CANINE babesiosis— A Terrible Tick-Transmitted Trouble!

Dr GM Arpitha

Dr A Sangaran

Dr Priya Chettri

Canine Babesiosis is most common with high tick infestation when the weather is hot and humid.
What is Babesia infection?
Babesiosis is a tick transmitted canine disease that’s caused by haemoprotozoan parasite of the genus Babesia. Victor Babes was the first person who recognised Babesia in the red blood cells of cattle in 1888. Later in 1893, Kilborne and Smith named it as Babesia classifying them as protozoans.
Breeds most susceptible
It can occur in any dog breed at any age, but the most susceptible two breeds are – Greyhounds and American Pit Bulls. Puppies tend to suffer with more serious illness.
Causes
There are two Babesia species that cause Babesiosis in dogs – Babesia canis and Babesia gibsoni.
There are three subtypes of Babesia canis – Babesia canis canis, Babesia canis vogeli and Babesia canis rossi.
Mentioned below are the major risk factors of the disease –
• Transmitted by the bite of brown dog tick. Dogs who spend a lot of time outdoors are at increased risk for tick bites and for contracting this parasite. This is especially true in the summer months, from May through September, when tick populations is higher.
• Recent dog bite.
• Blood transfusion from infected donor dog.
• Immunosuppression.
• Splenectomy.
• Transplacental transmission – from the bitch to the developing fetus through placenta.
The incidence of Babesia gibsoni is more compared to Babesia vogeli (canis) and also it causes a more serious disease in dogs. In severe condition, it leads to multiple organ failure with kidneys being the primary organs to suffer the most resulting in complication. Treatment may be attempted with a combination of clindamycin + atovaquone + metronidazole at the prescribed dosage which proves to be effective.
Life cycle
Dogs become infected with Babesia, when a tick feeds on the blood and releases ‘sporozoites’ into the bloodstream. These sporozoites invade the red blood cells and multiply leading to the formation of ‘merozoites’ which may be ingested by a new tick during a blood meal. Following ingestion by the tick, the parasites undergo rapid multiplication, resulting in numerous sporozoites (in the tick salivary glands) that can cause infection to healthy dogs by the infected tick feeding.
Babesiosis diagnosis
It can be difficult to confirm a diagnosis of Babesiosis. Blood tests may show a decrease in the number of red blood cells and platelet count, but this might not be specific to Babesiosis. Blood smears can be examined for the presence of the Babesia organisms. If they are present, the diagnosis can be confirmed, but they may not always show up on a smear (taking blood from a cut on the ear tip or from a toenail can improve the odds of finding the parasites). The most recent and best way to diagnose Babesia canis is polymerase chain reaction (PCR) testing. Blood can also be tested for antibodies, though this can sometimes produce misleading results. Specialised testing can check for genetic material from Babesia, and while this is the most sensitive test, it is not widely available and has some limitations as well. Generally, a combination of lab tests along with clinical signs and history are used by the vet to take the final decision.  The diagnosis can be further complicated by the fact that dogs infected with Babesia may also be infected with other diseases carried by ticks, such as Erlichia, Lyme disease, or Rocky Mountain spotted fever (RMSF).
Treatment
• If your pet is severely anemic, he may require a blood transfusion. Consult vet for Imidocarbdipropionate (Imizol).
• Diminazene Aceturate (Berenil) – This drug worked well especially against Babesia canis.
Prevention is better than cure
• The secret of keeping your pet free from Babesia is good tick control.
• Check your pet regularly for ticks, especially during peak tick season and if your pet spends a lot of time outdoors amidst tall grass.
• The best way to remove ticks is to grasp the tick’s mouth with the help of small tweezers and pull them. Try not to crush them.
• Brush or comb your pet regularly.
• Use tick collars and anti-tick sprays. These are quite effective in repelling ticks.
• Treat your yard and garden with acaricides to control ticks.
• Blood donor dogs should be screened for Babesia sp. by blood smear serology and molecular technique such as PCR.
Signs and symptoms
• Fever
• Lethargy
• Pale mucous membranes
• Vomiting
• Bounding pulses
• Splenomegaly (enlarged spleen)
• Lymphadenopathy(enlarged lymph node)
• Dark discolouration of the urine (Haemoglobinuria) – often coffee coloured
• Jaundice
• Hemolytic anaemia
Disease is less severe with Babesia canis vogeli than with Babesia gibsoni infection.

(Dr Priya Chettri, Dr GM Arpitha and Dr A Sangaran, a professor in veterinary parasitology, are from the Department of Veterinary Parasitology, Madras Veterinary College, Tamil Nadu Veterinary and Animal Sciences University (TANUVAS), Chennai).