Feline Comorbidities: Balancing hyperthyroidism and concurrent chronic kidney disease

Abstract

Practical relevance: Both hyperthyroidism and chronic kidney disease (CKD) are common long-term conditions in older cats, which might be diagnosed concurrently or develop at different times. Hyperthyroidism may mask the presence of CKD, and vice versa, by various mechanisms that are described in this review. Hyperthyroidism treatment options should be carefully considered when CKD has also been diagnosed. Clinical challenges: Although it can be difficult to diagnose hyperthyroidism and CKD simultaneously, given that one condition may mask the other, it is important to consider the presence of both diseases when examining an older cat presenting with vomiting, weight loss, polyuria/ polydipsia, anorexia or sarcopenia. The concurrent presence of hyperthyroidism and CKD requires careful monitoring of glomerular filtration rate biomarkers, and adequate and prompt support of kidney function when normal thyroid function is re-established. Iatrogenic hypothyroidism is a recognised complication of all of the treatment options for hyperthyroidism, and increases the risk of azotaemia. Therapy with levothyroxine is recommended for cats that are hypothyroid and azotaemic. Evidence base: The information in this review draws on current literature and guidelines related to the pathophysiology, diagnosis and treatment recommendations for feline hyperthyroidism and CKD.

The potential for senotherapy as a novel approach to extend life quality in veterinary medicine

“…Moving forward, evaluation of senotherapeutics to specifically target SC in the context of naturally occurring veterinary diseases presents a translational opportunity to explore the long-term safety and efficacy of senotherapeutics in spontaneous disease models ( Figure 3 ). Examples of potential applications of senotherapeutics in veterinary medicine include treatment of osteoarthritis which is prevalent in dogs, horses and cats ( 175 , 176 ), or more specific disease processes such as idiopathic pulmonary fibrosis in West Highland Terriers ( 177 , 178 ), canine cardiomyopathies ( 179 – 181 ), or renal disease and sarcopenia in cats ( 182 – 185 ) ( Figure 4 ). These collaborative prospects offer a new avenue to bridge the gap between in vivo rodent models and clinical trials in people, while simultaneously benefiting veterinary species suffering from similar disease processes.…”

“…Eliminating dysfunctional cells may reduce inflammation, decrease fibrosis, slow down the progression of kidney damage, and preserve renal function ( 100 , 214 ). Spontaneous chronic kidney disease (CKD) is well-described in cats ( 182 – 185 ). Feline patients suffering from CKD have renal senescence, telomere shortening, and nitrosative stress in renal cells ( 215 ).…”

Effects of Beraprost with or without NOS Inhibition on Plasma Aldosterone and Hemodynamics in Healthy Cats

“…Various complications and co-morbidities often occur in cats with CKD [18][19][20]. For instance, CKD is reported to be frequently the cause of death in cats with cardiomyopathy [21], hyperthyroidism is common in feline patients with CKD [22,23], and these disorders have been considered to affect the RA axis. Cats with cardiomyopathy reportedly have higher PAC and PRC compared to healthy cats [24].…”

Urine concentrating ability in cats with hyperthyroidism: Influence of radioiodine treatment, masked azotemia, and iatrogenic hypothyroidism

“…Hyperthyroid cats commonly have sub-maximally concentrated urine, with urine specific gravity (USG) <1.035. [1][2][3] This is of clinical importance, since hyperthyroidism is a reported risk factor for chronic kidney disease (CKD), [4][5][6] in which a USG <1.035 is expected. 7,8 Furthermore, hyperthyroidism can complicate (mask) the diagnosis of azotemic CKD by increasing renal blood flow and glomerular filtration rate (GFR) [9][10][11][12] and decreasing body muscle mass, 13,14 thereby lowering serum creatinine concentration to within its reference interval.…”