Viral Diseases in Animal Production (Foot and Mouth Disease)

HOG CHOLERA (CLASSICAL SWINE FEVER)

• Etiology: The virus is transmitted through direct contact and is shed in secretions and excretions.
• Infected swine can be long-term carriers, shedding the virus for up to 157 days.
• Symptoms and Clinical Signs:
  • Acute type:
    • Lethargy, inappetence, fever, and cyanosis in ear, tail, vulva, and snout.
    • Rapid abnormal breathing, premature farrowing, increased stillborn and mummified fetuses, and preweaning mortality.
    • Lost libido in boars.
  • Chronic type:
    • Secondary bacterial infections, decreased FCR.
  • Subclinical type:
    • Many herds are diagnosed as seropositive but show no clinical signs.
• Treatment: No effective treatment, vaccines are available.

GLOSSARY OF TERMS

• ssRNA: Single-stranded RNA.
• dsRNA: Double-stranded RNA.
• HPAI: Highly Pathogenic Avian Influenza.
• LPAI: Low Pathogenic Avian Influenza.
• Terms in Susceptible Population:
  • Amplifying host.
  • Indicator host.
  • Maintenance host.
• Clinical Sign Terms:
  • Ataxia.
  • Conjunctivitis.
  • Coronary band.
  • Ecchymosis.
  • Epithelium.
  • Farrowing.
  • Hyperkeratosis.
  • Hypoplasia.
  • Interdigital.
  • Malaise.
  • Masseter muscle.
  • Mucopurulent.
  • Nystagmus.
  • Opisthotonos.
  • Parameters.
  • Phonation.
  • Preweaning.
  • Prognosis.
  • Prostration.
  • Rhinitis.
  • Seropositive.
  • Torticollis.
  • Vesicular.

VIRAL DISEASES (RNA VIRUSES)

FOOT AND MOUTH DISEASE

• Definition: Considered the most economically devastating livestock disease virus in the world.
• Causative Agent: Aphthovirus, ssRNA.
• Susceptible Population: Mainly affects cloven-hooved animals, with sheep and goats as maintenance hosts, pigs as amplifying hosts, and cattle as indicator hosts.
• Etiology: Transmission primarily occurs through respiratory aerosols or direct and indirect contact.
• Symptoms and Clinical Signs:
  • In cattle: Fever, anorexia, depression, decreased milk production, drooling of saliva, and vesicles of interdigital skin and coronary band of the feet.
• Treatment: No treatment is available, control is mainly focused on culling infected animals, and vaccines are available.

PORCINE REPRODUCTIVE AND RESPIRATORY SYNDROME

• Other Name: Mystery Swine Disease, Swine Infertility and Respiratory Syndrome (SIRS), Blue-eared disease.
• Causative Agent: Lelystad virus, ssRNA.
• Susceptible Population: Swine.
• Etiology: Transmission primarily occurs through respiratory aerosols or direct and indirect contact.
• Symptoms and Clinical Signs: Not specified.