What is Anaplasmosis and how does it impact pets?

What is Anaplasmosis?

Morulae detected in a granulocyte on a peripheral blood smear, associated with A. phagocytophilum infection. Photo/Bobbi S. Pritt, Mayo Clinic

What is Anaplasmosis?

Anaplasmosis is a disease caused primarily by Anaplasma phagocytophilum in most pets. However, A. platys, A. bovis, and A. marginale can also cause anaplasmosis, though to a lesser extent in household pets. As such, we will be focusing on A. phagocytophilum.

Anaplasma phagocytophilum is a tick-born gram-negative intracellular bacterium that can have a significant impact on the health and well-being of our beloved pets. This pathogen is transmitted primarily through tick bites, making it essential for pet owners to be aware of the risks and understand the symptoms, diagnosis, and treatment options associated with anaplasmosis. In this blog, we'll delve into how Anaplasma phagocytophilum affects these three species and what you can do to protect your furry friends.

Anaplasmosis in dogs

Dogs are one of the most commonly affected species by Anaplasma phagocytophilum. If a dog develops symptoms after Anaplasma exposure, symptoms can be non-specific and vague. The clinical signs of anaplasmosis in dogs can vary, but common symptoms include:

1. Fever

2. Lethargy and fatigue

3. Dehydration

4. Decreased appetite

5. Lameness

6. Vomiting

7. Diarrhea

Less common symptoms include:

• Bleeding from the nose

• Neck pain

• Seizures

Anaplasmosis in dogs can be diagnosed through blood tests, which detect the presence of the bacterium or the antibodies produced in response to the infection. Treatment typically involves a course of antibiotics, such as doxycycline. Many dogs that test positive for Anaplasmosis never develop symptoms, but those that do should receive treatment quickly. Dogs often see improvements after treatment within 1-2 days. Even so, it is important for dogs to continue on a course of antibiotics for at least two weeks. It is important to note that after treatment and recovery from Anaplasmosis, a dog can be reinfected if exposed again.

Anaplasmosis in cats

Anaplasmosis in cats is less common than in dogs, but it can still occur. Cats infected with Anaplasma phagocytophilum may display similar symptoms to dogs, including fever, lethargy, and joint pain. However, cats often mask their illness, making it challenging to identify the disease in its early stages. Additional symptoms can include:

1. Decreased appetite

2. Stiffness

3. Limping

4. Enlarged lymph nodes

5. Bloody nose and stool

6. Bruising

7. Seizures

8. Conjunctivitis

9. Third eyelid protrusion

Like dogs, not all cats carrying A. phagocytophilum will be symptomatic. Testing cats often includes both blood and urine testing. Often cats are treated with oral antibiotics (doxycycline). Cats sometimes need blood transfusions due to anemia and blood loss. Cats generally respond quickly to treatment. However, if untreated, Anaplasmosis can be fatal in cats.

Anaplasmosis in horses

Severity of symptoms of Anaplasmosis in horses varies with the age of horse and duration of the illness. Typically symptoms are mild in horses less than a year old, moderate in horses 1-3 years old, and horses over 3 (particularly geriatric horses) can develop severe symptoms. Diagnosing anaplasmosis in horses may require specialized tests, including serologic assays or PCR tests.  Symptoms can include:

1. Fever

2. Depression

3. Limb edema

4. Ataxia

5. Reduced appetite

6. Reluctance to move

7. Icterus

Rare symptoms include

•  Myocardial vasculitis and transient ventricular arrhythmias

• Recumbency

• Sever myopathy

Oxytetracycline antibiotics are very effective against A. phagocytophilum Diluted antibiotic concentrations are recommended to reduce GI upset to the drug. Given severe illnesses, supportive care may be required.

Preventing Anaplasmosis

Preventing anaplasmosis in dogs, cats, and horses involves taking proactive measures to reduce the risk of tick bites:

1. Tick control: Use tick prevention products recommended by your veterinarian, such as topical treatments, collars, or oral medications.

2. Checking for ticks: Regularly inspect your animals for ticks, especially after outdoor activities. Remove any ticks promptly using fine-tipped tweezers.

3. Environment management: Keep your yard well-maintained by mowing grass, removing leaf litter, and minimizing wildlife habitats that may attract ticks.

4. Avoid tick-infested areas: When possible, avoid areas known to be infested with ticks, particularly during peak tick season.

5. If a bite does occur, testing the tick directly can help assess the risk of exposure to Anaplasma phagocytophilum.

Conclusion

Anaplasma phagocytophilum is a widespread bacterium that can affect dogs, cats, and horses through tick bites, causing anaplasmosis. While the disease can vary in severity, early detection and treatment are vital for a successful recovery. By taking preventive measures to reduce the risk of tick bites, you can help protect your furry companions from this potentially serious illness. Regular veterinary check-ups and discussions about tick prevention with your veterinarian are essential for ensuring your pets' well-being.