1 / 26

Fish Health Protocols

Fish Health Protocols. Chris MacWilliams, DVM. Principles of Disinfection Disinfection: process that reduces or eliminates pathogenic microorganisms. Cleaning is the most important step in the cleaning and disinfection process Cleaning process has 5 steps: Dry clean Wet wash

Antony
Download Presentation

Fish Health Protocols

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Fish Health Protocols Chris MacWilliams, DVM

  2. Principles of DisinfectionDisinfection: process that reduces or eliminates pathogenic microorganisms Cleaning is the most important step in the cleaning and disinfection process Cleaning process has 5 steps: Dry clean Wet wash Rinse Dry Inspect

  3. Methods of Disinfection • Physical • Moist heat • UV light • Drying • Exposure to sunlight • Chemical • Chlorines (bleach) • Iodines (Ovadine) • Quaternary ammonium compounds (Diquat, Roccal) • Oxidizing agents (Virkon, Ozone)

  4. Chemical Disinfectants • Considerations: • Proven efficacy against pathogens of interest: • Bacteria, virus, protozoans, fungus, spores • Safety • Fish, user, equipment, environment • Affordable • Other: • Presence of organic matter • Effects on metals/fabrics/rubber

  5. Ovadine Egg Disinfection • Why? • Vertically transmitted diseases • On the surface of the egg • Within an egg • Disinfecting eggs significantly decreases pathogen loads • When? • During water hardening • After egg shocking and picking • After eyed eggs are transferred to a site

  6. Ovadine Egg Disinfection • How? 100 ppm = 10 mls of Ovadine per litre of water • Determine volume of heath tray • Add appropriate amount of Ovadine to tray full of water • Gently pour rinsed, fertilized eggs into tray preloaded with Ovadine solution • After 10 minutes without disturbance, restore water flow

  7. Ovadine Egg Disinfection • 1 volume of eggs : 10 volumes of disinfectant solution • Solution colour indicates efficacy Brown = active Yellow = inactive and should be refreshed • Make a fresh Ovadine solution for each lot of eggs

  8. Ovadine Egg Disinfection • Spent solution disposal • Dilution is standard, combined with hatchery effluent, or can be disposed to ground Neutralize: Sodium thiosulfate 0.78 X grams of iodine x 2 (safety factor) or 0.15 gm per litre of 100ppm solution Water should be colourless before discharge to ground

  9. Managing Egg Fungal Infections • Egg picking • By hand • Mechanical pickers • Chemical treatments • Formalin (Parasite-STM) • Hydrogen Peroxide • Salt • Bronophol (EDR) • Malachite Green

  10. Egg Picking • Dead eggs are food for fungus • After shocking eyed eggs – observe eggs for mortalities

  11. remove dead eggs promptly

  12. Early – remove affected

  13. Grape cluster – remove clumps

  14. Beyond treatment – discard tray

  15. Formalin Egg Disinfection • 1670 ppm for 15 – 20 minutes • Static bath till last few weeks till hatch • Then keep water flow >11 lpm • Hanging IV bags or chicken feeders

  16. Hydrogen peroxide (Perox-Aid) • 500ppm for 30 – 35 minutes daily • Comparatively environmentally benign • Will not work on established fungal infections – only preventative

  17. Others • Salt – Robertson Creek every 2 – 3 days • Bronophol – no benefits vs approved • Malachite Green – absolutely not!

  18. Sample Shipping to a Diagnostic Facility • Mortalities are unexpected • Clinical signs are suggestive of a disease of concern (eg. popeye and/or swollen abdomens at a facility with a history of recurrent BKD infection) • Daily mortality rate exceeds 0.5% of the population

  19. Selecting the samples • Moribund fish preferred • There may be a need to randomly sample apparently healthy fish from the population • Ask Fish Path Lab staff re: sample type, numbers and shipping info

  20. Before shipping • Collect fish history: • population size • clinical signs • mortality and morbidity rate • diet and feed consumption • water quality conditions • records of recent stressful events (e.g. low water event, marking) • vaccination status • disease and treatment history • Fill out a submission form

  21. Shipping Live Fish • Line a cooler with ice paks or double bagged ice • Cover ice with newspaper • Live fish are added to heavy duty plastic bag filled ¼ to 1/3 full of aerated ambient water • Oxygen is pumped into the bag to refill it. • The bag is securely closed off using elastic bands or tape. Double bag and placed in the Styrofoam cooler. • Each bag is clearly marked with information identifying contents. • The remaining space in the cooler is filled with cubed ice to keep the fish and water cool. • The lid is placed on the Styrofoam cooler and securely fastened with duct tape to prevent accidental spillage.

  22. Shipping • Include a pathology laboratory submission form or an accompanying letter with more detail • Include copy of mortality records if available • Clearly mark sample bags • The container is addressed to the laboratory at PBS and is clearly labeled with information as to originating site. • Contact lab with estimated time of sample arrival

  23. Shipping fresh dead fish • Fresh morts (red gills, firm flesh) should be placed in labeled, sealed double plastic bags without water. • Ship dead fish in a container on ice as described above for live fish. • Fish should not come in contact with the ice or freezer packs.

More Related