Lameness in Pigs

Fundamental Nature of Lameness

• Definition: An abnormal gait of musculoskeletal, neurological, or integumentary origin.

• Economic & Welfare Impact: A perennial issue affecting growth rates, reproduction, and slaughter condemnations; a primary focus of animal well-being audits.

• Etiological Categories: Traumatic, infectious, nutritional, or developmental/congenital.

The Diagnostic Framework (The "Four Circle" Approach)

• Circle 1 (Premises): Evaluation of facility design, traffic patterns, and biosecurity.

• Circle 2 (Barns): Environmental features and specific management practices.

• Circle 3 (Rooms/Pens): Group health assessment, behavior, and prevalence estimates.

• Circle 4 (Individual Exam): In-depth clinical examination and identifying specific causes (e.g., swollen joints).

• Ancillary Tools: Restraint (snaring, sorting panels, lift chutes), sedation/anesthesia, and postmortem necropsy.

Infectious Agents (Common Bacterial Causes)

• Streptococcus suis: Common primary cause of arthritis, sepsis, and meningitis; high concern due to zoonotic potential.

• Glaesserella parasuis (Glässer’s Disease): Causes acute sepsis, polyserositis, and arthritis; severe in naive populations.

• Mycoplasma hyosynoviae: Causes acute hind-limb lameness in pigs 10–26 weeks old; characterized by clear, yellow synovial fluid.

• Mycoplasma hyorhinis: Predominant in nursery pigs (3–8 weeks); leads to polyserositis and fibrinous arthritis.

• Erysipelothrix rhusiopathiae (Erysipelas): Causes acute sepsis, "diamond skin" lesions, and chronic proliferative arthritis.

• Trueperella pyogenes: Ubiquitous opportunist causing abscesses and osteomyelitis.

• • Splayleg (Spraddle Leg): Muscle immaturity at birth; treated with limb hobbling.

  • Congenital Tremors: Often associated with Atypical porcine pestivirus infection in naive gilts.

• Nursery (Post-weaning):

  • Locomotor dysfunction is a major contributor to nursery morbidity and mortality.

  • Vertebral Deformities: Kyphosis (hump back) linked to nutritional deficiencies.

• Growing-Finishing:

  • Rickets: Nutritional deficiency (Vitamin D, Ca, or P) resulting in soft bones, "rachitic rosaries" on ribs, and spontaneous fractures.

  • Osteochondrosis: Joint lesions in rapidly growing pigs (relevant after 10 weeks of age).

Environment, Nutrition, and Management:

• Flooring: Slippery floors lead to trauma; abrasive floors wear claws; gaps in slats cause digit entrapment and loss of accessory digits.

• Nutritional Factors (Metabolic Bone Disease): Discrepancies in Vitamin D, Phytase, Calcium, or Phosphorus; Biotin deficiency causes weak, flaky hoof keratin.

• Management Stresses: Moving/mixing pigs, overcrowding, and viral coinfections (e.g., PRRSV or Circovirus) that compromise immunity.