

sole ulcers

Question 18

laminitis prevention *

Answer 18

• avoid sudden feed changes
• maintain adequate fiber (>22% EffNDF **)
• feed TMR
• avoid finely chopped feeds
• avoid acidotic rations
• add buffers to ration
• adjust cattle to concrete surfaces
• keep feet dry as possible

Question 19

how much weight on cow’s back feet?

Answer 19

65%!