Anaplasmosis (Parasitic Infection Caused by Anaplasma Species) in cats

  • Occurrence: rarer
  • Location of illness: General/Whole body
Author: Dr. med. vet. Gisa Löwe | Last modified: 03.12.2025

Anaplasmosis in cats is an infection caused by bacterial parasites of the genus Anaplasma, which is primarily transmitted by ticks. This infection can lead to a variety of clinical symptoms, ranging from mild to severe.

The most important facts at a glance

Anaplasmosis in cats is caused by bacteria of the genus Anaplasma, particularly Anaplasma phagocytophilum. These bacteria live in white blood cells and are primarily transmitted by ticks, especially Ixodes ticks. Cats can become infected through the bite of an infected tick. Common symptoms include loss of appetite, Fever, enlarged lymph nodes, and general weakness. In more severe cases, Joint pain, Lameness, and neurological disorders may occur.

Diagnosis is made through medical history, clinical examination, and blood tests, which can show signs of an infection such as anemia or thrombocytopenia. Specific tests such as the ELISA test or PCR are used to detect Anaplasma antibody or DNA. Treatment usually involves antibiotics such as Doxycycline for two to four weeks, depending on the severity of the infection. Supportive measures such as fluid administration and Pain management may be necessary.

Prevention is crucial and involves controlling tick infestation through veterinarian-recommended tick repellents and maintaining the environment to minimize ticks. Research focuses on improving diagnosis methods and understanding disease transmission, as well as developing new treatment strategies and potential vaccines. The prognosis is generally good with early diagnosis and treatment.

Causes

Anaplasmosis is caused by bacteria of the genus Anaplasma, with Anaplasma phagocytophilum being the most commonly affected species in cats. These bacteria are obligate intracellular parasites that live and multiply in the white blood cells of hosts. This type of bacteria is known to cause a disease called Human Granulocytic Anaplasmosis (HGA) in humans, and can also infect various mammals, including cats.

Anaplasmosis is primarily transmitted by ticks, particularly by Ixodes ticks, also known as deer ticks. These ticks are widespread in many parts of the world, especially in wooded and grassy areas, which provide an ideal habitat for these parasites. Cats can become infected through the bite of an infected tick, which transmits the bacteria into the cat’s bloodstream.

Other potential causes for the spread of the infection include blood transfusions and direct Contact with infected blood or tissue, although these transmission routes are less common. The prevalence of Anaplasmosis varies depending on geographical location, with regions having high tick populations posing a greater risk.

Symptoms

Rare symptoms:

The symptoms of Anaplasmosis in cats can vary greatly and depend on various factors, including the severity of the infection and the general health status of the affected cat. Common symptoms include Fever, lethargy, and loss of appetite. These non-specific symptoms can easily be confused with other diseases, which can complicate diagnosis.

Some cats may also show signs of Pain or Stiffness, which may indicate inflammation of the joints. In more severe cases, blood clotting disorders can occur, manifesting as symptoms such as bruising, Bleeding, or pale gums. An enlarged spleen or liver may also occur and is often detectable during a physical examination.

In rare cases, Anaplasmosis can cause neurological symptoms, such as Convulsions or Behavioral changes, indicating involvement of the central nervous system. These symptoms require immediate veterinary treatment to avoid serious complications.

Diagnosis

The diagnosis of Anaplasmosis in cats usually begins with a thorough medical history and a clinical examination by a veterinarian. Due to the non-specific symptoms, it is important to rule out other diseases with similar clinical signs. Blood tests are an important part of the diagnosis and can show signs of an infection such as anemia or thrombocytopenia (reduced number of platelets).

Specific tests for the detection of Anaplasma antibody in the blood, such as the ELISA test (Enzyme-Linked Immunosorbent Assay), can also be used. These tests indicate exposure to the pathogen, but do not necessarily indicate an active infection. Another diagnostic approach is the direct detection of Anaplasma DNA using PCR (polymerase chain reaction), a sensitive test that can detect the presence of bacterial DNA in the blood.

Therapy

The therapy for Anaplasmosis in cats usually involves the administration of antibiotics to combat the bacterial infection. Doxycycline is the most commonly used antibiotic and generally shows good results in treating this infection. The treatment usually lasts two to four weeks, depending on the severity of the disease and the cat’s response to the therapy.

In addition to antibiotic treatment, supportive measures may be necessary, especially for severely ill cats. These may include the administration of fluids to treat or prevent dehydration, Pain management, and, if necessary, the treatment of secondary infections. In severe cases, a blood transfusion may also be necessary to treat serious complications such as anemia.

Prognosis and follow-up care

The prognosis for cats with Anaplasmosis depends on various factors, including the cat’s health status before the infection, the severity of symptoms, and the timing of diagnosis and treatment. In most cases, cats respond well to antibiotic treatment, and symptoms usually improve quickly once therapy has begun.

With early diagnosis and appropriate treatment, the prognosis is generally good, and many cats recover completely without lasting damage. However, if left untreated, the disease can lead to serious complications that can significantly impair the cat’s quality of life.

Prevention

To minimize the risk of Anaplasmosis infection in cats, tick control is crucial. Regular application of veterinarian-recommended tick repellents can help prevent tick infestation and thus reduce the risk of Anaplasma transmission. These products are available in various forms, including spot-on treatments, collars, and oral medications.

In addition, the cat’s environment should be maintained regularly to minimize ticks. This includes mowing grass, removing leaves, and pruning shrubs. These measures reduce the likelihood of ticks getting close to the cat. If the cat has outdoor access, it is advisable to check it for ticks after each stay outdoors and remove them immediately.

Another way to reduce the infection risk is to limit the cat’s access to areas with high tick density, especially during tick season. Pet owners should also regularly consult their veterinarian about the latest prevention strategies and products to ensure the best protection strategy for their cat.

Outlook on current research

Anaplasmosis in cats is an emerging area of research, as this disease has historically been studied primarily in dogs and other animals. Researchers are focusing on better understanding the prevalence of Anaplasmosis in cats and identifying the specific types of Anaplasma that infect cats. Most studies to date have shown that Anaplasma phagocytophilum is the most common species affecting cats, but there is evidence that other species may also play a role.

A focus of current research is on improving diagnosis methods. Traditionally, serological tests have been used to detect antibody against Anaplasma in the blood. However, these tests cannot distinguish between a current infection and a previous exposure. Therefore, scientists are working on developing molecular diagnosis procedures such as PCR (polymerase chain reaction), which can directly detect the presence of Anaplasma DNA.

Another important research area is the study of Anaplasma vectors. Ticks are the main vectors of these parasites, but there are still open questions about the specific tick species relevant to cats. Studies on the distribution and behavior of these ticks help improve the understanding of disease transmission and can contribute to the development of better prevention strategies.

There are also ongoing investigations into the effectiveness of various treatment options. Doxycycline is the most commonly used antibiotic for the treatment of Anaplasmosis in cats, but researchers are exploring further treatment options to avoid resistance and increase treatment efficiency. Some studies focus on the combination of antibiotics or the application of new medications that could enable faster and more complete recovery.

Finally, the role of the feline immune system in Anaplasmosis infection is another area of research. Scientists are trying to find out why some cats become more severely ill than others, which could lead to a better understanding of the immune response and potential vaccine developments. Genetic predisposition and the influence of environmental factors are also subjects of current studies aimed at identifying risk factors for the disease.

Frequently asked questions (FAQs)

  1. What is Anaplasmosis in cats? Anaplasmosis is a disease caused by bacteria of the genus Anaplasma. It is primarily transmitted by ticks and can cause a variety of symptoms, including Fever, lethargy, and loss of appetite.

  2. How is Anaplasmosis diagnosed in cats? Diagnosis is usually made through blood tests that detect antibodies against Anaplasma. Molecular tests like PCR can also be used to directly identify the presence of Anaplasma DNA.

  3. What symptoms occur in an infected cat? Symptoms include Fever, Müdigkeit, loss of appetite, Joint pain, and in some cases neurological problems. However, the symptoms can be variable, and some cats may only show mild or no symptoms.

  4. How is Anaplasmosis treated in cats? The standard treatment for Anaplasmosis is the administration of antibiotics, mainly doxycycline. Treatment usually lasts several weeks, and most cats recover completely if the disease is detected and treated early.

  5. Is Anaplasmosis in cats contagious to humans or other animals? While humans can also get Anaplasmosis, the transmission does not occur directly from cats to humans. However, both can be infected by the same tick bite. Precautions against tick bites are therefore important.

  6. Can all cats get Anaplasmosis? Yes, in principle, all cat species can get Anaplasmosis, especially if they live in areas where ticks are common. Outdoor cats have a higher risk of becoming infected through tick bites.

  7. Is there a way to prevent Anaplasmosis in cats? The best prevention is to avoid tick bites. This can be achieved by using tick repellents, regularly checking for ticks, and avoiding tick-infested areas. Additionally, cats should be regularly examined for signs of infection.

  8. How quickly do symptoms appear after infection? Symptoms can appear a few days to weeks after the tick bite. The incubation period is variable and depends on several factors, including the cat’s immune response.

  9. Can a cat develop immunity after an Anaplasmosis infection? There is evidence that cats can develop some immunity after an infection, but this may not be complete or permanent. Therefore, reinfection is possible.

  10. What long-term consequences can Anaplasmosis have in cats? With timely and appropriate treatment, most cats recover completely without long-term consequences. However, if left untreated, the disease can lead to serious health problems, including chronic Pain and organ damage.

Content

When to visit the vet?

Non-urgent see a veterinarian within 2–3 days

If the condition worsens / symptoms persist, consult a veterinarian.

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An interesting overview of gastrointestinal problems in cats, supplemented by information on the intestinal microbiome and the importance of probiotics, can be found here: https://petsvetcheck.de/fachbeitrag/magen-darm-probleme-bei-katzen/