NationWide Labs NEWSISSUE 32 SPRING 2020

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Come and see us at BSAVA

Opening times & couriers

Welcome to our Spring Newsletter

NationWide Laboratories will be exhibiting at BSAVA 2020 bringing expertise and innovation into everyday life of a veterinary practice.

Three of our anatomic pathologists lead by Trevor Whitbread (BSc BVSc DipECVP MRCVS) will be delivering a CPD session on Saturday 4th April at 1pm in BSAVA Exhibition Education Zone Theatre talking about post-mortems and surgical biopsies and giving practical advice to veterinary surgeons.

We will be sharing information about personalised health care involving DNA-profiling and Life Plans. The service focuses on prevention and early detection of disease leading to more effective health management and improved outcomes. Additionally, we will assist with general diagnostic enquiries and have information to share on allervet.

Our expert team will be happy to see you at our stand to talk about a full range of veterinary diagnostic services we have successfully been providing since 1983.

Easter 2020

Date Day Couriers Laboratories

9th April Thursday Normal collection service* 8am - 5.30pm

10th April Good Friday No service Closed

11th April Easter Saturday Normal service 8am - 12.00pm

13th April Easter Monday No service Closed

14th April Tuesday Normal service 8am - 5.30pm

May Day 2020

7th May Thursday Normal service 8am - 5.30pm

8th May Bank Holiday Friday (VE Day) No service Closed

9th May Saturday Normal service 8am - 12.00pm

11th May Monday Normal service 8am - 5.30pm

May Bank Holiday 2020

22nd May Friday Normal service 8am - 5.30pm

23rd May Saturday Normal service 8am - 12.00pm

25th May Bank Holiday Monday No service Closed

26th May Tuesday Normal service 8am - 5.30pm

Reference intervals and flagging ranges

NEWSISSUE 32 SPRING 2020

There has been much interest, over recent months, in the role of cross-reactive carbohydrate determinants (CCDs) and their effect on the specificity of commercially available serology tests for allergen specific IgE.

CCDs are epitopes on the carbohydrate moieties of glycoproteins, which may result in the production of carbohydrate specific IgE antibodies. These antibodies, present in approximately 30% of canine and feline samples, can cause positive results in-vitro, leading to apparent polysensitisation. Whilst these are not false

positive results (the antibodies are there), CCD’s are incapable of cross-linking mast cell bound IgE (due to their monovalent structure) and do not result in mast cell degranulation. Thus, for the most part they are not clinically relevant, but can lead to the inclusion of some unnecessary allergens in immunotherapy.

allervet® are delighted to announce that, following 18 months of R&D, they are now able to include steps to block these non-specific IgEs, thereby improving the specificity of the assay and, more importantly, the relevance of allergens selected for immunotherapy.

Pr

oud sponsor

BVDSGSpring Event

2020See you there

At NWL, our traditional approach when reporting profiles has been to provide results with reference intervals but only highlight results which were likely to be clinically significant, by using flagging ranges. For example, considering canine liver enzyme activities, these need to be increased by 2-3 x the upper reference limit before they are likely to be clinically relevant. Whilst our reference interval (RI) for alkaline phosphatase in the dog is 7-173 IU/L, AP would only be highlighted (flagged) if >400 IU/L. In direct contract, electrolytes, which are subject to tight metabolic control, would flag if they deviated from the RI – Calcium RI 2.2-3.0 mmol/L would flag if <=2.1 or => 3.1 mmol/L.

The logic behind flagging ranges was to try and reduce unnecessary investigation of abnormal results which had no bearing on the clinical presentation of the animal.

That said, flagging ranges were like marmite, some people liked them, some did not. The pathologists at NWL, whilst recognising the clinical relevance of flagging ranges, felt that the more conventional approach of highlighting any results which fall outside of the RI was more transparent and the decision was made to remove flagging ranges.

This may translate as an increased number of highlighted results in you reports and it is important to correlate any results which fall outside the RI with the clinical presentation of the animal in question. Statistically, 5% of a healthy population will have a result for any analyte which falls outside of the RI, 2.5% will be lower than the interval, 2.5% will be higher. Thus, in a profile containing 20 or more analytes at least one is likely to fall outside the RI, but will be normal for that individual.

Conversely, result within RI’s do not rule out disease (ask any equine practitioner) and all results only become meaningful when correlated with the history, clinical presentation and any additional investigative findings, without this they are simply numbers.

NationWide Laboratories proudly presents a CPD session at BSAVAGetting the best from your pathologist. Post-mortems and surgical biopsies. Tips and tricks for vets in practice

Presented by:

Alison LeeBSc MVB MRCVS DipACVP

Anatomic Pathologist

Danilo WasquesMV MSc

Veterinary Pathologist

Trevor WhitbredBSc BVSc DipECVP MRCVS

will take part in Q&A following the presentation

NEWSISSUE 32 SPRING 2020

Post mortem examination (PME) can be a useful service provided by clinicians for the purposes of investigating sudden unexplained death or cases in which a diagnosis was not reached before the animal died/was euthanised. However, forensic/welfare cases or cases in which infectious/zoonotic diseases are suspected are best referred to qualified veterinary pathologists. Little in the way of extra or expensive equipment is required to carry out a PME. Consent from clients should be sought and arrangements made for disposal of the body. To avoid artefacts secondary to autolysis, PME should be carried out ideally within 24 hours of death and freezing of the body should be avoided. The body should be weighed and scanned for a microchip and radiographs may be taken in cases where death due to trauma is suspected. A number of different methods by which PMEs are carried out exist, but the exact technique does not matter so long as all organs are examined systematically. Notes describing (rather than interpreting) lesions should be made and photographs taken. Samples should be taken for histopathology of the liver, lung, kidney and any lesions in all cases. If no lesions are present, additional samples of heart and brain ideally should be taken. Samples of liver, kidney, stomach content, lung, and fat may be frozen for analysis in cases of suspect intoxication.

Surgical biopsies are essential for reaching a precise diagnosis before planning treatment in a living patient. This is especially true for neoplastic conditions, commonly seen in small animals. These can be classified as incisional biopsy (IB), performed with diagnostic intent, and excisional biopsy (EB), which is both diagnostic and potentially curative, and allows for evaluation of surgical margins. Although fine needle aspirates (FNA) are often sufficient to reach a diagnosis, there are some conditions in which a more accurate test is required for clinical decision-making. These include cases in which radical surgery is anticipated (e.g. limb amputation for osteosarcoma, maxillectomy for oral melanoma) or for lesions which are not easily assessed by FNA (e.g. feline alimentary lymphoma). Incisional biopsy is also useful for diagnosing inflammatory conditions which cannot be reliably assessed by FNA (e.g. hepatitis, cholangitis, dermatitis, gastroenteritis…).

Surgical margins of EBs should always be properly identified by the surgeon. If a large specimen (e.g. limb, spleen) cannot

be submitted in its entirety, samples of the relevant lesion should be submitted instead, and in this case regional lymph nodes should also be submitted for staging. The surgeon should retain the surgical specimen in formalin until a report is issued in case additional samples are needed.

Regardless of whether a sample from a PME, IB or EB is submitted, it is imperative that all relevant clinical history and differential diagnoses are communicated to the pathologist, as this information is often extremely helpful in forming and eliminating differential diagnoses.

References

Brooks, J.W., 2016. Post mortem changes in animal carcasses and estimation of the post mortem interval. Veterinary pathology, 53(5), pp.929-940.

Dobromylskyj, M., 2015. How to perform a small animal post mortem in practice. Companion Animal, 20(10), pp.565-571.

King, J.M., Roth-Johnson, L., Dodd, D.C. and Newsom, M.E., 2014. The Necropsy Book: A guide for veterinary students, residents, clinicians, pathologists, and biological researchers. The Internet-First University Press.

Parry, N., 2008. Sudden and unexpected death in small animal patients: Part 1. UK Vet Companion Animal, 13(8), pp.23-30.

Parry, N., 2008. Investigating cases of sudden and unexpected death in small animal patients: Part 1. UK Vet Companion Animal, 13(9), pp.31-37.

Histopathology of an invasive well differentiated squamous cell carcinoma from the ear skin of a cat

Biopsies should be fixed in 10% neutral buffered formalin (NBF). Maximum tissue thickness to allow optimal penetration of NBF is 10mm.

You can

1. Take multiple representative samples from different areas of the lesion.

2. For large samples you can slice through the tissue using parallel slices which do not quite reach the bottom of the sample and fix in NBF ideally for 48 hours at your practice before wrapping in wet paper towel prior to packaging.

Margins can be inked, or tagged using different colours, lengths or numbers of sutures. Please do not use needles to mark margins.

Small/friable specimens e.g. endoscopic samples, punch biopsies and needle core biopsies, are best placed in pre-soaked cell safe capsules. Pre-labelling the cassettes using a No2 pencil before immersion in NBF means that multiple cassettes can be placed in the same pot. Samples can be fixed free in NBF; however, although we endeavour to sieve these samples, inevitably some fragments can be left behind – particularly if they are placed in the same pot as larger biopsies. Submission on gauze or card can cause samples to rip when removing for processing.

A single line drawn along the centre of skin punch biopsies in the direction of hair growth prior to biopsy can help with orientation.

Bone biopsies can be difficult to obtain and frustrating to interpret. This is because of the high risk of fracture during the biopsy procedure and, histologically, due to the presence of large quantities of reactive periosteum in most lesions, regardless of pathogenesis. A diagnosis of reactive hyperplasia is often of little clinical help. It is

useful to take as large a sample as possible and/or to take multiple biopsies with some from the centre of the lesion. This is more likely to demonstrate the true lesion. Multiple biopsies reduce the risk of obtaining only haemorrhagic or necrotic tissue. Fixation in 10% NBF is adequate for routine diagnostic biopsies.

Eyes can be submitted whole in 10% NBF. There is no need to section the eye or inject the fixative as this causes significant artefactual damage.

Claws need softened and bones decalcified before processing. The digital site is naturally very restrictive, therefore any expansile mass will cause similar clinical signs; abnormal nail growth, swelling, pain, lameness and lysis of the bone. For this reason, amputation of one or more phalanges is the biopsy technique of choice. This includes inflammatory conditions of the nail bed, such as lupoid onychitis. Punch biopsy techniques have been described, however these can be very difficult to orientate and can result clinically in permanent disfigurement of the claw. If possible, an affected dew claw can be sacrificed.

Getting the Best Out ofYour Surgical Biopsies

NEWSISSUE 32 SPRING 2020

The large cell with several nuclei in the centre of this image is a multinucleated giant cell. This type of cell is found in certain bacterial infections (e.g. tuberculosis) or in “foreign body reactions” where foreign material is present within the tissue. This example is from an area of furunculosis: hair follicle rupture leading to an inflammatory reaction to keratin released into the tissue.

This is a splenic haemangiosarcoma: a tumour of blood vessel endothelial cells frequently found in the spleen. Rupture of splenic haemangiosarcoma, causing haemoabdomen, is a common cause of sudden unexplained death in dogs.

This beautiful image is actually a hair follicle as seen using Gram stain (a stain to highlight bacteria in histologic section). Special stains can help pathologists locate bacteria, fungi and certain types of material (e.g. copper, bile, iron) in tissue. They can also yield some lovely colours, as seen here!

AMH (Anti-Mullerian Hormone)

AMH (Anti-Mullerian Hormone) is produced by ovarian granulosa cells in females and sertoli cells in males and so is a very useful diagnostic test to detect the presence of ovarian or testicular tissue.

Neutered status can be very difficult to determine, especially in animals with an unknown history such as strays or rescue animals. AMH is a very useful to determine spay status in both cats and dogs. Our studies have confirmed it is more reliable than performing the GnRH stimulation test where no signs of oestrus are present.

AMH levels remain constant throughout the cycle so females do not need to be showing signs of oestrus.

AMH Analysis Update…

Following extensive use of our very sensitive AMH assay to detect ovarian reminant we have found that in some cases where the dog or cat is showing significant signs of being in oestrus or has been showing signs in the last 2 weeks,

the AMH may give a false negative result. We believe this is possibly related to the actual amount of ovarian tissue present and/or a negative feedback mechanism relating to Progesterone produced by luteal tissue.

We are now suggesting AMH is not performed alone if clinical signs of oestrus are present or have been present in the preceding 2 weeks.

Following on from our studies we are pleased to introduce three new profiles to further assist the accurate diagnosis of ovarian reminant in dogs and cats.

Please phone NationWide Specialist Laboratories if you would like more details, 01223 493400

ISSUE 32 SPRING 2020

Specialist NEWS

At NationWide Specialist Laboratory in Cambridge, we have a very reliable colorimetric KBr (Potassium Bromide) assay that has been correlated against the reference method. We have also performed a comprehensive haemolysis study which allows us to reliably estimate the positive interference across the spectrum of haemolysis encountered in veterinary serum samples.

Don’t forget

Code Name Exc. VAT

AMHP AMH & Progesterone £94.00

AMHE AMH & Oestradiol £109.00

AMHEP AMH, Oestradiol & Progesterone £140.00

Prices are correct in February 2020

NationWide Laboratories is a trading business of National Veterinary Services Ltd

NEWS

Wildlife Vets International was formed by a group of wildlife vets in 2004 to give the conservation community veterinary support and skills.

The charity enables the provision of independent veterinary advice and skills to front line conservationists around the world. Detailed sample analysis enables WVI to get a real grasp on the disease threats to endangered species. WVI is grateful to NationWide Laboratory Services for the service they provide and the support they give to WVI.

Wildlife Vets International, Station House, Parkwood Street, Keighley, West Yorkshire. BD21 4NQ.

Tel: +44(0)1535 661 298 www.wildlifevetsinternational.org Email: info@wildlifevetsinternational.org

Saving species from extinction is a complicated puzzle. There are many threats and as many interlocking conservation activities that are used to address them. However, illegal removal from the wild (poaching), habitat change, pollution and more recently climate change are all very pressing threats that conservation biologists are equipped to deal with.

Before Wildlife Vets International was set up, conservation biologists thought disease played little or no part in the regulation of animal populations. WVI was set up because wildlife vets Andrew Greenwood and Dr John Lewis (both of IZVG) were being asked to help as the conservation community realised that disease was increasingly playing a part. As populations of endangered species become smaller and more stressed, disease plays an ever-growing role.

Today the picture is very different and vets are working all over the world in different capacities. Zoos have had an important role in connecting the two disciplines – zoological medicine has grown exponentially and vets have carried their expertise in to the wild as zoos play a more active role in field conservation.

Species go in to decline for a number of interdependent reasons. Often the situation is so bad that conservation action has to occur before the threats are fully understood. For example, the Asian white-backed vulture numbers plummeted by 90% in ten years. Conservation action had to occur with very little understanding of the cause.

It took 15 years to find out that the use of diclofenac had become widespread once the patent finished and vultures

are extremely sensitive to its presence. The removal of diclofenac in an area is key to creating vulture safe areas where captive breed vultures can be released.

With other species we have a head start. Mauritius is home to endemic bird species that had reached desperately low numbers (as in, single figures). The Mauritius kestrel, the pink pigeon and the Mauritius parakeet have all be restored to viable numbers over the past 30 years using a multidisciplinary approach underpinned by detailed monitoring – preliminary observation, captive management, reintroduction, translocation, follow-up monitoring and disease surveillance.

All three species have similar species in captivity – hunting falcons, racing pigeons and pet parrots – that are familiar to avian vets. Their disease and captive management problems are well documented. Therefore, the initial rescue and captive breeding stages were relatively easy to support from a veterinary and husbandry point of view.

BUT when at such low numbers, the significance of any disease present in the population can be hard to spot. If one individual out of 12 dies is it a problem at individual or population level? The problems only become apparent during population recovery.

Working with familiar species has the advantage that disease testing is readily available. This means that populations and individuals can be screened and the risk of moving animals between areas, into captivity and from captivity can be assessed.

We want to put veterinary science at the heart of conservation through

funding experienced specialist vets to oversee programmes involving hands-on crisis species conservation.

You can help us train field staff to collect samples and even carry out preliminary post-mortems in areas where experienced vets are few and far between. Join our commercial supporters (such as Nationwide Laboratories) whose generosity enables us to cover equipment and laboratory costs.

Join us today and help complete the puzzle, allowing wildlife to survive and thrive.

To find out more follow us @WildlifeVetsInt on social media and www.wildlifevetsinternational.org

Delivering Excellence and Innovation in Animal Health

ISSUE 32 SPRING 2020

Veterinary Science on theFrontline of Conservation

Mauritius kestrel. Numbers got as low as 4 individuals in 1974. Today there are over 800 thanks to conservation efforts. Copyright: Jacques de Speville.