For AGD gill swabs can be used on both healthy and moribund/dead fish, but the sensitivity is higher on healthy fish. The sampling can therefore easily be done on random fish in connection with a routine sea lice count.
AGD analysis: better sensitivity with swabs than tissue
PatoGen has validated the use of swabs on gill tissue for the analysis of Paramoeba perurans (AGD). The experience with analyses on gill swabs is that there is better sensitivity compared to gill tissue. This gives a higher probability of detecting the gill amoeba at a early stage and the possibility of implementing measures.
AGD is an important gill disease in Atlantic salmon and is caused by the amoeba Paramoeba perurans. AGD is a highly infectious in the right environmental conditions and can cause major losses. PatoGen recommends using gill swabs for early detection of AGD in the risk period to keep control of the infection situation on the site, so that treatment can be implemented quickly enough.
Can also be used on other gill agents
Gill swabs can also be used to test for Candidatus Branchiomonas cysticola and Paranucleospora theridion. Analyses for these gill pathogens, in addition to AGD, can contribute with useful information on the gill health of the fish.