September 2006 Issue

Featured case study:
Ten-year-old spayed female yellow Golden retriever, Misty,
by Dr. Ernie Ward, owner and chief-of-staff at Seaside Animal Care, P.A., Calabash, North Carolina

Physical exam

• Weight: 86 lbs. with a body scoring index of 4/4 (obese) and an ideal weight of 70–72 lbs.
• Pain on extension and flexion of the hips bilaterally was noted with generalized loss of muscle mass and tone in both hind limbs.
• Temperature—100.8°F
• Respiration—36
• Mucous Membranes—pink and moist, CRT <2 seconds
• Oral Exam—Stage 2/4 periodontal disease
• Bilateral lenticular sclerosis, normal fundic examination
• Weight shifted forward when standing
• “Bunny-hopping” gait when trotting
• Normal neurological examination
• The initial physical examination was otherwise largely unremarkable.

Differential diagnoses
Based on breed predisposition, the observed obesity, and Misty’s age and clinical signs, our primary concern was osteoarthritis secondary to hip dysplasia. Other considerations included primary degenerative joint disease, spondylosis deformans, neuromuscular disease, or strain/sprain or supportive tissue injury.

Plan
To determine the specific cause of the lameness digital radiographs of the hips, knees and lumbar spine were performed.

Digital radiographs
Radiographs revealed extensive degenerative changes in both hip joints associated with osteoarthritis. Further, both hip joints were consistent with bilateral hip dysplasia. Mild spondylosis deformans was also observed, but was not considered significant at this time.

Final diagnosis
Based on the radiographic findings, a diagnosis of osteoarthritis secondary to bilateral hip dysplasia was made.

Therapeutic plan
The initial therapeutic plan for Misty included weight reduction using a therapeutic diet and low-impact aerobic activities such as swimming 15 minutes three times a week and/or walking on grass or trails 30 minutes daily, glucosamine/chondroitin sulfate dietary supplementation and non-steroidal anti-inflammatory drug (NSAID) usage. Before beginning NSAID treatment, blood and urine tests were performed to ensure that Misty did not have any pre-existing liver or kidney dysfunction that would preclude her from using an NSAID.

Pre-medication blood and urine tests

Kidney—No significant abnormalities are observed. There is no indication of decreased glomerular filtration rate (within reference interval BUN and Creatinine) or decreased concentrating ability (concentrated Specific Gravity). In addition, there is no obvious proteinuria. Pre-treatment screening is of value to establish baseline reference values.

Liver—There is no evidence of any significant hepatocellular injury (within reference interval ALT and AST) or cholestasis (within reference interval ALP). As with the pre-treatment screening for renal disease, it is important to establish baseline reference values for the liver.

Summary
These baseline chemistry and urine values will serve as valuable data points allowing early detection of any developing idiosyncratic therapy-associated disease so that therapy could be monitored before severe disease develops. Serial monitoring of these values is strongly recommended.

Initial medical treatment
A two-week NSAID therapeutic trial was prescribed in conjunction with weight reduction and glucosamine/chondroitin sulfate supplementation. A two-week period is used to determine whether the NSAID is beneficial in alleviating Misty’s clinical signs of discomfort and to allow us to re-evaluate kidney and liver function for any signs of potential drug-associated adverse effects.

Two-week recheck examination findings
Misty had lost two pounds and the owner reported moderate overall improvement in her perceived pain level. The owner reported that Misty had experienced four episodes of vomiting over the previous three to four days and hadn’t been eating the new diet as well as she did at first. She still went for her walks and enjoyed her car rides.

Kidney—Both BUN and Creatinine are within reference intervals; however, there is a slight increase in both values. These changes are too slight to confidently identify any decreased glomerular filtration rate; however, if therapy was continued, repeating these tests in addition to performing a complete urinalysis should be strongly considered.

Liver—Based solely on these values, there is indication of minimal hepatocellular injury (slight increase above reference interval for ALT and AST) and the mild increase in ALP indicates potential cholestasis or non-specific ALP enzyme induction. Even though the increase in these enzyme activities is slight, they are significant when compared to baseline values and the potential of a developing idiosyncratic NSAID hepatopathy would have to be strongly considered.

Based on the elevations and clinical signs, the NSAID was discontinued. No other treatment was prescribed at that time and Misty was scheduled to return in one week for repeat blood tests unless her condition deteriorated.

One-week follow-up examination
Misty returned the following week. Misty’s owner reported that she had observed an increase in stiffness and felt that there had been a definite return of arthritic pain. No additional vomiting or diarrhea was reported. Misty’s appetite had returned to a more normal level and she had not lost any additional weight.

Kidney—Renal parameters of glomerular filtration (BUN and Creatinine) are within reference interval limits similar to previous values indicating that there is no evidence of decreased glomerular filtration rate.

Liver—Indicators of hepatocellular injury (ALT and AST) have returned to within reference interval values. The clinical half-life of these enzymes is 3–4 days and both values have decreased greater than half the value they were only one week previously. The degree of changes and the relationship to discontinuing NSAID therapy suggests changes observed were therapy-related. Although ALP has not returned to within reference interval limits, it has significantly decreased compared to the value one week previously. Half-life is difficult to address for ALP since it is an induced enzyme; return to baseline values requires both removal of circulating enzyme as well as decreased protein production. The overall liver enzyme changes, when trended over a three-week period, suggest a relatively mild but reversible change, which is compatible with an NSAID idiosyncratic response. If serial data were not evaluated, early detection of a problem would not have been possible and more severe hepatopathy could have developed.

Clinical case outcome
Based on the liver enzyme elevations after administering the original NSAID and the return to normal values after discontinuing it, an alternate treatment plan was prescribed. Because of the improvement in clinical signs associated with osteoarthritis, a second NSAID was administered for another two-week trial period. The second NSAID did not cause the same liver elevations. Misty had the NSAID Monitoring Panel performed monthly for the first three months she received the medication and then resumed the normal six-month recheck protocol.

At her six-month recheck examination Misty had lost eight pounds, was taking daily brisk walks with her mom on a nearby golf course (mom had lost five pounds!) and was reported to feel “like she was five again!”

NSAID usage is one of the primary foundations of treating chronic pain in veterinary patients. By carefully monitoring our patients using simple blood tests at routine intervals, we can ensure that the medication is benefiting the patient by reducing pain while not causing any adverse effects. Failure to be vigilant about the medications we prescribe can result in inadvertent illness or harm to our pet patients. Misty avoided a potentially disastrous situation because we followed a simple drug monitoring protocol. Drugs alone rarely cause catastrophic results; their potential misusage and inadvertent inattentiveness by the attending veterinarian is usually a contributing factor. Protect your patients’ health by monitoring the long-term medications you prescribe.

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.

back to the top    

back to the top    

IDEXX Lactate Method Comparison Study

How do lactate test results compare between the reference analyzer VITROS® 250 Chemistry System and the IDEXX VetTest® Chemistry Analyzer? That question was the focus of a study comparing canine, feline and equine samples that were run on both analyzers.

Results

• The linear regression scatter plot (Figure 1 below) shows a high correlation between the VITROS 250 and the VetTest analyzer. Also, all of the data points fall very close to the x=y line.
• Figure 2 below shows the VetTest bias to the VITROS 250.

Read More (272 KB)

back to the top    

IDEXX LaserCyte® Users: Here's The Best Way to Prepare Whole-Blood Samples

back to the top    

Super Senior & New Edition Boards Will Delight Clients

Take Polaroid pictures of the seniors and new arrivals in your practice or encourage your clients to bring in pictures of their own to display for all to see! People love to see their pets recognized, and organizing photos by themes is a fun, unique approach. Keep the bulletin boards displayed prominently in the waiting area or checkout area.

back to the top    

Education and Events

We offer a variety of training events 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 upcoming educational events.

Seminars

• Canine Pancreatitis Diagnosis and Management
  David A. Williams, MA, VetMB, PhD, DACVIM, DECVIM-CA

• Tick-Borne Diseases: Lyme Disease, Anaplasmosis and Co-infection
  Rick Alleman, DVM, PhD, DABVP, DACVP, and Matt Eberts, DVM

• A Practical Approach to Feline Retroviruses
  Erin Evans, DVM

Visit the education and events calendar to view a full list of current offerings, click the date to view the details, fill out and submit the form to register.

back to the top    

Get Clients to Say "Yes" to Senior Screens
by Wendy S. Myers

When our cat, Ollie, had his 19th birthday in July, my husband and I celebrated his longevity. Thanks to twice-a-year wellness exams and regular diagnostic testing since he was 7, Ollie is now well into his geriatric years. He’s 92 in human years and will soon approach the 100th milestone. We know the first-hand benefits of taking a proactive approach to senior wellness.

As you prepare for National Senior Pet Health Month in September, consider organizing your senior care program so the entire healthcare team echoes the message of senior wellness. Ask your IDEXX representative about the free “Celebrate Seniors!” educational kit that features brochures, folders, an age analogy poster, questionnaire, check-writing pad and sample letters, consent forms and scripts.

Here’s how to incorporate these materials into your team’s daily practice:

Receptionist—Pull medical records for tomorrow’s appointments and identify senior pets. Put a bright-colored “I’m a senior pet” sticker on the record and stuff it inside a senior folder, brochure and questionnaire. When the client arrives the next day, the receptionist hands the “Celebrate Seniors!” folder to the client and pulls out the brochure and questionnaire. The receptionist says, “Let’s find out how old your pet is in human years.” Guide the client to the age analogy chart in the brochure and circle the pet’s age. Continue the conversation with, “The doctor would like you to answer these questions about your senior pet so we can provide preventative care. A technician will also talk with you about our senior wellness screen.”

Technician—Review answers to the senior pet questionnaire and explain your senior diagnostic testing to the client. The technician might say, “We recommend a senior wellness profile for pets age 7 and older, with additional tests depending on each pet’s specific health needs. You can read this brochure on senior screening before the doctor comes in. After your pet’s physical exam, the doctor will discuss the specific tests your pet needs today.” The technician can also present a “Senior Care Testing Consent Form” available from IDEXX that you can customize with your hospital’s offerings. The client can check “Please complete the recommended testing for my pet” or “I would like to discuss senior testing with a veterinarian before making a decision.”

Doctor—As part of a senior pet’s physical exam, the doctor conducts an arthritis exam, assigns a body condition score and grade of dental disease, and recommends appropriate testing. The doctor can have the technician collect blood and urine samples for accepted tests. If the client declines testing, have the owner sign a waiver that states, “I decline the recommended senior tests at this time. I understand a medical condition may exist which would be impossible to identify during a physical exam alone. I understand my pet’s health could be at risk if such a condition goes undetected.” For clients on the fence, signing a waiver may convince them of the importance of testing.

Receptionist—During checkout, the receptionist updates any reminders and callbacks. If the client declined the senior screen, enter a “Senior Screen Recommended” code in the computer. You can set this item up to automatically generate a callback in two weeks. Then a staff member calls and says, “The doctor asked me to call you about scheduling Ollie’s senior screen so we can establish a wellness baseline and detect any diseases early. When would be a convenient time for you to schedule Ollie’s senior screen? We just need to schedule a brief technician appointment to collect the blood and urine samples. I have an opening on Friday or Monday, which best fits your schedule?” Always direct the client to a possible appointment time because you’ll increase the likelihood she will say yes.

Contact your IDEXX representative today to order the free “Celebrate Seniors!” educational kit. You’ll have resources at your fingertips to start making a difference in the lives of older patients.

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.

back to the top    

NOW with FREE CE Credit!

The Challenge: In this high-power field of view (40x objective field of view) of an unstained urine sediment from a dog

1. Identify the type of cast indicated with arrow heads.
2. Are these types of casts formed in the proximal tubules, loop of Henie or distal nephron (distal convoluted tubules and collecting ducts)?

Step up to take the Interactive Challenge—and now you can step up your CE credits, too! Earn a half-hour of FREE CE credit for each month’s challenge.

Not a Diagnostic Edge subscriber? Subscribe now!

All fields are required for CE credit records.

Thanks for taking the Diagnostic Edge Interactive Challenge!

*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

Not a Diagnostic Edge subscriber? Subscribe now!

back to the top