How to take blood pressure in a conscious cat

In 1940 it was reported that blood pressure (BP) measurements in humans were higher when taken in a clinical setting, compared with those taken at home (Ayman and Goldshine, 1940). This phenomenon, known as ‘white coat hypertension’, can also be seen in veterinary medicine, where nurses have to measure blood pressure in conscious cats reliably and repeatably, in cats that are often anxious, fractious, or uncooperative. Despite this, blood pressure is a vital tool for veterinary surgeons to either rule in or to exclude many common clinical conditions seen in cats, such as renal hypertension, hyperthyroidism and hypertrophic cardiomyopathy. Once a diagnosis has been made and antihypertensive medication started, veterinary nurses will need to reliably repeat the BP measurements to assess the efficacy of treatment at subsequent check ups (Clapham, 2011).

Systemic hypertension has become increasingly recognised in feline medicine in the last two decades (Gouni et al, 2015). It can be idiopathic in origin, meaning that no other medical cause can be found. Stepien (2011) suggests that primary hypertension can account for up to 20% of feline hypertensive patients. However, secondary hypertension, high BP as a result of another disease process, is much more common. Systemic diseases such as chronic kidney disease (CKD) and endocrine disorders such as hyperthyroidism, diabetes mellitus, hyperadrenocorticism or hyperaldosteronism are regularly associated with systemic hypertension. The most common cause of secondary hypertension is CKD and although figures vary greatly between 20–60% of those cats with CKD and systemic hypertension, it is clear that there is a link between the two (Stepien 2011). Hyperthyroidism is commonly acknowledged as the second most common cause of secondary hypertension (Jepson, 2005). As these diseases are commonly seen in older cats, it is recommended that blood pressure measurement in geriatric cats should be a part of a normal screening process (Pittari et al, 2009; Stepien, 2011; Cannon and Brett 2012). One Belgian study looked at clinical findings in apparently healthy cats, and found that older cats had significantly higher systolic blood pressure (SBP) readings than middleaged cats (Paepe et al, 2013). Paepe et al (2013) also made an interesting link that several of the hypertensive cats were feline immunodeficiency virus (FIV) positive. This link has been made in human literature, but needs more research before being definitively linked in cats (Weiner et al, 2003). For a full list of indications of measuring blood pressure, see Box 1.