Diagnosing and treating bovine foot disorders (Proceedings)
Examined at a distance, then up close by hands-on.
Footrot (interdigital necrobacillosis, infectious pododermatitis)This is the most popular owner diagnosis but only really accounts for 15-20% of lameness. The etiology is as follows: maceration of intedigital skin via trauma, followed by invasion by Fusobacterium necrophorium and Bacteroides melanogenicus.
Clinical signs include swelling, redness, pain , skin fissures and necrotic tissue in the interdigital space. If allowed to persist, infection commonly invades deeper structures. (ie: DIP joint)
Treatment options include:systemic and/or topical antimicrobials and removing necrotic material that is unattached. As for vaccination, Fusobacterium necrophorum bacterin administered as 2 doses, 3-4 weeks apart followed by a yearly booster may decrease the severity and incidence of infection.
Interdigital dermatitis is nothing more than an acute to chronic inflammation of the interdigital skin. It does not extend into subcutaneous tissues. Chronic inflammation can result in heel horn erosion and undermining of the heel bulbs.
Etiologies:Continuous wet and unhygienic conditions, laminitis, Bacteroides nodosus and a spirochete
Clinical signs include: slight to moderate lameness – paddling?, mild to severe redness of the skin and mild to moderate swelling with pain to the touch.
Papillomatous digital dermatitis (hairy heel warts)
Transmissible dermatitis on the plantar/palmar surface of the pastern and on the heels. There is complete erosion of the epidermis that is replaced by granulation tissue.1
Etiologies: Moisture, Bacteroides, Campylobacter, Spirochete (Treponema)
Clinical signs include: Lameness and weight shifting – one small lesion can be extremely painful to touch, ulceration around the coronary band in the bulb area and papillary hyperplasia of epidermis – fronds (fingerlike projections)
Treatment options include: cleaning, topical oxytetracycline or lincomycin spray, oxytetracycline under a bandage, foot baths (agents in footbaths are frequently inactivated by organic debris, therefore, the baths need to be fresh- can get expensive to properly maintain)
Injectable oxytetracycline – not very effective
Etiologies include, puncture wounds, concrete or grinder burns, white line disease and bruising. Basically anything that compromises the horn. Clinical signs are obviously mild to severe lameness and an alteration of stance to shift weight, however, there is usually no swelling unless there is joint, tendon or soft tissue involvement above the hoof. Treatment and diagnostic modalities include:
Curettage all undermined horn. Protect unaffected sensitive laminae.
Explore all tracts, especially those areas with erupting granulation tissue.
Radiographs to examine deeper structures.
Place a wooden block on good claw
Systemic antibiotics if deep tissue is involved
The etiology of this condition usually includes an extension of digital disease into the deeper structures to involve the flexor tendon sheaths. However, trauma due to lacerations or punctures directly involving these structures also commonly occurs. Owners often consider lacerations that don't immediately make the animal lame as something they can treat themselves, however, when the trauma involves the tendon sheaths, it often progresses to something far more serious.
Clinical signs of tenosynovitis include:
Swelling and/or draining of synovial fluid from tendon sheath
Distended sheath – usually unilateral (remember, the digital flexor tendon sheaths don't communicate)
Ultrasound works well to differentiate between infection in sheath and surrounding tissue