Wolbachia, doxycycline and macrocyclic lactones: New prospects in the treatment of canine heartworm disease.

Abstract

Melarsomine dihydrochloride (Immiticide®, Merial) is the only approved adulticidal drug for the treatment of canine heartworm disease (HWD). However, in cases where arsenical therapy is not possible or is contraindicated, a monthly heartworm preventive along with doxycycline for a 4-week period, which targets the bacterial endosymbiont Wolbachia, might be considered. There are published reports on the efficacy of ivermectin and doxycycline in both experimentally and naturally infected dogs, but no data on the use of other macrocyclic lactones (MLs) with a similar treatment regime. Preliminary results of studies in dogs show that a topical formulation of moxidectin, the only ML currently registered as a microfilaricide, is also adulticidal when combined with doxycycline. It is not yet known if the efficacy of these combination therapies is due to pharmacokinetic synergism. A recent study showed that serum levels of doxycycline in dogs treated with the combination protocol were not statistically different compared to dogs treated with doxycycline alone. However, lungs from dogs treated with the combination therapy showed a marked reduction in T regulatory cells, indicating that treatment efficacy may be due to a heightened immune response against the parasite. Further studies are necessary to evaluate the long-term clinical outcome of combination protocols and to establish the most efficient treatment for HWD in dogs.

• Authors: L Kramer, S Crosara, G Gnudi, M Genchi, C Mangia, A Viglietti, C Quintavalla
• Journal: Veterinary parasitology (Vet Parasitol) Vol. 254 Pg. 95-97 (Apr 30 2018) ISSN: 1873-2550 [Electronic] Netherlands
• PMID: 29657018 (Publication Type: Journal Article, Review)
• Copyright: Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Chemical References

• Anti-Bacterial Agents
• Drug Combinations
• Filaricides
• Lactones
• Macrocyclic Compounds
• Doxycycline

Topics

• Animals
• Anti-Bacterial Agents (therapeutic use)
• Dirofilaria immitis (drug effects)
• Dirofilariasis (drug therapy, parasitology)
• Dog Diseases (drug therapy, parasitology)
• Dogs
• Doxycycline (therapeutic use)
• Drug Combinations
• Filaricides (therapeutic use)
• Lactones (therapeutic use)
• Macrocyclic Compounds (therapeutic use)
• Wolbachia (drug effects)