glub glub Flashcards
FS01-03
are fish covered by the UK’s veterinary surgeons act (VSA)?
no
are fish covered by UK medicines law?
yes
name 2 things that can hamper the ability of making a diagnosis in an aquaculture case
- inability to directly observe stock
- relatively limited range of clinical signs displayed
why are dead fish of limited value in diagnosis in an aquaculture case?
due to rapid decomposition
name 4 ways to lessen the stress on fish
- minimise handling
- increase oxygenation
- reduce effects of temperature
- decrease feeding
name the 8 PM samples you should take from a fish
- gills
- skin & muscle
- kidney
- spleen
- liver
- heart
- stomach & gut
- brain
PM samples for what diagnostic test are now standard for fish?
PCR
name 3 routes of treatment for fish
- injection
- in water (bath or dip)
- in feed
in freshwater fish, when are sedatives and anaesthetics principally used?
during vaccination process
on marine farms, when are sedatives and anaesthetics principally used?
during smpling
(eg lice counting)
what is fish metabolism dependent on?
temperature
what is the equation for a Degree day (°D) for fish?
°D = temp in °C x number of days
how long will it take for a drug with a withdrawal period of 500 degree-days at 10°C until the fish is safe to harvest?
50 days
does water hold more or less oxygen than air?
less
which temperature of water holds more oxygen?
warm or cold?
cold
what is the principal respiratory organ of a teleost?
gills
what is fish skin formed of and covered by?
formed of living cells
covered by a variable mucus layer
what is fish skin more like in terms of mammalians?
gut epithelium
cells in here can migrate to cover wounds in fish
hypodermis
what layer are scales embedded within in fish?
dermis (lower layer)
what does scale loss indicate in fish?
significant skin damage
what is the most common type of white blood cell in fish?
lymphocytes
name the white blood cell found in fish
sequester foreign material;
involved in encapsulation
melanomacrophages
is acute inflammation more or less dramatic in teleost fish compared to endotherms
less dramatic
this is a frequent finding in bacterial infections in fish
septicaemia
name 2 common responses of fish to insult
- hyperplasia
- hypertrophy
what is the generally accepted level of dissolved oxygen (DO) for salmon?
above 7 mg/L
this is the principal freshwater problem;
classified as oomycetes: fungus-like water moulds;
often affects maturing broodstock, their eggs and alevin
Saprolegnia spp.
name 3 parts of controlling fungal & associated pathogens in fish systems
- good hygiene
- water management
- careful husbandry
this is the only UK-authorised medicine for fish against fungal & accociated pathogens but may not be effective alone
Pyceze (active ingredient: bronopol)
name 3 treatments for fish against fungal & associated pathogens
- Pyceze (bronopol)
- formaldehyde
- salt
what are the 2 outcomes of principal bacterial syndromes in fish
- ulcerative skin diseases
- septicaemias
swabs from where in the moribund fish are most useful for diagnosis in septicaemias
the kidney
what is the most common way to give antibiotics to fish
in-feed
how are antibiotics typically given to high-value individual fish?
injection
name 2 UK authorised antibiotics for fish
- aquatet (oxytetracycline)
- florocol (florfenicol)
vetremox (amoxicillin) no longer made
this is a major production-limiting disease in the developing stage of European salmon farming;
bacterial septicaemia;
significant AMR issue
furunculosis
which bacteria causes furunculosis (bacterial septicaemia) in salmon?
Aeromonas salmonicida
this is the first choice treatment for Enteric Redmouth (Yersinia ruckerii) in fish even though it is now in category B - “restrict”
oxolinic acid
what are almost all smolts vaccinated against before sea transfer?
Furunculosis
what are most smolts vaccinated against before sea transfer?
viral diseases IPN and PD
how are the majority of effective vaccines for fish given?
injected intraperitoneally
how is the newest PD vaccine for fish given?
the first EU-authorised DNA vaccine
injected IM
what disease can be triggered in fish from giving vaccines?
Saprolegniasis
name 2 secondary infections that can be common in immunocompromised fish
- furunculosis
- piscirickettsiosis
name 2 signs of viral disease in fish
- decreased activity (less jumping)
- increased mortalities
name the Scottish viral challenge in fish
endemic in scotlans, ireland & parts of Norway;
can cause complete loss (necrosis) of pancreas and/or damage to heart and skeletal muscle (myopathies);
often associated with secondary lice infestation
Pancreas Disease (PD)
name 3 ways pancreas disease (PD) presents in fish
- sudden death
- periods of inappetance
- chronic ill-thrift
name the virus causing pancreas disease (PD) in fish
Salmonid Alphavirus (SAV)
name the virus causing heart and skeletal muscle inflammation (HSMI) in fish
Piscine Reovirus (PRV)
name the virus causing cardiomyopathy syndrome (CMS) in fish
Piscine Myocarditis Virus (PMCV)
name the Scottish viral challenge in fish
first recorded in Norway in 1984;
notifiable disease in the EU;
first notified in scotland in 1998;
control involves slaughter, with NO financial compensation;
virus is mutable:
CS: lethargy, loss of appetite, gasping at water surface, pale gills, dark liver, accumulation of fluid in body cavity, haemorrhage in internal organs
infectious salmon anaemia (ISA)
there is a wide range of these parasites affecting gills, skin and fins;
incidence decreases in more contained systems;
diagnosed via wet scrapes direct to microscope slide;
cause irritation, general morbidity
protozoan parasites
name 2 medical baths that can be used to treat fresh water pathogens
- bronopol (Pyceze, Cress)
- formaldehyde (Aquacen)
name 3 “traditional bath treatments” that can be used to treat fresh water pathogens in fish
- benzalkonium chloride
- Chloramine T
- common salt
name two species of sea lice that have been and continue to be a major problem in Salmon aquaculture;
can cause extreme damage to fish
- Lepeoptheierus salmonis (“Leps”)
- Caligus elongatus
if the average number of adult female Leps (sea lice) per fish per site is more than this number, then there must be action to bring it to <2 within 4wks
more than 6
the SalScot Code of Good Practice states that the average number of adult female Leps (sea lice) per fish per site should be les than this number from 1Feb-30 June
less than 0.5
the SalScot Code of Good Practice states that the average number of adult female Leps (sea lice) per fish per site should be les than this number from 1 July-31 Jan
less than 1.0
name 4 bath treatments that can be used to treat sea lice
- deltamethrin (AMX)
- azamethiphos (Salmosan Vet)
- hydrogen peroxide (Paramove or Asperix)
- freshwater
what in-feed medication can be used to treat sea lice?
emamectin (Slice)
name 4 reasons enclosed spaces can represent a challenging environment and creat issues with bath treatments
- potential for faecal contamination
- control of dissolved gases and pH
- physical damage
- complications from intercurrent disease
name 2 basic principles for physical treatment of sea lice
(require fish to be pumped from pens through a physical system which removes and collects lice)
- water jets (Hydrolicer)
- warm water (Thermolicer)
name 4 challenges of using Cleaner Fish to control sea lice on salmon farms
- polyculture
- nutrition
- environment
- pathogens
what is the minimum withdrawal for drugs used through the Cascade for fish?
500 degree-days
what is the aetiological agent causing Amoebic Gill Disease (AGD) in fish?
(Neo)Paramoeba perurans
name the fish disease
in Tasmania historically, relatively new phenomenon in European salmon aquaculture;
disease is seasonal;
presents as plaque-like lesions on the gill filaments;
fish will present with signs od resp dysfunction;
damage to gill tissue frequently causes haemorrhage and may result in anaemia in severe cases
Amoebic Gill Disease (AGD)
name 2 routine monitoring that farmers should be carrying out for Amoebic Gill Disease (AGD)
- gill-scoring system
- PCR tests
are there any authorised medicines for use against Amoebic Gill Disease (AGD)?
no
what is the treatment for Amoebic Gill Disease (AGD)
treatment baths
(freshwater, hydrogen peroxide)
name 2 other health threats that gill disease may be intercurrent with
- lice infestation
- viral cardiac myopathies
