Table 6.

Recommendations for moxidectin-doxycycline adulticidal treatment of asymptomatic and mild (Class 1 and 2) heartworm disease in dogs.

Element	Recommendation
General	•Not recommended in best practice guidelines •Viable treatment alternative if melarsomine is not a treatment option •Outcomes are likely to be less favorable and treatment duration longer for Class 3 disease, which is likely to represent higher worm burdens and more chronic infection
Moxidectin	•Topical formulation recommended •Administer at label dose, monthly until NAD •Consider sustained release injectable in remote communities or where significant compliance or accessibility concerns exist •Unknown whether sustained release formulation should be used per label or more frequently •No data to date for oral formulation
Doxycycline	•Essential component of any adulticidal treatment protocol •10 mg/kg PO q 12 or 24 h for 28 days •Repeat annually if still positive
Duration of treatment	•Continue until NAD
Exercise restriction	•Clinical PTE appears to be rare but timing is unpredictable •Insufficient data to be confident of required duration or stringency •Restrict exercise to the extent possible until NAD, commensurate with clinical severity, owner's ability to implement and dog's lifestyle and temperament
Testing for efficacy (NAD)	•Antigen testing at 6 months – cost:benefit analysis needed as approximately half are expected to remain positive at this point •Antigen testing at 12 months likely to give a negative result in the majority of cases •Test for microfilaremia at time of antigen testing to identify resistant parasites •Unclear whether 2 antigen tests, 6 months apart, are needed – current recommendation is to test twice where possible, as a precaution •No evidence that heat treatment is required to determine NAD status

NAD, no antigen detected; PTE, pulmonary thromboembolism.