Heart Worm Treatment

This is the most recent suggested protocol from the American Heart Worm Society and this is the only method to actively kill heart worms.

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Download a treatment schedule HERE

 

Day 1 (after being diagnosed)
In a dog diagnosed and verified as heartworm positive
• Positive antigen (Ag) test verified with 2nd Ag or microfilaria (MF) test
• If no MF are detected, confirm with second Ag test from a different manufacturer
• Apply an EPA-registered canine topical product labeled to repel and kill mosquitoes
• Begin exercise restriction - the more pronounced the signs, the stricter the exercise restriction
If the dog is symptomatic:
• Stabilize with appropriate therapy and nursing care
• Prednisone prescribed at 0.5 mg/kg BID 1st week, 0.5 mg/kg SID 2nd week, 0.5 mg/kg EOD 3rd and 4th week

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Day 2 (after being diagnosed)
Administer appropriate heartworm preventive
• If MF are detected, pre-treat with antihistamine and/or glucocorticosteroids, if not already on prednisone, to reduce risk of anaphylaxis
• Observe for at least 8 hours for signs of reaction

Check

 

Day 1- 30 (after being diagnosed)
Administer doxycycline 10 mg/kg BID for 4 weeks
• Reduces pathology associated with dead heartworms
• Disrupts heartworm transmission

Check

 

Day 31 (after being diagnosed)
• Administer appropriate heartworm preventive
• Apply an EPA-registered canine topical product to repel and kill mosquitoes

Check

 

Day 30-60 (after being diagnosed)
A one-month wait period following doxycycline before administering melarsomine is currently recommended as it is hypothesized to allow time for the Wolbachia surface proteins and other metabolites to dissipate before killing the adult worms. It also allows more time for the worms to wither as they become unthrifty after the Wolbachia endosymbionts are eliminated.

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Day 60 (after being diagnosed)
• Administer appropriate heartworm preventive
• Administer first melarsomine injection, 2.5 mg/kg intramuscularly (IM)
• Prescribe prednisone 0.5 mg/kg BID first week, 0.5 mg/kg SID second week, 0.5 mg/kg EOD for the third and fourth weeks
• Decrease activity level even further: cage restriction; on leash when using yard

Check

 

Day 90 (after being diagnosed)
• Administer appropriate heartworm preventive
• Administer second melarsomine injection 2.5 mg/kg IM
• Prescribe prednisone, 0.5 mg/kg BID first week, 0.5 mg/kg SID second week, 0.5 mg/kg EOD for the third and fourth weeks

 

Day 91 (after being diagnosed)
• Administer third melarsomine injection, 2.5 mg/kg IM
• Continue exercise restriction for 6 to 8 weeks following last melarsomine injections

 

Day 120 (after being diagnosed)
• Test for presence of MF
• If positive treat with a microfilaricide and retest in 4 weeks.
• Continue a year-round heartworm prevention program based on risk assessment

 

1 Year (after being diagnosed)
Antigen test 9 months after last melarsomine injection; screen for MF
If still Ag positive, re-treat with doxycycline followed by two doses of melarsomine 24 hours apart