25. Diseases caused by EHV-2, EHV-3 and EHV-5 viruses in horses.

Question 1

EHV-2 AND EHV-5 Causative agents epizootiology?

Answer 1

EHV-2 & EHV-5 infections of horses

• Causative agents: Equid herpesvirus 2 & 5 ʹ gammaherpesvirinae, propagated in horse-derived cells
• Epizootiology:
• widespread occurrence, isolation from clinically healthy horses too, low virulence

Question 2

EHV2 AND 5 Clinical signs?

Answer 2

Clinical signs:

• In few week old foals fever, mild resp signs (serous nasal discharge, coughing)
• recovery in approximately one week
• Rh. Equi colonisation on the weakened lung mucosa ʹ pneumonia
• Keratoconjunctivity, swollen LNs
• The role od EHV-5 is suspected in the background of horse multinodulary pulmonaru fibrosis

Question 3

Diagnosis and prevention of EHV 2 AND 5?

Answer 3

Diagnosis:

• virus isolation
• nasal swab, BAL (EHV-5),
• PCR; serology: VN

Prevention:

• hyperimmune serum (10 days of age protects for 6 weeks)

Question 4

Coital exanthema Causative agent and epizootiology?

Answer 4

Coital exanthema of horses

Causative agent:

• Equid herpesviruse 3 (EHV-3) ʹ alphaherpesvirinae, worldwide distributed, disease rarely
• Venereal disease affecting both sexes!

Epizootiology

• Spread:
• mating,
• iatrogenic (contaminated equipment),
• foal from the teats
• Long term carriage,
• short seroprotection
• repeated occurring signs

Question 5

Pathogenesis, clinical signs and prevention?

Answer 5

Pathogenesis, clinical signs:

• 6- 8 days of incubation
• Multiplication in the genital mucosa ʹ degeneration of the cells
• Nodules & pustules on the epithel of the vagina, penis & praeputium ʹ after eruption erosions,scabs
• recovery w/in 2-3 weeks
• depigmented spots remain
• Can spread to udder - to the lips of the suckling foals
• Benign; no foetopathy, no abortion, no change in pregnancy rates!

Prevention:

• no mating during signs & one month thereafter