Monitoring Renal Function in Chronic Kidney Disease: Serial Biochemistry

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-08-11

Key Takeaways

• Serial biochemistry is paramount for monitoring Chronic Kidney Disease (CKD) in dogs and cats, with the trajectory of biomarkers, not just single values, driving therapeutic decisions such as diet intensification and medication adjustments.
• Serum creatinine (sCr) remains the primary progression marker due to its low biological variability and cost-effectiveness, but its interpretation necessitates accounting for confounders like muscle mass and hydration status.
• Symmetric Dimethylarginine (SDMA) offers an earlier indicator of GFR decline and is less influenced by muscle mass than sCr, but its higher biological variability requires trend analysis over three or more measurements for reliable interpretation.
• Critical difference (CD) values, such as 0.89 µmol/L for sCr and 1.34 µg/dL for SDMA in healthy dogs, define the magnitude of change exceeding analytical and biological noise, guiding the distinction between true progression and random variation.
• Monitoring protocols must be individualized based on IRIS staging, with stable CKD patients requiring rechecks every 3-6 months, while IRIS stages 3-4 necessitate more frequent monitoring (1-3 months), adjusted for comorbidities and clinical signs.
• Serial monitoring should encompass not only creatinine and SDMA but also phosphorus and potassium levels, as hyperphosphatemia drives secondary hyperparathyroidism and hypokalemia can exacerbate renal dysfunction, particularly in cats.

Serial biochemistry is the backbone of chronic kidney disease (CKD) monitoring in dogs and cats. This article addresses the practicing veterinarian's central question: once a diagnosis of CKD is established, how should serial renal biomarkers be selected, timed, and interpreted to stage disease, detect progression, and assess response to therapy? The focus is deliberately narrow. Initial diagnosis, urinalysis interpretation, and non-biochemical monitoring tools are covered elsewhere. Here, the emphasis is on the quantitative logic of repeated measurements: what changes are real, what changes matter, and what changes should alter management.

The clinical value of serial biochemistry rests on a simple premise. A single measurement places a patient within a stage. A series of measurements reveals trajectory. Trajectory, not stage, drives most therapeutic decisions in established CKD, including the timing of renal diet intensification, blood pressure intervention, phosphorus restriction, and the introduction of appetite stimulants or antiemetics. The practitioner who understands the analytical and biological variability of each biomarker can distinguish true progression from noise, and can counsel owners with appropriate confidence.

At a Glance

Biological Variability and the Logic of Serial Measurement

Every laboratory value in a living patient fluctuates around a homeostatic set point. This fluctuation has two components: analytical variability, arising from the assay itself, and biological variability, arising from day-to-day physiological variation within the individual. For a monitoring biomarker to be clinically useful, the practitioner must know both components, because together they define the critical difference, the magnitude of change between two measurements that exceeds what would be expected from noise alone.

A prospective observational study of apparently healthy dogs provides the most directly applicable data for companion animal practice. The study measured SDMA and serum creatinine nine times in each of twenty dogs and calculated indices of individuality and critical differences. The index of individuality for SDMA was 0.87, classified as intermediate, while creatinine had a low index of 0.28. The critical difference between sequential measurements was 1.34 µg/dL for SDMA and 0.89 µmol/L for creatinine. The number of sequential measurements required to estimate an individual's homeostatic set point with 90 to 95 percent confidence was 8 for SDMA and 2 for creatinine. These figures, reported in the study of symmetric dimethylarginine variability in healthy dogs, carry a direct practical implication: creatinine is well suited to detecting change within an individual with relatively few measurements, whereas SDMA, despite being better suited to population-based reference intervals, requires more measurements to establish an individual baseline.

The distinction matters clinically. A single SDMA value above the reference interval in a dog with normal creatinine may prompt investigation, but a single value slightly above that same dog's prior SDMA should not trigger a change in therapy. Conversely, a creatinine rise of 1.0 µmol/L, while mathematically within the critical difference, should be viewed in the context of the patient's muscle mass and hydration. The study's healthy-dog data likely underestimate biological variability in azotemic patients, where tubular secretion and extrarenal clearance pathways may be altered.

Creatinine as the Primary Progression Marker

Serum creatinine remains the reference biomarker for CKD staging and progression monitoring in dogs and cats. It is inexpensive, widely available, and, critically, has low biological variability relative to other endogenous markers. The low index of individuality reported in healthy dogs means that population-based reference intervals are reasonably informative for an individual, and that small serial changes are more likely to reflect true renal function change than analytical or biological noise.

Interpretation of serial creatinine requires attention to confounders. Muscle mass is the most important. A cat with progressive CKD and concurrent weight loss may show stable or even falling creatinine despite declining glomerular filtration rate, because the reduced muscle mass generates less creatinine per unit time. The same phenomenon occurs in dogs with sarcopenia from chronic disease. Body condition scoring at each recheck is therefore not optional, it is a prerequisite for interpreting the creatinine trend. Dehydration, by reducing renal perfusion and concentrating the extracellular fluid, can raise creatinine acutely. A single elevated creatinine in a dehydrated patient should prompt recheck after fluid restoration before progression is declared.

The International Renal Interest Society (IRIS) staging system, published and updated by that body, uses fasting serum creatinine as the primary staging analyte. Practitioners should consult the current IRIS guidelines for stage boundaries, because these have been revised over time and differ between dogs and cats. Substaging by SDMA, proteinuria, and systolic blood pressure refines the stage and carries prognostic weight, but the creatinine stage remains the anchor for serial comparison.

SDMA: Strengths and Limitations in Serial Monitoring

Symmetric dimethylarginine is a methylated arginine derivative released during protein turnover and cleared predominantly by renal excretion. It correlates with glomerular filtration rate and may rise earlier than creatinine in some patients with reduced renal mass. For monitoring, however, its higher biological variability is a limiting factor. The healthy-dog study found that eight sequential measurements are needed to estimate an individual's SDMA set point with 90 to 95 percent confidence, compared with two for creatinine. In practical terms, this means that a single SDMA increase between two visits is weak evidence of progression. A trend across three or more measurements, particularly when accompanied by a creatinine trend in the same direction, is far more informative.

SDMA is less influenced by muscle mass than creatinine, which makes it valuable in sarcopenic patients. It is also useful when a creatinine-based stage and an SDMA-based substage disagree, a situation that should prompt investigation for extrarenal creatinine sources or early renal disease. The assay is stable and reproducible across commercial laboratories, but the practitioner should be aware that different laboratories may use different analytical platforms. When monitoring trends, samples should be analyzed by the same laboratory where possible, and ideally by the same method.

Reference Intervals and Laboratory Standards

The interpretation of any serial biochemistry result depends on the quality of the reference interval against which it is judged. The American Society for Veterinary Clinical Pathology publishes guidelines for reference interval establishment and quality assurance that are directly relevant to the monitoring setting. These guidelines address sample size, outlier handling, and the distinction between reference intervals and decision limits. A reference interval describes the central 95 percent of a healthy population, it does not define a therapeutic target or a threshold for intervention. In CKD monitoring, the relevant comparison is usually the patient's own prior values, not the population interval. The ASVCP quality assurance and laboratory standards guidance provides the framework for ensuring that the analytical component of variability is minimized, so that observed changes reflect the patient instead of the instrument.

Species Differences in Monitoring Strategy

Dogs and cats differ in the practical application of serial biochemistry. Cats are more prone to the sarcopenia confound described above, and their often labile hydration status in the outpatient setting makes isolated creatinine spikes common. A cat with stable CKD that presents with a creatinine rise of 20 percent should be rechecked after rehydration before the rise is attributed to progression. Dogs, particularly those with glomerular disease, may show proteinuria as an earlier and more sensitive marker of progression than creatinine, and serial biochemistry in these patients should be paired with serial urine protein-to-creatinine ratio measurement.

Feline CKD is also more frequently diagnosed at an earlier IRIS stage than canine CKD, which means the monitoring interval may be longer at diagnosis but must shorten as the patient advances. The IRIS guidelines provide stage-based recommendations for recheck frequency, and these should be followed with adjustment for individual patient trajectory.

Serial Sampling Protocols and Preanalytical Discipline

Serial biochemistry is only as reliable as the consistency of sample collection. A creatinine increase of 0.2 mg/dL can change IRIS stage in a borderline patient, so the clinician must control every variable that influences the measurement before attributing change to disease progression.

Blood should be collected after a 12 hour fast when possible. Feeding raises creatinine modestly in some dogs through the creatine content of meat, and it can affect urea nitrogen enough to confuse interpretation. Sample the patient at the same time of day on each visit. Circadian variation in creatinine is small in dogs and cats, but consistency removes one more source of noise. Avoid sampling immediately after voiding stress, transport, or an examination that has caused the patient to struggle. Excitement and muscle activity can elevate creatinine transiently.

The same laboratory should run all serial samples for a given patient. Interlaboratory variation in creatinine methodology, particularly between enzymatic and Jaffe assays, can exceed the critical difference that would trigger a staging change. If a laboratory change is unavoidable, run a paired sample through both laboratories and document the offset before comparing values. The same argument applies to SDMA, where assay platform differences are documented and the American Society for Veterinary Clinical Pathology quality assurance guidelines recommend method-specific reference intervals and validation before clinical use.

Hemolysis and lipemia interfere with enzymatic creatinine assays and with SDMA immunoassays. Reject visibly hemolyzed samples for serial monitoring and recollect instead of report a questionable value. In cats, sample volume is often limited. A microhematocrit tube is insufficient for a full renal panel. Use a pediatric tube or a lithium heparin tube designed for small volumes and confirm the laboratory's minimum volume requirement before the visit.

Constructing the Monitoring Algorithm

The monitoring algorithm begins with a baseline assessment that establishes stage, proteinuria status, and blood pressure category according to the current IRIS guidelines. The recheck interval then follows from the stability of that baseline.

For a stable patient in IRIS Stage 1 or early Stage 2 with no proteinuria and normal blood pressure, recheck biochemistry in 3 to 6 months. For a patient in late Stage 2 or Stage 3, recheck in 2 to 3 months. For Stage 4, recheck in 1 to 2 months. These intervals are starting points. The clinician shortens the interval when any of the following are present: progressive proteinuria, uncontrolled hypertension, a recent episode of dehydration, concurrent disease that affects renal perfusion, or a change in medication that alters renal hemodynamics.

Each recheck should include creatinine, SDMA, urea nitrogen, phosphorus, potassium, and a venous blood gas or total CO2 to assess acid-base status. A urine protein to creatinine ratio should be repeated at every other visit in proteinuric patients, or more frequently if the urine protein to creatinine ratio is rising. Body weight, body condition score, and systolic blood pressure are measured at every visit. These are not optional additions. A 5% weight loss between visits is a clinical event that matters even when biochemistry is static.

The decision to change therapy follows a structured sequence. First, confirm the change is real by repeating the abnormal value, particularly if the change is small or the sample quality was questionable. Second, search for a reversible cause: dehydration, vomiting, diarrhea, pyrexia, or a drug that reduces renal perfusion such as an NSAID or an ACE inhibitor at too high a dose. Third, assess whether the change represents progression or an intercurrent event. A creatinine rise with a proportionate SDMA rise and stable phosphorus suggests progression. A creatinine rise with a disproportionate SDMA rise, or with a normal SDMA, raises the possibility of a prerenal component or analytical error.

Interpreting Change Against Critical Difference

The critical difference, also called the reference change value, is the threshold beyond which a change between two measurements is likely to be biologically real instead of analytical or random variation. In a study of apparently healthy dogs, the critical difference for SDMA was 1.34 µg/dL and for serum creatinine was 0.89 µmol/L, approximately 0.01 mg/dL, with SDMA showing an intermediate index of individuality and creatinine a low index of individuality (variability of symmetric dimethylarginine in apparently healthy dogs). The practical consequence is that creatinine changes must be interpreted against a very small critical difference, while SDMA changes require a larger absolute shift before they are considered meaningful.

The same study estimated that establishing a homeostatic set point for an individual dog requires 2 sequential creatinine measurements but 8 SDMA measurements for 90% confidence. This does not mean SDMA is inferior. It means the clinician should not overinterpret a single SDMA value that differs from the previous one. A trend across three or more samples is more reliable than a pairwise comparison.

For cats, the published critical difference data are more limited. The clinician should apply a similar logic: a creatinine change of less than 0.2 mg/dL in a cat is within the noise of the assay and the patient's own variability, while a change of 0.4 mg/dL or more is likely real. SDMA changes of less than 2 µg/dL should be confirmed before altering therapy.

The Role of Phosphorus and Potassium in Serial Monitoring

Phosphorus rises as GFR falls below approximately 25% of normal in dogs and cats. Serial phosphorus is therefore a late marker, but it is a critical one because hyperphosphatemia drives secondary renal hyperparathyroidism and is associated with more rapid progression. The monitoring decision is straightforward: phosphorus above the IRIS target for the stage warrants dietary phosphate restriction, and if the patient is already on a renal diet, a rising phosphorus despite compliance indicates the need for intestinal phosphate binders.

Potassium monitoring is particularly important in cats. Hypokalemia is common in feline CKD and can worsen renal function through reduced renal blood flow and impaired concentrating ability. A potassium below the reference interval, or a downward trend within the interval, should prompt supplementation. Hyperkalemia is more common in dogs with advanced CKD and in cats with urethral obstruction or concurrent hypoadrenocorticism. Serial potassium also guides the use of ACE inhibitors, because these drugs can cause or worsen hyperkalemia in patients with reduced GFR.

Documentation and Longitudinal Tracking

Serial monitoring generates a dataset that is best reviewed graphically. A simple spreadsheet or the laboratory's cumulative report allows the clinician to see trends that are invisible when values are read in isolation. Record the date, body weight, blood pressure, creatinine, SDMA, phosphorus, potassium, urine protein to creatinine ratio, and the current drug doses at every visit. Note the patient's appetite and activity level in the same record, because clinical signs can change before biochemistry does.

The MSD Veterinary Manual and the AVMA practice resources both emphasize that monitoring is a shared decision with the owner. The recheck interval must be feasible for the owner and the patient. A cat that becomes fractious with travel may be better monitored at 4 month intervals with a home urine protein to creatinine ratio collected by the owner, instead of a 2 month interval that requires sedation. The algorithm should be adapted to the patient, not the reverse.

When to Escalate Monitoring Frequency

Escalation is indicated when the rate of change accelerates. A creatinine that rises 0.1 mg/dL over 6 months in a Stage 2 dog is different from the same rise over 6 weeks. Calculate the slope of the creatinine decline in GFR equivalents, or simply track the interval between stage changes. A patient that moves from Stage 2 to Stage 3 in less than 6 months warrants a search for a superimposed cause: pyelonephritis, ureteral obstruction, leptospirosis in dogs, or nephrotoxic drug exposure.

The following table summarizes the monitoring parameters, their primary utility in serial assessment, and the action a change should trigger.

A patient that develops azotemia after a period of stability should be rechecked within 7 to 14 days to determine whether the change is transient or sustained. A sustained change triggers a full restaging, including urine protein to creatinine ratio and blood pressure, and a revision of the therapeutic plan.

Recognized Failure Modes in Serial Monitoring

Serial biochemistry fails in predictable ways. The most common failure is interpreting a single value as a trend. A creatinine rise from 1.8 to 2.4 mg/dL on one sample may reflect progression, but it may also reflect prerenal dehydration, a high-protein meal, or laboratory drift. The critical difference for creatinine in healthy dogs is 0.89 µmol/L, approximately 0.1 mg/dL, but that figure applies to healthy animals with stable hydration and identical preanalytical conditions. In a CKD patient with variable water intake, the biological noise is wider. Confirm any apparent step-change with a second sample within 7 to 14 days before adjusting therapy or prognosis.

A second failure mode is over-reliance on SDMA as a standalone progression marker. SDMA has an index of individuality of 0.87 in healthy dogs, meaning population-based reference intervals are reasonably informative, but the critical difference between sequential measurements is 1.34 µg/dL. A change from 18 to 22 µg/dL exceeds that threshold and likely represents real change. A change from 18 to 19 µg/dL does not. The number of measurements needed to estimate an individual's homeostatic set point with 90% confidence is 8 for SDMA versus 2 for creatinine, so SDMA trends require more data points before they become interpretable. Use SDMA to corroborate creatinine trends, not to replace them.

A third failure mode is ignoring the trajectory of phosphorus and potassium while focusing exclusively on nitrogenous waste. Hyperphosphatemia drives secondary renal hyperparathyroidism and progresses independently of creatinine in some patients. Hypokalemia, particularly in cats, reduces renal blood flow and can itself worsen azotemia. Serial monitoring that tracks only creatinine and SDMA misses the two most actionable metabolic complications of CKD.

Common Errors and Corrective Action

Less experienced clinicians often compare serial values against the reference interval instead of against the patient's own baseline. A creatinine of 2.0 mg/dL that rises to 2.6 mg/dL is clinically meaningful even if both values fall within a broad reference interval. The corrective action is to plot each patient's values on a longitudinal chart and interpret change against the critical difference, not against population limits.

A related error is failing to standardize sampling conditions. A morning fasted sample, a post-prandial sample, and a sample taken after subcutaneous fluid therapy are not directly comparable. Creatinine rises modestly after a meat meal and falls after volume expansion. SDMA is less affected by diet but still varies with hydration. Document the time of sampling, fasting status, and any fluid therapy given in the preceding 48 hours. If a patient is sampled under different conditions, flag the comparison as unreliable.

A third error is escalating monitoring frequency without a clinical trigger. Measuring renal values weekly in a stable IRIS Stage 2 patient generates noise, increases cost, and invites over-treatment of insignificant fluctuations. The monitoring interval should be driven by stage, rate of prior progression, and the presence of complicating factors such as hypertension or proteinuria. A stable patient with two consecutive stable profiles can be monitored at the longest interval appropriate for stage. A patient with a rising trend or an intercurrent illness should be rechecked sooner.

Limitations of the Evidence and Areas of Contested Opinion

The evidence base for serial renal monitoring in dogs and cats is thinner than routine practice suggests. Most published data on biological variability, including the critical difference values cited above, come from healthy animals studied over weeks, not from CKD patients followed for years. Whether these variability estimates hold in azotemic patients with progressive disease is uncertain. Expert opinion differs on how aggressively to pursue early detection of progression. Some nephrologists advocate rechecking every 2 to 4 weeks in Stage 3 and 4 disease to catch acute-on-chronic decompensation early. Others argue that more frequent sampling does not change outcome because the therapeutic options at each IRIS stage are limited. Both positions are defensible with current evidence.

There is also genuine disagreement about the role of SDMA in monitoring. Proponents argue that SDMA detects functional decline earlier than creatinine and is less influenced by muscle mass. Critics note that the biological variability of SDMA is higher, the critical difference is proportionally larger, and the test adds cost without proven survival benefit. The practical resolution is to use both markers in parallel, interpret each against its own critical difference, and act only when both markers move in the same direction or when one marker moves persistently across three or more samples.

Referral, Specialist Consultation, and Laboratory Involvement

Referral to a specialist is warranted when progression is rapid, when the cause of CKD is unclear, when hypertension or proteinuria is refractory to first-line therapy, or when the patient requires interventions beyond the scope of primary care, such as placement of a feeding tube or dialysis. A creatinine increase of more than 30% above baseline over 4 weeks, or a doubling over 3 months, justifies specialist input even if the patient is clinically stable.

Laboratory involvement is appropriate when results do not match the clinical picture. If a creatinine value is implausibly high or low relative to the patient's appearance and history, ask the laboratory to re-run the sample, check the sample for lipemia or hemolysis, and confirm that the correct assay and reference interval were used. The American Society for Veterinary Clinical Pathology provides guidance on reference intervals and quality assurance that can help practices audit their in-house analyzers against laboratory standards. Regulatory reporting is rarely relevant in companion animal CKD monitoring, but clinicians should be aware of their obligations under local veterinary practice standards and, where applicable, international animal health codes if a patient's condition has public health or trade implications.

Frequently Asked Questions

How Often Should Serial Biochemistry Be Repeated in a Stable CKD Patient?

For a stable patient, repeat biochemistry every 3 to 6 months. The interval depends on IRIS stage, historical rate of progression, and owner compliance. A patient that has shown a rapid rise in creatinine or SDMA over the preceding 6 months warrants rechecking at the shorter end of that range. A patient stable for over a year across multiple visits can be extended toward the 6 month mark. Always pair biochemistry with a urine protein:creatinine ratio and blood pressure measurement. The goal is to detect change before clinical decompensation occurs, and the critical difference for creatinine is small enough that a 3 month interval captures meaningful progression in most dogs and cats.

What Do I Do When Serial Results Conflict, for Example Creatinine Rises but SDMA Falls?

First, verify preanalytical conditions. Confirm fasting status, hydration, and that the samples were handled identically. Check that the laboratory has not changed methodology or reference intervals, as this alone can produce apparent shifts. Repeat the panel promptly instead of acting on a single discordant pair. If the conflict persists, consider that creatinine reflects muscle mass and recent dietary protein intake, while SDMA is less influenced by those factors. A rising creatinine with stable or falling SDMA may indicate reduced muscle mass, increased muscle catabolism, or a laboratory artefact. Conversely, a rising SDMA with stable creatinine can be the earliest sign of progression. When results conflict, the more sensitive marker for glomerular filtration is SDMA, but neither replaces a thorough history and physical examination.

How Should I Monitor Renal Function When the Owner Has Severe Financial Constraints?

Prioritize a serum creatinine and symmetric dimethylarginine (SDMA) panel at each visit, as this single sample provides the most information per cost. Omit serial electrolytes unless the patient is on a potassium-wasting diuretic or has known hyperkalemia. Urine protein:creatinine ratio can be deferred to every second visit if proteinuria was previously negative. If SDMA is unaffordable, creatinine alone with a strict 3 month interval remains acceptable, though it will detect progression later. Communicate clearly that the minimum monitoring standard is a biochemistry panel and body weight at each visit. The American Society for Veterinary Clinical Pathology guidelines emphasize that laboratory quality matters more than test count, so choose one reliable laboratory and stay with it.

Does the Monitoring Protocol Differ for a Cat With Stable CKD Compared With a Dog?

Yes, in practical terms. Cats maintain stable creatinine values over longer periods, so the critical difference for detecting progression is proportionally larger. A rise of 0.5 mg/dL in a cat may be less meaningful than the same rise in a dog, particularly if the cat is lean. SDMA behaves similarly across species, but cats show greater day to day variability in creatinine due to muscle mass fluctuations. In dogs, creatinine is more tightly controlled and a smaller absolute change is clinically significant. The variability study in healthy dogs demonstrated that creatinine has a low index of individuality, meaning population reference intervals are useful, whereas SDMA has an intermediate index and requires more samples to establish an individual baseline. For both species, serial trends matter more than single values.

How Should I Document Serial Renal Values in the Medical Record?

Record the date, body weight, packed cell volume, creatinine, SDMA, phosphorus, potassium, and urine protein:creatinine ratio in a single table or flow sheet. Include the laboratory used and the reference interval for each analyte, because intervals vary between laboratories. Note the patient's hydration status and whether samples were fasted. Plot creatinine and SDMA on a simple graph in the record, as visual trends are easier to interpret than columns of numbers. Document any change in therapy, diet, or concurrent medication at each visit. This longitudinal record is the basis for calculating the rate of progression, which informs prognosis and the timing of referral. The MSD Veterinary Manual recommends consistent serial documentation to distinguish true progression from biological variation.

How Do I Explain Serial Monitoring to a Client Who Asks Why We Cannot Just Run One Test?

Explain that kidney function fluctuates from day to day, and a single value cannot distinguish a stable patient from one in early decline. Use the analogy of a blood pressure cuff: one reading is useful, but repeated readings over time show the true trend. State that creatinine and SDMA change slowly, so the only way to detect progression early is to compare values across visits. Emphasize that early detection allows dietary and medical adjustments that may slow progression and delay clinical signs. Reassure the client that the monitoring interval is chosen to balance cost with the need to catch change before the patient feels unwell. The health-related quality of life literature in human CKD shows that patients who understand their monitoring plan cope better with chronic disease, and the same principle applies to owners.

Related Clinical & Scientific Guides

• Peripheral Blood Smear Evaluation: A Step-by-Step Guide
• Reticulocyte Counts in Veterinary Medicine: Clinical Utility and Interpretation
• Cerebrospinal Fluid Analysis in Veterinary Neurology: Collection and Interpretation

References and Further Reading

• Variability of Symmetric Dimethylarginine in Apparently Healthy Dogs.. 2018.
• Transcutaneous assessment of renal function in conscious rats with a device for measuring FITC-sinistrin disappearance curves.. 2011.
• Structural, functional, and clinical aspects of gamma-glutamyltransferase.. 1980.
• Assessment of health-related quality of life among patients with chronic kidney disease.. 2007.
• Quantitative PCR assay to measure Aspergillus fumigatus burden in a murine model of disseminated aspergillosis: demonstration of efficacy of caspofungin acetate.. 2001.
• Pharmacokinetic, pharmacodynamic, and outcome investigations as the basis for mycophenolic acid therapeutic drug monitoring in renal and heart transplant patients.. 2001.
• American Society for Veterinary Clinical Pathology Guidelines. American Society for Veterinary Clinical Pathology.
• MSD Veterinary Manual, Professional Edition. MSD Veterinary Manual.
• American Veterinary Medical Association Practice Resources. American Veterinary Medical Association.

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This article is educational professional reference material for veterinary audiences. It is not a substitute for veterinary diagnosis, individual clinical judgment, current product labeling, or applicable regulatory requirements.