Seasonal and circadian variation in presentation of cats with congestive heart failure


  • Dr. Pelosi's current address: Department of Small Animal Clinical Sciences, Veterinary Medical Center D-208, Michigan State University, East Lansing, MI 48824-1314, USA.

  • Dr. Farabaugh's current address: Angell Animal Medical Center-Boston, 350 South Huntington Avenue, Boston, MA 02130, USA.

Address correspondence and reprint requests to Dr. John Rush, Department of Clinical Sciences, Tufts Cummings School of Veterinary Medicine, 200 Westboro Road, North Grafton, MA 01536, USA. Email:


Objective– To determine if cats with congestive heart failure (CHF) are presented to a referral clinic more frequently during different seasons, months, days, or times.

Design– Retrospective study.

Setting– University small animal hospital.

Animals– One hundred and eighty-six cats with CHF.

Interventions– None.

Measurements and Main Results– The medical records of 186 cats, presented for 238 episodes of CHF between July 1, 1997 and June 30, 2002, were reviewed. An episode of CHF was defined as documented clinical evidence of pulmonary edema, pleural effusion, pericardial effusion, or ascites attributed to a cardiac origin by a board-certified cardiologist. Chi-square tests revealed statistically significant differences in presentation between different days of the week, with Thursday being the most common day, and between different hours of the day, with the peak between 10 am to 4 pm. Evaluation of presentation for CHF by season of the year identified more cats in December, January, and February although this did not achieve statistical significance. No significant difference was identified for presentation based on the day of the month or the month of the year.

Conclusions– In this population of cats, there was daily, weekly and, possibly, seasonal variation in the frequency of presentation of cats with CHF. Additional studies are warranted to confirm these findings and to determine the cause for these differences.