June 2005 Issue

Featured Case Study: 15-year-old neutered male domestic short-haired cat, Gismo
by Matthew R. Krecic, DVM, MS, DACVIM

Acknowledgment: Thank you to Dr. Tyler Fields of Sandy Hill Animal Clinic for providing additional information for this case study.

This patient was diagnosed with unclassified cardiomyopathy and possible renal disease. Learn how the IDEXX VetTest® Chemistry Analyzer and IDEXX Telemedicine helped the clinic staff to quickly initiate appropriate therapy.

History: Labored breathing

Eye, ear, nose and throat examination: Numerous teeth are missing and severe periodontal disease is noted.

Heart and lungs: A grade I/VI murmur, a slight arrhythmia, and lung crackles were ausculted.

Gastrointestinal and urogenital systems: No significant findings

Musculoskeletal, lymphatic and integumentary systems: The patient is thin (body condition score of 2).

In-house laboratory findings:

Hematology: No significant abnormalities are noted.

Chemistry
Azotemia—Azotemia is an increased concentration of nonprotein nitrogenous compounds in the blood, usually urea and creatinine. Blood urea nitrogen (BUN) was mildly elevated at 41.9 mg/dL (reference range 16.0–36. mg/dL) and creatinine was mildly elevated at 3.06 mg/dL (reference range 0.80–2.40 mg/dL). Azotemia can be prerenal, renal or postrenal. Prerenal azotemia is caused by decreased renal perfusion (dehydration, heart failure). Renal azotemia is caused by parenchymal renal disease. Postrenal azotemia is caused by reduced excretion of urine (obstruction, uroabdomen). Prerenal and renal azotemia were suspected for this patient, with increased skin turgor and probable heart disease. Intravenous fluids were administered. Three days later, BUN and creatinine were re-evaluated; BUN (34.2 mg/dL) and creatinine (1.88 mg/dL) returned to within their respective reference ranges. Significant renal disease was now not suspected because azotemia resolved with IV fluid administration. However, a urine protein:creatinine (UPC) ratio could have been evaluated to determine the presence of some degree of renal disease. A UPC was not evaluated for this patient.

Glucose—Mild hyperglycemia (190.3 mg/dL [reference range 76.0–145.0]) was noted. Hyperglycemia is often caused by an increase in epinephrine in struggling, upset or aggressive cats, especially during venipuncture. Diabetes mellitus, another common cause of hyperglycemia, was not suspected for this patient with only a mild elevation of glucose and without historical polyuria and polydipsia.

ECG: To evaluate the ausculted arrhythmia and to evaluate for supportive evidence of heart disease, an ECG was transmitted via telephone to IDEXX Telemedicine. An irregular supraventricular rhythm is noted; heart rate is 220–230 beats per minute. This rhythm is a sinus tachycardia with atrial premature contractions. Atrial premature contractions often develop as a result of significant left atrial enlargement. See Figure 1.

Figure 1.

    Telephone-transmitted ECG from Gismo. One atrial premature contraction (APC) is noted in lead 2 (50 mm/second; 1 mV = 20 mm; P = P wave; R = QRX complex).

Diagnostic Imaging: Thoracic radiographs show severe cardiomegaly and severe pleural effusion.

Echocardiogram: Several digitized images from the examination were submitted to IDEXX Telemedicine for review. The left atrium is moderately enlarged compared to the aorta. The left ventricular internal diameter in diastole is reduced in size. The right heart chamber is mildly enlarged. A moderate amount of pleural fluid is noted. See Figure 2.

Figure 2.









This two-dimensional, longitudinal view shows a
large left atrium (LA) and pleural fluid (P),
(LV = left ventricle;
RV = right ventricle;
Ao = aorta).

Plan
Intravenous fluid therapy at maintenance rate, ACE inhibitor therapy, diuretic therapy, anti-arrhythmic therapy, antiplatelet therapy and thoracocenteses as needed. Monitor BUN and creatinine and re-evaluate thoracic radiographs.

Ancillary Test Results
Fluid analysis: Pleural fluid collected by thoracocentesis was analyzed. Fluid is consistent with a high protein modified transudate commonly associated with heart failure.

T₄: Hyperthyroidism can cause heart disease similar to cardiomyopathy in cats. T₄ was low at 0.46 µg/dL (reference range 0.8–4.0 µg/dL); therefore, this patient does not have hyperthyroidism.

Clinical Diagnosis
Clinical presentation, physical examination, and electrocardiographic, radiographic and echocardiographic findings are consistent with congestive heart failure secondary to cardiomyopathy.

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.

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Buy one 30-count box of SNAP® FIV/FeLV Combo Tests and 50 doses of qualifying Fort Dodge FeLV vaccines and receive a $50 credit.†

Vaccinate against leukemia using Fel-O-Vax®, the market-leading feline leukemia vaccine from Fort Dodge Animal Health.1 Effective Studies show a preventable fraction of over 90 percent Provides at least 12 months of protection Safe Low rate of adverse events Backed by our Feline Healthcare Partnership Convenient Easy-to-use killed combinations—no reconstitution necessary Color-coded caps for easy identification, and INFOVAX-ID® labels				Determine the retrovirus status of cats with the IDEXX SNAP® FIV/FeLV Combo Test Easy-to-use Screen for FIV and FeLV in one blood sample Easy-to-read ELISA technology Fast Total run time of 10 minutes; two minutes hands-on time Determine the status of cats in-house Accurate Trusted ELISA technology for proven accuracy

Testing before vaccinating for feline retroviruses provides thorough patient care.

Call your authorized IDEXX or Fort Dodge Animal Health representative to take advantage of this offer.

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Introducing a new, improved ECG teletransmitter that features ergonomic design, hands-free operation, and record and playback capabilities.

IDEXX Telemedicine is now offering a new and improved ECG teletransmitter that facilitates the transmission of an electrocardiogram signal from a patient to IDEXX Telemedicine for a cardiology consultation by a board-certified specialist.

The new transmitter features:

• New ergonomic design that is simple to set up and use

• Improved, gentler lead clips that are less stressful for the patient

• ECG recording ability so you can transmit at your convenience

• Optional limb plate electrodes available

• Manufacturer's warranty

The ECG teletransmitter is an inexpensive alternative to a costly ECG machine. The transmitter is a small, handheld, battery-powered device that uses four lead connections to the patient. The signal is transmitted over a telephone line to interpretive software that captures the lead trace for review by one of IDEXX Telemedicine's board-certified specialists for a consultation.

For more information on IDEXX Telemedicine services:

• Visit www.idexx.com/telemedicine
• Call IDEXX Customer Service at 1-800-726-1212, ext. 2235
• Or send an e-mail to telemedinfo@idexx.com

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Education and Events

We offer a variety of seminars and teleconferences about emerging trends and best practices in veterinary diagnostics—in a forum designed to involve, educate and motivate you and your staff.

Here are some of the educational events in June

• Practical Hematology with Robert Hawthorne, DVM
• Canine Lyme Disease for the Canine Practitioner with Steven Levy, VMD
• The Practitioner's Approach to Feline Retroviruses with Lynn Buzhardt, DVM

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

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Save time and provide faster patient care by running plasma samples on your IDEXX VetTest® Chemistry Analyzer

Your hospital's morning routine is suddenly interrupted by an emergency case—a border collie with hit-and-run trauma. You need to run bloodwork to assess the damage and begin treatment, but which type of sample should you run to provide the most responsive care?

You always have a choice with your IDEXX VetTest Chemistry Analyzer. You can run a serum sample or a lithium heparin plasma sample. The plasma sample will give you faster results, so you can quickly assess your patient's condition, make a diagnosis and begin treatment during the patient visit.

The key to success in using plasma is stopping the blood from clotting by introducing it to anticoagulant as quickly as possible. With proper technique, fibrin will not have the opportunity to begin forming in the sample. For even easier sample preparation, consider using a lithium heparin tube (e.g., Becton Dickinson's Microtainer® tube, pictured at left) with a gel barrier. This barrier is very effective in separating the plasma from fibrin or impurities. For more information on these tubes, call IDEXX Customer Support at 1-800-248-2483.

Download the complete poster, or call IDEXX Customer Support at
1-800-248-2483 for a full-color copy. (1 MB)

Kitten season is here!
Blood-draw and sample-usage tips for kittens
by Michelle Kahn, DVM, MS

Blood collection in the kitten doesn't have to be a painful and difficult experience for the patient or for you. Here are some suggestions to help you quickly and easily obtain your kitten blood sample:

• Use a 1-mL syringe with either a 25-g or 26-g needle.
• Use water instead of alcohol to wet the haircoat.
• A slower aspiration of blood is essential to avoid collapsing the vein.
• If you are sampling from the jugular vein, extend the head, but keep the neck slightly relaxed.
• Try distracting the kitten by gently tapping on its head.
• In the worst case scenario, try using an insulin syringe and drawing your sample from the spahenous vein while keeping the kitty in stretch-restraint.

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Do you have an interesting case study, helpful technical tip, or a question for our expert clinical pathologists that others could learn from?

If so, please send it in an e-mail and you could be featured in an upcoming issue of the Diagnostic Edge.

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