Camelidae and Cervidae Ulcerative Pododermatitis – NAVLE Study Guide

Overview and Clinical Importance

Ulcerative pododermatitis is an inflammatory and infectious condition affecting the foot pads and interdigital skin of camelids (llamas, alpacas) and the hooves of cervids (elk, deer). In camelids, the disease presents as ulcerative lesions of the soft foot pads, while in cervids, it manifests as treponeme-associated hoof disease (TAHD), causing severe lameness and hoof deformities. Understanding the unique foot anatomy of these species and the distinct etiologies is critical for NAVLE success.

This condition represents a significant welfare concern as it causes pain, lameness, decreased productivity, and in severe cases, can be life-threatening. Environmental factors, particularly wet and unsanitary conditions, play a crucial role in disease development for both species groups.

Comparative Foot Anatomy

Camelid Foot Anatomy (Llamas and Alpacas)

Camelids belong to the suborder Tylopoda (Greek for "padded foot"), which distinguishes them from other ungulates. Unlike cattle, horses, or sheep, camelids do NOT have hooves. Their feet have unique anatomical features:

• Two digits (toes): The third and fourth digits on each foot
• Soft foot pads: Leathery, cushioned pads similar to dog pads that provide traction and weight distribution
• Toenails (not hooves): Curved nails extending from each toe that require periodic trimming
• Weight-bearing on P2 and P3: Both the second and third phalanges are horizontal and weight-bearing (unlike horses/cattle where only P3 bears weight)
• No navicular bone: Absence of navicular bone reduces navicular disease risk
• Digital cushion: Supports both P2 and P3 for shock absorption

Cervid Foot Anatomy (Elk and Deer)

Cervidae are even-toed ungulates (order Artiodactyla) with cloven hooves similar to cattle and sheep:

• Cloven hooves: Two weight-bearing digits (III and IV) with keratinized hoof capsules
• Interdigital space: Soft skin between the two digits, common site for ulcerative lesions
• Coronary band: Junction between hoof and skin; lesions here can undermine hoof wall
• Dewclaws: Vestigial digits (II and V) positioned above and behind the main hooves
• Laminar structure: Sensitive laminae attach hoof capsule to underlying structures

Anatomical Comparison Table

Etiology and Pathogenesis

Camelid Ulcerative Pododermatitis

Camelids are generally considered resistant to classic foot rot, but can develop ulcerative pododermatitis when predisposing conditions are present.

Primary Bacterial Pathogens

Predisposing Factors

• Wet, muddy conditions: Macerate foot pads and provide anaerobic environment
• Trauma: Punctures, abrasions from rough terrain
• Chorioptic mange: Common in interdigital and heel areas; creates skin breaks
• Poor hygiene: Accumulated feces/manure in housing
• Overgrown toenails: Alters weight distribution

Cervid Treponeme-Associated Hoof Disease (TAHD)

TAHD is an emerging disease first documented in free-ranging elk (Cervus canadensis) in southwestern Washington State, USA around 2008. The disease shares similarities with bovine digital dermatitis (BDD) and contagious ovine digital dermatitis (CODD).

Primary Treponeme Species in TAHD

Clinical Signs and Presentation

Camelid Ulcerative Pododermatitis

Early Signs

• Mild lameness (may be weight-shifting between feet)
• Erythematous (reddened) interdigital skin
• Single or multiple punctate erosions on foot pads
• Mild malodor

Progressive Signs

• Moderate to severe lameness
• Crater-like ulcerations on foot pad (craterous erosions)
• Underrun foot pad tissue
• Sloughing of large portions of pad
• Strong foul odor (characteristic of F. necrophorum)

Cervid TAHD Clinical Signs and Lesion Grading

TAHD lesions are classified using a 5-grade system (0-IV) based on severity and progression:

Treatment Protocols

Camelid Treatment Protocol

Local Wound Management

• Debridement: Remove all loose, necrotic skin and pad tissue
• Cleaning: Scrub with topical antiseptics (chlorhexidine or povidone-iodine)
• Protection: Apply bandage or specialized llama boot; change every 2-3 days
• Environment: Move animal to clean, dry housing

Systemic Antibiotic Therapy

Note: All drugs are used extra-label in camelids.

Cervid TAHD Treatment Considerations

CRITICAL: Treatment of free-ranging elk with TAHD is NOT practical. Unlike livestock digital dermatitis managed with foot baths and repeated antibiotic treatments, wild elk cannot be captured and treated repeatedly.

Management Approach for Free-Ranging Elk

• Selective removal: Hunting permits to remove severely affected animals
• Surveillance: Monitor and report limping elk to wildlife agencies
• Biosecurity: Clean shoes and tires after visiting affected areas

Prevention and Control

Camelid Prevention Strategies

• Drainage: Ensure pastures and housing areas are well-drained
• Dry bedding: Maintain clean, dry bedding in shelters
• Regular toenail trimming: Every 6-8 weeks
• Treat chorioptic mange: Ivermectin or moxidectin; prevents skin damage

Prognosis

Camelid Prognosis

• Early/mild lesions: GOOD prognosis with treatment; healing in 2-4 weeks
• Moderate lesions: FAIR; may require several weeks for new pad tissue
• Severe/deep infections: GUARDED; if deep structures involved

Cervid TAHD Prognosis

• Grade I-II lesions: Some spontaneous improvement possible
• Grade III-IV lesions: POOR; progressive, often fatal