hoof revision and disease

Question 1

define keratinisation

Answer 1

Question 2

define cornification

Answer 2

Question 3

Define horn

Answer 3

Question 5

label the hoof capsule and corium

Answer 5

Question 6

Label the hoof capsule and corium

Answer 6

Question 7

Describe the composition of the hoof

Answer 7

Question 8

Describe the arterial supply to the equine foot

Answer 8

3 zones for blood supply:
proximal dorsal - via branches from digital arteries, supplies coronary band
Distal dorsal - via palmar/plantar digital arteries
Palmar supply - via branches from palmar digital arteries to heel bulbs, part of sole and frog

Question 9

Describe the venous drainage of the equine hoof

Answer 9

satellite veins (parallel to arterial supply)

Question 10

Why is the venous drainage of an equine hoof important in laminitis?

Answer 10

many arterio-venous anastomoses can divert blood away from corium
this exacerbates ischeamia and tissue damage, impaired blood flow and oxygen supply to corium contributes to pain and progression of laminitis

Question 11

How is horn/hoof produced?

Answer 11

• basement membrane and dermis form elongated dermal papillae at coronary band
• basal cells produce keratinocyes as usual, which become squames
• keratin squames glued together to form tubules
• tubules glued together by intertubular horn to form hoof/horn
• hoof slides over/between dermal lamella
• takes 12-15 months for hoof to grow from coronary band to ground

Question 12

What do the perioplic and sole dermis do in hoof/horn production?

Answer 12

Perioplic dermis - produces a thin, waxy, waterproof cover
Sole dermis - produces sole at same rate as coronary dermis

Question 13

Describe the anatomy of the coronary band/corium

Answer 13

Question 14

Label this diagram of hoof growth

Answer 14

Question 15

Describe the epidermal lamellae of the equine hoof

Answer 15

Question 16

Describe the dermal lamellae of the equine hoof

Answer 16

Question 17

What is the role of the dermis and epidermis in the hoof?

Answer 17

Dermis - blood, nerve supply
Epidermis - protection, hoof formation

Question 18

Label the dermis and epipdermis of the claw/hoof

Answer 18

Question 19

Describe the dermal epidermal junction and how this relates to horn growth

Answer 19

Horn (epidermis) slides over corium
Corium (dermis) attached to P3
These layers interdigitate

Question 20

What is secondary lamellae in the equine hoof?

Answer 20

increases area of basement membrane, increases strength of dermal-epidermal bond

Question 21

What is the function of secondary lamellae in the equine hoof?

Answer 21

This ensures structural integrity, distributes weight, absorved shock, stabilises coffin bone, facilitates blood flow, protects against injuries and infection

Question 22

How are hemidesmosomes linked to laminitis?

Answer 22

hemidesmosomes break down in laminitis as the basement membrane breaks down

Question 23

what are MMPs and TIMPs?

Answer 23

MMP = matrix metalloproteinases - enzymes that break down and remodel ECM in tissues
TIMPs - natural inhibitors that help control the excessive degradation of the ECM by MMPs