POM-V Prescription Required

K-Flor 100 mg/ml Solution for Use in Drinking Water for Pigs

Active ingredient: Florfenicol

Form

Solution

Species

Pigs

Manufacturer

Laboratorios Karizoo S.A

VMD MA No.

31223/4003

What it's used for

In pigs: Treatment and metaphylaxis at the group level where clinical signs are present of swine respiratory disease associated with Pasteurella multocida...

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 Florfenicol

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.

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Prescription required

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

Clinical information

K-Flor 100 mg/ml Solution for Use in Drinking Water for Pigs — SPC Details

Source: VMD Summary of Product Characteristics (SPC). Last updated 26 Mar 2026.

In pigs:
Treatment and metaphylaxis at the group level where clinical signs are present of
swine respiratory disease associated with
Pasteurella multocida susceptible to florfenicol. The presence of the disease should
be established in the herd before initiating metaphylactic treatment.

In drinking water use.
10 mg florfenicol per kg bodyweight per day in drinking water for 5 consecutive days.
Based on the recommended dose, and the number and weight of the animals to be
treated, the exact daily amount of the veterinary product should be calculated
according to the following formula:
X ml veterinary
product/ kg
b.w./dayx
Mean body weight (kg)
of animals to be treated
=
X ml veterinary
product per litre
drinking water
Mean daily water consumption (litre) per animal
The appropriate quantity of medicated water should be prepared based on the daily
water consumption. To ensure a correct dosage body weight should be determined
as accurately as possible. In order to avoid under- and over-dosing, treated animals
should be divided into groups of similar bodyweight and the dose should be
calculated for each group individually.
For Bulk Tank:
To treat pigs drinking 10% of their bodyweight, at the dose of 10 mg/kg: add the
florfenicol solution to the drinking water in the bulk tank. Use one bottle (500 ml) of
florfenicol solution for every 500 L of water, one bottle (1L) of florfenicol solution for
every 1000 L of water or use one barrel (5L) of florfenicol solution for every 5000 L of
water and mix thoroughly.

Revised: May 2019
AN: 00794/2018
For Proportioner:
To treat 5,000 kg of pigs, drinking 10% of their bodyweight, at the dose rate of 10
mg/kg:
1. Empty the content of one bottle/barrel of florfenicol solution in the proportioner and
dilute with drinking water as follows:
Bottle/BarrelAmount of drinking water500 ml50 L1L100 L5L500 L
2. Mix thoroughly.
3. Set the proportioner on 10%
4. Turn on the proportioner.
Warnings:
Solutions with concentrations higher than 1.2 g of florfenicol per litre may precipitate.
Do not use the product with chlorinated water.
The uptake of medicated water depends on several factors including the clinical state
of the animals and local conditions such as ambient temperature and humidity. In
order to obtain the correct dosage water uptake has to be monitored and the
concentration of florfenicol has to be adjusted accordingly. If however it is not
possible to obtain sufficient uptake of medicated water animals should be treated
parenterally.

Do not use in boars intended for breeding purposes.
Studies in rats have revealed evidence of potential adverse effects on the male
reproductive system.
Do not use in cases of hypersensitivity to the active substance or to any of the
excipient.

Revised: May 2019
AN: 00794/2018

A slight reduction of water consumption by the animals, dark brown faeces and
constipation may be observed during treatment, very commonly.
Diarrhoea and/or peri-anal and rectal erythema/oedema may occur very commonly
(may affect approximately 40% of the animals). These effects are transient. In a few
of the affected animals, prolapse of the rectum, that resolves without treatment may
be observed.

Revised: May 2019
AN: 00794/2018
Neurological signs and death can be observed in the animals treated on rare
occasions. In that case withdraw the treatment immediately
The frequency of adverse reactions is defined using the following convention:
- very common (more than 1 in 10 animals treated displaying adverse reaction(s))
- common (more than 1 but less than 10 animals in 100 animals treated)
- uncommon (more than 1 but less than 10 animals in 1,000 animals treated)
- rare (more than 1 but less than 10 animals in 10,000 animals treated)
- very rare (less than 1 animal in 10,000 animals treated, including isolated reports).

The treated pigs should be placed under special observation. On each of the five
days of treatment, unmedicated drinking water should not be given until the full daily
amount of medicated drinking water has been ingested by pigs.
If there are no signs of improvement after three days of treatment, the diagnosis
should be reviewed and, if necessary, the treatment changed.

Special precautions for use in animals
The veterinary medicinal product should be used in conjunction with susceptibility
testing.
Use of the product deviating from the instructions given in the SPC may increase the
prevalence of bacteria resistant to the florfenicol.
Official and local antimicrobial policies should be taken into account when the
product is used.
Treatment should not exceed 5 days.
Special precautions to be taken by the person administering the veterinary medicinal
product to animals
Florfenicol and polyethylene glycol may cause hypersensitivity (allergy).
People with known hypersensitivity to florfenicol or polyethylene glycols should avoid
contact with the veterinary medicinal product.
This product may cause skin and eye irritation.
In case of accidental spillage onto skin rinse with water. In case of contact with eyes,
rinse immediately with copious amounts of water.
Personal protective goggles should be worn when handling the veterinary medicinal
product.
Medical advice should be sought if irritation persists.
Other precautions
In order to prevent any adverse effects on algae and possible contamination of
groundwater, manure from treated pigs must not be spread onto land without dilution
with manure from untreated pigs. Manure from treated pigs must be diluted with at
least 5 times the weight of manure from untreated pigs before it can be spread onto
arable land.

No data available.

Do not store above 25C.

Revised: May 2019
AN: 00794/2018

Meat and offal: 20 days
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.