A robust diagnosis

December 16, 2020 | Janice Johnston | News, What's New

Veterinary specialist Chris Matthews and Pharmaq’s Nils Arne Gronlie talk about fish health

Fish Farmer magazine caught up with Chris Matthews, Operations Director of the Fish Vet Group which was recently acquired by the Norwegian diagnostics company PHARMAQ Analytiq, whose General Manager, Nils Arne Gronlie also shares his thoughts.

FF: Chris how long have you been with the Fish Vet Group and what is your role there?
Chris Matthews (CM): I joined Fish Vet Group in 2011, having spent six years in terrestrial animal vet practice in Inverness, with a spell in Australia followed by a Masters in Aquatic Vet Studies at Stirling. Initially I spent a few very useful years working with several founders of Fish Vet Group – Tony Wall, Pete Southgate and Dave Cox.

FF: What have been the main changes in aquaculture veterinary care that you have seen so far in your career?
CM: There’s a much greater focus on preventative health. Between our own practice vets and many talented colleagues working in production companies, work is focused on preventative strategies, starting with training site staff to recognise health and welfare issues. Fish health operatives on Scottish farms are now far more highly skilled than ten years ago.

Our understanding of disease dynamics has also greatly improved. Not so long ago, our ability to detect potential fish pathogens using qPCR had significantly outpaced our ability to understand the significance of such results. This is less true today; for instance longitudinal gill health monitoring using qPCR for Neoparamoeba perurans (AGD), has, over time, generated enough data to help optimise the deployment of management interventions such as freshwater bathing. This has reduced the incidence of losses due to primary AGD in Scotland.

FF: Diagnostics play a critical role in fish health, perhaps even more so than in say, companion animal medicine. Can you describe some of the key developments over the past decade as well as perhaps what the future has in store?
CM: The headline improvement has been the advent of digital pathology and I am proud that FVG were very early adopters of this eight years ago. Teams of histopathologists working remotely from one another – even in different continents – can quickly share and consult on cases without the need to post glass slides. High quality results are generated more quickly and the use of cutting-edge image analysis can also be deployed in certain cases. Whilst ultimately, artificial intelligence will almost certainly have some application, perhaps in screening large volumes of material, I do not see it replacing histopathologists at any time in the near future!

Non-lethal swab sampling for qPCR in gill health monitoring has also been a recent improvement and it is likely that non-lethal sampling of mucus, scales, blood and even water samples will emerge in the future. The hunt for biomarkers in such samples which might be diagnostic proxies for specific disease, general health or stress is ongoing. Some are described but have mostly failed to find specific, practical application on farms, but this will change in time.

Finally I suggest that, in the next decade, metagenomic sequencing will be a regular diagnostic tool. The skin, gill and gut microbiome at different life stages may well have relevance to fish health outcomes in the face of disease.

FF: The Scottish industry has always held the service offering from FVG in high regard. Are you able to provide assurances that this will continue and perhaps what additional benefits might be on offer following the merger?
CM: Firstly, we will continue to offer all our existing services whilst developing each of our core areas of diagnostics, consultancy and environmental services. For our clients, the key benefit is that the merger brings us together with a world class technical and R&D team at Pharmaq Analytiq, alongside the wider resources of Zoetis. I am encouraged that the Pharmaq Analytiq team share a similar vision of a holistic, evidence-based approach to aquaculture health – and very much an area of, now joint, focus between Inverness and Bergen. An immediate benefit for our clients is that we can now offer a more comprehensive suite of qPCR assays as well as Pharmaq Analytiq’s leading smoltification assay, SmoltVision. Beyond that, there are a number of exciting diagnostic products in the pipeline which we look forward to bringing to Scotland next year.

FF: From your close interactions with industry can you share some insight into what you consider to be the most important current and emerging fish health issues being faced just now?
CM: My principal hope is that we can further improve sea lice control through reducing the need to handle fish to treat them, by incremental gains in genetic improvement and perhaps even a sea lice vaccine. In the past two years, the generalist sea louse Caligus elongatus has occasionally necessitated treatments on a few farms in the summer. Whilst hitherto relatively uncommon, it is possible this may be a trend.

In gill health, I think we now recognize that gelatinous zooplankton or hydrozoans have been understated as a primary cause of autumnal gill disease. The questions now are how does oceanic change influence their frequency, and how can we respond? Whilst we can do little to prevent fish being exposed to zooplankton, it may, in the future be possible to avoid the cascade of secondary pathology which drives mortality on farms long after the inciting zooplankton species has gone.

Finally, both Norway and Scotland have seen outbreaks of Pasteurellosis in recent years. It is vital that bacterial diseases of Atlantic salmon in seawater do not become more prevalent. Presently the use of antimicrobials in farmed salmon in these countries is minimal and rare. To maintain this, farmers, health teams and animal health companies must cooperate to develop and enhance vaccines for existing and emergent bacterial diseases.

FF: Turning now to Nils Arne, what excites you most about the new tie-up?
NA: Our customers have ambitious sustainability goals. They want to foster sustainable fish farming practices that provide safe, affordable nutrition for a growing population while increasing animal welfare and ensuring a positive social impact. I believe the acquisition of FVG will help us strengthen that goal.

What also excites me is the opportunity to build upon an established strong base, to create an even better service offering for Scottish aquaculture. I believe the fish farming community will see the new partnership as a positive, bringing greater knowledge and value to their strategic thinking and day to day management.

FF: Are there any differences in approach to veterinary aquatic diagnostics in Norway compared to Scotland, and if so do you see scope for an exchange of ideas here?
NA: Whilst I think the basics are the same, we do see differences. For example, histopathology is widely used in Scotland as a primary diagnostic tool but less so in Norway, where PCR is more dominant. This has led us to start a cross-geography conversation to see what we can learn from these differing views, and how our customers may benefit from them.

FF: What changes, if any, do you think that fish health managers in Scotland might see now that FVG and PHARMAQ Analytiq are one?
NA: FVG will continue to provide its unique offering of combined consultancy and diagnostics, together with environmental services, delivered in the friendly, collaborative way to which our clients are accustomed. As a proud partnership we are excited to move forwards together with the Scottish industry as we invest in both facilities and new services.

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