49. Equine infectious arteritis. Flashcards Preview

Epidemiology final Topic (1-102) > 49. Equine infectious arteritis. > Flashcards

Flashcards in 49. Equine infectious arteritis. Deck (9)
Loading flashcards...
1
Q

Virus details?

A
  • 45-60nm diameter
  • Isometric nucleocapsid; enveloped (low resistance in environment)
  • +ss RNA genome (12-16kb)
  • 7 structural proteins (E, N, M, Gp2, 3, 4, 5)
  • Difficult to isolate; can survive in winter
  • Affects Eq, Su and Monkeys
2
Q

Equine viral arteritis OIE listed disease?

A

Equine viral arteritis ʹ OIE listed disease

Ethiology

  • Acute, contagious viral in equids ʹ fever, depression, anorexia, decreased WBC, edema, conjunctivitis, nasal discharge,
  • skin rash, temporary subfertility in stallions, abortion infrequent ʹ ill and foals die.
  • Variable % of post puberty colts and
  • stallions carry and shed through semen
  • Equidae: horses, ponies, donkeys and zebras (South American Camelids)
  • Present everywhere, but different distribution
3
Q

Epizootiology?

A

Epizootiology

  • 2 genotypes
  • 1 serotype ➝ difference in virulence, genetically (antigenic) more divergent strain in donkeys
  • Shedding

‣ Respiratory secretions

‣ Stallions: longterm carriers (10-70%), semen (for years), persistent infection in mature animals

‣ Mares: vaginal and uterine secretions

‣ Urine and faeces

  • Incubation period: 2-14 days
  • Sexual transmission: 1 week
  • Endothelia damage after 6-8 days
4
Q

Pathogenesis?

A

Pathogenesis:

  • Incubation period 2 ʹ 14 days
  • Viral intake: venereal, nasal (per os)
  • Primary replication: local lymphoid tissues (macrophage)
  • Viraemia:
  • Replicate in macrophages, endothelial cells, smooth muscle vascular cells
  • Damage of blood vessel walls (inflammation in the endothel and media)
  • 1) Solid haemorrhages, oedemas
  • 2) Placenta abruption, foetus is infected with virus
  • o Sexual transmission: 1 week, Endothel damages: after 6-8 days
  • Persistent infection
5
Q

Clinical signs?

A

Clinical signs

  • Mostly asymptomatic
  • Old or very young animals
  • Fever, depression, loss of appetite, somnolence, nasal discharge
  • Severe interstitial pneumonia / enteritis (very young may die)
  • Adult horses
  • Fever, depression, anorexia, somnolence, nasal discharge
  • Oedema: limbs, prepuce, scrotum, mammary gland, ventral abdominal wall, third palpebra -> hot painful
  • Urticaria: mainly on neck, head
  • Less frequently: conjunctivitis, photophobia, periorbital or supraorbital oedema, rhinitis
  • Gastrointestinal problems: Colic, obstipation -> diarrhoea
  • Mare: placenta lesions, abortion or stillbirth (10-60%)
  • Stallion
  • Temporary decrease of fertility, reduced sperm quality (increased scrotal temperature and
  • oedema), decreased libido, can persist for up to 4months
  • Quality of semen is not decreased in carrier stallions!
6
Q

Pathology?

A

Pathology

  • Oedema, congestion and haemorrhages
  • In subcutaneous tissues, visceral organs, lymph nodes,
  • Clear, yellowish fluid in body cavities
  • Pulmonary oedema, interstitial pneumonia, emphysema
  • Spleen infarcts, enteritis
  • Aborted foetuses
  • Partial autolysis
  • Excess fluid in the body cavities
  • Fibrinoid degeneration, inflammation and thrombus formation in small blood vessels
  • Interlobular interstitial pneumonia
  • Fibrinoid-necrotic enteritis
7
Q

Diagnosis?

A

Diagnosis

  • Clinical signs, pathology
  • Samples: nasal fluid, WBC, semen, caul
  • Isolation(CPE), IF, IHC, RT-PCR(semen)
  • Serology: VN (1:4), ELISA (gp5)
8
Q

Differential diagnosis

A

Differential diagnosis:

  1. equine influenza,
  2. equine infectious anaemia,
  3. African horse sickness,
  4. Getah virus,
  5. Hendra virus,
  6. equine rhinitis A and B,
  7. equine adenovirus,
  8. equine herpesvirus 1 and 4,
  9. leptospirosis
9
Q

Prevention?

A

Prevention

  • Control
  • Isolation of freshly infected animals
  • Symptomatic treatment (rest, NSAID)
  • Isolation & testing of new horses for 3-4 weeks(Serology)
  • Control of carrier stallions (test seropositive stallions with PCR)
  • Vaccination:
  • inactivated (in EU) 2X, eradication
  • attenuated USA

Decks in Epidemiology final Topic (1-102) Class (102):