One of the purported major health issues that is faced by the tuna industry in South Australia is blood flukes. These are flatworms that live within the blood vessels and the heart of the fish, sometimes lodging in different organs where they evoke severe inflammation and cause death to the fish.
To remedy the situation, fish are fed a diet containing the anthelmintic praziquantel with good results. The abstract below is some of the work that was generated…. But is there a better option than having to medicate the fish?
If fish were slaughtered pen-side and all the discards flow back into the same waters where the fish are reared, then diseases such as these would become amplified. Fortunately, all byproducts are captured by gutters and bins around harvest tables and are transported to an onshore processing facility for rendering.
Good management options should always be sought before reaching for medication.
| Aquaculture | |||||||||||||||||
| Volume 337, Number 1 (March 2012) | |||||||||||||||||
 |
In vitroand in vivoefficacy of anthelmintic compounds against blood fluke (Cardicola forsteri) | ||||||||||||||||
| Authors: | Paul Hardy-Smith, David Ellis, John Humphrey, Mathew Evans, Daryl Evans, Kirsten Rough, Victoria Valdenegro, Barbara Nowak | ||||||||||||||||
| Author Affiliations: |
|
||||||||||||||||
| Source: | Aquaculture, Volume 337, Number 1 (March 2012) | ||||||||||||||||
| Page Numbers: | 39 – 44 | ||||||||||||||||
| Available Full Text: |
|
||||||||||||||||
| Abstract: | Blood fluke, Cardicola forsteri, infects Southern Bluefin Tuna, particularly during ranching. Efficacy of four anthelmintics was tested against this parasite. There was an agreement between in vitroand in vivoresults. Praziquantel was the only effective anthelmintic. It was the most potent anthelmintic in decreasing fluke responsiveness in vitro, with concentrations ranging between 1.5µg/mL and 200µg/mL stopping adult fluke response within less than 5min. In vivo, both the higher (150 mg/kg) and the lower (75 mg/kg) dose praziquantel treatment resulted in a significant reduction of the number of flukes present in the hearts. A significant effect of treatment on the mean number of blood fluke eggs per cm2of tuna myocardium was observed, with fish treated with either of the two doses of praziquantel having at least 6 times lower numbers of eggs in their hearts. Control fish and fish treated with praziquantel (both doses) and lower dose Closal had very low average number of eggs per cm2of gill and were significantly lower than in fish treated with fenbendazole. While this research shows that praziquantel is the treatment of choice against blood fluke, C. forsteri, further research is needed to determine optimum dose, best treatment application method, palatability and any potential side effects. | ||||||||||||||||
| Citation: | Paul Hardy-Smith, David Ellis, John Humphrey, Mathew Evans, Daryl Evans, Kirsten Rough, Victoria Valdenegro, Barbara Nowak . In vitroand in vivoefficacy of anthelmintic compounds against blood fluke (Cardicola forsteri). Aquaculture, Volume 337, Number 1 (March 2012), pp. 39-44, | ||||||||||||||||
| URL: | http://ejournals.ebsco.com/direct.asp?ArticleID=41F6BCDCE248CFBEB2C6 | ||||||||||||||||
