Cat Diseases & Illnesses – Hyperthyroidism – Vidalta


What exactly is Vidalta for cats?

Vidalta is a drug that is used to treat cats with an overactive thyroid gland or that suffer with Hyperthyroidism. Vidalta is made by the manufacturer Intervet Schering-Plough and it is available in two sizes; 10mg and 15mg tablets. Vidalta is available in pots of either 30 or 100 tablets. They are small round, pink tablets. Carbimazole is the active ingredient in Vidalta. Vidalta tablets are given orally once a day.

What is Vidalta used for?

Vidalta is used to treat Hyperthyroidism in cats. Hyperthyroidism occurs when the thyroid glands, which are situated either side if the neck, enlarge and begin producing excessive amounts of thyroid hormone. Vidalta stops this process by reducing the uptake of iodine which is required to make thyroid hormones and it also blocks the pathway of reactions that forms the hormone. Excess thyroid hormone up regulates the metabolism causing increased hunger and thirst, weight loss and an increased heart rate amongst other symptoms. Vidalta will reduce these clinical signs as it reduces the amount of thyroid hormone being produced by the thyroid glands.

Vidalta Tips

  • Vidalta is only for use in cats
  • Vidalta is available in two strengths; 10mg and 15mg tablets
  • Your vet will decide the dose of Vidalta required by your cat
  • Only give Vidalta if directed to do so by a vet
  • Vidalta is normally given once daily.
  • Do not alter the dose  of Vidalta without first consulting with your vet
  • Vidalta can be given with or without food
  • Store Vidalta in a cool dry place, where the temperature is less than 25oC
  • If you see any side effects associated with Vidalta, you should call your vet for advice
  • If you suspect your cat may have had an overdose of Vidalta then call your vet immediately

Possible Side Effects of Vidalta

  • Do not use Vidalta in pregnant or lactating queens.
  • Vomiting and diarrhoea are the most common side effects of Vidalta.
  • These are usually mild and do not require that treatment with Vidalta be stopped
  • Occasionally skin lesions (such as dermatitis) may be seen with Vidalta
  • Side effects from Vidalta are more likely at high doses (>20mg per cat)
  • If you suspect side effects from Vidalta then you should call your vet for advice
  • Kidney and Liver parameters should be closely monitored during treatment with Vidalta
  • Women of child bearing age should wear gloves when handling Vidalta
  • Transient anaemia may also occur with Vidalta so this should be monitored

Dosage and Administration of Vidalta

  • Vidalta comes in two sizes; 10mg and 15mg tablets.
  • Vidalta should be given once a day.
  • Vidalta should be given at the same time each day
  • Vidalta tablets should not be broken or crushed
  • Treatment with Vidalta is often lifelong
  • Your vet will decide the dose of Vidalta required by your cat.
  • The dose of Vidalta can be altered by your vet according to your cat's response to treatment
  • Do not alter the dose without first checking with your vet
  • Regular monitoring is required while on treatment with Vidalta

More Information about Vidalta

Vidalta is a drug used to treat hyperthyroidism in cats. It contains the active ingredient carbimazole which blocks both the uptake of iodine by the thyroid gland and also the pathway of reactions that produce the thyroid hormones thyroxine (T4) and triiodothyronine (T3). Having an excess of thyroid hormone causes the metabolism to be up regulated which causes a high heart rate, increased hunger and thirst and weight loss as well as other signs. Giving Vidalta at a dose that suppresses production of thyroid hormone will reduce these clinical signs.

Vidalta can be used long term for medical management of hyperthyroidism but there are also other forms of treatment; The thyroid gland can be removed surgically but cats with hyperthyroidism are not good candidates for anaesthesia so Vidalta can also be used for two to three weeks leading up to surgery to stabilise the thyroid hormone levels. The third method of treatment is injecting the cat with radioactive iodine to destroy the thyroid gland and this would require hospitalisation at a specialist centre for a month.

Vidalta is manufactured by the manfacturers Intervet Schering-Plough and comes as 10mg or 15mg tablets. Vidalta is a POM-V (Prescription Only Medicine- Vet) medication which means that it can only be obtained from a vet or with a prescription from the vet who is looking after your cat.

More information about Dosage and Administration of Vidalta

The initial dose for Vidalta is 15mg per cat once a day. The 10mg tablets can be used, however, in cases where the thyroid hormone level is only mildly raised but the thyroid hormone level needs to be monitored regularly in order to tailor the treatment to each individual cat. The therapeutic dose range for Vidalta is 10mg-25mg per cat.

The tablets can be given with or without food but are only given once daily. It is important that the tablets are given at a similar time each day, especially with respect to feeding times as this maintains a stable level of the drug in the cat's system. Vidalta tablets should not be broken or crushed.

Monitoring of thyroid hormone levels as well as liver, kidney and red and white blood cell parameters should initially be done at 10 days then at 3, 5 and 8 weeks after starting treatment. If thyroid hormone levels have stabilised then rechecks can become less frequent but the exact regime will be determined by your vet and will depend on your individual cat’s response to the treatment. If the levels of thyroid hormone remain high then the dose of Vidalta can be increased, if however they have fallen too low, the dose may need to be decreased.

Frequently asked questions about Vidalta

Q. What does Vidalta actually do?                                                                                                                                                         
A. Vidalta is used to control hyperthyroidism in cats. It does this by blocking production of the thyroid hormones thyroxine (T4) and triiodothyronine (T3).

Q. How should Vidalta be given?                                                                                                                          
A. Vidalta is given once daily by mouth. It is important that it is given at the same time each day.

Q. Can Vidalta be given at the same time as food?                                                                                                                                 
A. Yes, Vidalta can be given with or without food but whichever you choose, this needs to remain constant.

Q. Can Vidalta tablets be split or divided?                                                                                                                           
A. No. Vidalta tablets should not be crushed or broken.

Q. How long will my cat need to take Vidalta for?                                                                                                                 
A. Usually lifelong if it is being used for medical treatment of hyperthyroidism or alternatively for 2-3 weeks prior to surgery to remove the thyroid gland.

Q. I forgot to give my cat a dose of Vidalta this morning, what should I do?                                                               
A. Just give the next dose as normal, do not give double the amount of Vidalta at the next dose.

Q. My cat managed to eat several Vidalta tablets in one go, what should I do?                                              
A. If you suspect that your cat has had an overdose of Vidalta then you should call your vet immediately for advice.

QHow soon after starting Vidalta should I see an improvement in my cat’s clinical signs?                                                                       
A. Vidalta starts to work quite quickly and so you should see an improvement within a couple of weeks.

Q. How often will I need to return to the vets for rechecks?                                                                             
A. Rechecks will be frequent initially but if your cat is responding well then they will reduce to every few weeks and then every few months. In the long term, follow up checks every 3-6 months are recommended.

Q. I’m not seeing a huge improvement in my cat, should I give them more Vidalta?                                                                    
A. No. You should not change the dose without speaking to your vet. Speak to your vet if you think the Vidalta is not working.


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