Volume 200 - Issue 4
The cat and the nap
Authors: William H Seligman and Ari Manuel
Med J Aust 2014; 200 (4): 229. || doi: 10.5694/mja13.10730
Published online: 3 March 2014
Published online: 3 March 2014
While dogs can detect some cancers, cats might have other diagnostic talents
A patient’s apnoea is discovered by his “owner”
We report the case of a 72-year-old man who presented to his general practitioner with cat scratch — not cat-scratch disease, but trauma to the face and nose caused by repeated savage night-time attacks perpetrated by none other than his trusty loyal cat. The patient had a history of stable coronary artery disease, type 2 diabetes mellitus, diabetic neuropathy and hypertension.
Why the cat would be doing this puzzled his GP, who concluded that perhaps the cat was witnessing something which it deemed required intervention. The GP subsequently requested overnight polysomnographic assessment. This revealed moderate obstructive sleep apnoea (OSA) with an apnoea–hypopnoea index of 30, and bradycardia with 7-second cardiac pauses. Although 7-second cardiac pauses do not normally require cardiopulmonary resuscitation, the patient’s cat rushed in, knowing no better, to perform C(at)PR. Biting the nose that sneezes at you is not normally a recipe for success, but in this case it appears that the patient has had nine lives thanks to his cat. Happily, at routine follow-up after starting treatment with continuous positive airway pressure, the patient reported that the cat was no longer traumatising his face.
It is not unusual in a patient with these comorbidities to have both OSA and bradycardia with cardiac pauses,1 but what makes the case fascinating is the fact that sleep apnoea can trigger cardiac pauses.1 This raises the possibility of a unifying hypothesis — the cat was responding to and intervening in the patient’s apnoeic and asystolic episodes.
OSA has been causally related to cardiac arrhythmias and sudden cardiac death. Several mechanisms seem to underpin the association between OSA and cardiac arrhythmias,2 including intermittent hypoxia associated with autonomic nervous system activation, alteration in myocardial excitability, recurrent arousals with sympathetic activation and increased negative intrathoracic pressure which may mechanically stretch myocardial walls. There is a high prevalence of OSA in patients with cardiac arrhythmias.
So it appears that this cat, although unable to identify the exact cause of the apnoeic and asystolic episodes, was aware of the patient’s ill health and impending doom. Perhaps we should not be surprised by this, given the anecdotal stories that appear in the popular press from time to time — for example, stories of cats being “aware” of a woman’s pregnancy.
How could this all work? Animals live in a sensory world that is very different to our primarily visual world. While dogs have been shown to be able to detect various forms of human cancers,3-5 cats can detect smells and vapours that humans cannot detect.
In times of economic austerity, at least in Europe, let us commend this “natural” intervention. We hope that guideline groups will take note of this case and recommend the prescription of felines to patients at risk of OSA rather than home oximetry.
Competing interests
No relevant disclosures.
References
- Guilleminault C, Connolly SJ, Winkle RA. Cardiac arrhythmia and conduction disturbances during sleep in 400 patients with sleep apnea syndrome. Am J Cardiol 1983; 52: 490-494. i1115603
- Rossi VA, Stradling JR, Kohler M. Effects of obstructive sleep apnoea on heart rhythm. Eur Respir J 2013; 41: 1439-1451. i1115605
- McCulloch M, Jezierski T, Broffman M, et al. Diagnostic accuracy of canine scent detection in early- and late-stage lung and breast cancers. Integr Cancer Ther 2006; 5: 30-39. i1115607
- Sonoda H, Kohnoe S, Yamazato T, et al. Colorectal cancer screening with odour material by canine scent detection. Gut 2011; 60: 814-819.
- Ehmann R, Boedeker E, Friedrich U, et al. Canine scent detection in the diagnosis of lung cancer: revisiting a puzzling phenomenon. Eur Respir J 2012; 39: 669-676. i1115612
Provenance: Not commissioned; externally peer reviewed.