Hyperthyroidism is one of the most prevalent endocrine disorders in cats, particularly those over the age of ten years.Thyroid hormones typically control a large number of metabolic activities in the body. As thyroid hormone levels in the blood rise in hyperthyroid cats, a gradual increase in their metabolic rate occurs, resulting in a variety of abnormalities throughout the body, including weight loss and muscle atrophy. Additionally, elevated thyroid hormone levels interact with and excite the central nervous system, often resulting in increased activity or restlessness, as well as other behavioural issues.
The clinical symptoms of hyperthyroidism may be very severe, and cats can get gravely sick as a result of this disease. Hyperthyroidism in cats, if left untreated, may result in heart or kidney failure and is deadly. However, this condition is curable, and the majority of hyperthyroid cats will recover completely. I’d cover the different treatment choices, as well as the advantages and disadvantages of each, later in this current series of articles on feline hyperthyroidism.
We have compiled a list of themost common symptoms of hyperthyroidism in cats, ranked from most frequently to least frequent.It is not necessary for your cat to exhibit all of these clinical signs or symptoms in order to have an overactive thyroid. However, if your cat exhibits one or more of these symptoms, particularly if he or she is above the age of 10, you should certainly get your cat checked for hyperthyroidism. Click here for more information.
- Loss of weight
The primary and most frequent symptom of hyperthyroidism in cats is weight loss despite a normal to increased appetite. Because hyperthyroidism is so prevalent, it should always be evaluated in any middle-aged to older cat that has lost weight, even if no other clinical signs of the illness are present.Weight loss is typically gradual and is first observed by the owner as a decrease of muscular mass around the cat’s back (spine).If the cat’s hyperthyroidism is not treated, severe muscular loss, emaciation, and death from hunger may ensue.
- Appetite stimulation
Weight loss is usually accompanied with an increase in the cat’s appetite in cats with hyperthyroidism. This hunger gain may be significant, with some cats tripling their food consumption and constantly asking for more. Unfortunately, the majority of cats are unable to completely adjust and will continue to lose weight even with a normal to increased appetite.
- Excessive energy, hyperactivity, or anxious behaviour
Hyperactivity, most often seen as anxiety or restlessness, is very frequent in hyperthyroid cats. Extreme hyperthyroidism may manifest as muscular tremor or twitching, and afflicted cats often exhibit an agitated or frenzied facial expression.Certain cats, particularly those in the early stages of hyperthyroidism, may misinterpret such increased activity and energy as a sign of health. Bear in mind that cats often become very sedentary as they age, and therefore this shift in behaviour resulting in greater energy and activity is usually always a symptom of an underlying illness condition.
- Vomiting or retching
In cats with hyperthyroidism, gastrointestinal symptoms such as occasional vomiting or regurgitation are quite frequent. Vomiting may be caused by thyroid hormones acting directly on a region of the brain called the chemoreceptor trigger zone. In certain cats, vomiting may be caused by gastric stasis.
- Anxiety, yowling at night, befuddlement, aimless pacing
The most apparent behavioural indication to owners is nocturnal yowling (a long loud mournful cry). This yowling is most often heard in the middle of the night for no apparent reason and usually wakes the owner. Some hyperthyroid cats may also exhibit aimless pacing and easily disrupted sleep habits.