Babesia (Babesia Canis, Tick Fever, Biliary Fever, Piroplasmosis)


Did you know?

• Biliary fever kills more dogs in South Africa than any other disease. 
• The best treatment for biliary fever is prompt treatment when clinical signs present. 
• Your dog will never develop immunity to biliary fever and can fall ill from this disease again and again.


About the disease

• Biliary Fever is caused by a tiny parasite, Babesia canis, which is transmitted by the yellow dog tick to your dog. 
• This parasite causes a disease similar to malaria in humans 
• The parasite is carried in the saliva of infected ticks (not all ticks on your dog will carry the parasite) 
• The tick must take a blood meal for at least 48 hours before it is able to transmit the disease. 
• Ticks become infected when they take a blood meal from an infected dog.
They then become carriers, transmitting the disease to their offspring through their lifecycle. 
• The incubation period is 10-28 days, in other words,
the tick might be gone long before your dog develops the infection. 
• When the parasite enters the body, it invades the red blood cells in the bloodstream of your dog
(red blood cells carry oxygen to the various parts of the body) 
• One parasite can multiply to as many as 64 parasites – each infecting a new blood cell. 
• The body’s immune system recognises the parasites in the red blood cells and destroys them together
with the red blood cells. 
• The infected cells are identified by the liver and spleen, removed from the bloodstream, 
and destroyed in these organs. 
• Occasionally a large number of red blood cells rupture in the bloodstream, leading to a large amount of red 
pigment (haemoglobin) in the blood. This is excreted in the urine, causing a red discolouration of the urine 
(owners usually think their dogs is urinating blood). 
• The products of the dead red blood cells are transformed by the liver into bile and excreted
into the stool (yellow faeces) 
• The process of destroying the cells gains momentum as the parasite multiplies. This process is faster than red 
blood cell production, thus the body is depleted of red blood cells and therefore oxygen carrying capacity. 
• The lack of oxygen can lead to multiple organ damage with a fatal outcome. 

Clinical symptoms

Early Cases 
• Depression/Lethargy 
• Loss of appetite 
• Fever (>39°) 

Advanced Cases 
• Anaemia: Pale mucus membranes and gums 
• Icterus: Yellow mucus membranes and gums
(Liver is not coping with the excretion of red blood cell components.) 
• Dark red urine 
• Severe lethargy 
• Deep laboured breathing/panting 
• Dies within a few hours

• Suspected on clinical signs 
• Confirm with a blood smear (made from a small prick on the dog’s ear) to visualize the parasites
in the red blood cells under the microscope. 
• The blood smear will also be evaluated to see whether new red blood cells are formed (is the body coping 
with the infection) and whether there are signs of any other parasitic infections (erlichia) 
• A red cell count will be done to determine the severity of the blood loss. 

The best treatment is prompt treatment! 
Treatment should only be given after a positive diagnosis, because the anti-babesial drugs are potentially toxic. 

Early infections 
• Injections with a specific anti-babesial drug. We recommend two treatments 24 hours apart. 
• Your dog should recover within 24 hours. 

More advanced cases 
• Hospitalisation is essential 
• Injections with a specific anti-babesial drug 
• Blood transfusions if necessary. We use blood from blood donor dogs in our practice.
They donate blood regularly, just like in humans. 
• Intravenous fluids to support the liver and kidneys
• Cortisone is often administered to prevent the body from attacking its own red blood cells 
• Oxygen supplementation 
• Nutritional support.

Aftercare at home
• Your pet should not perform any aerobic exercise and should be allowed to rest
as much as possible. It can take up to 3 weeks for the red blood cells to 
regenerate to their normal percentage. 
• Feed a good quality diet during this time so that they have all the nutrients and 
energy to produce new red blood cells. 
• A tonic to supply extra iron is always a good idea. 

Prevention is always better than cure!

Tick Control!!! 

Monthly treatments with a ‘spot-on’ drug to prevent ticks from attaching to 
your dog’s skin. There are other products available, such as sprays and 
dips, but their application is more time consuming. 


A vaccine was developed recently against biliary fever.
It is given as an initial vaccination, followed by a booster one month later and
a booster vaccination twice yearly (at R700/vaccine). 

The program should be done in winter and cannot co-inside with annual vaccinations.
The vaccine is not a 100% effective and the dogs may still develop the disease, but complications are less likely.