Ehrlichia Infosheet
by Lynda Adame




What Is It: Ehrlichiosis is a tick-borne rickettsial infectious blood disease. The organism is called Ehrlichia, the disease is called Ehrlichiosis.

Species: Ehrlichia canis, Ehrlichia risticii

Primary Vector: Brown Dog Tick (must feed a minimum of 2 -3 days to transmit) for E. canis. Horse manure and other unknown sources for E. risticii.

Other Vectors: Deer tick, blood transfusion, contaminated needles/instruments, transplacental.

Diagnosis: There are three tests being used by Veterinarians to detect infection:

  • The IFA (Indirect Fluorescent Antibody Assay) test is used to detect the presence of antibodies to the disease in a dog's blood serum. This test will determine a titer level: less than 1:40 is considered Negative (minimal exposure), a titer above 1:80 is considered positive for an active infection. The IFA is considered more reliable than the Giemsa Smear for detecting exposure/infection.
  • The Giemsa Smear is used to locate the actual organism in the dogs blood. Despite appropriate staining technique and intensive film examination, the organisms frequently cannot be found.
  • The PCR (Polymerase Chain Reaction) tests for the presence of the organisms DNA in the dogs blood. A positive PCR means the dog has an active infection. This test is not widely available.

Titer info: Titers counts double: 1:10, 1:20, 1:40, 1:80, 1:160, and so on. A high titer can be caused by repeated exposure to the disease, a large number of active organisms in the blood, or a better immune system response of a specific dog. (i.e. a dog responds naturally with more antibodies than another dog). Titer is an indication of exposure to a specific foreign protein. It does not indicate that there are active organisms in the blood.

Comments: Ehrlichiosis is believed to go through patent and dormant periods, much like Babesiosis does. It has been the experience of people who have owned many Ehrlichia infected dogs, that this disease does not remain dormant, it slowly and steadily grows within the dogs system. If used soon enough, both Tetracycline and Doxicycline (at variable treatment lengths) have a 98% success rate at curing dogs of Ehrlichiosis.

Phases: Acute - 

This phase is of short duration, and is where the dog is initially infected with the disease. If the dog does not die outright from the infection, then it moves on to the next phase.

Subclinical - 

This phase can last months or years. It is characterized by a fine equilibrium between the parasite and the immune system of the host. This equilibrium can be disturbed by a number of things: environmental stress, additional diseases/infections, (especially Babesiosis), immunodeficiency, spleen removal, surgery, stress, hard work, imunosuppressive treatment, use of corticosteroids (Prednisone is a non-no). The dog may exhibit few clinical symptoms during this phase, beyond intermittent fever and loss of appetite. If the equilibrium is disturbed, the parasite will begin to slowly grow in number and the dog will move into the next phase. Greyhounds are often in this phase when they are adopted out. 

Chronic - 

If the dogs system remains unable to clear the parasite, it enters this final phase. The most obvious initial signs to an owner are a cycle of: lethargy, loss of interest in food, and a gradual loss of body condition especially evident around the eyes and along the spine. Other symptoms are: viral tumors on the face/mouth/muzzle, hemorrhaging even when blood count looks normal, clotting problems, low or high calcium level, seizures, muscle wasting, skin infections, neurological signs (repetitive obsessive actions, or palsy), diarrhea, low Platelet count, urine too alkaline, vomiting, hyper reflective eyes, low White Blood Cell count (thrombocytopenia), anemia, glomerulonephritis, bleeding from the nose or eyes, ocular signs, arthritis, weakness, pallor, incontinence, pneumonia, cough, kidney failure, increased thirst and urination, incoordination, neck or back pain, bleeding under the skin or a rash (purpura), swelling of the legs or joints, enlarged lymph nodes, irreversible bone marrow suppression. 

Misdiagnosed as: reticulosis, systemic lupus erythematosus, brucellosis, blastomycosis, thrombocyto- penia, endocarditis, immune mediated disease, myelophthisis, cancer of spleen or liver, Valley Fever, plasma cell myeloma, leukemia. 

Treatment: Doxicycline at 11 mg/kg b.i.d. for 2 - 4 weeks, or longer. OR Tetracycline 22 - 33 mg t.i.d. (oral) for 2 - 4 weeks or longer.

Here are some Labs that perform tick disease testing:

University of Illinois (This Lab can run the PCR test)
Laboratory of Veterinary Diagnostic Medicine
ATTN: Dr. Kakoma
P.O. Box "U", 2001 S. Lincoln
Urbana, IL 61801
PH: 217/333-1620 or 217/333-1859
FAX: 217-222-4628

Protatek Reference Lab
ATTN: Dr. Cynthia Holland
574 E. Alamo St.
Suite 90
Chandler, AZ 85225
(480) 545-8499

Instructions for Tick Fever Panel:

Draw 3cc of blood, use a serum-separation tube, spin down, refrigerate until mailing. Try to mail early in the week, ship tube upright in ice and use priority mail.

Dr. T. McElwain
Washington State University
Vet Diagnostic Lab
Pullman, WA 99164

Dr. E.B. Brietschwerdt
Dr. M.G. Levy
North Carolina State University
College of Vet Medicine
4700 Hillsborough Rd.
Raleigh, NC 27606

Dr. D. Huxsoll
Louisiana State University
School of Vet Medicine
Baton Rouge, LA 70803

Corning Clinical Lab
P.O. Box 305125
Nashville, TN 37230

No instructions available.

This Lab also does the PCR test:

Antech Diagnostics
13633 N. Cave Creek Road
Phoenix, AZ 85022
(800) 745-4725