My Westie was recently diagnosed with tick fever and the vet seems uncertain of his recovery. I understand there are two strains and one is more difficult to treat than the other. What is the difference and how likely is he to recover?
The two most common strains of tick fever in Singapore are Ehrlichiosis and Babesiosis. Ehrlichia is a bacterium that affects white blood cells and gradually lowers a dog’s immune system, while Babesia is a parasite that infects and destroys red blood cells, resulting in anaemia or low red blood cell count. Both pathogens are spread by brown dog ticks, which can become carriers of the pathogens when they take a blood meal from an infected canine and subsequently feed on another dog. Both Ehrlichia and Babesia are potentially life-threatening, with the latter the more serious of the two.
There are three phases of tick fever: acute, sub-clinical, and chronic. The acute stage occurs one to three weeks after a dog is bitten by an infected tick. Symptoms are usually mild and may include lethargy, inappetence, and sometimes fever. If it goes unnoticed and/ or untreated, the disease will progress to the sub-clinical stage.
When a canine is in the sub-clinical stage of tick fever, it typically does not exhibit any indication of the disease as the bacteria/parasite hides from the immune system. The animal can remain in this state for months, or even years. A robust immune system could potentially fight off the disease, but if your dog’s body cannot overcome it, he will develop chronic infection.
The most serious phase is the chronic stage and symptoms are varied—these may include fever, lack of appetite, stiff joints, listlessness, vomiting, diarrhoea, nose bleeds, vision difficulties, lameness, limb swelling, uncontrollable bleeding due to low blood platelet count, and even seizures. If the animal receives treatment only during the chronic stage, the odds of recovery are lower.
Ehrlichia is almost completely curable with antibiotics if the dog is treated early. Babesia can be treated with antiparasitic medications, but more severely affected patients have to be hospitalised and might require blood transfusions. Likelihood of recovery is good if the animal survives the first 10 days.
Treatment for Ehrlichia does not fully eliminate the bacterium from the body, so the disease may flare up again when immunity is compromised. Hence, regular tick prevention is the best way to minimise the probability of contracting tick fever.
Expert: Dr Chong Lip Ren BVSc (Sydney) Veterinary Surgeon Pets Avenue Veterinary Clinic