WSAVA Nov 2021 Proceedings - Flipbook - Page 16
13–1 5 NOVEMBER, 202 1
to as being uncomplicated or complicated in its clinical characteristics.
The respective Babesia species is the most significant factor determining clinical outcome, yet host factors such as age, immune status and
the presence of concurrent infections all play a role. Clinical signs are
non-specific and include lethargy, reduced appetite, pyrexia, pallor, icterus,
pigmenturia, bleeding diatheses and, in complicated cases, hypovolaemia,
collapse, respiratory distress and CNS signs. The pathophysiology of
babesiosis reflects systemic inflammation and a haemolytic syndrome;
researchers have studied the mechanisms of anaemia, Babesia-induced
renal injury6, cardiac biomarkers, endocrine dysfunction, haemostasis7,
and cytokine profiles.8 Unsurprisingly numerous cytokine abnormalities
are consistent with a pro-inflammatory storm and the widespread acute
phase protein response. A study into the transcriptomics of canine
babesiosis (using B. rossi) was published recently9 that identified genes
and cellular pathways involved in the responses to haemolysis, metabolic
changes, and immune responses.
In marked contrast to the advances in understanding of Babesia speciation and pathophysiology in recent years, there has been disappointingly
little practical progress with respect to the specific treatment of canine
and feline babesiosis. This is despite a plethora of published experimental
studies that, to date, have not translated into registered products. The
same caveats that have existed for many years remain; most antibabesial drugs are relatively ‘old’ and not originally tested robustly, most
have variable efficacy, and some have significant side-effects. Different
Babesia spp. have dissimilar drug susceptibilities yet, regardless, sterilisation of the infection (‘cure’) seems to be achieved only rarely. Newer drug
combinations include atovaquone and azithromycin for the treatment of
B. gibsoni and other ‘small’ Babesia spp.; and metronidazole, clindamycin, and doxycycline with imidocarb or diminazine (Table 2). Controlled
studies are lacking, however.
Table 2. Specific treatment protocols for Babesiosis
Babesia
B. vogeli
B. canis
Size
Large
Large
Drug (or combination)
Dose(s) and route(s)
Imidocarb dipropionate
5-6.6mg-7.5/kg IM (or SC)
repeated at 14 days
Imidocarb dipropionate; OR
5-6.6-7.5mg/kg IM (or SC)
repeated at 14 days
Diminazene
Imidocarb dipropionate, OR
B. rossi
Large
Phenamidine isethionate, OR
Diminazene
3.5mg/kg IM once
5-6.6-7.5mg/kg IM (or SC)
repeated at 14 days
15mg/kg SC once, or repeat
at 24 hours
3.5mg/kg IM once
6.6mg/kg IM (or SC) repeated at 14 days
Babesia sp. Large
Imidocarb dipropionate
B. gibsoni Small
Atovaquone + Azithromycin; OR13.3mg/kg PO q8h + 10mg/
kg PO q24h x 10-17 days
Clindamycin + Diminazene +
30mg/kg PO q12h + as above
Imidocarb; OR
Metronidazole + Doxycycline + 15mg/kg PO q12h + 5mg/kg
q12h PO + 25mg/kg PO q12h
Clindamycin
B. conradae Small
Atovaquone + Azithromycin
13.3mg/kg PO q8h + 10mg/
kg PO q24h x 10-17 days
B. vulpes
Atovaquone + Azithromycin
13.3mg/kg PO q8h + 10mg/
kg PO q24h x 10-17 days
16
Small
WSAVA GLOBAL COMMUNITY CONGRESS
B. negevi
Small
Imidocarb dipropionate
Dose not stated by the
authors
B. felis
Small
Primaquine phosphate
0.5mg/kg PO once, or 3x at
72h intervals
B. canis
presentii
Large
Imidocarb dipropionate
2.5mg/kg IM once (note
different dose to dogs)
References
• Penzhorn BL and Oosthuizen MC (2020) Babesia species of domestic
cats: Molecular characterization has opened Pandora’s box. Frontiers in
Vet Science 7: 134.
• Baneth G et al. (2019) Establishment of Babesia vulpes n. sp. (Apicomplexa: Babesiidae), a piroplasmid species pathogenic for domestic dogs.
Parasites Vectors 12: 129.
• Schreeg ME et al. (2016) Mitochondrial genome sequences and
structures aid in the resolution of Piroplasmida phylogeny. PLoS One
DOI:10.1371/journal.pone.0165702.
• Schnittger L et al. (2012) Babesia: A world emerging. Infection, Genetics
and Evolution 12: 1788–1809.
• Jalovecka M et al. (2019) Babesia life cycle – when phylogeny meets
biology. Trends Parasitol 35: 356-368.
• Kuleš J et al. (2018) Glomerular and tubular kidney damage markers
in canine babesiosis caused by Babesia canis. Ticks Tick-borne Dis 9:
1508-1517.
• Kuleš J et al. (2017) Alteration of haemostatic parameters in uncomplicated canine babesiosis. Comp Immunol Microbiol Infect Dis 53: 1-6.
• Leisewitz A et al. (2019) Disease severity and blood cytokine concentrations in dogs with natural B. rossi infection. Parasite Immunol 41:e12630.
• Smith RL et al. (2021) Experimental Babesia rossi infection induces
hemolytic, metabolic, and viral response pathways in the canine host.
BMC Genomics 22: 619.