Moxidectin/Imidacloprid Spot-On Plus Doxycycline Treatment for Lymphatic Filariasis in a Dog: A Case Report


  • Supanee Teerawaratchanan Prince of Songkla University Veterinary Teaching Hospital, Faculty of Veterinary Science, Prince of Songkla University
  • Poonavit Pichayapaiboon Faculty of Veterinary Science, Mahidol University
  • Sivapong Sungpradit Faculty of Veterinary Science, Mahidol University
  • Sukanya Manee-in Faculty of Veterinary Science, Mahidol University


Brugia pahangi, Doxycycline, Lymphatic filariasis, Moxidectin


Lymphatic filariasis, a zoonotic problem found in many countries, involves Brugia pahangi as one of the causative agents, with domestic dogs and cats serving as the definitive hosts. In this case study, an 8-month-old American Pitbull dog presented with clinical signs of left hindlimb pitting edema and lymphadenopathy. Brugia spp. microfilariae were identified using the Modified Knott's test and buffy coat smear with staining technique. Species identification confirmed the presence of Brugia pahangi through acid phosphatase enzyme activity and PCR analysis. Histological examination of the lymph nodes revealed marked lymphoid follicular hyperplasia with medullary fibrosis, sinus histiocytosis, and evidence of old hemorrhage. For a period of 5 months, the dog received a monthly spot-on combination of moxidectin and imidacloprid. Additionally, doxycycline and prednisolone were prescribed during the first month of treatment. Microfilariae were monitored using the Modified Knott's test and buffy coat smear at intervals of 1 to 4 weeks, up to 22 weeks. After 2 weeks of treatment, there was no evidence of left hindlimb edema or left popliteal lymphadenopathy. However, at the 6th and 10th week, the edematous sign in the left hindlimb recurred following the completion of the prednisolone course and after the biopsy procedure, respectively. Microfilaremia became negative at 3 weeks after the initiation of treatment and remained negative thereafter. In conclusion, this case study demonstrates the effectiveness of the combination of moxidectin and imidacloprid with doxycycline for the treatment of Brugia pahangi infection in dogs.


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How to Cite

Teerawaratchanan, S., Pichayapaiboon, P. ., Sungpradit, S. ., & Manee-in, S. . (2023). Moxidectin/Imidacloprid Spot-On Plus Doxycycline Treatment for Lymphatic Filariasis in a Dog: A Case Report. Journal of Applied Animal Science, 16(1), 25–38. Retrieved from



Case report