Masivet UK (Kinavet US) Cancer Treatment Tablets for Dogs

Masivet UK (Kinavet US) Cancer Treatment Tablets for Dogs
50mg » 30 Pack
150mg » 30 Pack

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  • 50mg » 30 Pack £62.49
  • 150mg » 30 Pack £143.69

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If you live in the United States then it is still possible to buy Kinavet (licensed as Masivet in the UK) from VioVet.

We can accept a prescription from a US veterinary surgeon under a USDA permit obtained by VioVet. We have a template and description of the prescription process on our website here. We would need your vet to date, sign and stamp the prescription, which must also include pet details, product name, strength and dosage. We would recommend that you scan/photograph and then email your completed prescription from your vet to us on [email protected] or upload a file directly via your account on our website.

Orders must be placed by the owner of the dog being treated - we cannot supply veterinary surgeries with Masivet under any circumstances due to FDA / USDA regulations. We also require a specific written order from a licensed veterinarian stating that the animal should receive the unapproved product and provide a justification for the use of the unapproved drug. We also need an explanation as to why Masivet must be prescribed instead of an alternative medication.

We strongly recommend that you look into import regulations affecting you before placing an order. Royal Mail parcels are not routinely checked by customs but any regulations are applied by customs if they inspect a parcel. We will include all relevant documentation as required by our USDA Import Permit for Masivet with every order to smooth the importation process however the FDA may charge a $22.00 Adminsitration Fee for clearance of the documentation. This will be payable, if requested, to the UPS driver on delivery and is a Federal charge not a VioVet or UPS charge. Please be aware that Royal Mail Air Mail is an untracked service. We can offer delivery with UPS, which offers a tracking service and a quicker estimated delivery time, often under one week. The option for shipping with UPS will be available on orders only containing Masivet.

We can only send a maximum of a three month supply per animal per order. You will be contacted if your order exceeds this and your order will be amended to the appropriate quantity.

Orders can be placed on our website and payment can be made by card, PayPal or direct bank transfer (2.5% fee for for PayPal). Unfortunately we are unable to quote in US dollars- your card provider will be able to tell you the conversion rate they are currently using and will automatically take the correct amount for the payment.

If you would like any further information then email us at [email protected] and we'll do our best to help.

Masivet (licensed as Kinavet in the USA) is supplied as a tablet for use against a certain type of cancer affecting dogs. Masivet is regarded as safe enough to be used at home, and is given as a tablet once daily. It acts against mast cell tumours, by inhibiting cell division, therefore preventing further development of the tumours. Not all dogs respond, but the results can be very helpful for others. Close veterinary supervision is recommended at all times and Masivet is prescription only.

What is Masivet?

Masivet contains masitinib, which belongs to a class of medicines having an anti cancer action. It is available as round, orange tablets (50 and 150 mg).

What is Masivet used for?

Masivet is used to treat dogs with mast-cell tumours (a type of cancer). It is used for tumours which are severe in character (grade 2 or 3) and which cannot be removed with surgery. It is only used if the presence of a mutated form of the receptor protein c-kit in the tumours has been confirmed before the start of treatment.
The tablets are given by mouth, once a day. The dose depends on the weight of the dog being treated.. The duration of treatment depends on the dog’s response to treatment.

How does Masivet work?

The active substance in Masivet, masitinib, is a protein-tyrosine kinase inhibitor. This means that it blocks some specific enzymes known astyrosine kinases. These enzymes can be found in some receptors on the surface of cells, including the c-kit receptor. Some types of mast-cell tumour are linked to a mutation that causes excessive action of c-kit and stimulates the mast cells to divide uncontrollably. By blocking these receptors, Masivet might help to control cell division, preventing further development of the tumours with this particular mutation.

How has Masivet been studied?

A number of studies with Masivet were carried out either in laboratory dogs or in animal patients at veterinary practises in Europe and in the USA. The main study compared the effectiveness of Masivet at the recommended dose of 12.5 mg per kilogramme bodyweight once a day with placebo (a dummy treatment). The study included dogs of various breeds and both sexes with mast-cell tumours that had come back after surgery or could not be removed with surgery. The study population included dogs whose tumours contained mutated ornormal (‘wild-type’) c-kit receptors.

What is the risk associated with Masivet?

The most common side effects with Masivet are gastrointestinal reactions (diarrhoea andvomiting) and hair loss. These reactions are usually mild to moderate and temporary, lasting for up to four weeks. Dogs under Masivet treatment should be regularly monitored for side effects by the veterinarian (at least monthly). In the case of side effects, the veterinarian might decide to lower the dose of Masivet or to discontinue treatment.
Masivet must not be used in dogs with certain kinds of liver or kidney problems, or anaemia (low red blood cell counts) or neutropenia (low white blood cell counts). It must not be used in dogs less than six months of age or less than 4kg in weight, or bitches that are pregnant or lactating. It should not be used in dogs that may be hypersensitive (allergic) to masitinib or any of the other ingredients. For a full list of all side-effects reported with Masivet, see the Package Leaflet.
Four to six weeks after starting the treatment with Masivet, the veterinarian should check if the treatment is likely to be successful.

What are the precautions for the person who gives the medicine or comes into contact with the animal?

The tablets must be administered whole and should not be divided, broken or ground up. If broken tablets, or the vomit, urine or faeces of a treated dog comes into contact with the skin or eyes, rinse immediately with plenty of water. Children should not have close contact with treated dogs, or their faeces or vomit. If Masivet is taken accidentally, seek medical advice immediately and show the Package Leaflet or the label to the doctor. Do not eat, drink or smoke while treating a dog. For more information, see the Package Leaflet.

Why has Masivet been approved?

The Committee for Medicinal Products for Veterinary Use (CVMP) concluded that the benefits of Masivet exceed the risks for the treatment of non-resectable mast cell tumours(grade 2 or 3) that have a confirmed mutated c-kit tyrosine kinase receptor and recommended that Masivet be given a marketing authorisation. The benefit-risk balance may be found inmodule 6 of this EPAR.

Other information about Masivet

The European Commission granted a marketing authorisation valid throughout the European Union, for Masivet to AB Science S.A. on 17 November 2008. Information on the prescription status of this product may be found on the label/outer package. Because this disease is a life threatening condition and the overall number ofdogs affected is expected to be low, the CVMP guidelines on “Minor-Use-Minor-Species (MUMS) data requirements” were applied when assessing the dossier.

This summary was last updated on May 2009.

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Medication Datasheets

Reviews (106)

Summary of Reviews for Masivet UK (Kinavet US) Cancer Treatment Tablets for Dogs

Overall 5
Ease Of Use
Value For Money
Absence Of Side Effects
105 out of 106 (99%) customers would recommend this product.
5 stars (88 reviews)
4 stars (15 reviews)
3 stars (2 reviews)
2 stars (1 reviews)
1 stars (0 reviews)

Only verified purchasers of this product can leave a review.

45 Masivet
Verified Purchase

By on 14 December 2022

Very good product at this very worrying time but it’s a concern that they are having manufacturing problems.

Customer recommends this product

55 Great service
Verified Purchase

By on 21 July 2022

Excellent product and prompt delivery.

Customer recommends this product

45 It works for my dog
Verified Purchase

By on 7 March 2022

It must be very strong and I had my doubts how her kidneys etc would cope. But nearly 2 years on and so far so good.

Customer recommends this product

25 Sadly, no response
Verified Purchase

By on 10 February 2022

Bought for my dog with grade 3 MST. Had hoped for a miracle but no response at all. Tumour in lymph node continued to grow. Stopped after a month.

Customer does not recommend this product

55 Masivet
Verified Purchase

By on 24 November 2021

Our Labrador was diagnosed with mast cell tumour in July 2019, following major surgery he was prescribed Masivet, 450mg a day. His long term prognosis was not good but two and a half years on he is still taking this miracle drug, defying all logic!

Customer recommends this product

2 people found this review helpful

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Q & A

Below are some recent questions we've received regarding Masivet UK (Kinavet US) Cancer Treatment Tablets for Dogs, including answers from our team.

14 July 2023 at 7:48pm

Tumors due to a hemamgiosarcoma that cannot be removed? will it help?

irma murillo

tumors due to a hemamgiosarcoma that cannot be removed? will it help slow tumor growth? does this help with other types of cancer other then MCT's.

  • VioVet Staff

Masivet is specific for the treatment of non-resectable dog mast cell tumours (Grade 2 or 3) with confirmed mutated c-kittyrosine kinase receptor, and it is unlikely to assist with treating a haemangiosarcoma. It is advised to discuss this further with your vet.

16 August 2022 at 4:42am

Given to Cats?


My cat has a mast cell tumor and the Oncologist is recommending I purchase masitinib from your company for him. Do you have a similar medications cats or is this what I would order?

  • VioVet Staff

It is advised to go with the brand that your oncologist advises. In the UK Masivet is the only licensed version of masitinib and so this is all we can dispense. It is only licensed in dogs and any use in cats is off license, vets do prescribe off license though when not licensed versions are available. it is worth discussing this further with your vet if you have any concerns.

13 July 2021 at 8:30pm



I have 2 young children and another dog, do I need to keep them apart from our dog on masivet? My son spends loads of time petting him, do I need to stop this? How cautious do we need to be without being paranoid? Thanks

  • VioVet Staff

The precautions with regards to people around dogs treated with Masivet can be found in the following image, as taken from the datasheet. Essentially it is only the drug itself and your dog's discharges (faeces, urine and vomit) that you need to avoid skin contact with. There is a disclaimer to avoid dog to child contact once treated but I advise discussing this with the prescribing vet or the manufacturer if you are worried.Screenshot 2021-07-14 at 11.45.12.png

15 March 2021 at 6:54pm

Anal sac carcinoma


Is this product effective for treatment of anal sac carcinoma?

  • VioVet Staff

This product is licensed for the treatment of non-resectable dog mast cell tumours (Grade 2 or 3) with confirmed mutated c-kit tyrosine kinase receptor. Anal Sac Carcinomas are not Mast Cell Tumours and so use for this would be an off license use of the medication. I recommend discussing any off license use of the medication with your vet as they will be in a position to advise.

17 November 2020 at 9:42am

How to administer tablet

Gordana Grandosek Whiddon

Why can’t the tablet be crushed to be given?

  • VioVet Staff

The data sheet for Masivet states that the product cannot be split and
any damaged/split tablets should be discarded. It does not explain why
in the data sheet but in general film coatings either improve the
stability of the drug (light protection, moisture and gas barrier) or
are used to modify the drug release behaviour from the dosage form.
This means the film may help release the drug slower than if not coated,
or allow it to bypass the stomach into the intestines so it can be
absorbed more effectively. Removing the film (by crushing or splitting)
could seriously impact the effect of the medication.

If you are
struggling to give the tablet then I recommend trying to hide it in
tasty food, such as some cooked chicken/tuna. You can also use a Buster Pill Giver to put the pill directly at the back of the mouth to ensure it is swallowed correctly.

1 June 2018 at 12:06am




  • VioVet Staff

Masivet must not be used in dogs less than six months of age or less than 4kg in weight. The dose rate is 12.5mg/kg once daily.

15 April 2016 at 8:55pm


Cheryl Woodring

Is this a generic drug for masitinib? I sent in a prescription and just want to make sure I'm paying for the correct one. I need the 150 mg not the 50 mg.

  • VioVet Staff

The only brand name mastinib is sold under in the UK is Masivet. This is the original brand and not a generic. Other brand names can be chosen by the manufacturer when marketing it in other countries, but the product is the same. If your vet has prescribed mastinib, then Masivet is correct for you.

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