Cattle

Question 1

Sole ulcer

Answer 1

• Most common in lateral claws of rear feet and medial claws of forelimbs
• typical site = in cerium that overlies the flexor process of the 3rd phalanx
• ulceration at toe tip = most common in extensive grazing diaries
• ulceration at heel-sole junction = secondary to severe interdigital dermatitis

Question 2

Cause of sole ulcer

Answer 2

Over trimming at the toe or from wear that exceeds growth

Question 3

Signs of sole ulcer

Answer 3

Varies from slight haemorrhage visible at trimming to complete absence of a portion of the sole to extensive necrosis of the underlying curium

Question 4

Treatment for sole ulcer

Answer 4

• remove weight bearing from the affected portion of the digit
• hoof block applied to healthy claw
• re-examination in 4 weeks
• healing time for full-thickness sole ulcers = 2months

Question 5

Toe ulcer, toe necrosis

Answer 5

Results in thin sole at the top which is more susceptible to deformation from stepping on stones or irregular features of the flooring

If haematology results at toe tip, it may lead to a vascular necrosis of the soft tissue at the toe tip

If lesion is open to the environment, miscellaneous bacteria may invade and produce osteomyelitis or pathological fracture of the tip of the 3rd phalanx

Question 6

Cause of toe ulcer/toe necrosis

Answer 6

Overwear or over trimming at the toe tip

Question 7

Treatment for toe ulcer/toe necrosis

Answer 7

• hoof block and cleaning of the toe tip
• current approach: hoof block on sound digit and amputate the distal portion of the affected digit (either obstetrical wire or hoof nippers)
• tight bandage applied over some ATB powder to control haemorrhage and removed in a few days
• re growth of functional cornfield epithelium will cover the partial amputation in 1 months

Question 8

Thimbling or transverse wall separation

Answer 8

• results from an insult to the coronary corium that results in an interruption in growth
• always present in all 8 digits but usually noticed because of pain in only one
• distal portion of the hoof capsule separates from the more proximal section
• pain occurs when movement of the distal portion pinches the corium at the toe tip
• goals of trimming = minimise weight bearing at the toe tp by shortening as much as possible and thinning the sole at the toe relative to the rest of the hoof
• pain may shift from one limb to another as successive thimbles become more detached from the younger hoof wall.
• recovery is complete and without complications as the thimbles wear or are trimmed away

Question 9

Vertical wall cracks or sand cracks

Answer 9

Important to verify that the crack is the cause of lameness before proceeding, if the crack is causing pain, it should be carefully debriefed of foreign material

Question 10

Predisposition of vertical wall cracks or sand cracks

Answer 10

• more common in range cattle than in dairy but rarely occur
• vertical cracks in axial wall are more common in dairy cattle

Question 11

Treatment of vertical wall cracks or sand cracks

Answer 11

• Carme sur be taken to not extend the hoof wall detect during trimming
• removing granulation tissue may be necessary, followed by controlling haemorrhage and protecting the healing curium from damage
• standard procedure is to stabilise the adjacent portions of the hoof wall with acrylic and to place a block on the sound claw
• separated or detached horn should be removed, granulation tissue respected and a tight bandage with ATB powder
• tight bandage is to help rrpevent formation of granulation tissue
• hoof block is applied to the healthy digit

Question 12

Corkscrew claw, splayed toes - inherited defects

Answer 12

• doesn’t become evident until cow reaches 3 or more years old
• both lateral rear digits, both medial fore digits or all four may be affected
• entire configuration of the 3rd phalanx, soft tissues between the claw capsule and bone and the claw capsule are abnormal
• axial wall becomes dorsal, tip of the toe curls up from the ground = creates mild predisposition to lameness
  -> toe tip should be trimmed slightly longer than normal, removal of the overgrowth of the abaxial wall can return weight bearing to the sole and wall in a flat plane

Question 13

Traumatic exungulation

Answer 13

• cows might get a toe caught and detach the horny capsule of a claw while detangling itself
• clean, disinfect the exposed tissue and bandage with a tissue-friendly antiseptic
• hoof block is necessary on the healthy digit, parenteral ATB recommended for 7-10 days
• if curium/deeper structures are significantly damaged then amputation or slaughter

Question 14

Fracture of the 3rd phalanx (P3)

Answer 14

Cattle of any age or size

Question 15

Predisposition of fracture of P3

Answer 15

Dairy bulls, maybe young cattle/milking
Excessive dryness of hoof —> reduced cushioning of routine weight bearing/hoof trauma may predispose to P3 fracture
Fluorine toxicity exists

Question 16

Cause of fracture of P3

Answer 16

Hoof trauma from blunt injury or falling to the ground following mounting a cow

Question 17

Signs of fracture of P3

Answer 17

Acute severe lameness with no weight bearing in affected limb is observed
If one digit affected, the cow will attempt to touch the foot down only on the non affected digit

Question 18

Diagnosis of fracture of P3

Answer 18

• examination: warmth in the affected digit, flexión of hoof, hoof test pressure and percussion all elicit a painful response
• radiographs - at least two views
• elimination of more common cause of lameness

Question 19

Treatment of fracture of P3

Answer 19

Resting affected digit by use of a standard hoof block applied to normal claw
Comfortable box stall and block renewed as necessary during 4-8 weeks required for healing

Question 20

Interdigital fibroma

Answer 20

• redundant skin in interdigital space is hereditary condition associated with lax interdigital ligaments, resulting in a splay-toed conformation
• occurs in cattle secondary to chronic interdigital dermatitis
• predipspoe a risk to foot rot and are common sites of digital dermatitis
• removal of underlying cause rather than removal of fibromas, unless it’s painful
• sharp dissection of skin around base of fibroma
• to prompt healing g- remove interdigital fat
• ATB powder in wound then bandage (removed in few days)

Question 21

Cause of foot rot or interdigital phlegmon

Answer 21

Fusobacterium necrophorum and bactericides melaninogenicus

Question 22

Pathogenesis foot rot

Answer 22

Cow becomes lame over the course of a day/two with symmetrical swelling above the hoof

Question 23

Signs of foot rot

Answer 23

• pain may be severe with unwillingness to bear any weight on the affected limb (rear limbs more commonly affected)
• fissure in interdigital skin with necrosis of the underlying tissues (dry necrosis, no exudate)
• odour is strong and characteristics

Question 24

Treatment of foot rot or interdigital Philemon

Answer 24

• corrective claw trimming along with topical antiseptics to interdigital space
• bandaging is strongly discouraged so that air can reach interdigital tissue
• parenteral ATB most important of therapy

Question 25

Interdigital dermatitis, heel horn erosion and heel cracks cause

Answer 25

• dichelobacter nodosus - very common in cattle that live in moist environment

Question 26

Pathogenesis in interdigital dermatitis

Answer 26

• infection produces a mild irritation that results in underlying skin hypertrophy and may produce a faster growth rate of the adjacent axial hoof wall
• if infection spread across the heels, it may erode the horny portion of the heel in irregular patterns or create a transverse rack at the heel-sole junction
• D. Nodus —> proteases —> digest keratin of hoof tissue

Question 27

Signs of interdigital dermatitis

Answer 27

• subclinicl affected cattle by nonpainful erosions or ulceration of the interdigital skin
• moist, white exudate with characteristic odour distinct from that of foot rot
• lameness - stand with heel suspended over manure gutter/off the rear of a free stall curb

Question 28

Treatment of interdigital dermatitis

Answer 28

• corrective trimming should remove all the excessive horn and open the interdigital space so that it’s more self cleaning and more accessible to air
• hoof block indicated in rare cases of exposure of corium
• topical disinfectants (iodines or copper or zinc) effective in killing d.nodosus

Question 29

Cause of digital dermatitis

Answer 29

Several strains of spirochete bacteria, genus treponema

Question 30

Signs of digital dermatitis

Answer 30

• reddened circumscribed areas typically just above interdigital cleft on plantar aspect of pattern (strawberrry form of digital dermatitis) —> pain
• hair at periphery of lesions are erect and matted in exudate to form a rim
• lesion progresses, focal hypertrophy of dermis and epidermis leads to raised conical projections —> wet, grey terrycloth
• later stage, papilla form projections of blackened keratin extend from surface (hairy wart stage)
• hoof may be noticeably misshaped from abnormal wear caused by altered use of limb —> short rounded toes and exaggerated heel depth

Question 31

Treatment of digital dermatitis

Answer 31

Topical treatment of lame cows with oxytetracycine 5-15cc of 10% injectable form or powder