LAM 3 Midterm 1 Flashcards
What feedlot changes lead to lameness?
high energy diet + substrate changes - lameness
Where does 90% of dairy cow lameness occur?
rear limb lateral claw
What is the most common lesion associated with sheep lameness?
interdigital space lesions
How will cattle stand if they have lameness in their lateral digit?
base wide stance
How will cattle stand when they have medial claw lameness?
base narrow or limbs are crossed
What are the 3 synovial structures in the ruminant foot
Distan Inter tarsal Joint
Navicular Bursa
Flexor tendon sheath
What is graveling?
deep foot infection has to migrate to release the pressure at which tends to occur at the soft tissue planes
What is the role of the Periolic coria?
it is a moisture barrier to underlying coria
What spirochete is responsible for 50-70% of bovine lameness in the U.S?
Treponema
they live deep in the epidermis and create inflammation
What is considered the dirtiest foot zone + why
zone 0 because spray cleaners don’t reach between the claws
What are clinical signs of mild irritation of the interdigital skin (zone 0)?
small, red ulcers
mild swelling + pain
undermine heel: seperate perioplic corium from the underlying horn of the bulb
What do the cs related to mild irritation of the interdigital skin lead to?
overgrowth of the heel resulting in increased heel weight-bearing + concussive injury = rusterholz ulcer
What is the proper term that is commonly referred to as “foot rot”?
interdigital dermatitis
What bacteria are commonly involved in interdigital dermatitis?
Fuscobacterium +/- dichelobacter or porphoromonas
Define the pathology found in interdigital dermatitis
skin break caused by deep necrosis
What is super foot rot?
necrotizing, penicillin resistant necrobacillosis of the foot
What is the name of the disease condition associate with 80% of all lameness in sheep?
interdigital dermatitis (foot rot)
What are some cs + findings of interdigital dermatitis in sheep?
often malodorous
walk on their carpi (if forelimb disease)
Fuscobacterium + Dichelobacter
What are the 3 phases of digital dermatitis
heel ulcers
strawberry foot rot
hairy heel warts or “mortellaro”
Describe the “heel ulcer” phase of digital dermatitis
circumscribed erosion/ulcer on border of plantar commissure, or at skin horn jxn, near the declaws (zone 10) or interdigital space
Describe the strawberry foot rot phase of digital dermatitis
ulcer fills in with granulation tissue
Describe the hairy heel wart phase of digital dermatitis
papillomatous growth
As chronicity increases, granulation tissue toughens up + frong like growths can occur
What microbe is responsible for causing digital dermatitis
Tremonema spp.
spirochete in the skin leads to irritation then erythema and inflammation + skin breaks resulting in ulcers
What happens when tremonema enters a herd?
epizootics of foot problems and after the adult cows develop partial immunity + mild lesions but if new heifers are introduced they still get severe disease