November 2005 Issue

Featured Case Study: Ten-year-old spayed female mixed-breed dog, Yuka
by Matt Eberts, DVM, Medical Director, Lakeland Veterinary Hospital, Baxter, Minnesota

History

Yuka’s owners moved into the central Minnesota region approximately four months ago. She is current on her distemper, parvovirus and rabies vaccination, but has never been vaccinated for Lyme disease. Yuka has not had any health problems in the past. Since the beginning of spring, Yuka has had a constant problem with black-legged ticks (Ixodes scapularis) and is not currently on tick prevention. Yuka began limping two weeks ago, but this resolved spontaneously. Starting three days ago, she began limping on her hind limbs, which progressed to her forelimbs. She is now unwilling to stand and presents on emergency on Sunday afternoon.

Interpretive Summary

The SNAP® 3Dx® Test shows positive for Lyme disease, negative for Ehrlichia canis and negative for heartworm disease. This test detects C₆ antibody for Borrelia burgdorferi, which is very sensitive and specific for infection with B. burgdorferi. Yuka has a compatible history with heavy exposure to Ixodes scapularis, the vector for Lyme disease. Clinical Lyme disease is usually characterized by high fever, polyarthritis and lethargy. Lyme can also cause a nephropathy characterized by a protein-losing nephritis that is usually nonresponsive to therapy (this condition is rare).

Erythron—No significant abnormalities noted.

Leukon—Numbers and distribution within normal limits. However, evaluation of a blood film shows inclusions in approximately 2% of the neutrophils. These inclusions are diagnostic for granulocytic rickettsial infection, in this case with Anaplasma phagocytophilum (formally known as Ehrlichia equi). Ixodes scapularis serves as the vector for A. phagocytophilum, in addition to B. burgdorferi. Ehrlichia ewingii is another rickettsial organism that is capable of causing neutrophilic inclusions, however, this organism is not found in this area (the Lone Star tick, Amblyomma americanum, is not a resident of central Minnesota). Common clinical signs of canine anaplasmosis include high fever, lethargy, depression and polyarthitis. Neurologic signs (ataxia, seizures and neck pain) can also be seen.

Thrombon—Mild thrombocytopenia is present. Low platelet counts are commonly associated with rickettsial infections. In the case of A. phagocytophilum, low platelet counts are likely a consequence of immune-mediated destruction and a degree of myelosuppression. In this case, as with most cases of anaplasmosis, the platelet count is not low enough to expect spontaneous hemorrhage. In Lyme disease, thrombocytopenia is not a common finding.

Chemistry profile is within normal limits.

Diagnosis

Co-infection of Borrelia burgdorferi and Anaplasma phagocytophilum (Lyme disease and canine anaplasmosis). It is important to note that ticks can carry multiple parasites. No one diagnostic test can identify all of the possible infectious organisms; therefore, a thorough workup is indicated on sick dogs. It is very important to evaluate blood films to make sure infectious organisms are not missed.

Clinical Case Outcome

Yuka was started on 200 mg ofdoxycycline twice daily for 28 days. The fever resolved in 24 hours and the lameness began improving rapidly; however, the dog did not ambulate normally for four days. In my experience, dogs with co-infections of Lyme and anaplasmosis take a little longer to show abatement of lameness, while dogs with single infections are usually ambulating normally within 48 hours. Re-examination two weeks after the initial visit showed no physical abnormalities and a normal complete blood count. Tick prevention is a vital component of preventing future tick-borne disease.

We want to hear from you. Let us know what you think about this case and tell us about any other case topics that you would like to see. E-mail us at diagnosticedge@idexx.com.

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 history, 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.

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New from IDEXX—A quality-control panel for the VetTest® Chemistry Analyzer

Quality-control (QC) testing has become easier and more cost-effective with the new VetTest® Quality Control Panel. This new QC panel eliminates the need to take slides out of other prepackaged panels or pull single slides from your inventory.

The Quality Control Panel is packaged with four panels per box, giving you a four-month supply of quality-control slides. Each panel consists of all of the chemistries you need to efficiently perform quality control on your VetTest® analyzer.

As part of our ongoing commitment to ensure that you are receiving the most accurate test results, IDEXX recommends that you perform quality control monthly on your VetTest® Chemistry Analyzer.

We’ve made it easier to remember to run quality control on your VetTest Chemistry Analyzer by adding a monthly quality-control reminder to your VetTest software (version 8.05 and later) that automatically prompts you. For details on how the new quality-control reminder works, see the VetTest feature guide. (1.3 MB)

For more information about the VetTest Quality Control Panel and other IDEXX products, call IDEXX at 1-800-355-2896 or e-mail diagnosticedge@idexx.com.

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Keep your IDEXX VetLyte® Electrolyte Analyzer running smoothly and prevent any unexpected downtime

Your VetLyte® operator’s guide provides you with full instructions for each step, but here’s a quick review to ensure that your VetLyte® analyzer is receiving the proper preventive care.

After Each Sample Run

• Wipe the sample probe using a lint-free wipe.

• Run the electrode conditioning solution to prepare the sodium electrode to react properly with your samples.

• Pick a day of the week to run your cleaning solution to guarantee a balanced reaction with your sample. This step will strip away extra protein that has built up over the week from all of the electrodes and the sample sensor.

• Clean the reference housing and its aperture to keep them free from build-up.
• Run the VetTrol™ quality-control fluid once a month to verify your VetLyte analyzer's performance. This is the same quality-control material used for the IDEXX VetTest Chemistry Analyzer.

• Replace the peristaltic pump tubing every six months and replace the complete tubing every two years.
• Keep the sample probe and sample fill port clean to keep them free of bacteria and other build-up.

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To help prevent heat loss in surgical patients under anesthesia, place baby booties on the animals' paws. This is especially helpful in conjunction with warming blankets.

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Education and Events

We offer a variety of training events about emerging trends and best practices in veterinary diagnostics in forums designed to involve, educate and motivate you and your staff. Here are some of the educational events in November. Click here to see a full listing.

Webinar

Or to register, copy and paste this Web address into your browser:
http://livemeeting.viewcentral.com/reg/IDEXX/DE

Seminars

• The Most Commonly Misdiagnosed Diseases in Veterinary Medicine*
  by Fred Metzger, DVM, DABVP
• Blood-Film Evaluation in Dogs and Cats*
  by Rick Alleman, DVM, PhD, DABVP, DACVP
• A Practical Approach to Feline Retroviruses
  by Terri Wheeler, DVM, MS

Visit the education and event calendar, click the date to view the details, fill out and submit the form to register.

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Weigh and wand every patient at check-in
by Wendy S. Meyers, Communication Solutions for Veterinarians, Denver, Colorado

Hurricane Katrina separated thousands of pets from loving families. A blind man was forced to evacuate his New Orleans home and leave behind his guide dog, Jacob. Volunteers circulated flyers and asked National Guardsmen to check James Mercadel’s home again and again. After multiple trips to the flooded neighborhood, National Guardsmen found Jacob waiting at home. A microchip confirmed they’d found Mercadel’s beloved guide dog, and the pair was reunited at a Houston shelter.

You can educate pet owners about the benefits of permanent microchip identification, whether it’s an afternoon at the dog park or a natural disaster that separates us from our best friends. After you weigh each patient at the beginning of an appointment, use your microchip scanner to “wand” each pet. Clients may ask, “What does that scanner do?” You respond, “I’m checking to see if your pet has a microchip.” If the pet doesn’t have one, it’s the perfect conversation starter about the need for permanent identification. If a microchip is present, show the client the chip is working. Also, confirm the client has current contact information registered with the microchip manufacturer, and be sure the microchip number is entered into your veterinary software.

Does “weigh and wand” really work? One of our consulting clients sold 10 microchips the first day of implementing this check-in procedure. By making “weigh and wand” part of your daily routine, you’ll increase the number of pets with permanent identification and help keep best friends and their families together.

Wendy S. Myers owns Communication Solutions for Veterinarians in Denver, Colorado, and provides consulting services on client service, marketing and hospital management. She is the author of two books and four videos. You can reach her at 1-720-344-2347 or visit www.mycommunicationsolutions.com.

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Identify the Structures

Unstained urine sediment from a dog (40x objective field of view). Identify the different structures indicated by the black and red arrows.

Send your answer in an e-mail to: diagnosticedge@idexx.com. Please include your name, practice name, address and telephone number.

The first 10 respondents to correctly identify the cell and structures will appear in the next issue of the Diagnostic Edge.

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October Survey Results—Here is what you said...

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