Viruses

Question 1

What is calf respiratory virus

Answer 1

Multifactorial disease
Mixed infections typical, viruses and bacteria
IBR, RSV (Respiratory syncytial virus), Pi3V (parainfluenza 3)
Minimum of £43 per affected dairy calf
£82 per affected suckler calf

Question 2

Common feline viruses

Answer 2

Feline parvo (panleukaemia virus FPV), calcivirus, herpesvirus
Less common due to vaccination – but remain important diseases

Question 3

What is feline infectious peritonitis

Answer 3

Sporadic disease
Sequel to feline enteric coronavirus is some cats

Pathogenesis unclear
Virus change?
Stress?
Host genetics

Question 4

What is malignant catarrhal fever

Answer 4

In cattle
Caused by OHV2- Ovine herpes virus
Virus infection in dead-end host
causes corneal ulceration, lesions on and discharge from eye, nose and mouth

Question 5

Costs of a viral disease

Answer 5

Costs of lost production
Culling
Banning of imports/exports
Costs of control

BVD estimated to cost £36 million pa to UK cattle industry

Question 6

Common viral zoonoses

Answer 6

Most are exotic to UK but may pose a risk in future
Hantaviruses (rodent urine)
Louping ill virus (very rare)
European Bat Lyssavirus (EBLV2)- causes rabies

Question 7

Possible clinical signs seen in acute viral disease

Answer 7

Majority of virus infections?

Signs depend on site of infection:
Respiratory, intestinal, neurological, renal etc.
Pyrexia, depression, anorexia commonly seen
Secondary bacterial infections common for intestinal and respiratory infections

Question 8

What is cat flu and its clinical signs

Answer 8

Acute disease

Calcivirus, Herpesvirus
Nasal, ocular discharge, pyrexia, anorexia, lethargy
FHV: corneal ulcers
FCV: ocular ulceration

Question 9

Clinical signs of Calf Respiratory Disease

Answer 9

Cough
Nasal, Ocular discharge
Pyrexia
Depression

Question 10

Clinical signs of canine Parvovirus

Answer 10

Acute disease
Vomiting, bloody diarrhoea
Virus replicated in cryts of luberkein in intestines
Pyrexia
Neutropenia- virus also affects bone marrow
Has affinity for rapidly dividing cells- bone marrow and intestinal
Villus stunting, crypt dilation and necrosis

Question 11

Possible clinical signs of a chronic viral disease

Answer 11

Cancer
Immunological Effects

Question 12

Examples of chronic disease as a sequel to acute disease

Answer 12

Chronic rhinitis in cats

Cats who have had cat flu in the past have turbinate damage, likely to have recurrent bacterial nasal infections

Question 13

Clinical signs of FIV

Answer 13

Feline Immunodefcicieny
immunosuppression, occasionally lymphoma, type of retrovirus

Question 14

Examples of viruses which cause cancer

Answer 14

Retroviruses e.g. FeLV, FIV, JSRV (Jaagsiekte sheep retrovirus), KoRV (koala retrovirus)
Herpesviruses e.g. Marek’s Disease (highly contagious viral neoplastic disease in chickens)
Papillomaviruses e.g. BPV-2, BPV-4

Question 15

What is the difference between immunosuppression and immunopathology and examples viruses that cause each

Answer 15

Immunosuppression- inappropriate/lack of immune response
FIV
Infectious Bursal Disease
BVDV
Parvoviruses

Immunopathology- appropriate immune response
FIP

Question 16

Are clinicopathological changes helpful in diagnosing viral infection

Answer 16

Typically not that helpful to making a diagnosis of a viral infection
Reflect underlying pathology- e.g. with viral infection of kidney, it would give you an indication of the extent of kidney damage
Evidence of cell death and tissue damage?
Inflammatory response
lymphopenia?
neutrophilia with secondary infection?

Question 17

Important point to remember about pre-natal infections such as schmallengburg

Answer 17

Infection will have occurred some time ago when the dam was pregnant, long before you see the signs in offspring

Question 18

3 options for viral diagnosis

Answer 18

Detection of virus antigen
Detection of virus nucleic acid

Detection of antiviral antibody

Question 19

Influence of diagnostic test for canine parvovirus + 3 possible ways to test

Answer 19

May not change your approach but may change management
Can confirm presence with cage side antigen test
SNAP test or Lateral Flow
May help with prognosis
Neutropenia
Need for isolation to prevent spread
Can also send sample for PCR

Question 20

Influence of diagnostic tests for calf respiratory disease

Answer 20

Won’t change treatment but might impact which vaccinations you recommend to the farmer as you will know which viruses are present

Question 21

Diagnostic tests for feline infectious peritonitis

Answer 21

Very challenging- speak to clinical pathologist

Question 22

Diagnostic tests for BVD

Answer 22

Bulk milk antibody can be useful to detect how much infection is present

Question 23

Diagnostic tests for Avian Influenza
tissue, who does it, what is test

Answer 23

All done by APHA
Tracheal, oropharyngeal and cloacal swabs
Fresh tissue samples
Virus detection by RT-qPCR
Sequencing and/or serotyping to confirm virus subtype (e.g. H5N1)
Detect how pathogenic the virus is