Surgical removal of heartworms from a cat with caval syndrome.

Caval syndrome was diagnosed in a 4-year-old male domestic shorthair cat with severe dyspnea attributable to chylothorax. The diagnosis of heartworm infection was made on the basis of the ultrasonographic detection of a large number of adult heartworms in the right side of the heart and positive results for modified Knott's and heartworm antigen tests. Heartworms were surgically removed through an incision in the jugular vein, using a string-type horsehair brush and an alligator forceps. All clinical signs resolved after the surgery. Although treatment with agents that would kill the adult heartworms was considered, surgical treatment was used on the cat reported here. Surgical treatment may be the method of choice for use in cats with severe or persistent clinical signs attributable to infections with large numbers of heartworms.