POM-V Prescription Required Companion Animal

Synulox Ready-to-Use 140 mg/ml + 35 mg/ml Suspension for Injection

Active ingredients: Amoxicillin, Clavulanic Acid

Form

Injection

Species

Cats Cattle Dogs Pigs

Manufacturer

Zoetis UK Limited

VMD MA No.

42058/5174

What it's used for

range of bacteria, including strains resistant to amoxicillin alone because of beta- lactamase production: Gram-positive Actinomyces bovis Bacillus anthrac...

Full indications, dosage and side effects ↓

View official SPC (PDF)

The prescription itself has a price. See what practices near you charge for a consultation and the written prescription fee.

Paying less for Amoxicillin + Clavulanic Aci...

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.

Your prescription rights → VMD register of retailers →

Prescription required

Your vet must provide a written prescription on request. You can then purchase from any licensed online retailer.

Clinical information

Synulox Ready-to-Use 140 mg/ml + 35 mg/ml Suspension for Injection — SPC Details

Source: VMD Summary of Product Characteristics (SPC). Last updated 27 Mar 2026.

range of bacteria, including strains resistant to amoxicillin alone because of beta-
lactamase production:
Gram-positive
Actinomyces bovis
Bacillus anthracis
Clostridia
Corynebacteria
Peptostreptococcus spp.
Staphylococci
Streptococci
Gram-negative
Actinobacillus lignierisi
Actinobacillus pleuropneumoniae
Bacteroides
Bordetella bronchiseptica
Campylobacter spp.
Escherichia coli
Fusobacterium necrophorum
Haemophilus spp.
Klebsiellae
Moraxella spp.
Pasteurellae
Proteus spp.
Salmonellae
Clinically the product is indicated for the treatment of diseases including:
Cattle
Respiratory infections, soft tissue infections (e.g. joint-ill/navel-ill, abscesses etc.),
metritis and mastitis.
Combined Therapy for the treatment of bovine mastitis:
In the situation where systemic treatment as well as intramammary treatment is
necessary, Synulox Ready-to-Use injection can be used in combination with Synulox
Lactating Cow Intramammary.
Pigs
Respiratory bacterial infections in growing pigs.
Colibacillosis.
Periparturient infections in sows (e.g. mastitis, metritis and agalactia.)
Dogs and Cats
Respiratory tract infections, urinary tract infections and skin and soft tissue infections
(e.g. abscesses, pyoderma, anal sacculitis, gingivitis).

daily for 3-5 days.
Shake well before use. After injection, massage the injection site. Use a completely
dry sterile needle and syringe. Swab the septum before removing each dose.
For combined therapy, the following minimum treatment regime should be followed:
Synulox RTUSynulox LC
8.75 mg/kg bodyweight (7.0 mg
amoxicillin, 1.75 mg clavulanic acid)
i.e. 1 ml/20 kg bodyweight
24 hours
8.75 mg/kg bodyweight (7.0 mg
amoxicillin, 1.75 mg clavulanic acid)
i.e. 1 ml/20 kg bodyweight
24 hours
8.75 mg/kg bodyweight (7.0 mg
amoxicillin, 1.75 mg clavulanic acid)
i.e. 1 ml/20 kg bodyweight
Where necessary, Synulox RTU
Injection may be administered for
an additional two days for a total
of 5 daily injections
One syringe gently infused into the
teat of the infected quarter
12 hours
One syringe gently infused into the
teat of the infected quarter
12 hours
One syringe gently infused into the
teat of the infected quarter

The product should not be administered to rabbits, guinea pigs, hamsters, or gerbils.
Caution is advised in its use in other very small herbivores.

Cattle, pigs, dogs, and cats:
Very rare
(<1 animal / 10,000 animals treated,
including isolated reports):
Injection site pain, Injection site
reaction.
Allergic reaction
(allergic skin
reaction, anaphylaxis).
If allergic reaction occurs, discontinue use immediately. Treat symptomatically.
Reporting adverse events is important. It allows continuous safety monitoring of a
veterinary medicinal product. Reports should be sent, preferably via a veterinarian, to
either the marketing authorisation holder or the national competent authority via the
national reporting system. See the package leaflet for respective contact details.

None.

Special precautions for safe use in the target species:
Care should be taken to avoid contaminating the remaining contents of a vial with
water.
Clavulanic acid is moisture sensitive. It is very important that a completely dry syringe
is used when extracting the suspension for injection in order to avoid contaminating
the remaining contents of the vial with drops of water. Contamination will result in
obvious areas of dark brown discolouration corresponding to the introduced water
droplets. Material affected in this way should not be used as it may have significantly
reduced potency.
The veterinary medicinal product may contain minute brown spots, which are
considered to be an intrinsic characteristic of the formulation. Appearance of these
spots will not adversely affect the safety or efficacy of the product.
Special precautions to be taken by the person administering the veterinary medicinal
product to animals:
Penicillins and cephalosporins may cause hypersensitivity (allergy) following
injection, inhalation, ingestion, or skin contact. Hypersensitivity to penicillins may lead
to cross reactions to cephalosporins and vice versa. Allergic reactions to these
substances may occasionally be serious.
People with known hypersensitivity to penicillins and cephalosporins should avoid
contact with the veterinary medicinal product. Handle this product with great care to
avoid exposure, taking all recommended precautions.
If you develop symptoms following exposure such as a skin rash, you should seek
medical advice and show the doctor this warning. Swelling of the face, lips or eyes or
difficulty with breathing, are more serious symptoms and require urgent medical
attention.
Wash hands after use.
Special precautions for the protection of the environment:
Not applicable.

None known.

Do not store above 25
°
C.
Keep the vial in the outer carton.
This product does not contain an antimicrobial preservative.

Cattle (meat and offal): 42 days.
Cattle (milk): 60 hours (5
th
milking, if cows are milked twice daily).
Pigs (meat and offal): 31 days.
Combined Therapy: When using Synulox LC Intramammary and Synulox RTU in
combination, animals must not be slaughtered for human consumption during
treatment. Cows may not be slaughtered for human consumption until 42 days after
the last treatment. Milk must not be taken for human consumption during treatment.
Milk for human consumption may be taken only from cows after 60 hours from the
last treatment of Synulox RTU following the minimum posology regime as described
in Section 3.9.

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.