|
VETCARE Ô |
MEDICATIONS
|
AQUAHEALTH Ô |
OXYTETRACYCLINE
(OTC)
Characteristics:
The tetracyclines
are broad spectrum bacteriostatic drugs acting within
the bacterial cell and blocking the ribosomal functions as regards protein
synthesis, such as building of enzymes. They comprise either natural
fermentation products or semi-synthetic derivatives. Oxytetracycline
(OTC) belongs to the natural tetracyclines and is
widely used in aquaculture. Despite its long usage in aquaculture world-wide as well as in the Mediterranean
fish farming, it is a potent antibiotic against the most common bacterial fish
pathogens, both Gram negative and Gram positive as well as against rickettsiae. In addition, it is relatively cheaper than
other broad-spectrum antibacterial drugs.
Composition
of OTC compounds:
OTC compounds for veterinary use in
aquaculture comprise 50% water soluble feed premixes in powdered form. 1g of
such powders contains 500mg Oxytetracycline HCl (about 500mg oxytetracycline
base) bound to a water soluble agent.
Indications:
OTC compounds are wide spectrum antibacterials against Gram negative and Gram positive fish
pathogenic bacteria, indicated for the treatment of fish systemic bacterial
infections caused by Aeromonas spp., Vibrio spp.,
Photobacterium spp., Yersinia spp., Pseudomonas spp.,
Staphylococcus spp., Micrococcus spp.,
Enterococcus spp. and
many others.
Prior to administration, always investigate the
sensitivity/resistance of bacteria (antibiogramme).
Precautions:
Serious adverse pharmacodynamic
effects of OTC on fish comprise immunosuppression
(reduced cellular and humoral responses as well as
reduced immunological memory) and reduction in lymphocyte, monocyte
and erythrocyte counts. Thus, administering OTC compounds to fish prior or post
vaccinations is not recommended.
OTC should not be administered
together with compounds containing quinolones (oxolinic acid, flumequine) nitrofurans, potentiated sulfonamides (e.g. Tribrissen, Optiprime), or penicillins (ampicillin, amoxicillin). In addition, OTC should not be
administered to fish for more than 12 consecutive days without at least a few
days break.
Administration
and dosage:
OTC 50% premixes are orally
administered via compounding with the fish feed. They may be mixed with fish
oil, which is then top-dressed onto pre-pelleted diets.
Alternatively, they may be diluted in some water, which is then sprayed on the
feed. After the feed dries in air, some fish oil may be used for top coating.
- Recommended therapeutic dose of active OTC
for marine farmed fish (Mediterranean):
100mg/kg of biomass/day (or 10g/100kg of biomass/day)
continuously for 10 days
- Respective dose for 50% powdered
premix: 20g/100kg biomass/day (or
200g/1000kg biomass/day) continuously for 10 days
- Recommended daily dosage of an OTC
50% premix compounded in 25 kg of fish feed (1 sack), according to
the feeding rate (expressed as percentage of fish biomass).
|
Daily feeding rate |
Fish biomass fed 25kg of feed |
OTC 50% premix /25kg feed |
|
0.5% |
5,000 kg |
1,000 g |
|
1.0% |
2,500 kg |
500 g |
|
1.5% |
1,670 kg |
334 g |
|
2.0% |
1,250 kg |
250 g |
Withdrawal period:
360
degree-days (21 days after the last administration at water temperature no less
than 17° C).
Storage
and packing:
OTC premixes are
available often in 5kg plastic containers/tubs and in 20kg reinforced sacks.
May be stored for up to 36 months in a dry, dark and cool (up to 25°C)
environment.
Containers must be closed firmly after use.
top
|
|
|
Links with: |
Copyright (c) Dr Panos
Varvarigos