Dog - Ehrlichiosis

What is ehrlichiosis?

This is a tick borne disease caused by certain bacteria (Rickettsiae) that invade circulating white blood cells. A number of Ehrlichia species are known to infect dogs but canine Ehrlichiosis generally is due to infection with E. canis which is a pathogenic (disease causing) species found in many tropical and sub-tropical areas of southern Europe and the Mediterranean. It is spread by the tick Rhipicephalus sanguineus.

Does ehrlichiosis occur in Britain?

Occasionally. Cases have occurred in the UK. Spread depends upon the tick and at the moment Rhipicephalus sanguineus is restricted in its distribution in Britain. The danger is, of course, that if your dog is infected while abroad it takes up to three weeks before any signs appear and there is always the possibility that other British biting insects could transmit the disease when you return to Britain before you know your dog has the disease.

What can I do to reduce the risk?

If you are planning to take your dog to Mediterranean areas or Loire Valley where it is known that Ehrlichiosis is widespread, consult us and we will do our best to help. Using appropriate anti tick preparations is wise but there is still some risk because most preparations do allow the tick to bite and attach, and therefore possibly infect your dog, before they absorb the preparation and die.

Is it only dogs that are affected?

Infection with E. canis is restricted mainly to dogs although there are reports of people being affected in the southern United States. Cats can become infected with Ehrlichia species but these are not usually the same as those affecting dogs. Disease in cats is rare.

What are the signs of the disease?

A non-specific phase of the disease follows the incubation (time from infection to development of disease) period of 8–20 days. Signs include lack of appetite and enlarged glands. Blood tests will show anaemia and a low white blood cell count. Dogs usually recover from this stage spontaneously but then enter a sub-clinical phase. If their immune system is not compromised they will then recover. However if they are off colour for any other reason or their immune system is under challenge, chronic infection can develop.

German Shepherd dogs (Alsatians) and Dobermanns are particularly susceptible to chronic Ehrlichiosis and it is often associated with other diseases involving insect vectors. These include Leishmaniasis, which is transmitted by sandflies and Babesiosis which depends on the same tick vector, Rhipicephalus sanguineus, both diseases are rare in the UK.

With the chronic disease severe nose bleeds are one of the usual signs together with haemorrhages (bleeds) within the mouth and other severe bleeding disorders.

If my dog is off colour and showing these vague signs of the acute illness, can the condition be positively diagnosed?

The condition can be diagnosed from blood samples. The problem is that in Britain we are unused to seeing the disease and therefore it may take some time for a positive diagnosis.

Can the disease be treated?

Antibiotics and other drugs are available that are very effective. If chronic bleeding is taking place supportive therapy with intravenous fluids (a drip) and/or blood transfusions may be required.

Can the disease be prevented?

There is no vaccine presently available for ehrlichiosis. However certain drugs including those used to treat the disease have been shown to be effective in prevention. Please consult us and we will discuss this with you.

It must be remembered however that British dogs do not have any inbuilt resistance to diseases such as Ehrlichiosis and avoidance of exposure to the infection is the wisest precaution.