Anaplasmosis in Dogs: What It Is and How to Recognize It

Anaplasmosis in Dogs
Wyatt Robinson
Written by Wyatt Robinson

When the summer is in full swing the owners should pay more attention to their furry friends, especially when it comes to ticks. These little blood-sucking creatures are not only disgusting, they can be also very dangerous, not only for humans but for canine as well. Ticks are also known as the primary carriers of certain diseases also called the ‘tick-borne diseases’, (Lyme disease has been well known since the 70s), and canine Anaplasmosis is one of them. This disease has become, unfortunately, very common.

Anaplasmosis is also called a ‘dog-fever’ or ‘dog tick fever’ and it can be found throughout the United States, especially and primarily in the northeastern, mid-Atlantic, and north-central states, as well as in California.

Anaplasmosis comes in two forms: one is called Anaplasma phagocytophilum, which is an infection of the white blood cells that’s transmitted by the deer tick (the black-legged tick) and the western black-legged tick. This form is more common that the other one. These ticks are also responsible for transmitting Lyme disease, which means that they increase the risk of cross-infection with anaplasmosis.

The other form is Anaplasma platys, it is an infection of the blood platelets that can lead to bleeding disorders and is transmitted by tick species called the brown dog tick. This less common form of Anaplasmosis is more serious because the symptoms can prove to be fatal.

Tick attached

This article will provide you with a guide on symptoms, signs and treatment when it comes to this disease, including some tips on prevention and how to make sure that your dog avoids being bitten.

Origins of Anaplasmosis

The first noted infection with Anaplasma phagocytophilum dates back to 1996, in Minnesota and Wisconsin. This disease is zoonotic, which means that it can be transmitted from an animal to a human, and vice versa. Additionally, the appearance in dogs coincided with those in people too. The organism that is causing this disease is endemic in the upper Midwest, East, and Northeast regions of the United States as well as the western regions of the same country.

When it comes to Europe, the United Kingdom, Norway, Sweden, Switzerland, and Germany have also reported the cases of this infection in dogs and people. However, this disease is quite rare in Asia and South America. In the United States, the most outbreaks happen in May, June and September, which means that they are seasonal and these are the times when you should be extra careful with your dog, including yourself too.

The disease was widespread in the early 20th century, however in the 80s and 90s, the new treatments with antibiotics and acaricides proved out to be successful, to the point where this disease was no longer considered a major problem.


This disease can also affect a wide range of animals and mammals, such as cats, horses, ruminants, people, and other wildlife species.

Anaplasmosis has been most often noted in dogs that are considered seniors – 8 years of age and older. The dog breeds that are most often mentioned are Golden retrievers and Labrador retrievers, but it is unknown whether this information is the result of the breeds’ susceptibility or their popularity.

Rodents are usually the ones that are considered to be the main reservoir of this disease, but the infection is usually spread by the deer tick and by the black legged tick. Some say that even the brown dog tick may spread the disease. The bacteria of this disease invade the white blood cells, and then they spread throughout the body. In many cases, platelet, which is a vital part of the blood clotting system, is destroyed. White blood cells may also be affected which can lead to other more serious problems.

The destruction of platelet leads to the common symptoms – bleeding which is either direct, or it occurs under the skin in a form of bruising. However, these symptoms are usually fatal and the severe cases need more medications, including blood transfusion to replace lost red blood cells and platelets, and that is why some dogs do not survive even though in majority, pets respond favorably to the antibiotics.

Signs and symptoms

The infection with the first and more common form of Anaplasmosis — Anaplasma phagocytophilum, include lameness, joint pain, fever, lethargy, and the infected dog most usually stars rejecting food. The symptoms can last for one to seven days, however, some dogs may not show any or just minor symptoms. Some of the less common clinical signs are vomiting, diarrhea, coughing, and labored breathing including coughing.

Additionally, some neurological symptoms such as seizures have been reported too. Sometimes, dogs can get only bitten and you won’t find a tick, but that does not mean that the dog won’t get infected. That is why, if you notice similar symptoms, you should take your dog for a checkup.

Check up at the vet

When it comes to the infection with Anaplasma platys can lead to cyclic thrombocytopenia, which is a condition in which there is a periodic decrease in platelets (circulating cells that help in the blood clotting process). Some dogs also get bruising, bleeding or nosebleeds. These symptoms are caused by the platelet failure, and they are considered some of the most severe ones. This is more common during the early stages of infection.

It is not unusual, when it comes to anaplasmosis symptoms in dogs, to have a co-infection with both forms of this disease and they can also have the same symptoms as the ones with Lyme disease. However, that makes everything more complicated.

Additionally, the dogs that live in the areas where anaplasmosis is very common are usually exposed to this disease quite often and they sometimes come with a positive antibody test result. One study showed that more than 40% of dogs in these areas are seropositive (which means that they have a positive test result) and many of them have antibodies without any evidence of clinical disease.

Also, it has been revealed that some dogs that are clinically healthy have the infection with this disease and they are the chronically infected carriers of the organism, but it is not clear whether they will eventually become sick or not.

Ticks on dogs

If a dog is healthy but he comes up with a positive test result, that should not be taken lightly or disregarded. That means that you should take your dog through aggressive tick controls and checkups to ensure that he does not get sick and you should also decrease his exposure to ticks.

Some of the most prominent symptoms:

  • Joint pain and stiffness (similar to the symptoms of arthritis);
  • High fever;
  • Lethargy;
  • Lameness;
  • Loss of appetite;
  • Vomiting;
  • Diarrhea;
  • Bruising on the gums and belly;
  • Spontaneous nosebleeds;
  • Neurological signs resulting in seizures and neck pain (rare).

And when it comes to laboratory test results, the abnormalities in them may vary during the acute phase of the disease, and sometimes they may even seem normal if the disease is persistent. The most common hematologic abnormality, reported in more than 80 % dogs is a mild to severe thrombocytopenia. Many animals have lymphopenia in the beginning but later on may develop a reactive lymphocytosis. There were even some rare cases of neutropenia and mild to moderate nonregenerative anemia.

Dog with high fever

When it comes to people who get infected, sometimes they do not even remember being bitten, because the bite is usually painless. The first symptoms became obvious one or two weeks after the bite and the symptoms include fever, headache, malaise, muscle pain, chills, nausea, abdominal pain, cough, confusion, and sometimes even rash. Rash is usually reported in patients who have a coinfection with Lyme disease or Rocky Mountain Spotted Fever.

Even though the fatality rate is less than 1%, it can be fatal if it is not treated correctly or not at all. Some severe cases note even hemorrhage, renal failure, neurogical problems and difficulty breathing.


When it comes to anaplasmosis in dogs’ treatment, some of the most common tests, such as enzyme-linked immunosorbent assay (ELISA), indirect fluorescent antibody (IFA), and polymerase chain reaction (PCR), are used to determine the presence of the bacteria in the blood of your pet. Having in mind that the symptoms of this disease are common to many other various diseases, it makes it a bit more difficult to diagnose.

When a complete blood count is done, the test usually shows an anemia, and sometimes Anaplasmosis can be seen on the blood sample under the microscope.

Blood samples

Upon the examination, the vet will recommend some of the tests, including the urine tests to rule out urinary tract infections and to evaluate the kidneys ability to concentrate urine, then the chemistry tests to evaluate kidney, liver and pancreatic function as well as sugar levels, and then the complete blood count (CBC) to rule out any blood-related conditions. The electrolyte tests ensure that your dog is not dehydrated or suffering from an electrolyte imbalance.

  1. Light microscopy is used when anaplasmosis should be diagnosed. It is done by the identification of morulae in circulating neutrophils in the peripheral blood and sometimes in the synovial fluid.
  2. Serologic testing is what we have already mentioned – the indirect fluorescent antibody (IFA) testing as well as with the in-house ELISA, SNAP 4Dx (IDEXX Laboratories) etc. The IFA tests use the organisms of the disease as the source of antigens. The SNAP 4Dx assay uses a synthetic peptide based on the immunodominant p44 protein of the infection as the antigen.
  3. PCR testing is the most sensitive method for detecting and some laboratories offer polymerase chain reaction (PCR) analysis of peripheral blood for detecting A. phagocytophilum.

After the diagnosis has been made, the vet will most likely prescribe an antibiotic, such as doxycycline, oxytetracycline, imidocarb or tetracycline. An oral dosage of 5 to 10 mg/kg given twice a day for 30 days has been recommended and it is the fact that the infected dogs get better rapidly; their condition is improved 24 to 48 hours after the therapy is implemented. However, the treatment should last two to three weeks in order for it to be successful.

Additionally, the supportive therapies such as blood products and fluids may become necessary. The vet may also recommend repeating some of the test in order to ensure that the antibiotic treatment has been effective.

Dog antibiotic

There is no available vaccine for Anaplasmosis at present.

You should also know that even though many dogs clinically recover, it is difficult to determine whether or not they are still infected. The organism is cleared from a dog’s body if the dog stops producing antibodies to the organism. Sometimes even if a dog is treated and he returns to normal, he still may test positive, but that does not mean that the dog has an active infection, and the vets do not recommend a second round of antibiotic therapy to try to obtain a negative blood test.


Protecting your dog from ticks is probably the best cure and you should make sure to check and examine your dog every time you return from a walk, especially if that walk took place in a grass covered area. Another important step should be screening your dog routinely for vector borne diseases, because these tests are fast and helpful and you can start treating your dog as soon as possible if he has been infected.

Additionally, there are some tick prevention products in a form of medications that you can buy either in a specialized shop or at the vet’s. Some would even recommend tick collars too. There are even some owners who turn to natural tick repellents, especially if they pets cannot stand the traditional products bought at the shops. These natural products contain essential oils (clove, eucalyptus, lemongrass, etc).

However, the disadvantages of these products are that the odor is too strong and you must apply them frequently in order to really repel the ticks. If you decide to go for a commercial repellent, make sure to read the instructions carefully, because not all dog breeds would react the same to it, because they are maybe allergic to some of the components in them or they would dislike the odor. The same goes for natural essential oils, so be careful of the dosage and usage.

Dog tick collar

But, if you do find a tick on your dog, it is for best if you take him to the vet instead of trying to getting him out by yourself. The studies show that it takes one to two days for a tick to transmit bacteria, and that means that if you get out the tick as fast as possible, that can lessen the risk of any disease.

Using the tweezers is not recommended because you can break the tick and his head can stay in the skin, casing an infection. You should use a commercial tick removal tool, or if you are not sure or confident, visit your vet. After the tick is removed, you should clean the bite site with a surgical cleanser or hydrogen peroxide.

That is why everyone will tell you that it would be better to prevent tick bites and to avoid the tick-infested areas, which is always the best strategy. Additionally, treating the home yards with pet safe chemicals and keeping your shrubbery as closely trimmed as possible is the best option.

To sum up, we covered some of the signs and symptoms related to Anaplasmosis in this article, such as joint pain and stiffness (similar to the symptoms of arthritis), high fever, lethargy, lameness, loss of appetite, vomiting, diarrhea, bruising on the gums and belly, spontaneous nosebleeds and neurological signs resulting in seizures and neck pain which are quite rare, but none the less possible.

These symptoms become obvious soon after the tick bite and you should take your pet to the vet immediately. Even though this disease is not considered to be a major problem anymore, there were reports of dogs dying because their owners did not treat them or react soon enough.

Examining dog after walk

Additionally, the best way would be to pay attention to your dog’s whereabouts and examine him every time you come back from a walk. This is important, especially when it comes to dog breeds with long coats, because it is more difficult to spot a tick in their curly or very long fur. Annual checkups should be covered too, and some vets even recommend the tick prevention medications, collars etc.

The treatment for Anaplasmosis has proved very effective and not fatal if treated properly. The medications used are usually antibiotics and the dog can recover fast. The direct transmission from animals to people or animals to animals is highly unlikely and people consider it rare, however, it is not impossible.

Tiny but terrible tick

It is up to you, your dog’s best friend and owner, to take care of him and examine him, because a dog cannot do it on his own and he depends on you to make sure he gets a proper treatment, if it is needed.

About the author
Wyatt Robinson
Wyatt Robinson

Wyatt Robinson had a great 25-years career as a veterinarian in United Kingdom. He used to be a member of British Veterinary Association and worked in 3 pet hospitals in London and Manchester. He is shining when he sees his pets healthy and full of energy and it is his duty to help other dog owners to keep their best friends full of life.

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