Ehrlichia canis gram-negative bacteria, belonging to the alpha sub-group of proteo-bacteria that multiply only in mononuclear cell cytoplasm. Its diameter ranges from 2 to 10 µm.
The dog-tick Rhipicephalus sanguineus, and Dermacentor variabilis tick in the United States.
Learn more about the vectors: Ticks
In Europe, canine ehrlichiosis is enzootic in the Mediterranean basin (Spain, Portugal, Italy, southeast France, Greece etc..). The infection is mainly seasonal, during the tick season, from April to October. Nevertheless, it can be found year-round over the entire distribution area.
The acute form
The most frequent clinical signs are listlessness, anorexia, weight loss, sudden appearance of extremely high temperature (plateauing at up to 41ºC), pale mucous, adenomegaly, enlarged spleen, vomiting, periodic ophthalmia and haemorrhaging.
There may be petechiae in the mouth or genital mucous membranes
The subclinical form
Clinically non-apparent infection which only manifests itself as a variation of certain biological parameters such as thrombocytes and leukocytes.
Weight loss, adenomegaly and the appearance of oedema of the limbs and scrotum.
The chronic form
Haematoma appear. Bruises are noticeable on the abdomen, with bilateral epistaxis, a very characteristic symptom of severe ehrlichiosis (canine tropical pancytopaenia).
With regard to the eyes, hyphaema, periodic ophthalmia, conjunctivitis, opacification of the cornea and retinal haemorrhage can be observed. Runny eyes and nose are also frequent.
Laboratory
Indirect immunofluorescent blood diagnosis is the benchmark method, given its high levels of sensitivity and specificity.
Fast diagnosis testing based on ELISA or immunomigration seem to be reliable methods and are easy for a vet to use. Chain polymer reaction (CPR) helps detect the presence of Ehrlichia canis in blood or tissue (spleen, liver etc.).
Differential
Diagnosis with other Rhipicephalus-transmitted infections:
- Babesiosis
- Hepatozoonosis
- Doxycycline: 10 mg/kg/day, oral intake for a month. Symptoms regress often in less than 24 hours
For dogs suffering from haemorrhages, blood transfusions are recommended (total fresh blood or enriched plasma)
Monitoring infestations by vector ticks thanks to acaricide products
- Prescription of Doxycycline 3mg/Kg, administered orally each day
Ehrlichia canis transmitted for the vector Rhipicephalus sanguineus and Anaplasma phagocytophilum transmitted for Ixodes ricinus.
Cats are infested in areas where the disease is highly endemic. They are less receptive than dogs. The frequency of the disease is not known because there are a lot of underdiagnosed cases.
The treatment is the same as for dogs.
