Feline Panleucopenia



Antigenicity

  • One serotype

Hosts

  • Cats
  • Mink
  • Raccoons
  • Pandas

Pathogenesis

  • Also known as Feline Infectious Enteritis and Feline Panleukopenia
  • Often fatal
  • Pyrexia, severe enteritis (often bloody), dehydration, leukopenia, anemia
  • Kittens <2 weeks show cerebellar hypoplasia
  • Kittens more susceptible than cats
  • Oral infection
  • Initial replication in pharyngeal lymphoid tissue
  • Viremia
  • Virus targets rapidly dividing cells: lymph nodes, bone marrow, crypts of small intestine

Epidemiology

  • Infection by direct contact and fomites
  • Subclinical infections occur
  • Virus excretion can be persistent
  • Endemic worldwide

Diagnosis

  • Clinical signs
  • Hematology: leukopenia
  • Can be confirmed by haemagglutination (HA) or ELISA using feces

Control

  • Inactivated vaccines are available and essential for boarding
  • Administered parenterally post-weaning to induce a systemic immune response to neutralize viremia
  • Annual booster

Parvovirus Enteritis

  • Parvovirus enteritis is also know as feline infectious enteritis or feline panleucopenia
  • Since a vaccine is available, this disease is now uncommon.
  • Over the last 10/15 years this has been seen primarily in the cat, but it is now also seen in the dog.

Clinical

  • Manifests mainly in cats under 6 months old.
  • Common in groups of unvaccinated cats.
    • Produces big outbreaks, with vomiting and pyrexia.
  • Severe vomiting and diarrhoea occur.
    • diarrhoea is thin, watery and foul-smelling, and may also be blood-tinged.
      • Animals usually die despite treatment- die from dehydration.
  • Animals suffer from fever.
  • Pancytopaenia also occures.
    • White blood cell count drops very low so as to become almost non-existent.
      • Drops to 1/ml from 10000/ml.
    • Animals may therefore also die from other infections.

Pathology

Gross

  • Virus targets crypt cells and lymphoid areas.
  • In the cat, the intestine is thickened, turgid and swollen.
    • Has a pale, dull and mottled appearance.
    • The contents are rather dry - this gets worse lower down the gut.
  • Areas of depression in the mucosa can be seen in the upper small bowel.
    • Due to necrosis of tissue overlying Peyers patch.
  • Lower down in the gut, enteritis is apparent.
    • Cat- fibrinous.
    • Dog- haemorrhagic.
      • Blood in lumen.
    • Inflammation sometimes doesn't appear very severe.
  • There may be very few lesions
    • Histology is usually required for diagnosis.
  • A radiomimetic virus.
    • Affects all rapidly dividing cells and destroys them.

Histological

  • The crypt lining cells undergo complete necrosis, but very little inflammation occurs.
    • Collapse of villous architecture.
  • May be fibrinous exudates on surface of mucosa.
  • The submucosa and lamina propria are not affected and are left intact.
  • Cyst-like structures are seen in the deepest parts of the glands of the intestinal mucosa, if the animal survives for more than a few days.
    • Flattened epithelial cells line these cystic glands.
      • Are enterocytes trying to repair the damage.
      • However, animals usually die from dehydration or secondary infection before the mucosa recovers.
  • Inclusion bodies may be seen, but these are very hard to find.
  • May get lymphocyte invasion of mucosa.
  • Lymph nodes appear pale and oedematous, and almost aplastic.
  • Bone marrow appears pale and fatty looking and is depleted of cells.