Environmental Resources Unit C Animal Wildlife Management

Problem Area 3 Fish Management

Diagnosing Fish Diseases Lesson 7

Diagnosing Fish Diseases How many of you have had a cold or the flu lately? What was some of the symptoms you had? How did you treat this illness?

Terms Abscess Bacterial disease Bathing Chemical disease Cyst Dipping Environmental disease Feed additive Fungal disease Hosts Indefinite treatment Infectious disease Lesion Non-infectious disease

Terms Nutritional disease Parasites Parasitic disease Physiological disorders Prevention Quarantine Sanitation Symptom Treatment Ulcer Vigor Viral disease

Objectives Identify signs of disease in fish. Describe the types of fish disease. Identify methods of preventing and treating fish disease.

What are signs of diseases in fish? Diseases may cause fish to: –Stop growing –Grow slower –Even die Identifying signs of disease early allows for treatment of disease in time to reduce the losses. Healthy fish are alert and active. Unhealthy fish display symptoms of disease. –A sign that a disease may exist

Common symptoms of disease Lack of appetite –Fish are active eaters. –Consume all of the feed rapidly after being fed. –A change of eating habits may be a symptom. Lack of vigor –Healthy fish are active and vigorous. –Vigor is the movement of fish in the water.

Common symptoms of disease Skin abnormalities –Ulcers Open sores on skin containing pus. –Lesions Result of an injury. –Abscess Area of the skin that is swollen and usually contain pus. –Cyst Pocket in the skin that contains fluid or dead skin.

Common symptoms of disease Abnormal body shape –Bulging eyes. –Growths around fins or mouth. –Swollen bellies. Change in behavior –Healthy fish behave similarly from day to day. –Producer must be familiar with normal behavior of fish.

What are the types of fish diseases? Infectious disease –Can be passed from one fish to another. –Caused by germs or pathogens. Non-infectious diseases –Can’t be spread from one fish another. –Not caused by germs or pathogens.

What are the types of fish diseases? Dead fish –Immediately remove. –Evaluate for signs of disease. aquaculture/

What are the types of fish infectious diseases? Bacterial disease –Caused by bacteria. –Usually internal. –Lab test required to test for disease. Fungal disease –Caused by tiny organisms called fungi. –Grow on dead flesh. –Could be a sign of another disease.

What are the types of fish infectious diseases? Viral disease –caused by a virus. –often undetectable and difficult to treat. Parasitic disease –Caused by parasites animals or plants that live in or on other animals (hosts). –Harm hosts by chewing or sucking. –If live in digestive system steals nutrients from host.

What are the types of fish non-infectious diseases? Nutritional disease –Inadequate diet –Not enough food –Improper nutrition –Too much food can cause problems also Environmental disease –Substances in the water –Include heavy metals, gas or pesticides

What are the types of fish non-infectious diseases? Chemical disease –Level of a chemical in the water reaches point that injuries or death occurs. –Come from pesticides or other pollutants. Physiological disease –Abnormal functions in the organs of the fish.

How can fish diseases be prevented and treated? Diseases among fish can be controlled in two different ways. 1.Prevention Keeping fish healthy and free of disease. 2.Treatment Using medication or other practices to help fish overcome diseases.

How can fish diseases be prevented? Sanitation –Keeping the water and facilities clean. –Washing tanks. –Ensuring people don’t introduce a disease. Quarantine –Separating some fish from the others to prevent diseases. –New fish are brought in to a facility it is common to quarantine them for a few weeks.

How can fish diseases be treated? Dipping –Immersing the fish for a few seconds in a concentrated solution designed to treat disease. –Used when a few fish need to be dipped. –Common dips include: Formalin salt

How can fish diseases be treated? Feed Additives –Medications mixed in with the feed. Bathing –Similar to dipping. –Except fish are placed in solution for a longer time.

How can fish diseases be treated? Injecting –medications may be injected in to the fish using a needle and syringe. Indefinite treatment –adding a low concentration of a chemical to the water over a long period of time.

Review / Summary What are signs of diseases in fish? What are the types of fish diseases? How can fish diseases be prevented and treated?