Viral Gut Diseases

Question 1

What are the two main species of parvovirus?

Answer 1

1. Canine parvovirus
2. Porcine parvovirus

Question 2

What are the pathological features of parvovirus?

Answer 2

• Has a single stranded DNA genome
• icosahedral capsid
• non-enveloped which means it can survive well in the environment

Question 3

How long is the parvovirus genome?

Answer 3

4-6kb long

Question 4

Where does the parvovirus genome replicate?

Answer 4

It replicates in the nucleus

doesn’t encode its own replication enzymes

Question 5

During what phase of the cell cycle does parvovirus replicate?

Answer 5

DNA replication occurs in the S phase

Question 6

What are the general characteristics of parvovirus?

Answer 6

has a small genome, this means that small changes have large consequences
and it requires rapidly dividing cells

Question 7

What are the preferential replication sites for parvovirus?

Answer 7

• Intestinal crypt epithelial cells (adult hosts).
• Foetal lung and liver.
• Bone marrow cells (important in diagnosis)

Question 8

How is parvovirus transmissed?

foecal-oral route

Answer 8

Large quantities of virus particles are released into the environment in faeces
Infection of new hosts is via the oral route

Question 9

What plays an important role in the transmission of parvovirus?

Answer 9

Fomites
e.g farm setting in poultry and kennels in dogs/cats

Question 10

What is the pathogenesis of porcine parvovirus?

Answer 10

It is a global issue in pig farms (enzoonotic)
has a rapid and widespread transmission
* causes mild diarrhoea in adults
*

Question 11

How does porcine parvovirus enter the foetus?

Answer 11

via infected macrophages
then has a rapid growth in the foetus

Question 12

When is the virus excreted in the foetus?

Answer 12

10-14 days post infection

Question 13

How may you diagnose PPV?

Answer 13

Tissue faecal sample
-test for the virus isolation in tissue culture

Blood/Serum
-* Haemagglutination Inhibition test (HIT).
* Capsid proteins of PPV agglutinate red
blood cells
* ELISA

Question 14

From what virus did canine parvovirus evolve from?

Answer 14

Feline panleukopeania virus

Question 15

What are the clinical signs of feline panleukopaenia virus in adult cats?

Answer 15

• Fever
• Profound depression
• Rapid and severe weight loss
• Dehydration followed by vomiting
• Diarrhoea 1-2 days later
• abdominal pain

Question 16

What are the clinical signs of feline panleukopaenia virus in kittens?

Answer 16

• sudden onset depression
• jaundice, vomiting, diarrhoea
• up to 90% mortality ‘
  *

Question 17

How may you diagnose feline panleukopaenia?

Answer 17

Faecal and Blood Sampling, both using ELISA tests

Question 18

How can Feline parvovirus be treated?

Answer 18

Supportive therapy e.g
* Hospitalisation
* IV replacement of fluids and electrolytes

Question 19

How can you control feline parvovirus?

biosecurity wise

Answer 19

• Virological properties make it very difficult to exclude from catteries etc
• Bleach (hypochlorite) 3% :
• but its rapidly inactivated by organic material.
• Quarternary ammonium compounds ineffective.

Question 20

How can you control feline parvovirus?

vaccination wise

Answer 20

• Inactivated, modified live or multivalent vaccines.
• Newborns are protected by maternal antibodies – wane around 4-6 wo.
• May be a small window of susceptibility prior to first vaccination.
• Most frequent reason for vaccine failure is maternally derived antibody (MDA) interference.
• Example vaccination:
• Kittens at 6-9 wo, booster at 10-12 wo and 16-18 wo then annually

Question 21

What are the two forms of canine parvovirus?

Answer 21

• Enteric Form
• Cardiac Form

Question 22

What is the incubation period of canine parvovirus?

Answer 22

3-14 days

Question 23

What are the clinical signs of the enteric form of canine parvovirus?

Answer 23

• Sudden depression and loss of appetite.
• Fever (esp. in puppies).
• Vomiting and diarrhoea – can be haemorrhagic.
• Rapid dehydration.
• Shock and death (acute cases).

Question 24

What are the clinical signs of the cardiac form of FPV?

Answer 24

• Damage during development, symptoms
  after birth.
• Dyspnoea (laboured breathing).
• Depression.
• Cough.
• Ascites (fluid in abdomen).
• Death typically 12-16 wo.

Question 25

What is the laboratory diagnosis of canine parvovirus?

Answer 25

Lab testing is required to confirm the clinical diagnosis
Faecal samples are more appropriate than blood samples

Question 26

How can you treat canine parvovirus?

Answer 26

• Enteric form treatment similar to FPV – IV fluids.
• Cardiac form – treatment is ineffective and mortality is very high.

Question 27

What are two examples of rotaviruses?

Answer 27

• Bluetongue
• African Horse Sickness

Question 28

What family are coronaviruses members of?

Answer 28

Coronavirdae

Question 29

How would you control PPV?

Answer 29

In an unvaccinated herd, the clinical disease occurs in 4-5 year cycles
Expose the susceptible stock before breeding age- this reduces incidence

Question 30

How are inactivated vaccines used to help control PPV?

Answer 30

• They are more advantageous prior to herd infection
• Vaccination of all gilts 2-3 weeks prior to service with a booster 2 weeks later and then another annual booster
• Cost of vaccination is outweighed by the economic damage of an outbreak

Question 31

What blood samples may you take to help determine Canine Parvovirus?

Answer 31

• ELISA- Viral specific natibodies
• Haemagglutinin Inhibition Test
• Demonstarte Leukopenia in whole blood
• Antibodies may not always be instructive

Question 32

What is the best biosecurity for canine parvovirus?

Answer 32

• Virological properties make it hard to exclude
• Bleach 3% is a good disinfectant
• Isolation of sick puppies