Caseous Lymphadenitis

Caseous lymphadenitis:

• • C. pseudotuberculosis carried on skin of sheep
  • Non-nitrate-reducing biotype
  • Infection follows tissue trauma such as shearing wounds
  • Incubation period 3 months
  • Chronic suppurative infection of sheep, goats and occasionally cattle
  • Abscessation of superficial and internal lymph nodes if haemtogenous spread occurs
  • Caseous abscesses with green colour and onion ring appearance
  • Ill thrift and pneumonia may occur
  • Condemnation of carcasses and hides
  • Infection spread by pus from abscesses, and oculonasal secretions
  • Organism survives in environment for several months
  • Sandwich ELISA detects circulating antibodies to phospholipase toxin
  • Control: importation measures including screening; culling of infected sheep, stict hygiene; inactivated vaccine
• Ulcerative lymphangitis:
  • Nitrate reducing biotype
  • Disease in horses and cattle
  • Infection through skin wounds
  • Lymphangitis of lower limbs or abscessation in pectoral region
  • Slow onset, usually becomes chronic
  • Affected lymphatic vessels swollen and firm with nodules
  • Oedema in affected limbs
  • Ulcerative nodules exude thick green pus
  • Lymphangitis and lymphadenitis in cattle with abscesses as well as coronary band lesions causing lameness
  • Antibiotic treatment and topical iodophore shampoo
• May cause myositis