Dietary treatment for feline hyperthyroidism

Author: VioVet
Published: Wednesday 13th March 2013

Our customer asked:

I have two 17 year old cats, who have always been fed Science plan, graduating to Senior over the last 8 or so years. Both are 'healthy' and happy, however,

My female cat is grossly underweight, really light when lifted and generally feels like a bag of bones. When sitting next to her, you can also hear a noise which sounds like if you suck air through pursed lips (please try to see what I mean). Her coat is still shiny, good teeth, and she doesn't 'really' have any issues bar, if we leave clothes on the floor over the winter months, she will go and pee on them rather than go outside.
I often allow her to have anything she wants (aswel as her SP food), gravy, milk, custard, and generally leftovers from our diner plate (once we've finished of course!) She even has a tendency to push her head into an empty crisp packet, imp assuming for the salt? She has never been a big eater of meat or solid food we have tried to give her (other than SP), favouring liquids (hence gravy, custard etc) over ham, chicken fish etc!!!!!

I have taken her to the vets, who wanted to perform a lot of expensive tests to determine whether she was hyperthyroidic or not. I'm obviously not too keen on this.

Is it advisable to try T4 tablets on my female without a diagnosis, or is there a natural way I can combat an over active thyroid? (assuming she has one of course!)

Is there any treatment, medicine I could give to encourage weight gain? I thought about purchasing the Neuted/or sterilised Science plan products but as I have one of each sex, I'm unsure of which one. I was also concerned because she is so skinny, that this food may encourage further weight loss (if possible!).

My other male cat, is quite rotund, active and no problems what so ever, so I did like the idea of the neuted SP to encourage a little weight loss. He's not a fat cat, but could do with losing a little (can't we all!)

They feed together and it would be impossible to keep their food separate, as we operate a buffet system, with their bowl being mostly available. That's why I've always favoured Hills dry food, as they eat as much as they require or need, rather than with tinned food (Felix etc), where they (have) eaten more than they should!

Is it something that I should just nurse until the end, or are there any practical ways in which I can encourage weight gain (on the female!)

Our reply:

It sounds as if your female cat does have a medical problem. Ideally this should be diagnosed at the vets and then the most appropriate treatment provided. If you decide against this option, then it is a reasonable idea to try and support her in whatever other way you can. It is in fact possible to treat hyperthyroidism in cats using diet alone. Hills make a special diet - Hills Prescription Diet y/d. (The prescription name is just to indicate it is not suitable for all cats. You can still buy it  without a prescription.)

Hills y/d is effective because it restricts the amount of iodine in the diet to just the right amount to produce adequate, but not excessive, thyroid hormone. If you give any other food at all, it will not work because there will be too much iodine available. If she has hyperthyroidism and you feed her just Hills y/d and no other food at all, she will be a lot healthier and live a lot longer. If she is not hyperthyroid then the food will not help, though it should do no harm to her. You will have to be very strict though and change your lifetime policy on feeding. Health or indulgence I suppose, we often face that dilemma ourselves!

Hills y/d is normally showing good results after 1-3 weeks for hyperthyroid cats. The tinned food is probably more palatable and a better diet, but dried is available and is what your cats are used to.