Shana’s Story: Shana is a 10-year-old female spayed Laborador Retriever who was presented to VESCONE after being ill for several days. She was lethargic, had several episodes of vomiting, and had a poor appetite. Physical exam revealed a well-fleshed patient who was quiet. Shana appeared “stiff”, with an occasional limp noted. She had a high fever.
Shana was admitted to the hospital and placed on intravenous fluids, antinausea medication, and antibiotics. Blood work, urinalysis and culture, radiographs of her chest and abdomen, and an abdominal ultrasound were performed. All of these baseline tests were essentially normal with the exception of a low platelet count. Platelets are an integral part of the clotting system. When they are very low, patients may bleed or bruise. When platelets are mildly or moderately decreased, there are usually no overt signs. This was the case with Shana. There are many types of disorders that can cause low platelets, including some diseases that are carried by ticks. A complete blood count (CBC) was submitted to our local laboratory for review, along with a full tick panel, which includes tests for Lyme disease, Rocky Mountain spotted fever, and Ehrlichiosis. These are all diseases that can affect dogs if bitten by a tick that is carrying the disease. Patients with any of these diseases may present with a myriad of clinical signs and laboratory abnormalities.
Shana improved dramatically on supportive care. Her temperature normalized, she was no longer vomiting or lame, and she wanted to go home! The test results were now final. We were informed that the lab saw actual Ehrlichia organisms in her blood cells on her CBC. Interesting enough, the Ehrlichia titers on her tick panel were negative. A titer is a measurement of the amount of antibodies to a particular organism found in a patient’s blood. A negative titer can sometimes occur in the very early or “acute” stages of illness. Shana was sent home on a 4 week course of doxycycline, the antibiotic of choice for Ehrlichia infections. Shana was evaluated a week after discharge, and was doing very well at home on doxycycline. Baseline blood tests were rechecked, and although her platelets were now normal, her liver enzymes were elevated. This can be seen associated with Ehrlichia infections as well. Shana’s family elected to watch her blood tests over several weeks and not perform additional testing at that time. Her liver enzymes did improve over several weeks on the doxycyline. Follow up blood tests were recommended later in the Spring, however as Shana was doing so well, her family elected to hold off for the time being.
In late July of 2004, Shana started to show symptoms that were similar to her symptoms in March. After 24 hours of vomiting, lethargy, stiffness and limping, Shana was brought to VESCONE. Shana had a low grade fever. She was once again admitted to the hospital and placed on intravenous fluids, antinausea medication, and antibiotics. Baseline bloodwork, chest and abdominal radiographs, and an abdominal ultrasound were performed “in house”, while a tick panel and a CBC for review by the lab were submitted. In house blood work was essentially normal, including her platelet count and liver enzymes. Radiographs and ultrasound were normal with the exception of a mildly enlarged spleen. We took a small sample of the spleen with a very thin needle, using the guidance of ultrasound. The lab report revealed “lymphoid hyperplasia,” a non specific finding that can be seen as the body responds to an infectious or inflammatory process. Shana’s ehrlichia titer came back “positive” this time, which suggested exposure to or active infection with Ehrlichia. With Shana’s history (having seen organisms in her blood several month before), current similar clinical signs, and once again, response to therapy in just a couple of days, it was highly likely that Shana was either still and/or once again infected with Ehrlichia. Shana was discharged on a 6 week course of doxycycline and did very well.
Shana was fine until November of 2005. She returned to VESCONE with a several day history of vomiting, lethargy, reluctance to move, and was limping on several legs. She had a high fever. Shana had several swollen joints. She was admitted to the hospital for intravenous fluids, antinausea medication, pain medication, and intravenous antibiotics (doxycycline.) Baseline blood work, chest and abdominal radiographs, and an abdominal ultrasound were performed in hospital, while a CBC for the pathologist’s review as well as tick titers were submitted to the outside laboratory. All tests were normal with the exception of a low platelet count (similar to the first hospitalization) and a mild enlargement of her spleen (similar to the second hospitalization). The CBC review once again revealed the presence of ehrlichia organisms in some of the blood cells. Shana’s tick titers were all negative, which again, likely indicated that her symptoms were caught very early in the disease process. It was likely that Shana was reinfected with ehrlichia, as she had been well for over a year. A blood test referred to as a Polymerase Chain Reaction (PCR) was submitted to a specialized lab in North Carolina. This test is a very senstive test, and detects DNA (tiny, microscopic tissue) of specific organisms. The PCR was positive for Ehrlichia, confirming it’s presence.
Shana did very well after 48 hours of supportive care and intravenous doxycycline. She was sent home on a 6 week course of doxycycline.
Shana was re-evaluated in mid January, 2 weeks after the course of doxycycline was completed. All baseline blood tests were within normal limits. Review of her CBC was normal, and the follow up PCR was negative, consistent with elimination of the ehrlichia organism. Her ehrlichia titer was elevated however, which is most likely consistent with her history of exposure to the organism, and not active infection. Titers can remain elevated for months after an infection has been cleared.
At the time of this writing, Shana is doing well at home. Her case was interesting in that it appears she likely had 3 separate infections of the same organism over the course of 2 years, and different tests at different times were necessary to confirm Shana’s disease.
Ehrlichiosis is an infectious blood disease that is spread through the bite of an infected tick. Classically, canine ehrlichiosis presents as a non-specific multisystemic disorder with the primary complaints being lethargy, fever, vomiting, anorexia, with or without bleeding tendencies. Some patients may limp and have swollen joints as well. Other patients may present with signs associated with other organs as well, including kidneys, liver, nervous system, etc.
The diagnosis can sometimes be difficult, however we rely on a combination of clinical signs and several tests, including titers, PCR, and occasionally we are lucky enough to find the organism itself in the some blood cells. Serologic testing detects various antibodies produced by the body against Ehrlichia. Antibodies are often detected within a couple of weeks of exposure to infection with the organism, and may persist for months. It is sometimes difficult to determine whether an elevated antibody titer is due to chronic exposure to infected ticks, or whether these elevations are representative of active infection present in the dog.
Prevention of tick born disease is possible by minimizing our dog’s exposure to ticks. It is best to avoid tick-infested areas, and important to remove ticks as soon as possible, as they must be attached for a minimum of 24 to 48 hours in order to transmit the disease. There are many safe, effective products available through veterinarians to help prevent tick infestation in our pets. Be aware that although uncommon, ehrlichiosis has been reported in people. It is felt that human transmission probably occurs through the bite of a tick, and is not caught from an infected dog.
At VESCONE, we have a winning combination of highly skilled doctors, nurses and facilities such as our canine and feline blood bank available 24/7 so we can be ready for patients like Frankie. Our blood products are available to our clients and their referring veterinarians around the clock.
Please contact us anytime for more information on these and our many other services.