February 2007 Issue

Featured case study:
Featured case study: Seven-year-old neutered male Scottish terrier, Scotch
by David Fisher, DVM, DACVP, IDEXX Reference Laboratories

Physical exam
Slightly underweight with a body condition score of 3–4/9. Quiet but alert and responsive. Mucous membranes are slightly pale with a capillary refill time of less than two seconds. Thoracic auscultation and abdominal palpation are within normal limits. The remainder of physical examination is unremarkable.

Plan
Comprehensive CBC, chemistry panel and urinalysis.

Hematology results
Erythron—There is a mild-to-moderate normocytic, normochromic, poorly regenerative anemia. There are an inappropriately high number of nucleated red blood cells relative to the degree of the regenerative response, which can be seen with splenic disease, extramedullary hemopoiesis, lead poisoning, leukemia and bone marrow disease. Target cells present can occur in a number of conditions including liver disease, hypothyroidism and bone marrow disease.

Leukon—The white blood cell count and differential are relatively normal, except that a large number of unclassified cells are identified. A clinical pathology review of the slide indicates the cells are suggestive for neoplasia and most likely reflect the leukemic phase of malignant lymphoma.

Thrombon—There is a marked thrombocytopenia.

Chemistry results
Chemistry results were within reference interval limits.

Urinalysis results
No abnormalities

Additional diagnostics
Upon careful reexamination of Scotch, a moderate peripheral lymphadenomegaly and probable mild-to- moderate hepatosplenomegaly were detected. A fine-needle aspirate of his right prescapular lymph node revealed high-grade malignant lymphoma. Scotch’s owner declined further diagnostics for staging his lymphoma.

Assessment
The cause of the anemia is likely multifactorial; with causes including gastrointestinal bleeding from thrombocytopenia; immune-mediated destruction secondary to his lymphoma; and decreased production from his bone marrow, which is likely infiltrated with cancer cells. The increased nucleated red blood cells and target cells are likely a result of his bone marrow disease. Similarly, his thrombocytopenia probably has several causes, including: immune-mediated destruction, consumption from DIC secondary to his cancer, as well as decreased production from an infiltrated bone marrow. Successful treatment of his lymphoma should resolve the cytopenias.

Diagnosis
Multicentric malignant lymphoma; stage 5B

Treatment
Chemotherapy–University of Madison-Wisconsin protocol

Clinic case outcome
Hematologic abnormalities corrected during the course of treatment and Scotch remained in remission for ten weeks after the standard 25-week short protocol. Peripheral lymphadenomegaly recurred after this time, and the UW protocol was used again as the rescue chemotherapeutic protocol. Although Scotch went into only partial remission, he clinically did well for another eight weeks, after which time the leukemic changes on his CBC recurred and his owners elected humane euthanasia.

IDEXX CBC Results PLUS difference
Review of the blood smear by the technician identified the unclassified cells which prompted the CBC to be sent for a clinical pathology review. The pathology review indicated neoplasia suspected to be the leukemic phase of malignant lymphoma, and it was recommended to evaluate for lymphadenopathy and/or organomegaly. This led to the diagnosis of malignant lymphoma. Although full staging was not performed, knowing that Scotch was leukemic somewhat worsened his expected remission and survival times with chemotherapy. This additional knowledge allowed his owners to make an informed decision regarding treatment. Scotch and his owners enjoyed ten healthy months together after his original diagnosis.

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.

Do you have a case that you would like to submit? E-mail us at diagnosticedge@idexx.com to get the process started.

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Spec cPL® Test—change when and how you diagnose pancreatitis

The Spec cPL (canine pancreas-specific lipase) Test allows you to diagnose pancreatitis quickly and with unprecedented accuracy.

And now you can add a Spec cPL Test to any Chemistry/CBC panel and pay LESS than you would without Spec cPL!*

Try Spec cPL on more cases—even those with chronic or intermittent signs—and see the benefits for yourself. Results within 12–24 hours.

*Available in the U.S. only

Offer good through March 31, 2007. For more information, call IDEXX Reference Laboratories at 1-888-433-9987 or visit www.idexx.com/speccpl.

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Summary: Point-Of-Care
In-House Thyroid Testing
Comparsion of laboratory and in-house tests
Highlights of a summary by Peter P. Kintzer, DVM, DACVIM

The measurement of total thyroxine (T₄) is commonly used to diagnose hypothyroidism in dogs and hyperthyroidism in cats. While historically radioimmunoassay (RIA) in reference laboratories has been considered the gold standard, newer methods offer more affordable, convenient and quick alternatives.

This study compared four methods: canine total T₄ coated-tube RIA, in-house enzyme-linked immunosorbent assay (ELISA), RIA total T₄ and CEIA. Ninety-eight dogs and one-hundred cats were tested for comparison of the four assay methods for two species.

The results showed good correlation between T₄ concentrations and that a point-of-care system (IDEXX SNAP T₄ Test for the IDEXX SNAP® Reader) provided reliable and consistent results for screening and monitoring the success of treatment.

See the entire summary > (183 KB)

Kintzer P, Clinical Applications, Supplement to NAVC Clinician's Brief. January, 2007.

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IDEXX Learning Center

Visit the IDEXX Learning Center to see a full listing of available webinars, seminars, teleconferences and online training courses from IDEXX about emerging trends and best practices in veterinary diagnostics in a forum designed to involve, educate and motivate you and your staff. Click the date to view the details, fill out and submit the form to register.

Here are some of the opportunities available this month:

NEW Online Training Courses

• Announcing the VetTest® Certificate Course
  The NEW IDEXX VetTest® Chemistry Analyzer Certificate Course is a fun and interactive online training tool that helps increase productivity and streamline workflows through best practices in sample collection, sample preparation and more on the VetTest analyzer. Stay updated on the latest enhancements to the VetTest analyzer, such as no slide warm-up, results in 8 minutes, the Urine P:C Ratio and much more! Best of all, the program allows the entire staff to take the course and receive 3 CE Credits. Train where and when it’s convenient. It’s always there for new and existing team members to access.
  
  
  

• Building Your Feline Dentistry Practice

Webinar The Most Commonly Misdiagnosed Diseases in Veterinary Medicine Peter Kintzer, DVM, DACVIM and Fred Metzger, DVM, DABVP

Seminars A Practical Approach to Feline Retroviruses Dr. Erin Evans or Dr. Lynn Buzhardt Diagnostic and Preventive Strategies for Vector-borne Disease: a Clinical Perspective Dr. Richard Ford "Tick-Borne Diseases in Dogs an In-depth Review of Ehrlichiosis, Babesiosis, and Lyme Borreliosis Dr. Rick Alleman Lyme Disease for the Canine Practitioner Dr. Steven Levy

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Choosing digital radiology for your practice—involve your clients
Part One of a Three part series
by Ernest E. Ward, Jr., DVM

Deciding to purchase digital radiography for your practice can be a challenging prospect. You know the science supports the technology, you know the image quality will be superior to conventional radiography and you know your staff will be more efficient in obtaining radiographs. Still, it’s a big investment.

Whenever I’m faced with big expenditures, I involve the people that matter most—my clients. By surveying clients and determining their wants, needs and tolerances, I am better able to provide them with the types of veterinary services they value and are willing to pay for.

When digital radiography (DR) systems began appearing two to three years ago, I wanted to understand what all the buzz was about. My staff had been exposed to the new technology at several continuing education conferences and was very excited.

• The first step was to assemble a team to study the current offerings. I selected our practice manager, a senior exam room technician and a receptionist to assist me in the initial decision-making process.

• We then began by requesting information from several reputable manufacturers of DR systems.

• We narrowed our choice down to our top three based on:

  1. Ease-of-use and integration into our practice management software
  2. Features and quality
  3. Reputation of manufacturer
• We then invited each company to demonstrate their system at our hospital. After each demonstration, we requested a cost quote.

In the next months, see the key points raised in the discussion to decide which system to choose and how you can involve—and invest—your clients in the decision-making process.

• Part Two: Making an Informed Decision
• Part Three: Moving Ahead by Involving Your Clients

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NOW with FREE CE Credit!

Have you taken advantage of every qualifying Interactive Challenge for FREE CE credits?

Every Interactive Challenge from June 2006 on has been worth 0.5 CE credits—that's three credits so far this year—and you get the credits just for participating! Check out the Diagnostic Edge archive and take any qualifying challenges you may have missed. Don't let these fun credits slip away!

Question:
Can you correctly identify the erythrocyte-erythrocyte association indicated by the arrows?

Peripheral blood film from a cow with mastitis, monolayer region of blood film, Wright’s stain, 100x objective field of view.

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*Each interactive challenge meets the requirements for 0.5 hours of continuing education credit in jurisdictions that recognize AAVSB’s RACE approval, however, participants should be aware that some boards have limitations on the number of hours accepted in certain categories and/or restrictions on certain methods of delivery of continuing education.

AAVSB Provider Number 106

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