Transmission of haemotropic mycoplasma in the absence of arthropod vectors within a closed population of dogs on ectoparasiticides

• Published in: Scientific reports Vol. 13; no. 1; p. 10143
• Main Authors: Huggins, Lucas G., Baydoun, Zahida, Mab, Ron, Khouri, Yulia, Schunack, Bettina, Traub, Rebecca J., Colella, Vito
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 22-06-2023; Nature Publishing Group; Nature Portfolio
• Subjects: 631/326/2522; 631/326/41/1470; 631/326/417/1716; 631/326/421; Animals; Arthropod Vectors; Arthropods; Babesia; Candidatus Mycoplasma haematoparvum; Dog Diseases - epidemiology; Dogs; Ectoparasites; Ehrlichia canis; Humanities and Social Sciences; Infections; multidisciplinary; Mycoplasma; Mycoplasma haemocanis; Mycoplasma Infections - drug therapy; Mycoplasma Infections - epidemiology; Mycoplasma Infections - veterinary; Pathogens; Science; Science (multidisciplinary); Vectors
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-023-37079-z

Dog-infecting haemotropic mycoplasmas (haemoplasmas), such as
Mycoplasma
haemocanis
and
Candidatus
Mycoplasma haematoparvum are common blood-borne pathogens of canines that can potentially inflict a substantial burden of disease, particularly in immunosuppressed individuals. Nonetheless, the transmission of these pathogens remains debated as more evidence emerges that they may not be transmitted by vectors, but instead use alternative methods such as aggressive interactions and vertical transmission. Here, we treated forty dogs with two different topically-acting ectoparasiticide products able to prevent vector-borne pathogen infections during an 8-month community trial in Cambodia. A total absence of ectoparasites were observed at all time points, and no new infections caused by pathogens confirmed as being vectorially-transmitted were detected, i.e.,
Babesia
vogeli
,
Ehrlichia
canis
,
Anaplasma
platys
, and
Hepatozoon
canis
. Conversely, the number of haemoplasma infections in dogs on both ectoparasiticides rose significantly, with an incidence of 26 infections per 100 dogs at risk per year, providing strong evidence of non-vectorial transmission. Over the study period, dog aggression and fighting were frequently observed, highlighting a different potential mode of transmission. This study presents the first robust evidence that canine haemoplasmas may be transmitted without arthropod vectors drawing attention to the need for new methods to prevent their transmission.