Abstract

Objective: To evaluate the abnormal signs found in the domestic animals (pets) of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) patients.

Design: Retrospective study of the domestic animals (pets) of criteria-met ME/CFS patients using a standardized questionnaire which included patient comments.

Setting: University medical center and ME/CFS support groups throughout the United States.

Patients: A total of 127 patients met the surveillance criteria of the Centers for Disease Control and Prevention (CDC) for the establishment of the diagnosis of ME/CFS and were included in the study. This group of patients had a total of 463 domestic animals (pets), of which 348 animals demonstrated abnormal signs and 115 were considered healthy.

Measurements: Information from the standardized questionnaire was compiled and appropriate statistical tests, including mean, median, Z test, multivariant analysis, and Chi-square test, were used.

Results: One hundred six (83%) of the 127 ME/CFS surveyed reported that at least one of their animals (predominantly domestic pets) showed a wide range of unusual or atypical signs, many of which mimicked the signs and symptoms of ME/CFS. The sick animals' signs were divided into General (40%), Neurological (35%), Gastrointestinal (10%), Reticuloendothelial/Blood (9%), Neoplasia (4%), and Endocrine (2%).

One of the most striking result of the study was that 113 of the 127 ME/CFS patients surveyed felt their ME/CFS symptoms were somehow associated with their animals contact. Ninety (71%) of the 127 ME/CFS patients reported that they were the primary caretakers for multiple animals. Other less common findings were: the onset of ME/ CFS being associated with obtaining the animal; the onset of ME/CFS being associated with a flea bite episode; prior residents having sick animals and ME/CFS; other family member contracting ME/CFS from their close association with the sick animal (as opposed to their association with the family members who had ME/CFS); ME/CFS symptoms decreasing after the pet leaving or dying.

Conclusions: A large number of animals of ME/CFS patients have atypical or unusual diseases which at least mimic ME/CFS. Most of the 127 ME/CFS patients surveyed have significant animal interactions.