Bovine Musculoskeletal Disease, Pt. 2 Flashcards
What are sole abscesses? In what cattle are they most common?
area of subsolar infection, often found between the old and new sole
mature dairy cattle (relatively common in beef and young dairy)
How are sole abscesses diagnosed?
- follow black tracts and observe drainage
- hoof testers can help localize the area affected
What are the major signs of sole abscesses?
- lameness varies from mild to severe
- no swelling above the hoof unless a long duration
What are 5 important aspects of sole abscess treatment?
- paring out black tracts
- Kopertox
- bandage - not necessary if drainage is possible
- block good claw
- NSAIDs and antibiotics
What 3 things does the prognosis of sole abscess treatment depend on? When should improvement be seen?
- number of feet affected
- severity of the lesion and extension into deeper tissues
- amount of sole or wall removed
within 1-2 days
How can it be determined how far down a black tract can be pared out?
apply thumb pressure and pare out to the extent of the hardness —> sole is hard, as the cornium is reached it will become soft
- too deep = bleeding = difficult to see
In what direction should a black tract be pared out?
away from the sole
- toward the wall so that drainage is not blocked
What is circled in this picture?
black tract leading to a sole abscess
What technique is recommended when paring out black tracts?
leave as much of the walls of the hoof as possible to leave a larger surface for weight-bearing
In what shape should a black tract be pared out?
spatulate out with smooth edges, don’t leave a pit that can get plugged back up with dirt
What is an under-run sole? What is the most common color of the normal sole?
place where an abscess already burst through, allowing dirt, manure, and rocks to pack in between old and new soles
manure will stain it black/brown
Sole abscess, under-run sole:
rock was between false and new sole
What is the best means of controlling sole abscesses? What else is done?
regular hoof trimming every 6 months, especially in diary cows
- maintain a clean, dry environment
- proper feeding
- avoidance of bruising
What are 5 predisposing factors associated with sole abscesses?
- unsanitary conditions
- whiteline disease
- bruises (rock lodged in sole)
- laminitis
- puncture wounds
What is the pathogenesis of sole abscess formation?
- hole or crack in the horny sole becomes packed with dirt/manure
- this creates an environment for anaerobic, abscess-forming bacteria
- as the abscess enlarges, it dissects through the tissue until it finds a way out
- this causes pain due to pressure buildup
What should be the next step when seeing this sole?
pare out black tract
Where are vertical cracks of hooves most common? What should be done if it is an incidental finding on a routine hoof trim?
dorsal abaxial wall
open it up so it doesn’t pack with dirt
When does lameness occur with vertical cracks of the hoofs? How are they treated?
when it causes erosion into the coronary band or sensitive lamina
- trim and clean to allow drainage if infected
- horizontal grooving to stop crack extension
- natural oils
What 5 conditions predispose to vertical cracks? In what cattle is it most common?
- dry conditions (common in desert areas of the Southwest)
- poor nutrition
- trauma
- laminitis
- high selenium (not common in coastal US)
range > confined = more exposure to dry, sandy, and windy environments that can remove the natural oils, stratum extornum, and water of the hoof = BRITTLE
What are horizontal cracks? How are they treated?
cracks parallel to the coronary band —> laminitis type cracks, hardship grooves —> stress causes hair in hoof to stop growing for a period of time, leaving a weak spot
- pare out
- regular hoof trims
- control metabolic disease
When do horizontal cracks cause lameness?
when it develops into erosion of the sensitive lamina
Horizontal crack:
hardship groove
What is the pathogenesis of horizontal hoof cracks? How quickly do the claws grow?
- metabolic disturbance/stress results in temporary stoppage of horn growth
- space occurs between old and new horn
- “hang nail” develops as horn grows out
10-15 cm/year (1/4 in) —> measurement from groove to coronary band can estimate time point of development
Proper management of a sole abscess in a dairy cow may involve all of the following except…
a. bandage
b. Kopertox
c. long-term antibiotics
d. paring to allow drainage
e. wood block
C —> dairy cows = worry about residues
What is a major rule out for all types of lameness? How do they present?
laminitis
warped growth of hooves upward cause the appearance of slipper-like feet —> commonly the initial cause of other hoof diseases, like ulcers
What is indicative of a septic coffin joint? How is it confirmed? What differentials should be considered?
severe, three-legged lameness
radiographs
fractures and tenosynovitis
What is a common secondary event following the development of a septic coffin joint?
red area = rupture above the coronary band due to joint fluid buildup
What 3 treatments are preferred for septic coffin joints? Why?
- slaughter
- toe amputation
- arthrodesis (fuse joint)
conservative treatment with antibiotics and NSAIDs unlikely to work
What is prognosis for septic arthritis like?
- antibiotics and NSAIDs = poor
- toe amputation = depends on age, size, weight, and conformation
How is septic coffin joints controlled?
control of other foot diseases, like footrot, that can extend into the joint space
What is corkscrew claw? How are they treated? In what breed of cattle is it thought to be heritable?
twisting of lateral claw causes it to point upward
trimming every 6 months, as it will most likely recur
Angus
Corkscrew claw:
What is occurring in this cattle?
corkscrew claw —> sole points upward
Name this hoof condition.
corkscrew claw
What is scissor claw? How does it compare to corkscrew claw?
excessive growth of claws results in toes overlapping = cross over
no rotation seen
What are the 2 major causes of scissor claw? How is it treated?
- chronic laminitis
- lack of foot trimming
trim them as lameness occurs
(all external, no antibiotics necessary)
What is fescue foot? What 2 things is diagnosis based on?
toxicosis of cattle grazing on tall fescue pastures, characterized by avascular necrosis of body extremities —> most common in winter of southern states when fescue grows best
- physical exam findings
- fescue found on pasture
What clinical signs are indicative of fescue foot?
- begins as hindlimb lameness
- dry gangrene of feet, tail, and ears, typically resulting in sloughing past the line of demarcation
- weight loss, scruffy haircoat
- affected areas are cold and swollen
How is fescue foot treated?
- remove fescue from pasture
- antibiotics for secondary infection
- humane euthanasia or slaughter
(may recover within 2 weeks)
What is the pathophysiology of fescue foot? When is it considerably worse?
- fungal endophyte in fescue plant produces toxins
- toxins cause vasoconstriction
- this results in blood stasis, thrombosis, edema, and swelling
- extremities become ischemic and gangrenous
cold weather - peripheral vasoconstriction already occurring to conserve heat (low morbidity!)
Where has fescue foot been reported?
Midwest - MO, OK, AR —> anywhere fescue can grow
What does not aid in the control of fescue foot? What are the 2 most common control measures?
mowing
- mix fescue pastures with other legumes and grasses to decrease dose of fescue cattle get
- destroy infected fescue and reseed with clean fescue (neighbors will likely still have it growing)
What plant can be used to protect against fescue foot?
birdsfoot trefoil
A pastured 8 m/o Angus heifer was found with the pictured lesions. “Black bananas” were seen on tall grass seedheads. What is the most likely diagnosis?
a. ergot
b. fescue foot
c. frostbite
d. Salmonella
e. trauma
A
What is indicative of ergot toxicosis?
- gangrenous extremities with sloughing of skin
- owners may report seeing black material attached to the seedheads of their feed
In what cattle is frostbite more common?
calves
- can observe lines of demarcation and sloughing of skin
- humane euthanasia usually treatment of choice
What are the 5 top differentials for necrosis of extremities in cattle?
- fescue foot
- ergot
- frostbite
- salmonella (septic process)
- trauma
The scientific name for hairy heel wart is….
a. digital dermatitis
b. interdigital dermatitis
c. interdigital hyperplasia
d. viral dermatitis
e. widdershins
A
How is a P3 fracture diagnosed?
- hoof testers
- radiographs
ensure the foot is clean and lacking black tracts
What are the most common signs of P3 fractures?
- grade 3-4 lameness
- unlikely to have swelling above coronary band
- crossed feet to put pressure on lateral claws and protect medial ones
- prefer recumbency
What treatments are used for P3 fractures? What is prognosis like?
- wooden block
- casting/bandaging
- claw amputation when septic
good unless septic —> allow 4-8 weeks for healing
What are the 2 major causes of P3 fractures?
- trauma
- fluorosis —> increased fluoride in water or environment
What should be done if there is no obvious cause of lameness in a cow?
hoof testers!
What is seen on this hoof?
incidental bruising
True or false: When the complaint is lameness, you need to localize the lameness to a specific foot before you start timming and cleaning the feet.
TRUE —> confirm before putting on trimming table to allow concentration on the affected foot
True or false: Footrot requires laboratory testing to obtain a diagnosis.
FALSE
True or false: Culture is rarely necessary for footrot cases because the organisms are generally susceptible to most antibiotics.
TRUE
Name 3 treatment options when treating footrot.
- antibiotics
- debridement
- Kopertox/footbaths
The success rate when treating footrot early in the course of disease is nearly….
a. 10%
b. 35%
c. 50%
d. 90%
e. 100%
E
The prognosis of footrot becomes worse when _____ and ______ are infected.
- joint
- tendon sheaths
Name this foot condition.
footrot
What is occurring in this hoof?
corn - interdigital hyperplasia
A 3 y/o Holstein cow presents with acute 3-legged lameness. The producer knows that the cow was fine yesterday. What is the most likely diagnosis?
a. footrot
b. corn
c. foreign body
C
Footrot control consists of _______ and _______.
- hygiene
- footbaths
True or false: Hygiene is a must for footrot control because the organism can penetrate intact skin.
FALSE —> Fusobacterium necrophorum is opportunistic
A lactating dairy cow presents with grade 2 lameness in the left rear. The interdigital space was cleaned and looks great. The soles and white line has been pared out and only a few pinpoint black spots are left. The cause of lameness has not been found. What sound occur next?
use hoof testers to localize possible lesions and pare out tiny black spots
What is the weakest area of the sole?
a. area directly below tip of P3
b. heel-sole function
c. toe
d. white line
D
A sole abscess could be a sequela to all but which of the following:
a. corn
b. foreign body
c. sole bruise
d. sole ulcer
e. white line disease
A
What is the key to both treatment and control of many foot/horn disease of dairy cattle?
a. footbaths every 2 months, more frequently for treatment
b. maintaining hygienic environment
c. paring necrotic and loos horn as needed and regular/proper foot trimming
d. systemic or local antibiotics
C
A vertical crack was found to be the cause of grade 3 lameness in a 10 y/o Hereford cow. What should be done?
a. clean it
b. debride/pare away loos horn to allow drainage
c. horizontal grooxing
d. block
e. antibiotics
A, B, C, D, E
What is a common cause of horizontal cracks?
laminitis
A 3 cm diameter terry cloth towel appearing lesion on the plantar aspect of the foot was found It is sensitive to the touch. What is it?
a. digital dermatitis
b. footrot
c. hairy foot wart
d. interdigital dermatitis
e. interdigital hyperplasia
A, C
What are 3 aspects to controlling hairy foot warts? What is key to preventing this in herds that have not yet had cows with hairy foot warts?
- environmental hygiene
- footbaths every 2 weeks
- Kopertox spray
don’t bring in cows or heifers from herds that have had it in their lifetime
What is the suspected agent that causes digital dermatitis?
a. protozoa
b. fungus
c. spirochete
d. virus
C
Cows with _______ will be severely lame (3-legged).
a. digital dermatitis
b. footrot
c. interdigital dermatitis
d. septic coffin joint
e. sole abscess
D
What are the 5 options available for treating a left front septic coffin joint in a 2000 lb bull?
- slaughter
- toe amputation
- drill
- arthrodesis
- conservative medical care - antibiotics, NSAIDs
How often does a corkscrew claw need to be trimmed?
a. every month
b. every 2 months
c. every 6 months
d. every year
e. doesn’t need to be trimmed
C
