Tick Bite Fever

15/11/2022

Biliary fever is an illness of the liver affecting horses, dogs and cats. This is currently the most common infectious disease of dogs in Southern Africa. It is also known as tick bite fever or "Bosluiskoors" in Afrikaans. It is caused by a tiny parasite (Babesia canis) which is introduced into the body by a tick bite.

Biliary and ticks

Biliary (or as is casually referred to as "tickbite fever") is a disease that is caused by a parasite named Babesia canis rossi, or in short B. rossi.
B. rossi parasites are transmitted by the yellow dog tick.
Not all yellow dog ticks carry babesia parasites. The yellow dog tick becomes infected when taking a blood meal from a dog infected with biliary.

Signs of biliary

The first signs that are most commonly noticed by owners in dogs with biliary are lethargy and a loss of appetite. Other common signs that may also be noted by the owner include pale gums and inner eyelids.

Certain patients develop complicated biliary where several organs including the heart, kidneys, liver, stomach and intestines, brain and lungs are affected. These complications develop due to toxic substances called soluble parasite antigens (SPAs) that are released by the babesia parasites. These patients end up being hospitalised and require expensive intensive treatment. Approximately 10 to 12% of these admitted cases die and a further 2 to 3 % end up being euthanased.

How do vets diagnose biliary

Vets diagnose biliary by demonstrating the parasites on a bloodsmear evaluated under a microscope. The bloodsmear is made by using a drop of blood from the tip of the dog's ear.

Treatment

Non-complicated biliary cases will usually recover with treatment with an anti-protozoal drug such as Berenil RTU (Reg No. G2702 Act 36/1947) or Forray 65 (Reg No. G1442 Act 36/1947).

Complicated biliary cases with multiple organ involvement will need hospitalisation with more intensive treatment such as blood transfusions, drips, cortisone treatment, tube feeding, oxygen supplementation, sedation etc.

The yellow dog tick

The yellow dog tick most commonly attach on the neck and shoulders of dogs.
However when there are large numbers of ticks, they may be found elsewhere on the dog's body.
The yellow dog tick does however spend approximately 94 to 97% of their life off-host in the environment and this makes their control difficult.
Prevention: Environmental control

Avoid tick habitats by:
- Keeping grass and weeds cut short
- Seal off cracks and crevices
- Regular washing of bedding
- Use products registered for tick control in kennels