By Dr Stacey A Newton, Lead Clinical Pathologist, NationWide Laboratories

With the recent technological advances in diagnostic options available – both in in-house testing and external laboratory services – practices have got a wide choice of tools to meet some of the challenges of providing high-quality veterinary care. Rising client expectations coupled with increasingly complex caseloads and the need to ensure that every investment delivers value means that developing an effective diagnostic strategy for the practice has become both a clinical and business necessity.

It’s not so much a question of in-house versus outsourced diagnostics, but rather how to create a service that delivers timely clinical decisions, high-quality patient care and sustainable financial performance.

Practice objectives

The first step is to define what you are trying to achieve. What decisions are clinicians finding difficult to make? Which tests give information that could change clinical management and how quickly do clinicians need this information?

Consider which services the practice would like to offer in-house and how diagnostic plans could be developed to suit clients with different levels of budget. Where could an instant turnaround offer added value or increase client confidence, and where could specialist expertise provide the greatest benefits?

Carrying out a simple audit of current practice can identify if there are issues in clinical, operational or commercial areas which could be resolved by a different approach. For instance, there could be great advantages to having an integrated point-of-care diagnostic suite for a practice with a high volume of surgical cases and a workflow based around proactive testing, however if staff lack confidence in using the equipment or certain tests are underused, potential revenue could be missed.

Questions to ask when reviewing your diagnostic strategy

• Are we using our in-house equipment often enough to justify the investment?
• What in-house expertise do we have?
• Which tests genuinely need immediate results?
• What are the latest developments in point-of-care tests?
• Are clinicians making full use of pathology expertise?
• How much clinician time is spent interpreting complex results?
• Could changes to our diagnostic pathway improve both patient care and profitability?
• Are we making the most of digital tools such as online result portals and sample tracking?

Working out an approach should aim to find the best balance for the practice between investment, efficiency and clinical quality.

Where in-house diagnostics deliver the greatest value

In situations where immediate results influence treatment and patient outcomes, in-house or portable point-of-care diagnostics can be immensely valuable. This includes emergencies where time is of the essence and patient-side tests enable rapid triage, decision-making and action.

Rapid in-house results can also streamline the patient journey, allowing some animals to proceed to surgery, begin treatment or be discharged without unnecessary delay. This may reduce hospitalisation and repeat visits, while also giving clients greater reassurance at a time when they may be facing difficult clinical, emotional or financial decisions.

The value of in-house diagnostics is not limited to emergency care and the same principle applies to in-house microscopy and cytology. For example, ear cytology can quickly confirm whether bacteria or yeast are present and help guide appropriate treatment during the consultation. This supports more targeted prescribing and can reduce reliance on empirical treatment based on clinical signs alone.

Choosing the right diagnostic route: a case comparison

	When speed is the priority: the blocked cat	When expertise adds value: suspected haematopoietic disease
Presentation	Collapsed, bradycardic male cat with suspected urethral obstruction and hyperkalaemia	A stable older dog with weight loss, reduced appetite, generalised lymphadenopathy and splenomegaly
Key tests or expertise	In-house electrolytes, renal parameters, glucose and blood gas analysis, where available	Haematology, biochemistry, specialist blood-film review and cytology of lymph node aspirates, with flow cytometry or PARR if indicated
Clinical considerations	Results directly guide stabilisation and anaesthetic planning	Specialist interpretation can help reach a diagnosis sooner and support timely treatment decisions.

Where external laboratories add value beyond the test result

An external laboratory can offer more specialised tests than can be performed in practice, including histopathology, endocrine panels and genetic and breed testing. But even when a test could be run in-house, there can still can be advantages in sending the sample to an external lab. One of the key benefits is access to specialist veterinary and pathology advice.

For example, consider an older cat with weight loss, increased thirst, equivocal renal results and mild non-regenerative anaemia. An external laboratory can assess SDMA alongside creatinine, urine concentration and protein loss, while specialist review of the haematology and blood film can help determine whether the anaemia is consistent with chronic kidney disease or warrants further investigation. Interpreting the findings together can support earlier staging and more targeted management. More broadly, pathologists can identify subtle abnormalities, distinguish genuine findings from analytical artefacts and advise whether additional testing is likely to be useful. This can be particularly valuable in borderline or conflicting cases, or when the laboratory results do not fit the clinical picture.

When should you call a pathologist?

• unexpected results
• conflicting findings
• unusual cytology
• interpreting trends
• advice on additional tests

Another area where external laboratories can provide confidence for the practice team is in quality assurance. A commercial diagnostic laboratory will have External Quality Assurance (EQA), will use validated methods, ensure rigorous calibration and will ensure consistency in their testing and results.

There can also be efficiency benefits to an outsourced lab service, especially if the practice’s demand for tests fluctuates or larger volumes of testing are periodically required. The logistical support offered by an external lab can contribute to a smoother workflow and greater confidence for practice teams. Reliable sample collection and turnaround, online portals for tracking samples and results, advanced tracking of trends from historical data and responsive customer support can make the process straightforward for vet teams to navigate alongside complex case management.

Understanding the real cost of diagnostics

There’s more to calculating the costs of diagnostics than working out the cost per test. For in-house labs, the direct costs such as the purchase of an analyser, reagents or service contracts are only one element. There can be significant hidden costs around clinicians’ time, staff training and maintenance – not least running and cleaning up after multiple tests. A vet spending 20 minutes interpreting a blood film or cytology sample may represent a greater cost to the practice than submitting it for specialist review. There can also be unexpected costs associated with quality control and repeat testing, and the downtime when equipment – and precious practice space – is not being used.

Balancing this are some significant potential benefits. If in-house and patient-side testing is resulting in earlier diagnosis, fewer repeat appointments, improved client confidence and better case outcomes, the cost-benefit analysis could be looking quite rosy.

The value of a diagnostic strategy isn’t measured purely by the direct unit cost. The value it creates through faster decision-making, better use of clinical time, improved patient outcomes and stronger client relationships also needs to be considered.

In-house costs	Outsourced costs
Equipment purchase	Submission fee
Maintenance contracts	Courier/collection
Consumables	Professional interpretation
Staff time	Included pathology expertise
Quality assurance	Laboratory QA included

Building an integrated diagnostic pathway

The most effective diagnostic pathway often uses both in-house and outsourced testing using principles such as:

Run in-house when:

• immediate treatment decisions are needed
• monitoring critical patients
• emergency presentations

Send to an external laboratory when:

• complex investigations
• cytology
• histopathology
• endocrine testing
• microbiology
• specialist assays
• cases requiring interpretation
• uncertain diagnoses

The article continues beyond this point. Read the full article in the Veterinary Business Journal (VBJ) No. 283 October 8^th , 2026 – https://www.vettimes.com/more/digital-edition

More about the author:

Dr Stacey A Newton, BVSc, DipRCPath, FRCPath, CertEM (Int Med), PhD, MRCVS, graduated from Bristol Veterinary School in 1993. After building up experience in general practice, she became a resident in equine medicine at Leahurst, University of Liverpool. She was awarded a Certificate in Equine Medicine (Internal) in 1997. Stacey then went on to complete her PhD in equine neuroanatomy and neurology in 2001. She obtained her Diploma of the Royal College of Pathologists (DipRCPath) in 2007 and was awarded Fellowship of the Royal College of Pathologists (FRCPath) in 2010. Dr Newton now works as lead clinical pathologist for NationWide Laboratories.