Introduction

This study aimed to evaluate the prevalence of core blood infectious agents in healthy, client-owned dogs from a blood donor population in Portugal and Spain, and to address the importance of a screening protocol on every donation.

Currently, guidelines indicate the need to test donors annually.

Methods

Client-owned healthy dogs, dewormed and following strict donor acceptance criteria, were tested before each donation on a veterinary blood bank. Blood samples from new potential donors, and from regular donors, were tested by real-time PCR (LightCycler 480II, Roche) for Leishmania spp., Ehrlichia spp., Brucella spp., Babesia spp. and Anaplasma spp. Serological tests were also performed for Leishmania spp., Ehrlichia spp. and Dirofilaria immitis (ELISA, Gemini Stratec, Novatec). All donors were tested for every agent. Some donors donated more than once. Animals tested positive for RT-PCR and/or serology were excluded from the donor program.

Results

Overall, samples from a total of 5970 donations performed in 4170 dogs were tested between May 2021 and January 2022. For RT-PCR, 1.51% (90 screenings) tested positive for at least one of the agents: 0.12% (7) for Leishmania spp.; 0.40% (24) for Ehrlichia spp.; 0.18% (11) for Babesia spp. and 0.80% (48) for Anaplasma spp. No positive dogs were identified for Brucella spp. Serologies revealed positive in 5.13% (306) screenings. A total of 3.18% (190) detected antibodies to Leishmania spp.; 1.46% (87) to Ehrlichia spp. and 0.49% (29) revealed antigens to Dirofilaria immitis.

Some of these positive results were from dogs with negative results in donations performed 3–8 months before: Leishmania spp. (n=59), Ehrlichia spp. (21), Babesia spp. (7), Anaplasma spp. (24) or for Dirofilaria immitis (9).

Conclusions

The results obtained in this study evidenced a low prevalence of infectious agents in canine blood donors. Considering that only non-symptomatic dogs were involved, this study highlights the importance of performing a strict blood screening protocol in donor programs. The evidence of positive results in donors with negative results in the previous donations, emphasizes the importance of testing the blood donors on every donation instead annually.

E-mail: barbaracorreia@bsanimal.com