2. Foot rot
Definition
An anaerobic infection of the soft tissues of the
interdigital space causing lameness in cattle
,sheep and goat.
3. Foot rot
In cattle:
Synonym: Bovine Interdigital Necrobacillosis
Etiology: Fusobacterium necrophorum
Gram-negative bacteria is a non-spore forming obligate anaerobe
and a normal inhabitant of the alimentary tract (particularly the
rumen), the respiratory tract, and the genital tract.
In sheep:
Synonym: Ovine interdigital dermatitis' and is also called 'foot
scald'.
Etiology: bacteriodes nodosus in combination with
Fusobacterium necrophorum
5. Epidemiology:
●The disease is common in all ages. The disease
has a worldwide distribution
●usually the disease is sporadic and accounts for 5-
15% of cases of lameness in dairy cattle.
● Transmission by discharges from the feet of
infected animals
6. Environmental risk factors
In many but not all regions, the incidence is much higher
during wet, humid weather or when conditions are wet
underfoot.
Stony ground, lanes filled with sharp gravel and pasturing
on coarse stubble also predispose to the condition.
Host risk factors
Cattle of all ages, including young calves ,may be affected
but the disease is much more common in adults.
The highest incidence occurs in cows in the first month of
lactation
7.
8. Economic impacts:
In beef cattle at range the incidence is usually low but many
cases may occur in pure-bred herds and in
feedlot cattle.
Lame cows will lie down for longer and eat less, have
difficulty rising and are at greater risk for teat trampling and
mastitis.
Loss of production occurs and an occasional animal may
suffer a serious involvement of the joint and other deep
structures of the foot necessitating amputation of a digit.
The disease is not fatal but some cases may have to be
slaughtered because of joint involvement.
9. Clinical signs:
lameness appears suddenly, usually in one limb only and
may be accompanied with a fever(39-40℃).
There is temporary depression of milk yield in cows and
affected bulls may show temporary infertility.
The typical lesion occurs in the skin at the top of the
interdigital cleft and takes the form of a fissure which is
moist, red, swollen, and has a characteristic foul odor.
Deeper tissues, such as bone, tendons, and joints, can also be
affected in severe and advanced cases.
10.
11. Pathogenesis:
injury or constant wetting of the skin of the cleft
allow to the organism invade the tissues leading to
acute swelling and necrosis of the skin and SC
tissues may spread to adjacent tendon sheaths,
joint capsules and bone if treatment is delayed or
ineffective.
12.
13. Necropsy Findings
Necropsy examinations are rarely carried out in cases of
foot rot.
Clinical Pathology
Bacteriological examination is not usually necessary for
diagnosis but direct smears of the lesion will usually reveal
large numbers of a mixture of Fusobacterium and
Bacteroides spp.
Diagnosis
The diagnosis is based on history and clinical findings of a
moist, red fissure in the Interdigital space.
15. D.D in sheep:
☞ Foot abscess (It usually affects only one foot, is not contagious and is
characterized by extensive suppuration. The abscess occurs in a single claw on
the foot and there is obvious local heat and pain on palpation).
☞ contagious ecthyma (proliferative lesion with scabs around mouth and
coronet skin)
☞Bluetongue ( coronitis severe erosions around mouth and nasal cavities,
high fever)
☞Foot and mouth disease (vesicles at coronary band and interdigital cleft
and mouth, as outbreak infect all age).
☞Ulcerative dermatitis (spread by physical contact with20% at mating,as
granulating ulcer around mouth, genitalia, on coronet and digits).
☞Strawberry foot rot
☞Laminitis
16. Treatment
Immediate treatment as soon as possible after the onset of
swelling and lameness will give excellent recovery in 2-4
day. (systemic and locally).
procaine penicillin G, 22 000 IU/kg BW.IM twice daily, or
once daily for three consecutive days are effective .
Sodium sulfadimidine (150-200 mg/kg BW) solution given
by IV injection is highly effective.
17. antibiotic treatment for sheep can use any one of
the following :
● Single IM dose of 70 000 U/kg procaine penicillin and
70 mg/kg dihydrostreptomycin.
● Single IM dose of 10 mg/kg. Erythromycin.
● Single IM dose of 20 mg/kg Long-acting oxytetracycline.
18. local treatment by applying a local anesthetic
(xylazine)then the foot is scrubbed, all necrotic tissue
curetted away and apply Any suitable antibacterial spray.
19. it is recommended that the animal be kept standing on
clean dry ground for a few hours after treatment
Ointment preparation may be applied and secured with a
bandage, which may be left on for several days.
20. control:
Foot bathing with copper sulfate 5% in a doorway so that cattle
have to walk through it twice daily . Employ pasture
modifications if possible (e.g., rotate pastures more often, fill
mud holes, remove sharp objects). sheep that are affected with
severe lesion are treated with parenterally administered
antibiotics or culled.