Bovine Limb

Question 1

Bovine lameness

Answer 1

• Very common in dairy cows; due to cows being on concrete
• Vets job to fix lame cows and prevent other cows going lame

Question 2

Why do Cows go lame?

Answer 2

• Degenerative processes and infection
• Not overuse or trauma like horses

Question 3

What area is most important in the bovine leg?

Answer 3

• More than 95% of clinical conditions affect the last 3 inches of the bovine limb
• Lameness in the proximal limb are rare and very bad… we are not going to be able to fix it

Question 4

Key to fixing distal bovine limb

Answer 4

You always have a spare! Another toe.

Ex. Glue plastic block on good toe, will raise up enough to rest other toe

Question 5

Bovine skeleton

Answer 5

• Separate P1, P2, and P3
• MC/T III and IV
• Proximal sesamoids
• Distal sesamoids

Question 6

Bovine Joints

Answer 6

1. Carpus/tarsus
2. Fetlock (metacarpal/tarsal phalangeal joint)
   o 2 metacarpal joints surrounded by 1 synovial joint
3. Proximal interphalangeal joint
4. Distal interphalangeal joint

Question 7

Distal interphalangeal joint

Answer 7

Most important joint; most prone to damage

Question 8

Bovine muscles of leg

Answer 8

Most important muscles are in the back of leg
- Superficial digital flexor (SDFT)
- Deep digital flexor (DDFT)
- Suspensory ligament

Question 9

Bovine muscles and hyperextension

Answer 9

• All of the joints are trying to hyperextend the limb
• SDFT and DDFT, interosseus muscle preventing this hyperextension

Question 10

Deep digital flexor tendon

Answer 10

• Inserts deep into the bottom back of the leg
• Keep everything stable

Question 11

Necrosis of DDFT

Answer 11

• Clinically called “knocked up toe”
• If toe is not touching ground, means the DDFT is torn but the cow can just stand on the other toe

Question 12

Blood vessels and Nerves in the bovine leg

Answer 12

Almost everything important is on the back of the leg. There is a bundle of vessels and nerves on the back of the leg, and a laceration there can be detrimental.

Question 13

Important components of the bovine foot

Answer 13

Hoof which includes the wall and the sole

Question 14

Hoof wall

Answer 14

Full of tubules, very strong

Question 15

Hoof sole

Answer 15

Less tubules and more matrix which is why it is the softer part of the hoof

Question 16

Where does hoof grow from?

Answer 16

Grows from the coronary bone

Question 17

White line

Answer 17

• Point where the sole meets the wall
• Composed only of matrix which makes it the weakest part of the foot

Question 18

White line disease

Answer 18

Cow walking on gravel, the debris can break down the white line and reach the dermis (corium) which is where abscesses occur

Question 19

Movement of abscesses in bovine

Answer 19

• Progress horizontally
• If they burst, it will typically occur at the heel
• Complications are rare because the dermis (corium) is a very good defense system. Infection enters but is stopped by the dermis which forces it to move horizontally.

Question 20

Ungulate standing position

Answer 20

Weight is transferred to P3, and the connection with the laminae allow for weight transfer to the hoof wall. The dermis (cornium) and the hoof wall are extremely strong allowing the P3 to hang inside the hoof capsule.

Question 21

Founder

Answer 21

• Laminae start to fall apart. P3 is no longer hanging inside and is instead sinking into the sole
• Very detrimental to cow

Question 22

What part of the foot does most of the weight bearing in cows?

Answer 22

• Most of weigh bearing done by the frog and wall
• Sole does very limited work.

Question 23

Two ways that infection can bypass the cornium (dermis)

Answer 23

1. Foot rot
2. Sole ulcers

Question 24

Foot Rot

Answer 24

• Infection of the fat pad found between the digits
• There is a pouch of the joint in this area which can allow infection to enter the foot and bypass the dermis (cornium)

Question 25

Sole Ulcers

Answer 25

• A hole in the sole
• Not considered an abscess
• Erosion of heel, overgrowth of toe

Question 26

Steps of sole ulcer formation

Answer 26

• Happens due to weight bearing on concrete. Toe continues to grow and becomes too long, causing the weight to be transferred back onto the heel.
• Weight shift causes the dermis (cornium) to be pinched causing damage to blood vessels which causes damage, breakdown, and death of the cornium
• Without cornium, the horn will not grow and there will be a hole forming from the inside outwards
• No cornium results in no protective barrier so infection persists.

Question 27

How to fix sole ulcers?

Answer 27

Amputation (3 ways)
1. Remove low P2
2. Disarticulate PIPJ
3. remove low P1
** must ensure cutting below artery

Question 28

Surgical anesthesia

Answer 28

• Nerve blocks difficult, easiest method is intravenous regional anesthesia (IVRA)
• In IVRA, use tourniquet around lower cannon, lidocaine in dorsal vein, and blocks entire area
• Amputate parallel to the coronary band (cut where there are hair follicles because not any hair on band)