Lucy, a 17-year-old domestic short hair, had been a healthy cat since her owners adopted her as an eight-week-old kitten.
She enjoyed a comfortable indoor lifestyle with access to an enclosed courtyard, with no history of accidents or trauma.
She was fed a balanced diet and had annual veterinary health checks.
Lucy's owners ensured there were plenty of activities to engage her, including providing a climbing tree, a selection of toys and cardboard boxes to hide and scratch in.
Until recently, Lucy was sprightly for her age, but over the last two months her appetite and thirst had increased.
She vomited a couple of times each week (always on the rug) and her coat was looking a bit shabby.
When I weighed Lucy she was 400 grams lighter than her previous recorded weight.
Her thyroid gland - just over her throat - felt slightly enlarged, while her kidneys felt a little small.
Blood and urine tests revealed Lucy had at least two conditions: an overactive thyroid (hyperthyroidism) and kidney disease.
As with humans, senior companion animals can suffer from multiple diseases.
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The combination of thyroid and kidney disease is not unusual in older cats.
Both diseases can cause similar symptoms, including weight loss, vomiting, increased thirst, increased urination and even reduced appetite.
When these diseases occur at the same time, they can be tricky to diagnose.
Normally, an overactive thyroid is indicated by high levels of thyroid hormone in the blood. But kidney disease can suppress these levels, masking the thyroid disease.
Similarly, thyroid disease can artificially increase the filtration rate of the kidneys and decrease muscle mass, lowering blood levels of creatinine, a key marker of kidney disease.
Kidney disease is a progressive disease for which there is no cure.
Nonetheless, cats can live for years with managed kidney disease.
Ideally, tests are performed to determine at which stage the cat's kidney disease is and management tailored accordingly.
Thyroid disease may be treated definitively through radiation or surgery, or managed medically.
When combined with kidney disease the treatment for one, can complicate treatment for the other.
Lucy was fortunate in that her chronic kidney disease was in its early stages.
However, to ensure this was not worsened, by treatment of her thyroid disease, she was put on a low dose of thyroid hormone-suppressing medication and prescribed a kidney-friendly diet.
Her owners are now measuring her water intake at home, with instructions to report any significant changes.
They do this by ensuring they fill her water bowl from a measuring jug, noting the amount they replace each day.
Lucy is now scheduled for three-monthly veterinary visits. She also has her blood pressure measured, as cats with thyroid disease, kidney disease or both, are at increased risk for high blood pressure.
Lucy's vomiting has already resolved and her owners report her food intake is normalising.
While it may seem like a tricky balancing act, cats with concurrent kidney and thyroid disease can be managed successfully and enjoy excellent quality of life.
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