Clinical signs Abnormal swimming ( Flashing, circling, sluggish and itching ). Surfacing and gasping ( Asphyxia ). Excessive skin mucus ( patchy then generalized ). Pathognomonic white spots (Ichthyophthiriosis), Yellow shine or Rust (Oodiniosis). Emaciation and death. Skin haemorrhages, erosions and ulcerations.
White spot disease
Cryptocarion irritans infection in marine fish
Surfacing and gasping in gill infection
Diagnosis of External parasitic Diseases 1. History ( new introduced fish, water parameters,……… 2. Clinical signs and lesions. 3. Demonstration and identification of the causative parasites Skin and gill mucus scraping (wet mount). Stained skin and gill mucus smears.
Treatment of External parasitic Fish Diseases External chemical treatment Dip treatment Bath treatment Flush treatment Indefinite bath treatment Non-chemical treatment Increase water temperature in White Spot disease Change water facility Use of ultraviolet radiation in re-circulating system
Types of Chemical treatments 1. Disinfectants: Pot. Permenganate. Malachite green. Formaline. Na Cl. Acriflavin. Methylene blue.
Control of Fish diseases in infected fish farms In infected earthen ponds: o Drainage o Dryness o Disinfection using quick lime In infected concrete or fiberglass fish tanks: o Drainage o Disinfection with strong antiseptics
Hexa mitiosis Systemic infection caused by an internal flagellated protozoa Causative protozoa Hexamita truttae Hexamita salmonis Hexamita intestinalis
Mode of infection and transmission: 1. Infection through ingestion. 2. Transmission is from dead fish and contaminated water body. Pathogenesis Hexamita is normal inhabitant of intestine Small numbers Large numbers Intestinal irritation Intestinal destruction No signs Excess mucus Systemic form Off food & emaciation Hole in head
Clinical signs: 1. Off food. 2. Emaciation and tucked up abdomen. 3. Mucus shreds from the vent. 4. High mortality in severe cases. 5. Hole in the head in systemic form (Fistula behind the head exuding white material).
Diagnosis Clinical signs and lesions (Non-confirmative) Laboratory ( Confirmative) Sampling ( Intestinal mucus ) Qualitative Quantitative (Count/ MF) = Negative 5 – 15 = Mild = Moderate 30 – 100 = Severe More than 100 = Marked
Treatment and control 1. Expulsion 2. Hexamiticides Saline purgative (MgSO 4 ) 1.Aresenical (Carbersone). 2.Murcurial (Calomel). Not to be used in food fishes Sulfonamides Can be used in food fishes
Fish Helminthosis Helminthes infection or infestation ? Helminthes of fishes Platy helminthes Round worms Trematodes Cestodes LarvaeA dults