Issue Description Canine babesiosis is a disease caused by the
intraerythrocytic protozoan parasites Babesiacanis and Babesiagibsoni.
Babesiosis is transmitted by ticks to susceptible canine hosts.
Rhipicephalussanguineus is the most common tick vector in the United
States. Splenectomized dogs, immunocompromised dogs and young dogs
between the ages of two and eight months are most susceptible to
infection. Canine babesiosis occurs worldwide. Within the United
States it is most common in the southeast. Although canine babesiosis
is considered uncommon in the U.S., it is of clinical significance due
to its morbidity and mortality. It is an important differential when
history and clinical signs are consistent with infection and other
more common diseases have been ruled out.
Diagnosis In Animals Babesiosis is suspected by
observation of clinical signs (haemoglobinuria and anaemia) in animals
in endemic areas. Diagnosis is confirmed by observation of merozoites
on thin film blood smear examined at maximum magnification under oil
using Romonovski stains (methylene blue and eosin). This is a routine
part of the veterinary examination of dogs and ruminants in regions
where babesiosis is endemic.
Babesia canis and Babesia
bigemina are "large babesias" that form paired merozoites in the
erythrocytes , commonly described as resembling "two pears hanging
together", rather than the "Maltese Cross" of the "small babesias".
Their merozoites are approximately twice the size of small babesias.
Cerebral babesiosis is suspected in-vivo when neurological signs
(often severe) are seen in cattle that are positive for babesia bovis
on blood smear. Outspoken red discoloration of the grey matter on
post-mortem further strengthens suspicion of cerebral babesiosis.
Diagnosis is confirmed post-mortem by observation of babesia infected
erythrocytes sludged in the cerebral cortical capilaries in a brain
Treatment Veterinary treatment of Babesiosis does not
normally use antibiotics. In animals diminazene (Berenil), imidocarb
or trypan blue would be the drugs of choice for treatment of Babesia
canis rossi (Dogs in Africa), Babesia bovis, and Babesia bigemina
(cattle in Southern Africa). There is a vaccine that is effective
against Babesia canis (dogs in the mediterranean region) but this is
ineffective against Babesia canis rossi. Babesia imitans causes a mild
form of the disease that frequently resolves without treatment (dogs
in South East Asia).
The most effective drugs used in the
treatment of canine babesiosis include diminazeneaceturate,
phenamidineisethionate, and imidocarbdipropionate which are not
available or approved for use in the United States. Treatment of
canine babesiosis in the U.S. is therefore mostly aimed at treating
symptoms. The majority of babesia cases diagnosed in dogs in the U.S.
are caused by the less virulent strains of B. canis and dogs
frequently recover from these infections naturally with supportive
therapy. Clindamycin has been successfully used to treat canine
babesiosis and may be considered in refractory or more severe and
Prevention Prevention of canine babesiosis is mostly aimed
at controlling the vector. It is an important aspect since treatment
is not always successful. The environment should be treated to
decrease tick numbers, dogs should be treated to control tick
infestations, and ticks should be removed from parasitized animals as
quickly as detected.
Recently, a vaccine which minimizes
the severity of infection was developed. The vaccine is reported to be
70 to 100% effective in diminishing the pathologic effects which
typically ensue upon infection. The vaccine is currently available in
Europe where canine babesiosis is more common life-threatening
Blood transfusion poses a significant risk to
recipient animals, therefore it is recommended that donor animals be
tested for infection with babesia organisms. Splenectomy prior to
testing significantly improves the likelihood of finding organisms in
a blood sample from an infected donor.