POM-V
Prescription Required
AMX 10 mg/ml Concentrate for Solution for Fish Treatment
Active ingredient: Deltamethrin
Form
Concentrate
Species
Atlantic salmon
Trout - Golden/Rainbow/Redband/Steelhead
Manufacturer
Pharmaq AS
VMD MA No.
21714/4004
What it's used for
For treatment of adult and preadult sea lice (Lepeophtheirus salmonis) on Atlantic salmon () and rainbow trout (Oncorhynchus mykiss).
Full indications, dosage and side effects ↓The prescription itself has a price. See what practices near you charge for a consultation and the written prescription fee.
Paying less for Deltamethrin
-
1
Ask your vet for a written prescription
They must provide one on request. Under the CMA Order the fee is capped at £21 from 2027.
-
2
Fill it at a registered online retailer
The CMA found online pharmacies 50–60% cheaper than practice dispensing on common medicines — typically £200–£300 a year.
Done — we'll email you when prices land.
Prescription required
Your vet must provide a written prescription on request. You can then purchase from any licensed online retailer.
Clinical information
AMX 10 mg/ml Concentrate for Solution for Fish Treatment — SPC Details
Source: VMD Summary of Product Characteristics (SPC). Last updated 26 Mar 2026.
For treatment of adult and preadult sea lice (Lepeophtheirus salmonis) on Atlantic
salmon () and rainbow trout (Oncorhynchus mykiss).
salmon () and rainbow trout (Oncorhynchus mykiss).
The delousing should be performed in a well-boat or in a sea-cage with a raised net
enclosed by a tarpaulin. This is to ensure proper control of the treatment volume and
the treatment dosage, in addition to reduce the amount of AMX used and the
environmental exposure. Calculate the water volume as exactly as possible to ensure
correct dosing.
Revised: November 2023
AN: 00944/2023 & 01613/2023
Treatment dose: 0.2 ml AMX per m
(1000 l) sea water in the treatment unit.
This corresponds to 2 microgram deltamethrin/litre sea water.
For calculation of the treatment volume in the unit, please refer to
the section below; “Treatment volume”.
Treatment period: 30 minutes
Treatment volume:
Well-boat: The dosage is calculated according to the actual volume of the treatment
unit.
Tarpaulin:
The dosage is calculated according to the actual volume of the treatment unit
(tarpaulin volume).
Method of administration:
The product should be brought to room temperature before use in order to flow more
easily out of the bottle. Shake the bottle well before use. Calculate the volume in the
treatment unit and the AMX dose. Use a suitable container and dilute the calculated
quantity of AMX in seawater. Diluting the product in a large volume of seawater will
ensure a better dispersion and thereby the efficacy of the treatment. After a short
period of stirring, the diluted solution must be spread evenly throughout the treatment
unit. It is recommended to use a pump with low or moderate pressure to further
improve an even dispersion. Do not disperse under high pressure as this may cause
atomising and/or foaming.
It may be necessary to repeat the treatment if reinfestation with sea lice occurs, but
due to the environmental properties of the product (see section 5.3) the use of the
product should be kept to a minimum. As a minimum requirement a period of at least
14 days should elapse between treatments in order to provide a protection of the
environment.
enclosed by a tarpaulin. This is to ensure proper control of the treatment volume and
the treatment dosage, in addition to reduce the amount of AMX used and the
environmental exposure. Calculate the water volume as exactly as possible to ensure
correct dosing.
Revised: November 2023
AN: 00944/2023 & 01613/2023
Treatment dose: 0.2 ml AMX per m
(1000 l) sea water in the treatment unit.
This corresponds to 2 microgram deltamethrin/litre sea water.
For calculation of the treatment volume in the unit, please refer to
the section below; “Treatment volume”.
Treatment period: 30 minutes
Treatment volume:
Well-boat: The dosage is calculated according to the actual volume of the treatment
unit.
Tarpaulin:
The dosage is calculated according to the actual volume of the treatment unit
(tarpaulin volume).
Method of administration:
The product should be brought to room temperature before use in order to flow more
easily out of the bottle. Shake the bottle well before use. Calculate the volume in the
treatment unit and the AMX dose. Use a suitable container and dilute the calculated
quantity of AMX in seawater. Diluting the product in a large volume of seawater will
ensure a better dispersion and thereby the efficacy of the treatment. After a short
period of stirring, the diluted solution must be spread evenly throughout the treatment
unit. It is recommended to use a pump with low or moderate pressure to further
improve an even dispersion. Do not disperse under high pressure as this may cause
atomising and/or foaming.
It may be necessary to repeat the treatment if reinfestation with sea lice occurs, but
due to the environmental properties of the product (see section 5.3) the use of the
product should be kept to a minimum. As a minimum requirement a period of at least
14 days should elapse between treatments in order to provide a protection of the
environment.
Do not use on fish with infectious diseases, as treatment against sea lice may
aggravate the clinical signs and increase the mortality.
aggravate the clinical signs and increase the mortality.
The fish tend to move closer to the surface during treatment and increased
restlessness and jumping frequency are observed. Occasional mortalities have also
been observed after treatment with the recommended treatment regimen.
Miscalculation of the treatment volume (overdosing), extended exposure period or
low water temperature may increase the frequency of adverse reactions or signs of
intoxication (see section 4.10 “Overdose”).
restlessness and jumping frequency are observed. Occasional mortalities have also
been observed after treatment with the recommended treatment regimen.
Miscalculation of the treatment volume (overdosing), extended exposure period or
low water temperature may increase the frequency of adverse reactions or signs of
intoxication (see section 4.10 “Overdose”).
The efficacy of this medicinal product declines with water temperatures below 6°C.
Avoid treatment if large amounts of organic material are present in the sea water or if
the sea-cage is overgrown, as this may reduce the efficacy of the treatment.
Dead sea lice may remain on the fish for a few days after treatment (depending on
the water temperature).
Revised: November 2023
AN: 00944/2023 & 01613/2023
AMX does not prevent reinfestation with sea lice after treatment.
Lack of efficacy and reduced sensitivity to deltamethrin has been observed.
Suboptimal treatment regimen and frequent treatments as well as the use of
pyrethroids only for sea lice treatment, can induce reduced sensitivity in the sea lice
with lack of efficacy as a possible consequence.
Special precautions for use in animals
All fish should be oxygenated during treatment. Ensure that the oxygen level is above
7 mg/l before the treatment is initiated and that it is kept above 7mg/l during the entire
duration of the treatment.
At water temperatures below 6°C the product’s safety margin is reduced. Extra
precautionary measures should be exercised if treatments are performed at low
water temperatures.
The risk of intoxication may increase in fish with severe skin lesions.
Overgrowth of algae on the sea-cages/nets may prevent water exchange after
treatment. This may extend the exposure period and increase the risk of intoxication
of the fish.
Treatment should not be carried out unless some degree of water current is present.
Without a current the exposure period may be extended and increase the risk of
overdosing. If water currents are low at the time of removal of the tarpaulin the use of
an artificial water-current (e.g. a boat motor propeller) is recommended in order to
speed up the water exchange in the treatment unit.
Special precautions to be taken by the person administering the veterinary medicinal
product to animals
Wear protective clothing (i.e. cotton overalls and nitrile rubber or neoprene gloves
(0.3mm thick)) and disposable face mask when handling the product and tarpaulins
and nets of treated cages.
Wear protective clothing, gloves, eye protection and a disposable face mask when
mixing and administering the product.
Do not smoke, drink or eat while handling the product.
Avoid contact with the skin, eyes, nose and mouth. If clothing becomes
contaminated remove without delay and wash skin thoroughly with soap and water.
Change out of protective clothing and wash hands thoroughly after using the product.
Launder protective clothing before re-use.
The product is of low hazard by oral and dermal routes. Inhalation of product may
cause irritation to the mucous membranes and respiratory tract. Skin exposure may
Revised: November 2023
AN: 00944/2023 & 01613/2023
cause transient sensations (tingling, numbness) which disappear after a few hours.
Obtain medical advice if symptoms persist.
All equipment which has been in contact with the product should be thoroughly
cleaned after completion of treatment.
Laboratory studies in rabbits and rats with the excipient N-methyl pyrrolidone have
shown evidence of foetotoxic effects. The veterinary medicinal product should not be
administered by pregnant women and women suspected of being pregnant. Personal
protective equipment consisting of gloves should be worn when handling the
veterinary medicinal product by women of childbearing age.
Other precautions
The substance is toxic to crustaceans and should not be used in sea farms where
crabs or lobsters are kept in the close vicinity of the treated sea-cages (<200 m), or
when local water-currents increase the likelihood of exposure.
To prevent toxic effects on local aquatic organisms and to prevent toxic waste of
deltamethrin to be washed into the littoral zone, bath treatment should be performed
at outgoing tide or during periods with a local outgoing current.
See also 5.3
Avoid treatment if large amounts of organic material are present in the sea water or if
the sea-cage is overgrown, as this may reduce the efficacy of the treatment.
Dead sea lice may remain on the fish for a few days after treatment (depending on
the water temperature).
Revised: November 2023
AN: 00944/2023 & 01613/2023
AMX does not prevent reinfestation with sea lice after treatment.
Lack of efficacy and reduced sensitivity to deltamethrin has been observed.
Suboptimal treatment regimen and frequent treatments as well as the use of
pyrethroids only for sea lice treatment, can induce reduced sensitivity in the sea lice
with lack of efficacy as a possible consequence.
Special precautions for use in animals
All fish should be oxygenated during treatment. Ensure that the oxygen level is above
7 mg/l before the treatment is initiated and that it is kept above 7mg/l during the entire
duration of the treatment.
At water temperatures below 6°C the product’s safety margin is reduced. Extra
precautionary measures should be exercised if treatments are performed at low
water temperatures.
The risk of intoxication may increase in fish with severe skin lesions.
Overgrowth of algae on the sea-cages/nets may prevent water exchange after
treatment. This may extend the exposure period and increase the risk of intoxication
of the fish.
Treatment should not be carried out unless some degree of water current is present.
Without a current the exposure period may be extended and increase the risk of
overdosing. If water currents are low at the time of removal of the tarpaulin the use of
an artificial water-current (e.g. a boat motor propeller) is recommended in order to
speed up the water exchange in the treatment unit.
Special precautions to be taken by the person administering the veterinary medicinal
product to animals
Wear protective clothing (i.e. cotton overalls and nitrile rubber or neoprene gloves
(0.3mm thick)) and disposable face mask when handling the product and tarpaulins
and nets of treated cages.
Wear protective clothing, gloves, eye protection and a disposable face mask when
mixing and administering the product.
Do not smoke, drink or eat while handling the product.
Avoid contact with the skin, eyes, nose and mouth. If clothing becomes
contaminated remove without delay and wash skin thoroughly with soap and water.
Change out of protective clothing and wash hands thoroughly after using the product.
Launder protective clothing before re-use.
The product is of low hazard by oral and dermal routes. Inhalation of product may
cause irritation to the mucous membranes and respiratory tract. Skin exposure may
Revised: November 2023
AN: 00944/2023 & 01613/2023
cause transient sensations (tingling, numbness) which disappear after a few hours.
Obtain medical advice if symptoms persist.
All equipment which has been in contact with the product should be thoroughly
cleaned after completion of treatment.
Laboratory studies in rabbits and rats with the excipient N-methyl pyrrolidone have
shown evidence of foetotoxic effects. The veterinary medicinal product should not be
administered by pregnant women and women suspected of being pregnant. Personal
protective equipment consisting of gloves should be worn when handling the
veterinary medicinal product by women of childbearing age.
Other precautions
The substance is toxic to crustaceans and should not be used in sea farms where
crabs or lobsters are kept in the close vicinity of the treated sea-cages (<200 m), or
when local water-currents increase the likelihood of exposure.
To prevent toxic effects on local aquatic organisms and to prevent toxic waste of
deltamethrin to be washed into the littoral zone, bath treatment should be performed
at outgoing tide or during periods with a local outgoing current.
See also 5.3
No data available.
The fish tend to move closer to the surface during treatment and increased
restlessness and jumping frequency are observed. Occasional mortalities have also
been observed after treatment with the recommended treatment regimen.
Miscalculation of the treatment volume (overdosing), extended exposure period or
low water temperature may increase the frequency of adverse reactions or signs of
intoxication (see section 4.10 “Overdose”).
4.7 Use during pregnancy, lactation or lay
The safety of the veterinary medicinal product has not been established in Atlantic
salmon and rainbow trout intended for breeding. Laboratory studies in rabbits and
rats with the excipient N-methyl pyrrolidone have shown evidence of foetotoxic
effects. Use only according to the benefit-risk assessment by the responsible
veterinarian.
4.8 Interaction with other medicinal products and other forms of interaction
No data available.
4.9 Amounts to be administered and administration route
The delousing should be performed in a well-boat or in a sea-cage with a raised net
enclosed by a tarpaulin. This is to ensure proper control of the treatment volume and
the treatment dosage, in addition to reduce the amount of AMX used and the
environmental exposure. Calculate the water volume as exactly as possible to ensure
correct dosing.
Revised: November 2023
AN: 00944/2023 & 01613/2023
Treatment dose: 0.2 ml AMX per m
(1000 l) sea water in the treatment unit.
This corresponds to 2 microgram deltamethrin/litre sea water.
For calculation of the treatment volume in the unit, please refer to
the section below; “Treatment volume”.
Treatment period: 30 minutes
Treatment volume:
Well-boat: The dosage is calculated according to the actual volume of the treatment
unit.
Tarpaulin:
The dosage is calculated according to the actual volume of the treatment unit
(tarpaulin volume).
Method of administration:
The product should be brought to room temperature before use in order to flow more
easily out of the bottle. Shake the bottle well before use. Calculate the volume in the
treatment unit and the AMX dose. Use a suitable container and dilute the calculated
quantity of AMX in seawater. Diluting the product in a large volume of seawater will
ensure a better dispersion and thereby the efficacy of the treatment. After a short
period of stirring, the diluted solution must be spread evenly throughout the treatment
unit. It is recommended to use a pump with low or moderate pressure to further
improve an even dispersion. Do not disperse under high pressure as this may cause
atomising and/or foaming.
It may be necessary to repeat the treatment if reinfestation with sea lice occurs, but
due to the environmental properties of the product (see section 5.3) the use of the
product should be kept to a minimum. As a minimum requirement a period of at least
14 days should elapse between treatments in order to provide a protection of the
environment.
4.10 Overdose (symptoms, emergency procedures, antidotes), if necessary
Equilibrium problems, behaviour disturbances, gasping for air in the water surface,
alteration in pigmentation and mortalities are symptoms of an overdose. If any of
these symptoms occur, the treatment should be terminated and unmedicated sea
water let in. If the fish are treated in a raised net enclosed by a tarpaulin, the tarpaulin
should be removed and the net released to normal depth immediately. An artificial
water-current in order to speed up the water exchange in the treatment unit is
recommended (e.g. by using a boat motor propeller).
The acute toxicity of deltamethrin in fish is high. The toxicity is affected by the dose,
exposure period and the water temperature. Signs of intoxication have been seen in
laboratory trials with doses 5 times the recommended dose at 30 minutes exposure
and doses 3 times the recommended dose at 60 minutes exposure. Experience from
clinical use of the product indicates that lower doses and/or other exposure
conditions may also cause signs of intoxication.
Revised: November 2023
AN: 00944/2023 & 01613/2023
4.11 Withdrawal period(s)
5 degree days for treated Atlantic salmon
5 degree days for treated rainbow trout
5.
restlessness and jumping frequency are observed. Occasional mortalities have also
been observed after treatment with the recommended treatment regimen.
Miscalculation of the treatment volume (overdosing), extended exposure period or
low water temperature may increase the frequency of adverse reactions or signs of
intoxication (see section 4.10 “Overdose”).
4.7 Use during pregnancy, lactation or lay
The safety of the veterinary medicinal product has not been established in Atlantic
salmon and rainbow trout intended for breeding. Laboratory studies in rabbits and
rats with the excipient N-methyl pyrrolidone have shown evidence of foetotoxic
effects. Use only according to the benefit-risk assessment by the responsible
veterinarian.
4.8 Interaction with other medicinal products and other forms of interaction
No data available.
4.9 Amounts to be administered and administration route
The delousing should be performed in a well-boat or in a sea-cage with a raised net
enclosed by a tarpaulin. This is to ensure proper control of the treatment volume and
the treatment dosage, in addition to reduce the amount of AMX used and the
environmental exposure. Calculate the water volume as exactly as possible to ensure
correct dosing.
Revised: November 2023
AN: 00944/2023 & 01613/2023
Treatment dose: 0.2 ml AMX per m
(1000 l) sea water in the treatment unit.
This corresponds to 2 microgram deltamethrin/litre sea water.
For calculation of the treatment volume in the unit, please refer to
the section below; “Treatment volume”.
Treatment period: 30 minutes
Treatment volume:
Well-boat: The dosage is calculated according to the actual volume of the treatment
unit.
Tarpaulin:
The dosage is calculated according to the actual volume of the treatment unit
(tarpaulin volume).
Method of administration:
The product should be brought to room temperature before use in order to flow more
easily out of the bottle. Shake the bottle well before use. Calculate the volume in the
treatment unit and the AMX dose. Use a suitable container and dilute the calculated
quantity of AMX in seawater. Diluting the product in a large volume of seawater will
ensure a better dispersion and thereby the efficacy of the treatment. After a short
period of stirring, the diluted solution must be spread evenly throughout the treatment
unit. It is recommended to use a pump with low or moderate pressure to further
improve an even dispersion. Do not disperse under high pressure as this may cause
atomising and/or foaming.
It may be necessary to repeat the treatment if reinfestation with sea lice occurs, but
due to the environmental properties of the product (see section 5.3) the use of the
product should be kept to a minimum. As a minimum requirement a period of at least
14 days should elapse between treatments in order to provide a protection of the
environment.
4.10 Overdose (symptoms, emergency procedures, antidotes), if necessary
Equilibrium problems, behaviour disturbances, gasping for air in the water surface,
alteration in pigmentation and mortalities are symptoms of an overdose. If any of
these symptoms occur, the treatment should be terminated and unmedicated sea
water let in. If the fish are treated in a raised net enclosed by a tarpaulin, the tarpaulin
should be removed and the net released to normal depth immediately. An artificial
water-current in order to speed up the water exchange in the treatment unit is
recommended (e.g. by using a boat motor propeller).
The acute toxicity of deltamethrin in fish is high. The toxicity is affected by the dose,
exposure period and the water temperature. Signs of intoxication have been seen in
laboratory trials with doses 5 times the recommended dose at 30 minutes exposure
and doses 3 times the recommended dose at 60 minutes exposure. Experience from
clinical use of the product indicates that lower doses and/or other exposure
conditions may also cause signs of intoxication.
Revised: November 2023
AN: 00944/2023 & 01613/2023
4.11 Withdrawal period(s)
5 degree days for treated Atlantic salmon
5 degree days for treated rainbow trout
5.
This information is sourced from the official Summary of Product Characteristics (SPC) published by the Veterinary Medicines Directorate (VMD). It is provided for informational purposes only and does not replace professional veterinary advice. Always consult your vet before administering any medication.
Medication costs adding up?
Pet insurance can cover prescription medications. Find the right policy for your pet.
Same active ingredient
Other Products Containing Deltamethrin
These products share the same active ingredient and may be suitable alternatives. Always consult your vet.
Butox Swish, Pour-on Suspension 7.5 mg/ml
POM-VPSIntervet International B.V.
spot-on
Cattle
Canishield 0.77 g Medicated Collar for Small and Medium Sized Dogs
NFA-VPSBeaphar B.V.
collar
Dogs
Canishield 0.77 g Medicated Collar for Small and Medium Sized Dogs
AVM-GSLBeaphar B.V.
collar
Dogs
Canishield 1.04 g Medicated Collar for Large Sized Dogs
NFA-VPSBeaphar B.V.
collar
Dogs
Canishield 1.04 g Medicated Collar for Large Sized Dogs
AVM-GSLBeaphar B.V.
collar
Dogs
Dectospot 10 mg/ml Spot-on Solution for Cattle and Sheep
POM-VPSBimeda Animal Health Limited
spot-on
Cattle
Sheep
Alternative options to consider
Retailers we earn a commission from. It costs you nothing and never changes what we show.
The Pharm Pet Co.
Flea & Tick Treatments for Dogs
Vet-strength flea and tick treatments at pharmacy prices. Frontline, Advocate, Bravecto, Nexgard and more.
From £8.99
Shop now
Pharmacy2U
Pet Flea Treatments at Pharmacy2U
Frontline, Advantage and own-brand flea treatments at pharmacy prices. Trusted UK pharmacy since 1999.
From £7.99
Shop now
VetBox
VetBox Flea & Worm Protection for Dogs
Vet-founded monthly parasite subscription. Flea, tick and worm protection delivered to your door. Founded by Dr Will Woodley, protecting 30,000+ pets.
From £9.99/month
Shop now
We may earn a small commission if you purchase through these links, at no extra cost to you.
Also in flea-tick
Related Medications
Advantage 100 mg Spot-on Solution for Medium Dogs
AVM-GSLImidacloprid
spot-on
Dogs
Advantage 100 mg Spot-on Solution for Medium Dogs
AVM-GSLImidacloprid
spot-on
Dogs
Advantage 100 Spot-on Solution for Dogs
NFA-VPSImidacloprid
spot-on
Dogs
Advantage 100 Spot-on Solution for Dogs
NFA-VPSImidacloprid
spot-on
Dogs
Advantage 250 mg Spot-on Solution for Large Dogs
AVM-GSLImidacloprid
spot-on
Dogs
Advantage 250 mg Spot-on Solution for Large Dogs
AVM-GSLImidacloprid
spot-on
Dogs
Find cheaper vets near you
Compare vet consultation prices in your area. Save on procedures and get a prescription to buy medications online.