OBJECTIVES

An outbreak of dysautonomia occurred in a colony of eight pet cats in Scotland during November 2001. After nine days 6/8 cats were clinically affected. 2 cats remained clinically normal. 3/6 of the clinically affected cats died (2) or were euthanized in extremis (1) within 21 days of the outbreak onset. A diagnosis of dysautonomia was confirmed by histopathology in 2/3 of non-surviving cats. All other cats survived. Clinically affected cats were treated medically with prokinetic drugs.

Aim: to assess and score oesophageal function abnormalities in the cats and determine if the scores change with treatment or are prognostically useful.

MATERIALS

5/6 clinically affected cats were screened at presentation, after 2 days of therapy, and, if surviving, after a further 88 days therapy. 2/2 clinically normal, untreated cats were screened 96 days after the start of the outbreak.

10 mls of radiographic contrast (Gastrografin) were administered by syringe to cats without sedation. Boluses were monitored through the cervical and thoracic oesophagus in the lateral plane by fluoroscopy and recorded by DVD. Each swallow were scored on an increasing severity scale of 0, 1, 2, and 3 for the following markers of oesophageal dysfunction: retention of barium, retrograde peristalsis, gastro-oesophageal reflux, delayed transit time, and oesophageal pooling of contrast at the thoracic inlet and caudal to the base of the heart. Scoring was performed by review of DVD recordings on a single occasion by one author (MS).

RESULTS

5/5 clinically affected cats had abnormal oesophageal function fluoroscopically (median total score (MTS) 8). 2/2 clinically normal cats had abnormal oesophageal function (MTS 6) suggesting that they represented subclinical cases.

Therapy failed to improve fluoroscopic oesophageal function scores despite a reported reduction in the frequency of regurgitation. The scores of individuals did not alter significantly over the time of the study.

Neither total score nor any individual marker was prognostically useful. The MTS for surviving cats was 8 and for cats that died it was 7.5.

CONCLUSION

Contrast fluoroscopy can detect abnormalities of oesophageal function in cases of feline dysautonomia. It also detected abnormalities in cats that were apparently unaffected clinically. These may represent subclinical cases of feline dysautonomia. Use of the subjective scoring system for markers of oesophageal dysfunction did not detect a response to therapy in any cases. Nor was it predictive of survival.