The efficacy of a generic doxycycline tablet in the treatment of canine monocytic ehrlichiosis

Authors

  • Josephus J Fourie Universitas
  • Ivan Horak University of Pretoria
  • Dionne Crafford Universitas
  • Heidi L Erasmus Universitas
  • Ockert J Botha Vetsbrands

Abstract

The objective of the present study was to evaluate the therapeutic efficacy of a generic doxycycline tablet (DoxyVet®) against Ehrlichia canis infection in dogs. Canine monocytic ehrlichiosis is caused by the bacterium E. canis and transmitted by the brown kennel tick (Rhipicephalus sanguineus). Six disease-free and tick-free dogs were infested with E. canisinfected ticks. Once diagnosed (with polymerase chain reaction [PCR] analysis and platelet counts) as positive for infection, doxycycline tablets were  administered orally once a day for 20 consecutive days, at a target dose level of 10 mg/kg. The actual dose administered was
calculated as ranging between 10 mg/kg and 11.7 mg/kg. The PCR analysis, 28 days after the first administration of the tablets, failed to detect E. canis in any of the dogs. On Day 56 of the study, four of the dogs were diagnosed with E. canis for the second time and a fifth dog was diagnosed on Day 70. The platelet counts of the sixth dog remained within normal levels and it was discharged from the study on Day 84. Doxycycline tablets were then administered to the remaining five infected dogs for 28 consecutive days. Four of these dogs had no positive PCR results during the following 3 months. The fifth dog was diagnosed with E. canis for the third time 58 days after the last tablets of the second treatment had been administered, after which it was rescue treated (doxycycline for a further 28 days). The results indicate that doxycycline administered in tablet form (DoxyVet®) at 10 mg/kg – 11.7 mg/kg body mass once daily for 28 consecutive days clears most dogs of infection. The importance of a concomitant tick-control programme is therefore stressed.

Author Biographies

  • Josephus J Fourie, Universitas

    ClinVet International, Universitas, South Africa

  • Ivan Horak, University of Pretoria

    Department of Veterinary Tropical Diseases, University of Pretoria, South Africa

  • Dionne Crafford, Universitas

    ClinVet International, Universitas, South Africa and Department of Zoology, University of Johannesburg,
    South Africa

  • Heidi L Erasmus, Universitas

    ClinVet International, Universitas, South Africa

  • Ockert J Botha, Vetsbrands

    Vetsbrands, Fairland, South Africa

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Published

2021-12-09

Issue

Section

Original Research