Disease Treatment

Methods of Disease Control in Fish Test and Slaughter Quarantine or restrict movements Destruction of transmission link Immunity/disease resistance Drug therapy

Types of Drug Therapies Drug/chemotherapeutics are small part of any health management plan - May increase carrying capacity - May be detrimental Types - Systemic - Topical - Disease prophylaxis - Injections - Disinfectants

Laws governing Drug use Federal food drug and cosmetic act of Limits use of most substances till safety to animals is proved Three Criteria for approval 1. Examined for effectiveness 2. Toxicity of Compound 3. Time of clearance of compound or metabolites The Revised act of 1965 included food additives

Drug Regulation Food and drug Administration is responsible for regulating drugs and chemotherapeutics Three levels of drugs 1. Approved 2. Low Regulatory Priority 3. INAD (Investigation New Animal Drug)

Good Management Practices Avoid/Limit disease occurrence treat on a population basis Questions to consider 1. What is the prognosis without treatment? 2. Does potential mortality warrant treatment? Four criteria to know 1. Water 2. Fish 3. Chemical 4. Disease

External Treatments Success is a balance of time in treatment and concentration of treatment Treatments are used to eliminate /reduce potential pathogens Also used as a tool for maintenance of fish health - Bactericides, fungicides, parasides

Types of External Treatments Dip Flush Bath Flow through Pro’s/Cons of Different approaches? - Handling aspect, mucous is primary line of defense - Concentration of treatment - Stress factors related to treatment

Systemic Treatment Administered in an oral route, sometimes parentally (BKD) An effective treatment must be able to control reproduction of the pathogen as well as safe and economical Limitations: Mixing Consistent feeding Each fish gets required amounts Prophylaxis (Not recommended)

Considerations with treatments Withdrawal Time - Drug - Fish Species - Water Temperature

x Wt. or volume of water % activity Desired concentration Wt. or volume of chem./drug x= Constant-Flow Treatments Flow rate (l/min) x Treatment time (min) x final concentration (ppm) x.001 Chemical strength (decimal fraction) = Wt. of chem./drug needed Amount of drug to feed Static Treatments Wt. of fish % activity Wt. of drug needed x = x Treatment level (mg/kg/day)