Management of Fish Parasiticides

Question 1

37% formaldehyde in aqueous solution
FDA approved as parasiticides for use in finfish and penaeid (saltwater) shrimp
*used as a prolonged bath at concentrations of 15–25 mg/L.

Answer 1

Formalin

Vigorous aeration during formalin treatment is essential

Question 2

“low regulatory concern” by the FDA and has many uses in fish medicine, including *destruction of single-celled protozoans and *management of osmoregulation

Answer 2

Salt
*Salinity (1 ppt = 1 g/L).

Seawater is typically 32–37 ppt salt.

Question 3

a 30 ppt dip for 0.5–10 min,

Answer 3

For freshwater fish,is an effective ectoparasiticide and is strongly recommended when moving fish

Question 4

When fish show signs of distress, commonly manifested by they should be removed from the bath.

Answer 4

rolling on their side

Question 5

The use of salt is a quick and effective way to minimize the introduction of some ___

Answer 5

protistans into a system with new fish.

Question 6

is recommended for transportation of freshwater fish; most species will tolerate this concentration for several hours or days.

Answer 6

A solution of 5–10 ppt salt

Question 7

Lowering salinity to ___can be very useful when treating some parasitic diseases, particularlyCryptocaryon.

Answer 7

16–18 ppt

Question 8

___in saltwater systems, is sometimes applied in a chelated form, because it stays in concentration longer.

Answer 8

Copper,

*extremely toxic to invertebrates and plants, which must be removed before the water is treated.

Question 9

can be used to treat marine fishes, but the concentration of active copper (Cu2+) must be closely monitored (test kits are available) and should be maintained at 0.18–0.2 mg/L for up to 3 wk.

Answer 9

Copper sulfate (CuSO4)

Question 10

have been used in nonfood fish practice for decades to control monogenea, parasitic crustaceans, and leeches

Answer 10

Organophosphates

Question 11

used in freshwater systems, for ornamental fishes only, at concentrations of 0.25 mg/L as an indefinite bath.

Answer 11

Organophosphates

*sold as 37.3% active ingredient liquid.

Question 12

Toxicity and efficacy are affected by ___

Answer 12

pH, with more acidic pH resulting in increased toxicity

Question 13

Some veterinarians add____to the food of sensitive freshwater fishes and marine exhibit fish before treatment with organophosphates.

Answer 13

atropine(0.1 mg/kg, PO, IM, or IC)

Question 14

Because of ____organophosphates should not be used in outdoor ponds, unless specific provisions for such use exist in state law and are followed by the veterinarian.

Answer 14

environmental concerns,

Question 15

After treatment with organophosphates, most facilities hold water for______

Answer 15

up to 96 hr before allowing any discharge, and divers are usually restricted from entering exhibit tanks for at least 48 hr

Question 16

a chitin synthesis inhibitor effective against anchor worms (Lernaea), fish lice (Argulus), and other crustacean parasites in aquarium fish only.

Answer 16

*Diflubenzuron
-used as a prolonged bath at concentrations of 0.03 mg/L
-long half-life (>1 wk)
_treated water should be retained for 28 days and then run through a carbon filter before discharge.

Question 17

used to control intestinal protozoans and can be delivered in a medicated food or as a bath when fish are anorectic.

Answer 17

Metronidazole

• very effective againstSpironucleusspp
• not seem to be effective against gastric infections withCryptobia iubilans.
• concentration of ~7 mg/L (~250 mgmetronidazoledissolved in 10 gal. of water) can be administered daily for 5 days.
• can be administered in medicated feed at 50 mg/kg, PO, for 5 days.
• not be used in food fish in the USA.

Question 18

used to control intestinal helminths in fish.
dosage of 25 mg/kg
delivered in food for 3–5 days

Answer 18

Fenbendazole

• has been used in a bath treatment, high mortality has occurred
• not recommended

Question 19

administered in a bath treatment at a concentration of 2 mg/L
*not be used in food fish in the USA.

Answer 19

Levamisole

Question 20

• selective for flatworms, so consequently is used to control cestodes and external monogeneans

Answer 20

Praziquantel

• prolonged bath in large marine aquaria for control of capsalid monogeneans
• applied at a concentration of 5 mg/L

Question 21

PO dose of Praziquantel

Answer 21

*35–125 mg/kg for up to 3 days or as a * short-term bath treatment at a concentration of 10 mg/L for 3 hr

Question 22

controlAmyloodiniumspp in ornamental marine fish
Results are mixed, but advantages include decreased labor, because intensive water testing is not required (as is the case for Cu2+).
.

Answer 22

Chloroquine

bath 10 mg/L