POM-V Prescription Required Companion Animal

Ronaxan 20 mg Tablets for Dogs and Cats

Active ingredient: Doxycycline

Form

Tablet

Species

Cats Dogs

Manufacturer

Boehringer Ingelheim Vetmedica GmbH

VMD MA No.

61700/5022

What it's used for

susceptible to doxycycline. For the treatment of canine ehrlichiosis caused by Ehrlichia canis. Cats: For the treatment of respiratory tract infections inc...

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 Doxycycline

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

Ronaxan 20 mg Tablets for Dogs and Cats — SPC Details

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

susceptible to doxycycline.
For the treatment of canine ehrlichiosis caused by Ehrlichia canis.
Cats:
For the treatment of respiratory tract infections including rhinitis, tonsillitis and
bronchopneumonia caused by Bordetella bronchiseptica and spp.
susceptible to doxycycline.

The dosage is 10 mg doxycycline per kg bodyweight per day corresponding to one
tablet per 2 kg bodyweight. To ensure a correct dosage, body weight should be
determined as accurately as possible to avoid overdosing or underdosing. To adjust
the dosage, the tablets can be divided into two equal parts. The dosage can be
divided into two daily administrations. The duration of treatment might be adapted
depending on the clinical response, after benefit/risk assessment by the veterinarian.
DiseaseDosage regimenDuration of treatmentRespiratory tract infection10 mg/kg per day5-10 daysCanine ehrlichiosis10 mg/kg per day28 days

Do not use in cases of hypersensitivity to the active substance or to any of the
excipients.
Do not use in animals with renal or hepatic insufficiency.
Do not use in animals with diseases associated with vomiting or dysphagia.
Do not use in animals with known photosensitivity.
Do not use in puppies and kittens before completion of teeth enamel formation.

Dogs and cats:
Very rare
(1 animal / 10 000 animals treated,
including isolated reports):
Gastrointestinal disorders (e.g. vomiting,
diarrhoea, hypersalivation, nausea and
oesophagitis)
Photosensitization (and photodermatitis)
Dental discolouration
1
After exposure to intense sunlight or ultraviolet light.
If used during the period of tooth development.
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.

Ehrlichia canis infection: treatment should be initiated at the onset of clinical signs.
Complete eradication of the pathogen is not always achieved, but treatment for 28
days generally leads to a resolution of the clinical signs and a reduction of the
bacterial load. A longer duration of treatment, based on a benefit/risk assessment by
the responsible veterinarian, may be required particularly in severe or chronic
ehrlichiosis. All treated animals should be regularly monitored, even after clinical
cure.

Special precautions for safe use in the target species:
Tablets should be administered with food to avoid vomiting and to reduce the
likelihood of oesophageal irritation.
The veterinary medicinal product should be administered with caution to young
animals, since tetracyclines as a class may cause permanent discolouration of the
teeth, when administered during tooth development. However, human literature
indicates that doxycycline is less likely than other tetracyclines to cause these
abnormalities, due to its reduced ability to chelate calcium.
Use of the veterinary medicinal product should be based on identification and
susceptibility testing of the target pathogens. If this is not possible, therapy should be
based on epidemiological information and knowledge of susceptibility of the target
pathogens at local/regional level.
Use of the veterinary medicinal product deviating from the instructions given in the
summary of product characteristics (SPC) may increase the prevalence of bacteria
resistant to doxycycline and may decrease the effectiveness of treatment with other
tetracyclines, due to the potential for cross-resistance.
Use of the veterinary medicinal product should be in accordance with official, national
and regional antimicrobial policies.
Special precautions to be taken by the person administering the veterinary medicinal
product to animals:
People with known hypersensitivity to doxycycline or other tetracyclines should avoid
contact with the veterinary medicinal product.
Personal protective equipment consisting of gloves should be worn when handling
the veterinary medicinal product.
In case of skin irritation, seek medical advice immediately and show the package
leaflet or the label to the physician.
Accidental ingestion, especially by children, may cause adverse events such as
emesis. To avoid accidental ingestion, blisters should be inserted back into the outer
packaging and kept in a safe place. In case of accidental ingestion, seek medical
advice immediately and show the package leaflet or the label to the physician.
Special precautions for the protection of the environment:
Not applicable.

Doxycycline should not be used concurrently with other antibiotics, especially
bactericidal drugs such as the Cross-resistance to tetracyclines may
occur.
The half-life of doxycycline is reduced by concurrent administration of barbiturates,
phenytoin and carbamazepine.
Dosage adjustments may be necessary in subjects under anticoagulant therapy, as
tetracyclines depress the plasma activity of prothrombin.
Simultaneous administration of oral absorbents, antacids and preparations including
multivalent cations should be avoided as they reduce doxycycline availability.

Do not store above 25°C.
Keep the blister in the outer carton.

Not applicable.

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.