Everyone will no doubt be aware of the increasing number of ‘flu outbreaks in the UK this year and, more concerningly, reports from Newmarket involving infection in vaccinated horses. Given recent history it is assumed that the recent outbreaks involve Florida clade 1 virus.

In view of the evidence of infection in vaccinated horses, it is crucial that an accurate message is given to horse owners to avoid loss of confidence in vaccination which will make the situation even worse. In this respect it is important to realise that it is not simply a case of vaccine failure, and we should point out that:

This event is now fully booked! We do have a wait list. Please contact tasha.wilson@theleh.co.uk

Do you have any members of the practice that would be interested in attending our Essentials of Equine Practice course?

This is a 3-day residential course held at West Dean College, Chichester, and at the Liphook Equine Hospital. The course is aimed for recent graduates and more experienced colleagues wishing to refresh their knowledge of general equine practice. The course is also suitable for final year veterinary students. The course focuses exclusively on what you need to know in ambulatory equine practice and has a very practical emphasis.

There is a charge of £495 which includes 2 nights’ accommodation, food and entertainment for all 3 days.

For further information please click here.

If you would like to book a place (or places), please complete a booking form. For further information please email tasha.wilson@theleh.co.uk

Do you have any members of the practice that would be interested in attending our Essentials of Equine Practice course?

This is a 3-day residential course held at West Dean College, Chichester, and at the Liphook Equine Hospital. The course is aimed for recent graduates and more experienced colleagues wishing to refresh their knowledge of general equine practice. The course is also suitable for final year veterinary students. The course focuses exclusively on what you need to know in ambulatory equine practice and has a very practical emphasis.

There is a charge of £495 which includes 2 nights’ accommodation, food and entertainment for all 3 days.

For further information please click here

If you would like to book a place (or places), please complete a booking form. For further information please email tasha.wilson@theleh.co.uk

There is no doubt that molecular biologic technologies such as PCR testing have dramatically increased the sensitivity of diagnostic tests designed to detect the presence of several infectious pathogens including Streptococcus equi subsp. equi (Strep equi), Salmonella sp., CEMO and Dermatophytosis. Following on from an outbreak of strangles it is important to establish freedom from infection in all affected animals before “a line is drawn” under the outbreak and horses are free to mix and attend shows. Evidence suggests that guttural pouches are the only logical target for post-outbreak sampling with latest research indicating a greater than 50 times chance of detecting the presence of Strep equi in the guttural pouches of carriers compared to their nasopharynx (Boyle and others 2017). Furthermore, recent studies indicate that around 40% of culture-negative strangles submissions may be positive by PCR (Boyle and others 2017; Pusterla and others 2018).

However, the main drawback to reliance on PCR testing is that the technique simply detects the presence or absence of the DNA or RNA of the organism in question, whether or not that material is present in live or dead organisms. Indeed one recent study indicated that less than 20% of PCR positive and culture negative samples contained viable organisms (Pusterla and others 2018). It has been suggested that the lack of mucociliary clearance mechanisms in the guttural pouch could facilitate retention of DNA from dead Strep equi organisms leading to positive PCR results that do not actually indicate any risk of contagion.

A new PCR assay has been developed at Liphook which can distinguish live from dead Strep equi organisms. Use of this PCR will enable much greater confidence in the clinical relevance of positive PCR results. Results from examination of 10 washes, 5 of which had been boiled to kill the organisms, is shown in the graph below. The PCR was able to distinguish the live from dead organisms. Further validation in greater numbers of samples is ongoing.

In order to avoid the possible confounding effect of death of organisms between sampling and testing, it is important that samples are shipped in chilled saline (ACTH chiller packs for example), as previous evidence indicates that viability of Strep equi is excellent in cold and wet conditions (Durham and others 2018).

BOYLE, A. G., STEFANOVSKI, D. & RANKIN, S. C. (2017) Comparison of nasopharyngeal and guttural pouch specimens to determine the optimal sampling site to detect Streptococcus equi subsp equi carriers by DNA amplification. BMC Vet Res 13, 75

DURHAM, A. E., HALL, Y. S., KULP, L. & UNDERWOOD, C. (2018) A study of the environmental survival of Streptococcus equi subspecies equi. Equine Vet J

PUSTERLA, N., LEUTENEGGER, C. M., BARNUM, S. M. & BYRNE, B. A. (2018) Use of quantitative real-time PCR to determine viability of Streptococcus equi subspecies equi in respiratory secretions from horses with strangles. Equine Vet J 50, 697-700

How does the seasonal influence on the pituitary gland influence the diagnosis of PPID at this time of the year?  And how does it impact follow-up blood samples in cases that were previously under control?  What happens if you try to start pergolide treatment in July or August?

Let us take the stress out of managing your PPID cases – download our latest (free) podcast with Victoria South and Andy Durham who discuss what happens to our basal ACTH reference intervals at this time of the year, and chat through some common case scenarios that are affected by the pituitary hyperactivity observed at this time of the year – Seasonal PPID Podcast

We appreciate that is can be tricky to keep in touch with the latest publications on endocrinopathic laminitis especially those relevant to the diagnostic tests that we use in practice. We have produced this handy summary of the best evidence-based protocol for the Karo Light Challenge Test. Please click here to view the protocol.

We are all now recognising that most cases of liver disease that we encounter are part of a wider outbreak amongst herd-mates, even if the others appear externally healthy. This suggests a common toxin or infectious aetiology. It is useful to rule out “old favourites” such as ragwort by biopsy. Fluke is rare and almost impossible to rule out as no antemortem tests are reliable.

Work performed at Liphook over the last few years has identified fumonisin B1 contamination of forage as a possible cause of some outbreaks and international work looking at various causes of viral hepatitis in horses has identified a number of candidates including equine Hepacivirus, equine Pegivirus, Theiler’s disease associated virus and equine Parvovirus.

See Cornell University Laboratory website:

https://ahdc.vet.cornell.edu/news/equinehepatitis.cfm

and recent publication describing equine Parvovirus: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5782890/pdf/17-1031.pdf

Continued work at Liphook has identified equine Parvovirus in some horses with liver disease and we hope to offer this, and other, new PCR assays shortly.