Lameness in Breeding Gilts, Sows, and Boars

• Piglet Welfare: Increased preweaning mortality caused by clumsy or lame sows treading on or crushing piglets.

• Salvage Value: Decreased value of culled sows due to excessive weight loss and higher mortality rates.

• Pathogenesis: Driven by inadequate or unbalanced Calcium, Phosphorus, or Vitamin D; worsened by the high calcium demands of milk secretion during lactation.

• Clinical Presentation: Acute lameness, paraplegia, or fractures (femur, humerus, lumbar vertebrae, ribs) during late gestation, lactation, or post-weaning.

• Risk Factors: Limited exercise and short recovery times (less than 7 days) between breeding cycles.

Osteomyelitis and Spinal Abscesses:

• Etiology: Often secondary to vertebral fractures or "showering" of organisms from superficial wounds or respiratory/GI tracts.

• Primary Agent: Trueperella pyogenes is the most frequent cause of suppuration and abscesses.

• Clinical Signs: Nonspecific lameness, ataxia, hypermetria, or bilateral flaccid paralysis of the pelvic limbs.

• Prognosis: Recovery is highly unlikely; affected animals should be culled.

• Clinical Indicators (Specific Gaits):

  • "Knee walking": Indicates severe DJD in the elbows.

  • "Elephant on a ball" stance: Indicates DJD in the stifles, tarsi, or intervertebral joints.

  • Hopping/Collapse: Associated with separation of the ischial tuberosity.

• Risk Factors: Genetic predisposition (certain boars); fastest-growing, most muscular, and heaviest pigs are at higher risk.

Foot Disorders:

• • Prevalence: High (20%–68% morbidity); significantly impacts productivity and longevity.

  • Common Lesions: Heel erosions, white line separation, toe/sole erosions, and vertical hoof wall cracks.

  • Infectious Agents: Mixed infections involving Trueperella pyogenes, Fusobacterium necrophorum, and various cocci.

  • Management Challenges: Effectiveness of systemic penicillin is unproven and decreases as the lesion becomes chronic.

Trauma and Environmental Risks:

• Social Stressors: Fighting during mixing to establish social order; mounting by other sows in estrus.

• Environmental Hazards: Entrapment in farrowing crate bars; slippery floors; tearing of dewclaws on concrete slats.

• Handling: Anxiety in gilts during movement into farrowing facilities.

Prevention and Strategic Gilt Development:

• Selection: Cull gilts with conformational abnormalities or abnormal ambulation.

• Environment: Provide at least 1.1 square meters of space per animal; use nonslip, clean flooring; resurface abrasive areas.

• Nutrition: Ensure adequately fortified rations; supplement with biotin and trace minerals to enhance hoof strength.

• Strategy: Purchase gilts at < 75 kg; restrict feed intake to slow growth; wait until 8–10 months of age for first breeding.