Ticks are often associated with Lyme disease, but they also transmit many other diseases that lead to illness in cats, dogs, and people. Here in Tennessee, cytauxzoonosis—”bobcat fever”—in cats and ehrlichiosis in dogs are more common than Lyme disease.

Ehrlichiosis in dogs

Complicated to pronounce and complicated to diagnose, ehrlichiosis can cause a variety of symptoms in our canine friends. And, those symptoms depend on the Ehrlichia bacteria that have caused the disease.

  • Canine monocytic ehrlichiosis develops after a dog has become infected with the Ehrlichia canis strain, which is primarily carried by the brown dog tick. There are three stages in this form of ehrlichiosis:

    • Acute phase — This stage occurs within the first few weeks of infection, and symptoms last for two to four weeks if left untreated. Signs seen during the acute phase include:
      • Fever
      • Lethargy
      • Decreased appetite
      • Enlarged lymph nodes
      • Abnormal bleeding
      • Eye inflammation
      • Neurological issues
      • Joint pain and lameness

Many dogs appear to recover on their own, and then enter the subclinical stage.

    • Subclinical phase — This stage has the potential to quietly smolder for months to years. Usually, a pet in the subclinical phase has no apparent signs of illness, but will show changes in laboratory testing. Blood work will reveal a decreased number of platelets, which leads to increased blood-clotting time. Dogs in the subclinical phase either clear the Ehrlichia organism on their own or progress to the chronic phase.
    • Chronic phase — Severe illness develops during the chronic phase, and signs are similar to those seen during the acute stage. Dogs progress to this phase if their immune systems are unable to fight off the Ehrlichia organism. With multi-organ dysfunction, treatment of chronic infections is more difficult. 
  • Canine granulocytic ehrlichiosis develops after a dog has become infected with the Ehrlichia ewingii strain, which is primarily carried by the lone star tick. Dogs with this disease will show similar signs as dogs with canine monocytic ehrlichiosis, but they may also experience vomiting, diarrhea, and more frequent stiffness and lameness.

Diagnosis of ehrlichiosis in dogs

Because most tick-borne diseases cause similar signs of illness, pinpointing the appropriate culprit can be challenging. False negative test results can occur when dogs are tested too soon after a bite because antibodies take several weeks to develop and appear during testing. To help us diagnose ehrlichiosis, we complete a thorough history and physical exam, blood work, and a urinalysis. Ehrlichia and Lyme disease screening are also included with annual heartworm testing.

Treatment of ehrlichiosis in dogs

Once treatment begins, most dogs with ehrlichiosis improve quickly. Doxycycline, a common antibiotic used to combat tick-borne diseases, is often prescribed for up to three to four weeks to completely clear the bacteria. Dogs with severe cases may also require blood transfusions, intravenous fluids, pain medications, and other supportive care to make a complete recovery.

Cytauxzoonosis in cats

Transmitted through a tick bite, this parasitic disease—known as “bobcat fever”—infects the blood cells of cats. The natural host of this parasite is the bobcat (hence the name), but all feline species can be infected. House cats have severe, adverse reactions to Cytauxzoon felis that can often lead to death if treatment is not provided. Signs of bobcat fever include:

  • Fever
  • Loss of appetite
  • Crying in pain
  • Lethargy or depression
  • Yellowing of the skin and mucous membranes
  • Enlarged lymph nodes
  • Difficulty breathing due to fluid in the lungs
  • Anemia
  • Coma

Diagnosis of cytauxzoonosis in cats

To diagnose bobcat fever, we conduct blood tests, including a complete blood count (CBC), chemistry panel, and a blood smear.

Treatment of cytauxzoonosis in cats

Treatment of cytauxzoonosis in cats is difficult, and early detection and treatment only offer a 60 percent chance of survival. Intense hospitalization is required to provide the supportive nursing care necessary for an infected cat. Treatments include intravenous fluids, heparin (a blood thinner), pain medication, an antibiotic, a malaria medication and possibly a blood transfusion, oxygen treatment, and a feeding tube.

Prevention of tick-borne diseases in pets

As a responsible pet owner, it’s important to understand the nasty diseases carried by ticks and their potentially deadly outcomes. It’s even more important to take appropriate preventive measures for your furry friend. Be sure to choose a quality tick preventive, avoid heavily wooded or tall grassy areas, and always check your pet for ticks after an outdoor adventure.

Is your pet on a regular tick preventive? Make an appointment  to protect your dog or cat from ticks and the diseases they carry.