The thyroid gland plays an important role in regulating metabolism in cats. Issues with the thyroid can impact various bodily functions and cause health issues if left untreated. Since cats cannot express their discomfort verbally, regular screening of thyroid levels is recommended to keep our feline companions healthy. This article discusses the importance of thyroid tests for cats and how it is conducted.
The main hormone produced by the thyroid gland is thyroxine, also known as T4. In cats, total thyroxine (fTT4) level is used to evaluate thyroid function. fTT4 test measures the total concentration of T4 hormone in the blood. An abnormal fTT4 result may indicate hyperthyroidism or hypothyroidism. Repetition of the test helps monitor the response to treatment.
Hyperthyroidism refers to an overactive thyroid gland that produces excess thyroid hormones. It is a common endocrine disorder in older cats. Clinical signs include weight loss despite increased appetite, hyperactivity, arrhythmia, vomiting, and diarrhoea. Untreated hyperthyroidism can lead to heart and liver diseases. It is caused by benign thyroid adenomas or carcinomas in most cases (Wakeling, Elliott, & Syme, 2010).
Both hypo- and hyperthyroidism can impact heart function and metabolism in cats. Hyperthyroidism raises the risk of heart diseases like arrhythmias and cardiomyopathy. Left untreated, it may result in liver disease, high blood pressure, and fractures. Hypothyroidism causes obesity, lethargy and skin issues. It weakens the immune system and increases susceptibility to infections. Prompt diagnosis and treatment of thyroid disorders are important to prevent potential complications (Mooney, 2010).
The primary test used for feline hyperthyroidism diagnosis is the measurement of fTT4 levels. Higher than normal fTT4 indicates hyperthyroidism. A radioactive iodine uptake test or thyroid scan may also be performed to locate enlarged thyroid tissues when fTT4 results are inconclusive. Ultrasound helps visualize the thyroid glands, and a biopsy can confirm nodular hyperplasia or adenoma/carcinoma causing the condition (Peterson, 2013).
For hypothyroidism diagnosis in dogs, both T4 and T3, along with TSH are measured. However, in cats, the tests for T3 and TSH are not reliable diagnostically. Unlike dogs and humans, a cat's TSH does not decrease in response to elevated T4 levels in hyperthyroidism. Therefore, feline TSH levels remain within normal limits and are not helpful indicators of thyroid status. fTT4 alone is sufficient for feline thyroid evaluation.
A small blood sample is collected from the cat. For accurate results, samples should be taken in a non-fasted state, at least 2 hours after eating. The blood is centrifuged and the serum is separated. fTT4 levels in the serum are then measured quantitatively using a Veterinary Immunofluorescence Quantitative Analyzer like FIA680/880. It provides results in minutes along with interpretation. Repeat testing monitors treatment response over time.
The cost of fTT4 test varies depending on the clinic and location but ranges from $50-$80 per test usually. Additional tests like ultrasound may cost more. Quantitative analyzer like FIA680 costs $1000 for single channel and $1500 for six channels. It offers quick, accurate and affordable testing with no recurring costs for reagents or calibrators. Overall, the investment allows timely diagnosis and management of thyroid disorders in cats at reasonable prices.
Yes, using a quantitative analyzer like the FIA680/880 is recommended for feline thyroid testing. Compared to in-house rapid tests, these analyzers provide exact fTT4 concentration values along with reference ranges. They reduce the chances of interpretation errors and ensure consistent results across multiple samples. Features like onboard storage of test history and multiple language interface add to their user-friendliness. Their high throughput of 300 samples per hour make them suitable for veterinary clinic settings.
The FIA680/880 veterinary immunofluorescence quantitative analyzer has multilingual capabilities. It supports display and operation in four languages - Chinese, English, Russian and Italian by default. However, other languages can also be implemented according to customer requirements. This multi-language function enhances usability for global users. Clinics catering to diverse clientele can opt for additional language integration as per their needs.
Proper sampling and handling are critical for accurate test results. Samples should be collected aseptically into red or tiger top tubes containing no additives or preservatives. After collection, the blood tube is gently inverted 2-3 times and allowed to clot at room temperature for 30 minutes. It is then centrifuged at 3000-5000 rpm for 5 minutes. The separated serum is extracted using a pipette and loaded on the test cartridge for analysis on the FIA680/880. Following guidelines ensure quality test results.
In conclusion, regular testing of fTT4 levels is recommended to monitor thyroid function in cats and detect disorders early. Quantitative analyzers provide fast, reliable and cost-effective testing. Adhering to sample collection standards yields accurate diagnostic information for timely clinical intervention and management of thyroid problems in our feline companions.
References
Mooney, C. T. (2010). Feline hyperthyroidism: diagnosis and management. Journal of Feline Medicine and Surgery, 12(5), 365-378.
Peterson, M. E. (2013). Hyperthyroidism in cats: what's causing this epidemic of thyroid disease and can we prevent it? Journal of Feline Medicine and Surgery, 15(8), 713-722.
Wakeling, J., Elliott, J., & Syme, H. M. (2010). Evaluation of predictors for the diagnosis of hyperthyroidism in cats. Journal of Veterinary Internal Medicine, 24(5), 1057-1063.
