Fish (MC) Flashcards
Damage to the dermis/epidermis leads to damage of what underlying structure?
scales
**Response to insult - impact upon what 4 things
Ammonia excretion Gas exchange Acid-Base balance Salt Regulation
***Where would you want to look for pathogens that are systemic or affect the tail? Why?
- Look at the kidney
- Sinusoids of anterior kidney and peritubular capillaries are lined by renal portal MOs
- which pick up most of the pathogens in the body and from the tail
- Sinusoids of anterior kidney and peritubular capillaries are lined by renal portal MOs
Which heart layer contains coronary blood vessels? What types of fish is it best developed for?
Compact layer Fast-swimming, active fish
Spongy heart does not contain coronary blood vessels so it uses venous blood instead of oxygenated blood. Which metabolic pathway does it use?
Glycolytic
In fish, Cardiac Output is more of a fnx of ___________
more a fnx of stroke volume than heart rate
***Does ammonia by itself damage gills?
NO fish can adjust to increase ammonia levels; can lead to coma
***Why is it best to have a hospital tank set up to tx fish instead of treating the tank they are in most of the time?
B/c when you treat the tank –> treat filtration system –> fish may survive dz but then die from water quality problems
***What are the levels of free vs. ionized ammonia dependent upon
Dependent upon temp & pH
How can you remove chlorine from water
Aeration Zeolites (clays) Activated charcoals
What are melanomacrophages? Where are they found?
“cellular trashcans” –> lock away AG, dead cells Found in places w/high cellular turnover (spleen, kidney, liver, ovary hematopoietic tissue)
What is the function of retinal pigmented epithelium
Controls the amt of light (photoreceptors encased in melanin –> protects during day)
How can you tell if a fish dies in the day? night?
Day - photoreceptors will be tall Night - photoreceptors will be short
Fish tissues that regenerate
Muscle & Cardiac Myocytes CNS Retina
When does supersaturation of water occur?
Rapid increase in water temp or decrease pressure
What causes gas bubble dz? Tx?
Water is supersaturated w/gas Oxygen or Nitrogen –> bubbles of gas in blood cause emboli in vessels of gills, pseudo branch, &choroid gland Tx: Vigorous aeration or agitation
Nitrite causes _______
suffocation by irreversibly binding Oxygen (via methhemaglobin)
What agent is responsible for characteristic “hole in head”/white spot dz
Edwardsiella ictaluri
What agent is responsible for gas filled dermal & muscular lesions; emphysematous = putrid
Edwardsiella tarda
Atypical bacterial gill dz is a condition commonly affecting _____.
C/S? Lesions?
- salmonids in low water temperatures
- C/S: Lethargy/”Sleepy”, decreased fright response, will still eat
- Lesions: atrophied/”stumpy” lamellae covered in Pseudomonas
Why is nitrite not as big of a concern in salt water fish?
Cl- competes w/nitrite in gills
What causes respiratory distress syndrome
In warm or polluted waters, where O2 levels are low, the cost of extraction by the gills may be too high (the energy required for ventilation exceeds that released by the O2 so obtained)
What happens if there is a build up of CO2
Acidiosis–> increased gas levels (swim bladder & choroid) Exophthalmia Distended swim bladder Won’t submerge properly
What agent is responsible for Hemorrhagic Septicemia Dz
Aeromonas hydrophila
What agent is responsible for Furunculosis
Aeromonas salmonicidia
Pathognomonic for Furunculosis
Cardiomyopathy (will see bact. in spleen, kidney, and heart)
Function of gills
Respiration Osmoregulation Acid-Base balance Excretion of Nitrogenous Waste Salt Regulation
***Where is a good place to look for inflammation in gills?
Central venous sinus of filaments (can see neutrophils pouring out)
What is unique about the endocardial cells lining the trabecular
They increase surface area, highly phagocytic & have CYP-450
Most common cause of cataracts
zinc deficiency
2 most important dz affecting Koi
Costia (Icthyobodo neator)
Parasites restricted to GI –> PLE –> protein casts
Hexamitids salmonis
What does histozoic & coelozoic mean? Which is more damaging?
Histozoic –> w/in tissue –> more damaging Coelozoic –> w/in cavities & lumens
***What feature allows Gyrodactylids to multiply fast?
Some are viviparous –> they give live birth –> can multiply fast
***Which is more problematic: adult cestodes or larval cestodes?
larval cestodes
What causes coffee ground nucleus w/dark cytoplasm w/in skin/gill epithelium and affected fish seem agitated and exhibit flashing? What is the major issue with this?
Ichthyophthirius multifillis/Ich/White spot Breaks osmoregulation of tissue
***Fish tumors do NOT metastasize EXCEPT ________
Aflatoxin induced hepatic carcinoma
Reportable dz that invades the cartilage of head & spine –> labyrinth involvement –> whirling & spinal deformities
Myxobolus cerebralis (Whirling Dz)
What measures can be taken to prevent Whirling Dz?
parasites are mud dwelling –> keep young fish in concrete pond until >6m & cartilage ossifies to bone
What can occur if O. pseudophyllidea cestodes get too large?
pressure necrosis of visceral organs & parasitic castration
Causes gastric granulomas in people
Anisakis and Pseudoterronova
Viruses reportable to OIE
IHN (Infectious Hematopoietic Necrosis) VHS (Viral Hemorrhagic Septicemia) ISA (Infectious Salmon Anemia) EHN (Epizootic Hematopoietic Necrosis) SVC (Spring Viremia of Carp) Oncorrhynchus Masou Virus (Herp 2) Koi Herpes
Infectious Pancreatic Necrosis (IPN) path.
Necrosis of pancreatic acinar cells & mesenteric fat
IPN C/S
Anorexia, darkening, distended abdomen , exophthalmia NO myocarditis
Infectious Hematopoietic Necrosis (IHN) causes
acute necrosis of all cell types in the kidney and spleen Classic lesion - Melanomacrophages are totally necrotic in kidney
Causes viral encephalopathy vacular degeneration in brain and retina
Nodavirus (like BSE)
Causes hemorrhage in muscle as well as other places like choroid gland and heart –> exophthalmia and vascular damage
Viral Hemorrhagic Septicemia (VHS)
Carp Pox agent? Koi Herp agent?
Carp pox - Herp 1 Koi herp - Herp 3
1 of 2 top dz in Koi; high mortality
Koi Herp
Very common, doesn’t kill; iridovirus is the agent
Lymphocytosis
Lymphocytosis pathogenesis –> C/S
fibroblast replicate in dermis –> cytomegaly - grapelike clusters of cysts on skin
Alphavirus cause what dz in salt water fish? What is the “equivalent” in fresh water fish?
Pancrease Dz Sleeping Dz - freshwater
Alphavirus in pancreas dz causes
loss exocrine pancreas rhabdomyopathy - heart and skeletal muscle
Low Vit E associated with alpha virus leads to
oxidative stress
The difference b/w pancreas dz and sleeping dz beside salt vs fresh water is that sleeping dz has really severe ____
red muscle necrosis (heart and skeletal)
Infectious Salmon Anemia causes
hepatonecrosis, interstitial hemorrhage, & acute coagulative kidney tubular necrosis
