Fish

Question 1

Non-lethal testing you can do on fish

Answer 1

Mucous scrape
Gill smear (mucus only or biopsy – not ideal
Faecal sample
Blood sample (may be lethal in small fish) for haematology (manual), limited biochemistry, PCR for known pathogens (gill swabs)

Question 2

Lethal testing you can do on fish

Answer 2

Post-mortem examination
Histopathology (take ALL organs)
Microscopy of gill filaments
PCR for known pathogens on specified organs
Bacteriology of internal organs eg kidney

Question 3

Why is sampling dead fish for histopathology srongly discouraged and PM assessment (unless fish are very recently dead) may be of limited use in many cases

Answer 3

Fish tissues decompose faster than mammals

Question 4

HPE interaction

Answer 4

Host
Pathogen
Environment

Question 5

What disease is common in suboptimal environmental conditions or in the presence of parasites

Answer 5

Gill disease

Question 6

Fish with large skin lesions likely to die of ____________?

Answer 6

Osmoregulatory failure

Question 7

NOTIFIABLE DISEASES IN FISH

Answer 7

Epizootic Hematopoetic Necrosis (EHN)
Viral Haemorrhagic Septicaema
Infectious Salmon Anemia
Infectious Hematopoetic Necrosis
Koi herpes virus
Gyrodactylus
Bacterial kidney disease
Spring viraemia of carp

Question 8

Epizootic haematopoietic necrosis virus affects what kind of fish

Answer 8

Rainbow trout & red-fin perch

Question 9

First signs of EHN infected perch are…

Answer 9

large-scale mortalities of the population
Swollen spleen and kidney, along with petechial haemorrhaging seen internally
In rainbow trout, more chronic presentation

Question 10

the most serious disease of rainbow trout in aquaculture

Answer 10

VIRAL HAEMORRHAGIC SEPTICAEMIA (VHS)

Question 11

Disease Characterised by lethargy interspersed with periods of frenzied, abnormal activity.

Answer 11

INFECTIOUS HAEMATOPOIETIC NECROSIS

Question 12

GYRODACTYLUS SALARIS

Answer 12

External parasite primarily affecting Atlantic salmon

Question 13

Chronic disease affecting salmonid species caused by Renibacterium salmoninarum.

Answer 13

BACTERIAL KIDNEY DISEASE (BKD)

Question 14

Rhabdovirus carpio.
Affects all varieties of carp and other coarse fish species.

Answer 14

SPRING VIRAEMIA OF CARP (SVC)

Question 15

Disease of Scottish salmon causing- Skin damage, stress and general weakness

Answer 15

Sea lice

Question 16

What is one of the biggest health challenges facing salmon industry in Scotland.

Answer 16

Poor gill health
Increasing incidence and apparent complexity of gill disorders and other emergent diseases.

Question 17

Pathogens of interest causing gill disease

Answer 17

Neoparamoeba perurans (AGD)

Question 18

AMOEBIC GILL DISEASE (AGD) SCORE CARD

Answer 18

0-5
0- No sign of infection and healthy red colour
3- Established thickened mucus patch or spot groupings up to 20% of gill area
5-Extensive lesions covering most of the gill surface (50%+

Question 19

How Does Plankton Harm Fish?

Answer 19

How Does Plankton Harm Fish?
Reducing O2 content in water
Physical damage
Toxic damage
Supersaturation
Vectors for bacteria

Question 19

Monitor gill health using

Answer 19

Monitor gill health using:
Environmental measurements
Gill appearance + scores (AGD)
Other fish/site observations
Mucus scrapes
Regular qPCR from gill swabs
Histopathology ahead of any handling events or if any other concerns

Question 20

Pancreas Disease (PD) is a disease caused by infection with a virus

Answer 20

Salmon Alphavirus

Question 21

Cardiomyopathy Syndrome (CMS) is a disease caused by infection with a virus

Answer 21

Piscine myocarditis virus

Question 22

Heart and Skeletal Muscle Inflammation (HSMI) is a disease caused by infection with a virus

Answer 22

Piscine Reovirus