Introduction

Classification

Taxonomy

• Phylum: Apicomplexa.
• Class: Sporozoea.
• Subclass: Piroplasmea.
• Order: Piroplasmida.
• Family: Babesiidae.
• Genus: Babesia.
• Three subtypes or strains exist:
  • Babesia canis canis.
  • Babesia canis vogeli: only subtype common in North America.
  • Babesia canis rossi.

Active Forms

Clinical Effects

Epidemiology

Transmission

• Via tick bite - the principal vector is Rhipicephalus sanguineus Rhipicephalus sanguineus also transmitted by dermacentor, hemaphysalis and hyalomma species.
• B. canis canis is transmitted by D. reticulatus Dermacentor reticulatus, B. canis vogeli by R. sanguineus and B. canis rossi by H. leachi.
• Rarely transplacental or by blood transfusion.

Pathological effects

• Premunition- chronically infected dogs, where immune response vs parasite is 'balanced'.

• Infection of erythrocytes → intravascular and extravascular hemolysis.
• A wide variety of clinical manifestations may be seen.
• In the majority of cases: incubation period of 10-21 days, then fever, malaise, depression, lethargy and anorexia occur together with signs of hemolytic anemia. Death usually occurs at this stage.
• In chronic cases: irregular temperature, intermittent anorexia and loss of condition.
• Different strains ofB. canishave varying pathogenicity.

Control

Control via animal

• Regular treatment of dogs and kennels to prevent tick infestation.
• Some dogs in endemic areas remain immune in the presence of a very low parasitemia. Dogs that have receovered from clinical disease may also remain carriers. These dogs should not be used as blood donors.

Control via chemotherapies

• Imidocarb dipropionate Imidocarb.
• Clindamycin Clindamycin.
• Doxycycline Doxycycline.
• Treatment is of clinical babesiosis and is unlikely to elilminate infection completely.

Control via environment

• Tick control using acaricides Tick control.
• Tick products that kill rapidly or repel/expel ticks are required as B. canis takes at least 24 hours after ticks in initial feeding to be transmitted.

Vaccination

• A strain specific vaccine is available in some countries.
• No commercial vaccine is available.

Other countermeasures

• Chemoprophylaxis - imidocarb dipropionate (5 mg/kg IM, repeated 14 days later) is the treatment of choice.
• Can be painful at injection site and atropine Atropine may be required to mitigate short-term side-effects.
• Not licensed in some countries including UK.
• If unavailable, high dose clindamycin (12.5 mg/kg per os BID) or doxycycline may be used as alternatives with some efficacy.

Diagnosis

Further Reading

Publications

Refereed papers

• Recent references from PubMed and VetMedResource.
• Swainsbury C, Bengtson G & Hill P (2016) Babesiosis in dogs. Vet Rec 178 (7), 172 PubMed.
• Matjila P T, Penzhorn B L, Bekker C P et al (2004) Confirmation of occurrence of Babesia canis vogeli in domestic dogs in South Africa. Vet Parasitol 122 (2), 119-125 PubMed.
• Lobetti R G (1998) Canine babesiosis. Comp Cont Ed Pract Vet 20 (4), 418-431 VetMedResource.