Atenolol for Hyperthyroid Cats

Henik, R. A., R. L. Stepien, et al. (2008). "Efficacy of atenolol as a single antihypertensive agent in hyperthyroid cats." Journal of Feline Medicine & Surgery 10(6): 577-582.

Hypertension is a common complication of hyperthyroidism and chronic renal disease in cats. Various drugs may be used to treat feline hypertension, but the drug of choice appears to be amlodipine due to its efficacy and low incidence of adverse effects. However, in cats with hypertension caused by hyperthyroidism, beta-blocking drugs such as atenolol have been suggested to slow the heart rate and block effects of thyroid hormone on the cardiovascular system. While atenolol has been shown to be ineffective in treating hypertension associated with chronic renal disease, it has not been previously investigated for treatment of cats with hyperthyroidism. In this retrospective study, 20 hyperthyroid cats with systolic blood pressure over 160 mmHg were treated with atenolol (1-2 mg/kg, PO, BID). All cats were treated for a minimum of 5 days before reassessment and treatment with radioactive iodine. While both heart rate and systolic blood pressure decreased in the cats, successful clinical control of blood pressure was not achieved in 70% of the cases. The investigators concluded that while atenolol successfully controls heart rate in hyperthyroid cats, the addition of another drug is needed to treat hypertension.
>> PubMed Abstract

Related articles:
Trepanier LA. Pharmacologic management of feline hyperthyroidism. Vet Clin North Am Small Anim Pract. 2007 Jul;37(4):775-88
>> PubMed Abstract

More on cat health: Winn Feline Foundation Library

Henik, R. A., R. L. Stepien, et al. (2008). "Efficacy of atenolol as a single antihypertensive agent in hyperthyroid cats." Journal of Feline Medicine & Surgery 10(6): 577-582.

Hypertension is a common complication of hyperthyroidism and chronic renal disease in cats. Various drugs may be used to treat feline hypertension, but the drug of choice appears to be amlodipine due to its efficacy and low incidence of adverse effects. However, in cats with hypertension caused by hyperthyroidism, beta-blocking drugs such as atenolol have been suggested to slow the heart rate and block effects of thyroid hormone on the cardiovascular system. While atenolol has been shown to be ineffective in treating hypertension associated with chronic renal disease, it has not been previously investigated for treatment of cats with hyperthyroidism. In this retrospective study, 20 hyperthyroid cats with systolic blood pressure over 160 mmHg were treated with atenolol (1-2 mg/kg, PO, BID). All cats were treated for a minimum of 5 days before reassessment and treatment with radioactive iodine. While both heart rate and systolic blood pressure decreased in the cats, successful clinical control of blood pressure was not achieved in 70% of the cases. The investigators concluded that while atenolol successfully controls heart rate in hyperthyroid cats, the addition of another drug is needed to treat hypertension.
>> PubMed Abstract

Related articles:
Trepanier LA. Pharmacologic management of feline hyperthyroidism. Vet Clin North Am Small Anim Pract. 2007 Jul;37(4):775-88
>> PubMed Abstract

More on cat health: Winn Feline Foundation Library

Read More

Feline Thyroid Palpation Techniques

Paepe, D., P. Smets, et al. (2008). "Within- and between-examiner agreement for two thyroid palpation techniques in healthy and hyperthyroid cats." Journal of Feline Medicine & Surgery 10(6): 558-565.

The most common endocrine disorder of senior cats is hyperthyroidism. Early diagnosis and treatment can prevent serious complications. One of the most important diagnostic tools is palpation of the thyroid gland for enlargement, a standard part of the physical examination, especially for senior cats. There are two thyroid palpation techniques for cats described in the literature. The classic technique has the cat in a sitting position with the neck extended. Another technique has the cat standing with the head elevated and turned to one side. The diagnostic value of these techniques has not been compared. In this prospective study, 9 client-owned hyperthyroid cats and 10 healthy control cats were examined twice by 3 blind-folded clinicians using each palpation technique. A score from 1 to 6 was assigned to thyroid gland size each time. After clipping the hair of the ventral neck region, a final palpation session was performed, followed by ultrasonography of the gland. The classic palpation technique led to smaller within- and between-examiner differences. Clipping the hair coat did not make a significant difference. While both thyroid palpation techniques had good within- and between-examiner results, the investigators concluded that the classic palpation technique is preferred.
>> PubMed Abstract

Related Articles:
Norsworthy, G., V. Adams, et al. (2002). "Relationship between semi-quantitative thyroid gland palpation and total thyroxine concentration in cats with an without hyperadrenocorticism." J Fel Med Surg 4(3): 139.
>> PubMed Abstract

Norsworthy, G., V. Adams, et al. (2002). "Palpable thyroid and parathyroid nodules in asymptomatic cats." J Fel Med Surg 4(3): 145.
>> PubMed Abstract

More on cat health: Winn Feline Foundation Library

Paepe, D., P. Smets, et al. (2008). "Within- and between-examiner agreement for two thyroid palpation techniques in healthy and hyperthyroid cats." Journal of Feline Medicine & Surgery 10(6): 558-565.

The most common endocrine disorder of senior cats is hyperthyroidism. Early diagnosis and treatment can prevent serious complications. One of the most important diagnostic tools is palpation of the thyroid gland for enlargement, a standard part of the physical examination, especially for senior cats. There are two thyroid palpation techniques for cats described in the literature. The classic technique has the cat in a sitting position with the neck extended. Another technique has the cat standing with the head elevated and turned to one side. The diagnostic value of these techniques has not been compared. In this prospective study, 9 client-owned hyperthyroid cats and 10 healthy control cats were examined twice by 3 blind-folded clinicians using each palpation technique. A score from 1 to 6 was assigned to thyroid gland size each time. After clipping the hair of the ventral neck region, a final palpation session was performed, followed by ultrasonography of the gland. The classic palpation technique led to smaller within- and between-examiner differences. Clipping the hair coat did not make a significant difference. While both thyroid palpation techniques had good within- and between-examiner results, the investigators concluded that the classic palpation technique is preferred.
>> PubMed Abstract

Related Articles:
Norsworthy, G., V. Adams, et al. (2002). "Relationship between semi-quantitative thyroid gland palpation and total thyroxine concentration in cats with an without hyperadrenocorticism." J Fel Med Surg 4(3): 139.
>> PubMed Abstract

Norsworthy, G., V. Adams, et al. (2002). "Palpable thyroid and parathyroid nodules in asymptomatic cats." J Fel Med Surg 4(3): 145.
>> PubMed Abstract

More on cat health: Winn Feline Foundation Library

Read More