Ehrlichia and Anaplasma: Tick-Borne Infections, and Why Where You Live Matters
Ehrlichia and Anaplasma are tick-borne bacteria. Ehrlichia can hide for years and then cause bleeding. Where they're found, the signs, and why ticks are key.
Written by thecanineledger
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If your dog has nosebleeds, small red or purple spots on its gums or skin, bruises easily, or has blood in its urine or black stools, see a vet the same day. If its gums are very pale or it collapses, go now. These signs can mean a bleeding problem, whatever the cause.
Our note: These signs come from the European guideline. The urgency levels are ours.
A 2015 European guideline describes how Ehrlichia canis can behave: after the first illness, “some dogs that show clinical improvement may remain persistent subclinical carriers for months and years” (Sainz et al., Parasites & Vectors 2015). Some of those dogs later become seriously ill.
While that sounds alarming, how worried you should be depends on where you live and where your dog has travelled. This page explains what these infections are, where they’re found, the signs, and what prevention involves.
1. Two kinds of tick-borne bacteria
Ehrlichia canis is spread in Europe by “the tick Rhipicephalus sanguineus sensu lato, known as the brown dog-tick.” The guideline says this tick “is abundant in the Mediterranean basin.”
Anaplasma phagocytophilum is spread by a different tick. “Ixodes ricinus is the only known vector” in Europe, and this tick is found in the UK and Ireland.
Anaplasma platys is a third species, linked to a condition with cycles of low platelets (the blood cells that help clotting).
The guideline’s verdict on severity. E. canis “seems to cause more severe clinical signs than anaplasmosis”. Many dogs infected with A. phagocytophilum “probably remain healthy”.
Our note: This page is built on a 2015 European guideline. We haven’t read the 2002 North American consensus, and advice there may differ.
2. Where they’re found
In Europe, the guideline’s table shows E. canis in 0.3% of dogs tested in France and Finland, and in 46% of one Italian sample. Different studies tested different dogs with different methods, so the figures aren’t directly comparable.
Travel spreads the tick. The brown dog-tick can be carried north by “dogs travelling to and returning from the Mediterranean region”. It can then survive “in kennels and other protected areas provided by man-made constructions”.
In the UK, a 2026 review says the country “sees sporadic imported canine E. canis cases, and in 2012, two autochthonous cases were reported in untravelled dogs in southeast England” (Simonson et al., Veterinary Record 2026). Autochthonous means caught locally.
3. How Ehrlichia infection unfolds
Three phases. After “an incubation period of 1 to 3 weeks, three typical phases of the disease may develop sequentially: acute, subclinical, and chronic”.
The first illness can pass on its own. “The acute phase can last 2 to 4 weeks; then, clinical signs may vary or disappear spontaneously, even without treatment.”
The hidden phase. In the subclinical phase, dogs “present no clinical signs; therefore, they may not seem to require veterinary attention.”
The serious phase. “Some, but not all infected dogs may advance to a chronic phase.” Then “the clinical signs are more severe”, and the bone marrow can stop making enough blood cells.
Breeds. “German Shepherd dogs and Siberian Huskies are predisposed to develop more severe clinical signs of ehrlichiosis”.
4. The signs
General signs can include “fever, weakness, lethargy, anorexia”, swollen lymph nodes, and weight loss. Anorexia means loss of appetite.
Bleeding signs. The guideline lists pale gums from anaemia, nosebleeds, small bleeds under the skin, “prolonged bleeding during estrus”, and blood in the urine or stools.
What vets look for. “The most common finding in ehrlichiosis and anaplasmosis is thrombocytopenia; this finding should alert clinicians.” Thrombocytopenia is a low platelet count.
5. People and prevention
Can people catch it? E. canis “is not considered an agent with important zoonotic potential.” But A. phagocytophilum “has important zoonotic potential, because humans can acquire the infection through a bite from a tick infected with the pathogen.” People catch it from ticks, not directly from dogs. The guideline notes dogs “may act as sentinels for human exposure”.
Prevention means tick control. The guideline is clear: prevention “must be focused on tick control.” It explains that the brown dog-tick is mainly found indoors, but also in gardens and fields in the Mediterranean.
If you travel with your dog to southern Europe, ask your vet about tick prevention before you go, and about testing when you return.
Our note: The travel advice is ours, based on the guideline’s point about travelling dogs. Ask your vet whether your dog should be tested after travel.
Disclosure. The guideline thanks a veterinary drug company as “the sponsor of the manuscript publication”.
Our note: We don’t cover tick prevention here. Ask your vet what suits your dog.
→ A Positive Lyme Test in a Healthy Dog · → Adopting a Dog From Abroad: Rabies Rules, Brucella, and What Changed · → Flea and Tick Tablets and Seizures: What the FDA Warning Means
6. What we could not verify
| Commonly said | What we found |
|---|---|
| “If my dog got better, the infection’s gone” | Not necessarily. Some dogs carry E. canis for months or years without signs. |
| “Ehrlichia is everywhere ticks are” | No. Its main European tick is common around the Mediterranean, not across all of Europe. |
| “UK dogs can’t get Ehrlichia” | Rarely, but they can. Cases are mostly imported, and two locally caught cases were reported in 2012. |
| “My dog can give me Ehrlichia” | E. canis isn’t considered an important risk to people. Anaplasma can infect people, but through tick bites. |
| “Anaplasma is always serious” | No. Many infected dogs probably stay healthy. |
| “North American advice is the same” | Not checked. We read only the European guideline. |
Sources
- Sainz Á, Roura X, Miró G, et al. Guideline for veterinary practitioners on canine ehrlichiosis and anaplasmosis in Europe. Parasit Vectors 2015: expert guideline with literature review. Publication sponsored by a veterinary drug company
- Simonson P, Bhattacharyya T, Miles MA. ‘Reservoir dogs’: The emerging zoonotic risk associated with European dog imports to the UK. Vet Rec 2026: scoping review. No conflicts or specific funding declared
Always confirm with your vet before acting on anything on this page.