Lymph. 1

• What is the aetiology of Granulomatous Lymphadenitis?

  • Mycobacterium species (e.g., Mycobacterium bovis, Mycobacterium avium ssp. paratuberculosis)
  • Fungal infections (e.g., Histoplasma capsulatum)
  • Foreign body reactions
• What causes Granulomatous Lymphadenitis?

  Chronic infection with slow-growing organisms such as mycobacteria or fungi.
• What are the pathognomonic lesions associated with Granulomatous Lymphadenitis?

  Granulomas surrounding the infectious agent and possible caseous necrosis.
• What pathology is associated with Mycobacterium bovis?

  Granulomatous lymphadenitis often in regional lymph nodes after primary infection.
• What is Johne's disease caused by?

  Mycobacterium avium ssp. paratuberculosis leading to granulomatous ileocaecal lymphadenitis in sheep.
• What are the sequelae of Granulomatous Lymphadenitis?

  Progressive caseous necrosis, regional lymph node enlargement, and potential spread to other organs.
• What is the aetiology of Pyogranulomatous Lymphadenitis?

  • Fungal infections (e.g., Histoplasma capsulatum, Pythium insidiosum)
  • Bacterial infections (e.g., Rhodococcus equi)
• What causes Pyogranulomatous Lymphadenitis?

  Infections that lead to both neutrophilic and granulomatous inflammation.
• What are the pathognomonic lesions of Pyogranulomatous Lymphadenitis?

  Combination of granulomatous and suppurative inflammation with pus and granulomas.
• What pathology is associated with Rhodococcus equi infection?

  Pyogranulomatous lymphadenitis in horses with multifocal pneumonia.
• What are the sequelae of Pyogranulomatous Lymphadenitis?

  Abscess formation and necrosis if infection persists, with potential spread to other organs.
• What is the aetiology of Suppurative Lymphadenitis?

  • Pyogenic bacteria (e.g., Streptococcus equi, Corynebacterium pseudotuberculosis)
• What causes Suppurative Lymphadenitis?

  Acute bacterial infections leading to neutrophil infiltration and pus formation.
• What are the pathognomonic lesions of Suppurative Lymphadenitis?

  Abscesses and necrosis in the affected lymph nodes.
• What pathology is associated with Strangles in horses?

  Suppurative lymphadenitis with abscess formation in regional lymph nodes.
• What are the sequelae of Suppurative Lymphadenitis?

  Abscess formation and necrosis of affected nodes, with potential spread of infection.
• What is the aetiology of Caseous Lymphadenitis (CLA)?

  • Corynebacterium pseudotuberculosis
• What causes Caseous Lymphadenitis (CLA)?

  Wound infections leading to chronic lymphadenitis.
• What are the pathognomonic lesions of Caseous Lymphadenitis (CLA)?

  Caseous necrosis with laminated appearance in the lymph nodes.
• What pathology is associated with Caseous Lymphadenitis (CLA) in sheep and goats?

  Chronic suppurative lymphadenitis with abscesses replacing lymph node tissue.
• What are the sequelae of Caseous Lymphadenitis (CLA)?

  Chronic, encapsulated abscesses in affected lymph nodes with potential spread to other organs.
• What is the aetiology of Eosinophilic Lymphadenitis?

  • Parasitic infections (e.g., migrating larvae)
• What causes Eosinophilic Lymphadenitis?

  Parasitic infections causing an eosinophilic inflammatory response.
• What are the pathognomonic lesions of Eosinophilic Lymphadenitis?

  Eosinophils packed in the subcapsular sinuses of affected lymph nodes.
• What pathology is associated with parasitic enteritis in small ruminants?

  Granulomatous lesions centered around remnants of parasitic larvae.
• What are the sequelae of Eosinophilic Lymphadenitis?

  Chronic inflammation and possible fibrosis of affected lymph nodes.
• What is the aetiology of Haemorrhagic Lymphadenitis?

  • Septicaemias and viral infections (e.g., endothelial damage)
• What causes Haemorrhagic Lymphadenitis?

  Vascular endothelial damage leading to bleeding into the lymph nodes.
• What are the pathognomonic lesions of Haemorrhagic Lymphadenitis?

  Dark red, moist lymph nodes due to hemorrhage.
• What pathology is associated with septicemia or viral infections?

  Haemorrhagic Lymphadenitis due to blood vessel damage.
• What are the sequelae of Haemorrhagic Lymphadenitis?

  Shock or hemorrhagic shock if systemic infection occurs.
• What is the aetiology of Parasitic Lymphadenitis?

  • Migration of parasitic larvae (e.g., nematodes)
• What causes Parasitic Lymphadenitis?

  Parasitic larvae migrate through tissues, causing granulomatous inflammation in the lymph nodes.
• What are the pathognomonic lesions of Parasitic Lymphadenitis?

  Granulomas and sometimes mineralized nodules in the lymph nodes.
• What pathology is associated with chronic parasitism in lymph nodes?

  Parasitic Lymphadenitis, particularly in the mesenteric lymph nodes.
• What are the sequelae of Parasitic Lymphadenitis?

  Fibrosis and chronic inflammation in affected nodes.
• What is the aetiology of Porcine Multisystemic Wasting Disease (PMWS)?

  • Porcine circovirus type 2 (PCV2)
  • Co-infections with other viruses (e.g., PRRS or PPV)
• What causes Porcine Multisystemic Wasting Disease (PMWS)?

  Porcine circovirus type 2 infection leads to immune system dysfunction.
• What are the pathognomonic lesions of Porcine Multisystemic Wasting Disease (PMWS)?

  Grape-like inclusions seen histologically and enlarged, firm lymph nodes.
• What pathology is associated with PMWS?

  Interstitial pneumonia and lymphoid depletion in various organs.