POM-V Prescription Required Companion Animal

Thiamacare 10 mg/ml Oral Solution for Cats

Active ingredient: Thiamazole

Form

Liquid

Species

Cats

Manufacturer

Ecuphar NV

VMD MA No.

32742/4013

What it's used for

For the long-term treatment of feline hyperthyroidism.

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 Thiamazole

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

Thiamacare 10 mg/ml Oral Solution for Cats — SPC Details

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

For the long-term treatment of feline hyperthyroidism.

The veterinary medicinal product should be administered directly into the mouth of
the cat. Do not administer in food as efficacy of the veterinary medicinal product
when administered via this route has not been established.
For the stabilisation of feline hyperthyroidism prior to surgical thyroidectomy and for
the long term treatment of feline hyperthyroidism, the recommended starting dose is
5 mg of thiamazole (0.5 ml of the veterinary medicinal product) per day.
The total daily dose should be divided into two and administered morning and
evening. In order to enhance stabilisation of the hyperthyroid patient the same dosing
schedule relative to feeding should be used daily.
Haematology, biochemistry and serum total T4 should be assessed before initiating
treatment and after 3 weeks, 6 weeks, 10 weeks, 20 weeks, and thereafter every 3
months. At each of the recommended monitoring intervals, the dose should be
titrated to effect according to the total T4 and to clinical response to treatment.
Standard dose adjustments should be made in increments of 2.5 mg of thiamazole
(0.25 ml of the veterinary medicinal product) and the aim should be to achieve the
lowest possible dose rate. In cats that require particularly small dose adjustments,
increments of 1.25 mg of thiamazole (0.125 ml of the veterinary medicinal product)
can be used. If total T4 concentration drops below the lower end of the reference
interval, and particularly if the cat is showing clinical signs of iatrogenic
hypothyroidism (e.g. lethargy, inappetence, weight gain and/or dermatological signs
such as alopecia and dry skin), consideration should be given to reducing the daily
dosage and/or dosing frequency.
If more than 10 mg of thiamazole per day is required animals should be monitored
particularly carefully.
The dose administered should not exceed 20 mg of thiamazole per day.
For long-term treatment of hyperthyroidism, the animal should be treated for life.
AN: 01407/2024 & 01408/2024Page 5 of 7

Do not use in cats suffering from systemic disease such as primary liver disease or
diabetes mellitus.
Do not use in cats showing signs of autoimmune disease.
Do not use in animals with disorders of white blood cells, such as neutropenia and
lymphopenia.
Do not use in animals with platelet disorders and coagulopathies (particularly
thrombocytopenia).
Do not use in cases of hypersensitivity to the active substance or to any of the
excipients.
Do not use in pregnant and lactating females (refer to section 3.7).
AN: 01407/2024 & 01408/2024Page 2 of 7

Cats:
Adverse reactions have been reported following long term control of hyperthyroidism.
In many cases, signs may be mild and transitory and not a reason for withdrawal of
treatment. The more serious effects are mainly reversible when medication is
stopped and.
Uncommon
(1 to 10 animals / 1,000 animals
treated):
Vomiting
, Inappetence
/Anorexia
, Lethargy
Pruritus
1,2
, Excoriations
1,2
, Bleeding
1,3,4
Icterus
1,4
,
Hepatopathy
Eeosinophilia
, Lymphocytosis
, Neutropenia
,
Lymphopenia
, Leucopenia
), Agranulocytosis
,
Thrombocytopenia
1,5,6
, Haemolytic anaemia
Rare
(1 to 10 animals / 10,000
animals treated):
Serum anti-nuclear antibodies
Anaemia
Very rare
(<1 animal / 10,000 animals
treated, including isolated
reports):
Lymphadenopathy
,
Resolve within 7-45 days after cessation of thiamazole therapy.
Severe, in head and neck.
Sign of a bleeding diathesis.
Associated with hepatopathy.
Treatment should be stopped immediately and alternative therapy considered,
following a suitable period for recovery

Following long-term treatment with thiamazole in rodents, an increased risk of
neoplasia in the thyroid gland has been shown to occur, but no evidence is available
in cats.
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 its local representative, or the national
competent authority via the national reporting system. See the package leaflet for
respective contact details.
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In order to enhance stabilisation of the hyperthyroid patient the same feeding and
dosing schedule should be used daily.

Special precautions for safe use in the target species
If more than 10 mg per day is required animals should be monitored particularly
carefully.
Use of the veterinary medicinal product in cats with renal dysfunction should be
subject to careful risk:benefit assessment by the clinician. Due to the effect
thiamazole can have on reducing the glomerular filtration rate, the effect of therapy
on renal function should be monitored closely as deterioration of an underlying
condition may occur.
Haematology must be monitored due to risk of leucopenia or haemolytic anaemia.
Any animal that suddenly appears unwell during therapy, particularly if they are
febrile, should have a blood sample taken for routine haematology and biochemistry.
Neutropenic animals (neutrophil counts <2.5 x 10
/l) should be treated with
prophylactic bactericidal antibacterial drugs and supportive therapy.
Please refer to section 3.9 for monitoring instructions.
As thiamazole can cause haemoconcentration, cats should always have access to
drinking water.
Special precautions to be taken by the person administering the veterinary medicinal
product to animals
People with known hypersensitivity (allergy) to thiamazole, or vanillin should avoid
contact with the veterinary medicinal product. If allergic symptoms develop, such as a
skin rash, swelling of the face, lips or eyes or difficulty in breathing, you should seek
medical attention immediately and show the package leaflet or label to the physician.
Thiamazole may cause gastrointestinal disturbances, headache, fever, joint pain,
pruritus (itching) and pancytopaenia (decrease in blood cells and platelets).
The veterinary medicinal product may also cause skin irritation.
Avoid dermal and oral exposure, including hand-to-mouth contact.
Do not eat, drink or smoke while handling the veterinary medicinal product or used
litter.
Wash hands with soap and water after administration and handling of the veterinary
medicinal product and cleaning the vomit of, or litter used by, treated animals. Wash
any spillages or splatter from skin immediately.
Following administration of the veterinary medicinal product any residual veterinary
medicinal product remaining on the tip of the dosing syringe should be wiped clean
with a tissue. The contaminated tissue should be immediately disposed of.
The used syringe should be stored with the veterinary medicinal product in the
original carton.
In case of accidental ingestion, seek medical advice immediately and show the
package leaflet or the label to the physician.
This veterinary medicinal product may cause eye irritation.
Avoid eye contact including hand to eye contact.
In case of accidental eye contact, rinse eyes immediately with clean running water. If
irritation develops, seek medical advice.
AN: 01407/2024 & 01408/2024Page 3 of 7
As thiamazole is a suspected human teratogen, women of child-bearing age
must wear non-permeable single-use gloves when administering the veterinary
medicinal product or handling the litter/vomit of treated cats.
If you are pregnant, think you may be pregnant or are attempting to conceive,
you should not administer the veterinary medicinal product or handle the
litter/vomit of treated cats.
Special precautions for the protection of the environment:
Not applicable.

Concurrent treatment with phenobarbital may reduce the clinical efficacy of
thiamazole.
Thiamazole is known to reduce the hepatic oxidation of benzimidazole wormers and
may lead to increases in their plasma concentrations when given concurrently.
Thiamazole is immunomodulatory, therefore this should be taken into account when
considering vaccination programmes.

Keep the bottle tightly closed.

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.