FELINE HYPERTHYROIDISM

Feline hyperthyroidism

Feline hyperthyroidism

Introduction

Feline hyperthyroidism multiple system disorders resulting from excessive circulating concentrations of L-tri-iodothyronine (T3) and, or, L-thyroxine (T4). Disease occurs in middle age to older cats, with a reported range of 4-22 years (average age 13 years) .4 Only 5% of hyperthyroid cats younger than 10 years at the time diagnosis.4 disease was first reported in cats in 1979 and since been recognized with increasing frequency.

Currently accepted as the most common endocrine disorders in cats and the most important cause of morbidity in middle-aged cats in the United States and the United Kingdom.3 disease is also often seen in Australia, Canada, Europe, Japan and New Zealand.

Not much is known about the worldwide distribution of feline hyperthyroidism, and there are very few published incidence and prevalence estimates. Report on the prevalence of hospital veterinary hospitals in North America, noted that there was a marked increase between 1979 and 1985.8 average in 1979 was 0,3%, while in 1985 their number had increased to 4,5%. Edinboro et al al19 reported that adjusted for age distribution of the hospital in North America increased from 0,1% in 1978-1982 to 2% in the period 1993-1997. The rise of the hospital was also registered in Germany, where the number of affected cats had increased from 0,2% in 1987-1994 to 2,6% in 1998.20 Miyamoto et al al16 reported the prevalence of 8,9% in cats 9 years and older who were taken to hospitals in two regions of Japan while Sassnau reported prevalence 11.4% in cats 8 years and older in the urban population in Germany.

Wakeling et al reported an annual incidence of 11.92% for cats over 9 years in view of the first hospital in the United Kingdom. Until now, the cause of the world, as well as the increasing number eluded scientists, and it was assumed that the immunologic, infectious, nutritional (eg, iodine), environmental (eg, toxins or goitrogens), or genetic factors may play a role in the development of this disease.

First published case-control study of cats with hyperthyroidism, the connection between hyperthyroidism and consumption of canned food in the 5 years before diagnosis, partial or complete indoor, not Siamese breed, and regular exposure of fertilizers, herbicides and pesticides used on lawns and flea products .8 subsequent studies have shown that consumption of canned commercial cat food and the use of cat litter were significantly associated with greater risk of hyperthyroidism. Use of topical ectoparasite was less strongly associated with increased risk of hyperthyroidism.

In this study, the risk of hyperthyroidism was greater for females than for males. Olczak et al Al1 also found that cats, cats eating canned food and a cat sleeping on the floor, were at greater risk of developing hyperthyroidism. In addition, they found that purebred cats were at much lower risk with a diagnosis of hyperthyroidism than domestic short and longhaired cats. In a small survey in 2006, Sassnau found that the prevalence of feline hyperthyroidism increases with age. Significantly more men than women were affected cats in this ...