44. Feline calicivirus infections.

Question 1

Feline Calicivirus Infection: Summary

Answer 1

• Affecting domestic cat & other felids; Marine mammals; Dog
• Resistance: Survives in the environment for weeks
• Bleach inactivates the virus; detergent is ineffective
• One serotype; Antigenic variants
• Significant virulence changes

Question 2

Feline Calicivirus Infection: Epidemiology

Answer 2

• Worldwide; Shelters & breeding catteries
• FIV: Infection facilitates shedding
• 20-30% of cats are carriers - Ø Vaccination effect on shedding

Question 3

Feline Calicivirus Infection: Pathogenesis

Answer 3

Oronasal infection → Pharynx → Viraemia →

• Lungs; Mouth; Throat; Joint synovial membranes; Pads; Viscera
• Highly virulent strains: Haemorrhages & oedema
• Shedding via nasal, ocular & oral excreta
• Direct contact transmission

Question 4

Feline Calicivirus Infection: CSx

Answer 4

Differs with virulence

• 1^st Fever → Mild depression; 2^nd fever → Lesions
• Vesicles: Oral cavity; Nose; Pads
• Sneezing; Lacrimation; Nasal discharge; Dyspnoea; Pneumonia
• Lameness & fever (limping syndrome)
• Severe systemic syndrome
• Chronic stomatitis

Question 5

Feline Calicivirus Infection: CSx → Severe systemic syndrome

Answer 5

VS-FCV: Virulent systemic FCV (feline calicivirus) strains

• Fever (90%)
• Vasculitis - face & pad (50%)
• Resp. Signs (50%)
• Icterus (20%)
• Nose & intestinal bleeding (35%)

Up to 60% mortality

Question 6

Feline Calicivirus Infection: Pathology

Answer 6

• Oral mucosa & pads: Blisters; Epithelial necrosis - erosions
• Lungs: Alveolitis; Exud. pneumonia; Prolif. interstitial pneumonia
• Joints: Synovitis; Liquid accumulation

Highly virulent cases: Vasculitis; Hepatomegally; Pancreatitis; Pericarditis

Question 7

Feline Calicivirus Infection: Dx

Answer 7

• CSx
• Oropharyngeal swab: ELISA; IF; RT-PCR
• Serology: Virus isolation

Question 8

Feline Calicivirus Infection: DDx

Answer 8

• Feline Rhinotracheitis: Severe upper resp. lesions; Ocular lesions
• Bordetella bronchiseptica: Coughing; Pneumonia
• Chlamydophilia felis: Conjunctivitis; Pneumonia
• FLV/FCoV

Question 9

Feline Calicivirus Infection: Tx

Answer 9

• Supportive tx; Enteral nutrition; Parenteral fluid; Hyperimmune sera
• Maternal Igs protect for a few weeks
• Attenuated & Inactivated vaccine (bivalent)
  
  • ​Live vaccine
  • Protects for 10-12 months; Annual booster
  • May not prevent against infection or being a carrier
  • Protection from CSx