Repeat blood tests for a cat with thyroid problems.

I have an elderly cat with thyroid issues, the vet insists on repeating blood tests every 3 months, is this really necessary. The blood test are around £200 a go and even with insurance this is very costly. In addition to this there are regular blood pressure checks and medication. This is all very expensive. I'm just wondering how necessary it is.

Hello - and thank you for introducing this topic.  There are several reasons that vets take regular blood tests from cats on hyperthyroid meds.  The aim is to ensure that the T4 levels - the Thyroid levels - remain within the desired range.   It is possible to correct hyperthyroidism too much and cause a second illness, 'Iatrrogenic Hypothyroidism,' which shortens the life expectancy, depresses the patient's enthusiasm for life and furthermore leads to azotaemia (high kidney levels due to under-filtration), which can in turn shorten the life expectancy.  It is also possible to correct hyperthyroidism to little, thus maintaining an artificially high blood-pressure, which can damage the kidneys and the heart.  In some cats, it's possible to get an idea of thyroid control by monitoring the heart-rate, eating, blood pressure and body-weight.  However, heart-rate and blood pressure can be unreliable in a vets' setting (where cats are stressed, affecting their heart-rates and blood pressures) and the weight and eating can be affected by a long list of other bodily problems, so relying on these perameters isn't the most reliable.  I would tend to agree that regular blood tests are the most useful, objective way to assess a cats' thyroid.  More to follow

So, regular thyroid tests are important / the standard and I would argue that it is your vets' job not only to offer but to strongly encourage these.  However, the financial cost is not trivial and it is the heartbreaking reality of veterinary practise - especially where chronic (ongoing / lifelong) diseases is involved - that the cost can frequently be the success-limiting factor of treatment (the same is also true of human healthcare, but this is less in-your-face in my country because treatment is free at the point of use - pet owners here are therefore frequently shocked by the financial aspect of veterinary healthcare).  In situations where money is scarce, weighing-up has to be done.  This can only really be carried out between yourself and the veterinary team who know the patient concerned and understand how stable they are.  It may involve phone calls to meds companies or entering into active discussions with the RCVS or other vets, to find the imperfect solution - or compromise - that best meets the patient's interests.    The RCVS is the governing body of vets - i.e. the people who lay down the rules, 'the code,' that veterinary professionals are obliged to follow - and they have the following to say.

• 4.17  Whether a physical examination is necessary for the prescription of (meds)..... is a matter for the veterinary surgeon’s judgement depending on the circumstances of each individual case (please note that the Animals (Scientific Procedures) Act 1986 should be followed where it applies). When deciding whether a physical examination is required, the following factors are relevant, however veterinary surgeons should note this list is not exhaustive:
• a.  The health condition(s), or potential health condition(s), being treated and any associated risks (see further guidance below at paragraph 4.18 and 4.19)
• b.  The nature of the medication being prescribed, including any possible risks and side effects (see further guidance below at paragraphs 4.20 and 4.21)
• c.  Whether the medication is being prescribed under the cascade (see further guidance below at paragraph 4.24)
• d.  When the animal was last physically examined by a veterinary surgeon, or premises physically inspected in the case of production animals, farmed aquatic animals or game
• e.  Whether there is access to the animal’s previous clinical history or, in the case of production animals, farmed aquatic animals and game, knowledge of the health status at the premises
• f.  The understanding and knowledge of the owner/keeper in relation both to animal health and welfare, and the importance of open and honest communication with the veterinary team
• g.  Whether the individual animal, herd, flock or group of animals is/are known to the veterinary surgeon and/or whether there is an existing relationship with the client or animal owner/keeper
• h.  The practicality of a physical examination for individual animals
• i.  The health status of the herd, flock or group of animals
• j.  The overall state of the animal’s health
• k.  The impact of any prescription made without physical exam on the ability to gather subsequent diagnostic information

4.18  The more complex or unusual the health needs of the animal, or where a differential diagnosis includes serious conditions not yet ruled out, the more likely a physical examination will be necessary.

I assume that your vet will do the best they can to help your cat within this framework; if they cannnot follow these rules, their profesisonal standing will be at stake.

These are the RCVS requirements - i.e. the UK ones.  I'm sure you'll agree that it is important for vets to work to these guidelines in order that patients receive an accetable standard of treatment.  I would frequently regard taking bloods as an important part of the examination in this case.  I hope that something there is of help.

At the end of the day,  vet should make the best judgement that they can, with aimal wealfare at the forefront of their decision-making.

You may also find this article helpful about hyperthyroidism in cats:  https://vethelpdirect.com/vetblog/2021/04/21/what-are-the-symptoms-of-hyperthyroidism-in-cats-and-how-is-it-treated/ And this one about recent changes to the precribing of medications:  https://vethelpdirect.com/vetblog/2023/09/05/new-prescribing-rules-for-uk-vets/