"We have been very pleased and impressed with our LaserCyte® machine and the level of accuracy it has achieved. During our first few months of LaserCyte ownership, if we had any unusual results, we would confirm them with an outside laboratory. Our LaserCyte results were consistently similar. It is very reassuring to know we have a diagnostic machine that produces consistently reliable results."

Mandy Clarkson, Partner
Riverside Veterinary Practice
Livingstone, Scotland

Hematology and Canine Health

Canine Ehrlichiosis
Etiologic agent: Ehrlichia canis.

Although several species of the genus Ehrlichia have been recognized as infectious agents of dogs, E. canis is one of the more common causes of clinical illness, and results in the most severe disease state. Ehrlichiosis has been classified as acute, subclinical and chronic disease states. The primary vector of disease is the brown dog tick, Rhipicephalus sanguineus.

Ehrlichiosis is most commonly diagnosed in the late summer to early fall, but in Texas, cases have been identified in nearly every month of the year. Chronic infections can also be identified in nontick months. Clinical signs can vary markedly between dogs due to the differences in pathogenicity of Ehrlichial strains, the dog's natural immunity, possible concurrent diseases and the stage of disease. There appears to be no breed, age or sex predilection, although this is controversial and several authors have suggested that pure bred dogs, particularly German shepherds, are more susceptible. Ehrlichia caused significant morbidity and mortality among U.S. military dogs during the Vietnam War.

The primary clinical signs observed in dogs with ehrlichiosis are nonspecific and include depression and lethargy, weight loss, bleeding and lymphadenopathy. Ticks can be often found on dogs, but are not always demonstrated. Other commonly observed signs include anorexia, oculonasal discharge, increased lung sounds, pyrexia, pale mucous membranes and limb edema. In the chronic disease state, variable ocular signs and blindness have been described. Neurologic ehrlichiosis can appear similar to canine distemper in puppies.

Hematologic findings
Canine ehrlichiosis has also been called canine monocytic ehrlichiosis (CME) because rickettsial morulae can be found in the cytoplasm of monocytes, and canine tropical pancytopenia because of the classical hematology findings in chronic ehrlichiosis. Acute ehrlichiosis occurs 8–20 days following transmission of the agent from an infected tick, and presents with thrombocytopenia, leukopenia (primarily a neutropenia) and mild anemia (pancytopenia). Subclinical infections vary markedly in clinical presentation; however, this stage occurs approximately 40–120 days after infection and presents with mild thrombocytopenia, although many patients may also have slightly decreased leukocyte counts and mild anemia. Dogs that cannot mount a successful immune response to clear the parasite will become chronically infected. Chronic infections appear similar to acute infections with often severe pancytopenia, and marked bone marrow hypoplasia may occur.

Diagnosis
Diagnosis of canine ehrlichiosis is based on a combination of clinical signs, serology and hematologic abnormalities. PCR testing for Ehrlichia is now available and should be used in concert with serological testing. Examination for morulae in leukocytes by examination of buffy coat smears is often unrewarding.

Why screen for tick-borne disease?
Tick-borne diseases such as Ehrlichia can have devastating outcomes in our canine companions. Although the clinical manifestations can vary depending on the offending Ehrlichia species, hematologically theses infections are typically characterized by a reduction in cellular blood components. E. canis is probably the most concerning of the Ehrlichia infections, given its broad geographical distribution and potential for severe morbidity. Clinical signs of E. canis are characterized by anemia, weight loss, lymphadenopathy, bleeding tendencies, anterior uveitis and seizures. Additionally concerning is the subclinical phase of this disease, which can allow this disease to go undetected on routine physical exam.

Explaining the Importance of Ehrlichia Testing to Your Clients
With the widespread adoption of SNAP® 3Dx®, the industry has its first accurate and inexpensive tool for screening all dogs for Ehrlichia canis, as well as Borrelia burgdorferi (Lyme disease) and heartworm. The use of the test has uncovered the dramatic extent of E. canis in our dog population and because the prognosis is good for early-stage infection, but variable to guarded for chronic infections, annual screening's encouraged by industry experts and well-accepted by dog owners.

Screening also increases testing compliance and preventative medicine by heightening awareness to the threat of tick-borne diseases. Additionally, screening will provide clinics with their own prevalence data for Ehrlichia, Lyme and heartworm, giving them sound data for the risk to their practice population of dogs.

IDEXX can also provide your clinic with educational client brochures designed to educate on the disease, the risks, testing and prevention. (377 KB)

The recommendations contained in Diagnostic Edge educational materials are intended to provide general guidance only. As with any diagnosis or treatment, you should use clinical discretion with each patient based on a complete evaluation of the patient, including physical presentation and complete laboratory data. With respect to any drug therapy or monitoring program, you should refer to product inserts for a complete description of dosages, indications, interactions and cautions.

This summary was written by Drs. Jim Matthews and Leif Lorentzen of IDEXX Laboratories.

Bibliography:
Irwin PJ. The first report of canine ehrlichiosis in Australia. Aust Vet J. 2001;79:552–553.

Varela AS. Tick-borne ehrlichiae and rickettsiae of dogs. In: Bowman DD, ed. Companion and Exotic Animal Parasitology. Ithaca, NY: International Veterinary Information Service, 2003.

Greene CE, Burgdorfer W, Cavagnolo R, Philip RN, Peacock MG. Rocky mountain spotted fever in dogs and its differentiation from canine ehrlichiosis. J Am Vet Med Assoc. 1985:186;465–472.

Hibler SC, Greene CE. Rickettsial infections in dogs, part I. Rocky mountain spotted fever and Coxiella infections. Compend Cont Ed Pract Vet. 1985:7;856–865.

Hibler SC, Greene CE. Rickettsial infections in dogs, Part II. Ehrlichiosis and infectious cyclic thrombocytopenia. Compend Cont Ed Pract Vet. 1986:8;106–114.

Kuehn NF, Gaunt SD. Clinical and hematologic findings in canine ehrlichiosis. J Am Vet Med Assoc. 1985:186;355-358.

Troy GC, Vulgamott JC, Turnwald GH. Canine ehrlichiosis: a retrospective study of 30 naturally occurring cases. J Am An Hosp Assoc. 1980:16;181–187.

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IDEXX LaserCyte® adds Sneakers DVMax™ to the Growing List of Intergrated Practice Information Systems

We are pleased to announce that the IDEXX LaserCyte® Hematology Analyzer now interfaces with the latest software version of DVMax veterinary practice-management software. If you use DVMax, this connectivity allows the flow of information from the LaserCyte analyzer into your patients' records, making a paperless practice possible and providing detailed diagnostics onscreen in minutes. LaserCyte also interfaces with ImproMed Infinity, IntraVet® and OmegaSoft in addition to our own IDEXX Cornerstone® practice-management software.

For inquiries, please contact:
IDEXX LaserCyte at 1-800-340-4579 or e-mail diagnosticedge@idexx.com
IDEXX Computer Services at 1-800-283-8386 or e-mail cornerstone@idexx.com

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Providence, Rhode Island
Sunday, August 8, 2004, 1:00—3:00 p.m.
Northeast Veterinary Conference (NEVC)
Rhode Island Convention Center

Blood-Smear Evaluation: The Good, the Bad and the Ugly (Technician Training)
Alan Rebar, DVM, PhD

Providence, Rhode Island
Monday, August 9, 2004, 8:00 a.m.—4:30 p.m.
Northeast Veterinary Conference (NEVC)
Rhode Island Convention Center

Red and White Cell Responses in Disease/Case-Oriented Approach to Hemogram Interpretation
Alan Rebar, DVM, PhD

Kansas City, Missouri
Monday, August 30, 2004, Noon–2:30 p.m.
Central Veterinary Conference (CVC)
Kansas City Marriott Downtown
Marriott Tower—Third Floor, MaryLou Williams Room

Blood-Smear training and LaserCyte demonstrations
Dennis B. DeNicola, DVM and Fred Metzger, DVM, DABVP

Greenlands, Henley-on-Thames, Oxfordshire, United Kingdom
Monday, September 13, 2004, 9:00 a.m.–4:00 p.m.
Henley Management College Conferences Centre

Advancing In-House Hematology with your IDEXX LaserCyte Analyzer
Dennis B. DeNicola, DVM

Wetherby, West Yorkshire, United Kingdom
Wednesday, September 15, 2004, 9:00 a.m.–4:00 p.m.
IDEXX Laboratories Limited

Advancing In-House Hematology with your IDEXX LaserCyte Analyzer
Dennis B. DeNicola, DVM

Grapevine, Texas
Friday, September 24, 2004, 1:30 p.m.–5:30 p.m.
Southwest Veterinary Symposium (SWVS)
Gaylord Texan Resort and Convention Center

Interactive Lab
Clinical Pathology/Cytology (review of basic blood and cytology techniques)
Dennis B. DeNicola, DVM and Mary Anna Thrall, DVM

Grapevine, Texas
Saturday, September 25, 2004, 8:00 a.m.–6:00 p.m.
Southwest Veterinary Symposium (SWVS)
Gaylord Texan Resort and Convention Center

Interactive Lab
Hematology/Cytology
Dennis B. DeNicola, DVM and Mary Anna Thrall, DVM

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LaserCyte's single-dose tubes and qualiBeads® verifies fast, accurate results every time.

Unit-dose IDEXX CBC5R tubes (grey-topped) make running samples on the LaserCyte analyzer consistent and nearly effortless. Each CBC5R tube contains new methylene blue dye and our proprietary qualiBeads—distinct types of latex particles that act as a within-sample internal quality assurance to ensure instrument performance.

Every tube is bar-coded so the instrument can compare the reference information and expected values against measured parameters. The information on the bar code for each CBC5R tube includes the quantity of qualiBeads in that tube. This information is used to verify that the on-board mixer properly mixes the sample, that the correct dilutions are made, and that the sample is introduced to the laser in the correct position. This innovative design makes the LaserCyte analyzer reliable and easy to use.

In the event that the anticipated number of qualiBeads with the correct size and complexity are not identified, then the message "Internal QA failure, qualiBeads not recovered" will be printed on the bottom of the results printout. If this message is displayed on the results page, simply rerunning the sample is usually all you need to do to obtain the results for that sample. This ensures the user that the instrument performance of the LaserCyte analyzer is accurate, and prevents erroneous results from being displayed.

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How does your LaserCyte® Hematology Analyzer help you deliver better patient care?

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