Running veterinary clinical trials isn’t just science. It’s logistics, planning, regulatory strategy, and a whole lot of coordination across species, clinics, and experts. Animal health companies know that clinical studies are essential for generating the evidence needed to bring diagnostics, therapeutics, and vaccines to market—but the path is rarely smooth.

At ZoaDx, we’ve supported trials across a range of species and study types, and we’ve seen where even the most well-resourced studies can run into trouble. Here are six of the most common challenges we see in animal health clinical trials—and more importantly, how you can avoid them.

1. Under-Enrollment: Not All Species Are Easy to Find

In human trials, enrollment often hinges on outreach and education. In veterinary trials, the issue is often more fundamental: the right animals simply aren’t available in the right places.

Whether you’re working with dogs, cats, cattle, or a more specialized species, enrollment success hinges on feasibility. Some common missteps:

• Assuming high disease prevalence based on limited or outdated data
• Designing eligibility criteria that exclude too many animals
• Over-relying on academic institutions that may not have routine access to real-world cases

How to avoid it:

• Start with species-specific feasibility: Work with your animal health CRO to understand the disease landscape in specific regions and practice types.
• Choose sites based on access and real-world caseloads, not just institutional reputation: For production animals like cattle, poultry, or swine, that may mean partnering with commercial farms, research operations, or mobile veterinary networks in the field. For companion animals, successful enrollment often comes from general practice clinics with high caseloads and motivated staff, rather than academic institutions with limited access to everyday cases.
• Incentivize enrollment: Ensure sites are equipped with the materials, support, and compensation structure they need to prioritize your study.
  

2. Sourcing Biological Samples: Not as Simple as Swab and Ship

Sample sourcing is one of the most overlooked challenges in veterinary trials—especially diagnostic studies. You may need nasal swabs from symptomatic horses, fecal samples from calves under two weeks old, or blood from cats with specific biomarkers. The logistics get complex quickly.

Why it’s tricky:

• Sample type, volume, and collection method vary by species
• Storage and transport requirements (cold chain, labeling, timing) can cause breakdowns
• Regulatory requirements for biological sample movement across borders can lead to delays or confiscation
• New tariffs or trade restrictions can unexpectedly increase shipping costs or delay imports of diagnostic kits, reagents, or raw materials

How to avoid it:

• Plan for sample logistics early: Build sample collection, storage, and shipment protocols into the study startup phase.
• Use local labs when possible: Reduce shipping time and customs delays by working with regional lab partners or affiliates.
• Coordinate closely with import/export teams: If samples or materials need to cross borders, confirm not just regulatory requirements but also potential tariffs, duties, or trade barriers that could impact timing and cost.
  

3. Site Noncompliance: Same Protocol, Many Interpretations

Even when you select experienced clinical sites, protocol deviations can still happen, especially in multi-site studies across diverse geographies.

What causes it:

• Misunderstandings about eligibility or data capture requirements
• Variations in how different species are handled and monitored
• Lack of resources or bandwidth at busy clinics
  

How to avoid it:

• Invest in training that’s species- and site-specific: Don’t assume all veterinarians are familiar with your study procedures, especially if the species is uncommon.
• Engage sites continuously: Site initiation visits aren’t enough. Maintain check-ins, offer help when needed, and respond quickly to questions.
• Monitor proactively: Frequent communication and regular data checks can catch small problems before they become big ones.
  

4. Poor Protocol Design: Looks Good on Paper, Falls Apart in the Field

In animal health studies, a poorly designed protocol doesn’t just cause frustration, it can derail the entire study.

Examples could include designing a multi-visit protocol for backyard poultry owners who can’t (and won’t) bring their birds in more than once or requiring advanced imaging on goats in rural areas where that equipment isn’t available.

How to avoid it:

• Write with the clinic in mind: Involve practicing veterinarians and field-experienced CROs in your protocol development.
• Tailor endpoints to species realities: A diagnostic test endpoint that works in dogs may not translate to livestock or equine settings.
• Pilot when possible: Run a small test at a key site to ensure your inclusion criteria, procedures, and timelines are feasible.
  

5. Regulatory Hurdles

The regulatory landscape for veterinary pharmaceuticals and biologics varies not only between countries, but also by product type (therapeutic vs. diagnostic vs. vaccine) and target species. Getting tripped up here can lead to serious delays or data that won’t hold up under scrutiny.

One increasingly common issue is import delays of investigational products or raw materials, due to local regulatory requirements.

Common regulatory missteps:

• Not confirming import requirements for test kits, reagents or biologics
• Overlooking species-specific guidance for product approval
• Not preparing a comprehensive regulatory strategy that aligns preclinical and clinical study designs with agency expectations and engaging early with FDA CVM or USDA CVB.
• Not preparing for facility inspections and compliance audits
• Not streamlining Manufacturing and Quality Control

How to avoid it:

• Work with regulatory experts early: Outline data requirements for safety, efficacy, and manufacturing processes.
• Regulatory Strategy Development: Is your product a biologic or a pharmaceutical drug? Different regulations apply impacting everything from study design to import/export requirements.
• Plan for international hurdles: If you’re importing veterinary biological products, you will need the correct import permit(s) from Animal and Plant Health Inspection Service (APHIS).

6. Inconsistent Data Collection: It’s Not Just a Tech Problem

Even the best software can’t fix gaps in how, when, or what data is entered. In veterinary studies, data collection is often decentralized, done by busy clinic staff, and varies across species.

Common data issues:

• Manual entry errors
• Missed timepoints due to animal behavior or owner availability
• Confusion over how to record species-specific observations (for example: herd-level signs in livestock vs. individual symptoms in companion animals)

How to avoid it:

• Use tools made for animal health: Don’t retrofit human health tech. Choose EDC systems that account for species, groupings, and field constraints.
• Offer job aids and data entry guides: Not every tech knows what “normal” looks like in a horse’s nasal discharge. Make it clear.
• Perform regular quality control checks: Your CRO should be actively monitoring data submissions and working with sites to clean and clarify entries in real time.

A Note on Planning: Don’t Rush What Matters

Many of the above issues aren’t due to bad decisions. They’re due to rushed decisions. When timelines are driven by funding deadlines or commercial pressure, important pieces like feasibility, training, or import requirements get overlooked.

Build time for the “unseen” work: contracting, regulatory submissions, material sourcing, import/export planning, and site engagement. It will save time, and sanity, later.

Final Thoughts: Better Animal Trials Start with Better Planning

Veterinary clinical trials are complex, multi-layered, and species-specific, but they don’t have to be overwhelming. Most common challenges in animal health research are preventable with the right upfront planning and a partner who knows the terrain.

At ZoaDx, we specialize in navigating these challenges. From feasibility and site selection to logistics, data management, and regulatory support, we help sponsors run smarter studies—ones that respect the realities of animal care while delivering the data needed to move innovation forward.

Got a study coming up?

Let’s talk about how to make it run smoother across species, sites, and borders.

Contact us to learn more.