New strains of leptospirosis emerging
A leader in global animal healthcare has addressed the threat to vaccinated dogs posed by new strains of leptospirois.
While dogs are commonly protected against two "traditional" strains of the disease, called canicola and icterohaemorrhagiae, there is evidence that the vaccine is no longer as effective as in the past.
Tests have shown that new strains australis and grippotyphosa are becoming more and more prevalent in the UK and across Europe.
As a result, MSD Animal Health took steps to increase awareness at the recent British Small Animal Veterinary Association (BSAVA) Congress, held in Birmingham.
It announced that veterinary surgeons from six European countries and the United States met last year to discuss the issue of leptospirosis resistance in dogs.
During the meeting, the most up-to-date research was shared and the conclusion was that the current bivalent leptospirosis vaccinations were no longer providing adequate protection.
Canine leptospirosis is an infectious disease that most commonly damages the liver and kidney. While the disease tends to be very difficult to diagnose, it can cause fatality within a short period of time.
The case of a six-year-old, fully-vaccinated and otherwise healthy labrador was shared by Jonathan Horlock, of Marches Vets, Herefordshire.
"All the symptoms shown were generalised – the dog was off its food and had a slightly raised temperature. We were suspicious of leptospirosis as we'd already seen a couple of cases, so we sent the dog to Bristol University for a diagnosis."
Despite confirmation of leptospirosis, Mr Horlock said the symptoms were too acute and the dog didn't respond to treatment.
"Unfortunately, the dog died."
Mr Horlock added that a more up-to-date vaccine is needed to ensure dogs are safe from new strains of the disease.
"The difficultly with leptospirosis is that it's hard to diagnose, because the symptoms are generalised, yet treatment needs to be immediate," he commented.
BSAVA is to partner with BVA Live (11-12 June 2026) to champion clinical research.
