Bovine Orthopoedics and sudden death Flashcards Preview

Year 4 > Bovine Orthopoedics and sudden death > Flashcards

Flashcards in Bovine Orthopoedics and sudden death Deck (94)
1

Where is digital dermatitis usually seen?

Just above interdigital cleft, between heel bulbs
Often erected hair around lesion

2

How is digital dermatitis diagnosed?

Clinical signs only, no diagnostic tests

3

What are the stages of digital dermatitis?

M0- normal
M1- early lesions, <2cm, ulcerative
M2- classical ulcer >2cm, painful
M3- scab formation after topical treatment
M4- chronic lesion, dyskeratosis, proliferation
M4.1- same as M4 but also has an ulcerative area

4

What does 'acute' digital dermatitis mean?

There is an ulcerative lesion

5

How do you treat digital dermatitis?

Put cow in crush
Clean and dry the lesion
Topical antibiotics (oxytetracycline)
Trim foot while waiting to dry, look for other lesions
Repeat daily for at least 3 days

6

What causes interdigital necrobacillosis (foul in the foot/foot rot)?

Fusobacterium necrophorum (biotypes A and AB)
Enters through an interdigital lesion

7

How is interdigital necrobacillosis diagnosed?

Clinical exam
Typically only one foot affected, can be swollen
Swelling above the claws/characteristic odour
Lesions between the 2 claws

8

How do you treat interdigital necrobacillosis?

Cow in crush
Check for foreign body
Clean lesion
Remove necrotic tissue
Systemic broad-spectrum antibiotics for 3 days

9

What causes interdigital dermatitis?

Dichelobacter nodosus

10

Where is interdigital dermatitis seen?

Milder infection of interdigital skin, can spread across heels (heel horn erosion)

11

Give some controls for digital dermatitis

Footbaths
Good hygiene measures

12

How do you treat heel horn erosions?

Foot trimming, topical antibiotics

13

Give 3 non-infectious foot lesions

Sole haemorrhages/bruising
Sole ulcers
White line lesions
All associated with subclinical laminitis/ SARA (weakening of suspensory apparatus)

14

Describe sole haemorrhage/bruising

Contusion of the corium
Pressure from pedal bone (abnormal decent/movement)
External pressure (eg from stones), esp if soles are thin

15

Describe sole ulcers

Exposure of the corium
Disrupted sole horn production
Mainly caused by trauma/contusions of the corium from the pedal bone

16

How do you treat sole haemorrhages/ulcers?

Put cow in crush
Functional trimming (Dutch method)
Block unaffected claw
NSAIDs

17

Describe white line disease/abscess

Caused by stones/separation/manure
Associated with shearing/sideways forces on the feet
Can have abscess formation

18

How do you treat white line lesions?

Put cow in crush
Functional trimming (Dutch method)
Explore impacted white line, drain abscess, remove detached horn/under run sole
Block unaffected claw
NSAIDs

19

Give some possible causes of interdigital hyperplasia

Chronic skin irritation (eg digital dermatitis)
Hereditary?

20

What causes digital dermatitis?

Treponema spp, various strains
Identified in hair follicles and sebaceous glands

21

How do you treat interdigital hyperplasia?

Surgical removal under regional anaesthesia if causing lameness

22

Toe ulcers/necrosis are associated with what?

Overwear or over-trimming of the toe sole
Can get infected

23

How do you treat toe ulcers/necrosis?

Trim/block unaffected claw
Partial or full digital amputation

24

How do you treat a vertical wall crack?

Trim
Can block unaffected claw
Can stabilise hoof wall

25

How does deep digital sepsis occur?

Untreated foul in the foot, complicated sole ulcers, untreated white line abscesses, puncture wounds

26

How do you treat deep digital sepsis?

Amputation?
Arthrodesis?
Euthanasia?

27

Where do retroarticular abscesses form? What do they look like?

Above heel bulb
One claw, extensive painful swelling of the heel on a single digit

28

How do you treat retroarticular abscesses?

Surgery
Digital amputation

29

What is a corkscrew claw?

Dorsal edge of claw wall deviates from a straight line

30

Laminitis is associated with what?

Grain overload
SARA
Weakening of suspensory apparatus/ poor horn quality
Endotoxins
Increased activity of MMPs

31

How long do cows lie down for in a day?

12-14 hours

32

If a cow is sitting 'half in half out' of a cubicle, what does this mean?

Cubicle is too short -> more pressure on back legs -> risk factor for lameness

33

What is the best bedding choice for cow cubicles and why?

Sand:
Inert (lack of bacterial growth), cushioning, comfortable

34

What features must a cubicle have?

Needs a metre of forward lunge space to be able to stand up
Good to not be against a wall
Want defecation to be done outside cubicle (ie cubicle not too long)

35

Why does cubicle bedding need to be dry?

Once wet, increased bacterial load -> increased risk of mastitis

36

What is 'green bedding' for cubicles?

Dried faecal matter

37

Give some negative factors of using green bedding in cubicles

Potential for disease spread as increased bacterial load
Potential risk of antibiotic resistance
Kit is expensive to buy
Potential public health risk -> bugs on bed could end up in milk
Not to be used for cows <12 months old

38

Give some negative effects of using sand as bedding in cubicles

Needs topping up as cows dig it out
Clogs up drainage systems
Increases wear on machinery

39

Why is over-crowding a problem in housed areas?

Increased standing times -> increased risk of white line disease
More aggressive interactions between cows

40

How many cubicles should a farmer provide?

One per cow = bare minimum
5% extra (DEFRA)
20% spare for freshly calved cows

41

How much feed barrier space should a cow have?

76cm yokes, one per cow
At least 70cm per cow (if not using yokes)
Up to 1m for transition cows

42

A BCS less than what increases the risk of lameness?

< 2.5

43

What are the 4 mobility scores?

0 = sound
1 = abnormal gait but not identifiably lame
2 = slightly lame
3 = severely lame

44

When should we foot trim?

At drying off (60 days before calving)
60-100 days in milk

45

How big of a lying area should transition cows have?
What about feed space?

10-15 square metres per cow lying area
75-100cm per cow feed space

46

What BCS should a cow be at calving?

3

47

Which part of the pain pathway do NSAIDs affect?

Level of inflammatory mediators, possibly some central action aswell

48

Which part of the pain pathway do local anaesthetics affect?

Nociceptor stimulation

49

Give some clinical responses to pain

Impaired rumen function
Activities aimed at minimising pain eg lying down
Increased HR, RR, temp
Dull, depressed
Vocalisation
Facial expression
Decreased food intake and bodyweight

50

Give some clinical signs of lameness

Arched spine
Hanging/nodding head as they walk
Shortened stride length
Adducting/abducting HLs
Paddling/shuffling of feet
Unwilling to walk
Reduced weightt-bearing of affected limbs
Decreased milk yield

51

How are hock lesions caused?

Excess pressure on joints
Inadequate bedding, poor cubicle design

52

Give some effects of lameness on fertility

Delayed cyclicity and oestrus behaviour
Increased calving to 1st service
Increased calving to conception
Increased number of serves per conception

53

How can you manage pain in lame cows without drugs?

Reduce standing times at milking
Reduce walking times
Increase comfort in cubicles/yards eg straw yards
Increase foot hygiene

54

How do you calculate cow comfort quotient?

No of cows using cubicles correctly
divided by
No of cows interacting with cubicles

55

Give a problem with using deep straw bedding in cubicles

Increased risk of bacterial growth eg Streptococcus uberis (mastitis risk)

56

How big should a passageway be?

3-4.5m

57

Give some factors which contribute to hygiene of cubicles

Cubicle length (not too long -> faeces in cubicles)
Frequency of scraping out
Passageway width (3-4.5m)
Bedding plus lime
Ventilation and drainage
Frequent disinfection
Foot bathing

58

What are the 3 scores for cow cleanliness?

0= no dirt/ minor fresh dirt/ dried splashing
1= an area of dirtiness at least palm size
2= am area of dirtiness at least forearm length

59

What size should floor slat widths be?

140-160mm for mature dairy cows
Spacing of 35-40mm
Reduce the spacing for smaller breeds/heifers

60

Give some indications for doing a digital amputation/arthrodesis surgery

Deep digital sepsis/septic arthritis of DIP joint
Complications associated with sole ulcers, white line abscesses, foul in the foot, penetrating injuries
Retroarticular abscess
Non-healing wall lesions
Toe necrosis (amputation)

61

What is the method of choise for digit amputation?

Disarticulation at proximal interphalangeal joint (method 1)

62

What nerve block should be used when doing digit amputation/arthrodesis?

Intravenous regional block
20-30ml LA (eg lignocaine, procaine)
19-21G butterfly catheter

63

Why is method 2 of digital amputation not recommended?

Involves cutting through 2nd phalanx
Disruption of blood supply to part of 2nd phalanx that is left/prolonged recovery

64

When bandaging a foot after digital amputation, why are the 2 accessory digits left out of the 1st softban layer?

So that when the next bandage layer is applied, they are being pressed against a soft bandage rather than skin (which could cause necrosis)

65

How should the foot be treated before doing an arthrodesis/digital amputation?

Washed and disinfected

66

What post-op care should be carried out after an arthrodesis/digital amputation?

Dressing changes
Antibiotics
Analgesia

67

What can go wrong after a digital amputation/arthrodesis?

Poor post-operative care
Problems with remaining claw (after amputation)
Ascending infections
Chroninc pain
Failure to achieve ankylosis of the joint (after arthrodesis)

68

What does it mean when cows 'dog-sit' in cubicles?

Poor cubicle comfort

69

How much space should cows have in a straw yard?

At least 10 square metres of resting area per cow

70

How would you identify a weight-bearing lameness?

Shortened stride of the sound leg
Head position at point of weightbearing: head up if front leg affected, head down if back leg affected

71

How do you treat contracted tendons in calves?

If you can manually extend feet so calf can stand plantigrade, splinting should be sufficient
If not: tendonectomy

72

How do you treat upward patellar fixation?

Cut the medial patellar ligament on both legs

73

Give some clinical signs of osteodystrophies

Stiffness/recumbency
Bone distortion
Long bone fractures
Swelling joints

74

How do you diagnose osteodystrophies

Joint fluid analysis
Bloods: increased AlkPhos, decreased calcium
PM, histopath

75

What causes white muscle disease?

Vit E and selenium deficiency

76

How would you identify white muscle disease in a cow?

'Flying scapula' (scapula appears to be raised above the body)

77

What would you see in the serum of the blood of a cow with white muscle disease?

Decreased vit E and selenium
Increased AST and CK (muscle enzymes)

78

How would you recognise hip dysplasia?

Stifle is rotated outwards, hock is rotated inwards

79

How do dislocated hips occur in cows?

Connected with oestrus or calving (slackening of ligaments)

80

How can you treat hip dislocation?

Closed reduction: sedate, lie cow on side, extend leg as much as possible, push stifle down and hock up.
Must be done within 24 hours, before a blood clot has formed

81

Give a cause of a spontaneous fracture in a cow

Hypophosphataemia

82

Can you splint a fracture above the elbow and stifle?

NO
Must be able to splint up to a joint above the fracture

83

How do you treat septic arthritis?

Conservative: aggressive ABs, anti-inflammatories
Surgical: lavage, arthroscopy, arthrotomy (opening the joint)

84

When does the Food Hygiene (England) Regulations 2005 state that emergency slaughter can be used?

An otherwise healthy animal must have suffered an accident that prevented its transport to the slaughterhouse for welfare reasons

85

Which criteria must a cow fit in order to be sent for slaughter at a slaughterhouse?

Likely to be fit for human consumption
Clean
Free from residues
Properly identified with at least one official eartag and passport
Fit to be transported to a slaughterhouse

86

When may a cow be slaughtered on farm and the body sent to a slaughterhouse with a veterinary certificate?

If it is otherwise healthy but has suffered an accident preventing transport

87

When may a cow be slaughtered on farm and have its body disposed of as fallen stock?

Not fit for human consumption
Not properly identified eg no ear tags
Not fit to be transported to a slaughterhouse

88

Is on-farm burial permitted for cows that die on the farm?

No

89

What must happen to cows that die on farm that are aged over 48 months?

Tested for BSE

90

Give some differentials for sudden death in cows

Haemorrhage (eg calving injury)
Plant toxicity (eg yew)
Lightening
Electrocution
Hypomagnesaemia
Hypocalcaemia
Toxaemia
Bloat
Blackleg (Cl chaevoei)
Blacks disease (Cl novyi type B)
Anthrax

91

What would you see in a cow that has died of anthrax?

No rigor mortis, blood not clotted- black and tarry

92

Who is authorised to do anthrax tests?

OV

93

What must happen if a farmer suspects anthrax on their farm?

Farmer informs vet of sudden death
Vet telephones local APHA office
Out of hours can do the test first, but must telephone next working day
Given a reference number if DEFRA want the test
You may do a private investigation, without telling the Ministry of a negative finding, but you will not be paid
APHA will tell the police and Local Authority if positive
(Don't move the animal until tested negative)

94

How do you test for anthrax?

Thick blood smear from dead cow, stained with methylene blue