{"id":74982,"date":"2023-09-28T16:02:01","date_gmt":"2023-09-28T16:02:01","guid":{"rendered":"https:\/\/todaysveterinarybusiness.com\/?p=74982"},"modified":"2024-01-30T12:25:18","modified_gmt":"2024-01-30T17:25:18","slug":"using-immiticide-melarsomine-dihydrochloride-sterile-powder-to-treat-heartworm-disease","status":"publish","type":"post","link":"https:\/\/navc.sitepreview.app\/todaysveterinarybusiness.com\/using-immiticide-melarsomine-dihydrochloride-sterile-powder-to-treat-heartworm-disease\/","title":{"rendered":"Using Immiticide\u00ae (melarsomine dihydrochloride) Sterile Powder to Treat Heartworm Disease"},"content":{"rendered":"
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Presentation<\/span><\/h2>\n

Possum is a 15 kg, 2-year-old blue heeler who, according to her owners, was the picture of health and extremely active until a few days before presentation, when she became lethargic, started coughing and lost her appetite. When her abdomen started to swell and she vomited a few times, her concerned owners took her to her regular veterinarian.<\/span><\/p>\n

The veterinarian found that Possum\u2019s temperature was 105\u00b0F and she had harsh lung sounds, and made a presumptive diagnosis of pneumonia and possible intestinal blockage, since Possum was notorious for ingesting foreign objects. The veterinarian prescribed antibiotics, discharged Possum and instructed her owners to bring her back the next day for X-rays if the vomiting continued. That evening, Possum\u2019s abdominal distention worsened and her breathing became labored, so her owners took her to a critical care facility.<\/span><\/p>\n

Diagnosis<\/span><\/h2>\n

On physical examination, the emergency veterinarian noted a grade 3\/6 heart murmur, and blood work revealed leukocytosis and a normal biochemistry profile. Thoracic radiographs revealed an enlarged reversed-D cardiac silhouette, large tortuous caudal lobar arteries and consolidated areas that indicated heartworm disease. Possum\u2019s heartworm antigen test was positive but negative for microfilariae. Possum was current on her core vaccines, her owner said, and she received a monthly ivermectin-based heartworm preventive. However, on further questioning, the owner said she did miss an occasional dose and had not started the medication until Possum was 6 months old. So, Possum was likely infected during her first few months. The heartworm preventive Possum received was essentially acting as a \u201cslow kill\u201d heartworm treatment, which the American Heartworm Society does not recommend. While these methods can be effective, rigid exercise restriction is necessary for the entire treatment period to minimize pathology. In Possum\u2019s case, the dying worms led to multiple pulmonary thromboembolisms and right-sided heart failure at an early age.<\/span><\/p>\n

Treatment<\/span><\/h2>\n

Possum was stabilized with flow-by oxygen, and 450 ml of blood-tinged fluid was removed from her abdomen to decrease abdominal pressure that was interfering with her respiration. Her condition progressed as follows:<\/span><\/p>\n