Animals
Leptospirosis is a very serious bacterial infection of dogs, with a high fatality rate. It is caught through contact with the urine of infected animals – most commonly rats and mice.
Many dogs were vaccinated against Leptospirosis in the second half of 2022, and booster vaccinations are due after 12 months. Unfortunately, vaccine is once again unavailable. This document is to advice you of our perception of risk, and the preventative measures you can take.
SUMMARY
– there have been no further cases of Leptospirosis in and around Canberra
– 18 cases occurred on the South Coast in 2022, with further cases this year in and around Wollongong (including Robertson, Southern Highlands)
– Leptospirosis vaccine (Protech C2i) is once again unavailable until First Quarter 2024,
– Booster vaccinations can be given for up to 6 months after the due date (18 months since the previous vaccination) without having to re-commence the vaccine course (2 doses 2-4 weeks apart)
Vaccine was unavailable from late 2022 until June 2023, when we received 200 doses, with the expectation of further vaccine supply in September. Once again, the manufacture has failed to supply. From June until September 2023, we vaccinated dogs who were definitely at risk (this was about 1 in 5 of the dogs due for a booster). Despite this careful approach, the failure of supply has left us without vaccine, and we are unable to vaccinate dogs for the immediate future.
We will be sending out vaccination reminders by SMS (or email) in the weeks preceding your dog’s due date. This is to remind you of the need to be vigilant in protecting your dog (see below) Leptospirosis is a very serious bacterial infection of dogs, with a high fatality rate (up to 75% of affected dogs in the Sydney outbreak 2019 to 2022). Cats appear very resistant to getting sick, but humans can be infected and become very sick also.
Leptospirosis is caught through contact with the urine of infected animals – most commonly rats and mice although livestock (especially dairy cattle) and wildlife can also be carriers and shedders of the organism. Infection occurs through swallowing the organism or by it contaminating mucous membranes (eyes, mouth, nasal cavity etc) and cuts or scrapes on the skin. The greatest risk is if rats or mice are eaten by dogs, but rodent urine and water (puddles, pools of water, creeks etc) contaminated with rodent urine are also a major risk.
Leptospiras are categorised into various species and serovars, with more than a dozen present in Australia and causing disease. There is only one commercially available Lepto vaccine (Protech C2i), and this contains only one serovar (Leptospira interrogans serovar Copenhageni). Cases on the South Coast appear to have been mostly caused by serovar Australis. Although typically protection from Leptosira vaccines is very serovar specific, anecdotal evidence from the Sydney and South Coast outbreaks suggest some degree of cross protection (25% mortality rate amongst infected dogs which had been vaccinated vs 75 % in unvaccinated dogs in Sydney, the two vaccinated dogs on the South Coast survived their infections). The veterinary Specialist from Sydney university investigating this outbreak has advised that in the face of risk, any vaccine is worthwhile compared to not vaccinating.
Preventing infection with Leptospirosis
Regardless of vaccination status, “risk mitigation methods are the most important measures to prevent leptospirosis. Contact with sources of infection should be limited. This includes limiting swimming or drinking of stagnant water and avoiding contact with possible reservoir hosts such as rodents and farm animals, which can be achieved by fencing and rodent control.” (University of Sydney, May 2023). For Canberrans, the most effective prevention may well be to avoid taking dogs into “at-risk” areas.
Cases have occurred in various parts of Sydney, Newcastle, Wollongong and the South Coast, specifically Albion Park, Annandale, Ashfield, Balmain, Bardia, Bayswood, Bondi Junction, Burradoo, Cambewarra, Cardiff, Cardiff Heights, Cheltenham, Clovelly, Cooks Hill, Crows Nest, Darlinghurst, Elanora Heights, Erskineville, Falls Creek, Figtree, Firefly, Glebe, Gresford, Horsley Park, Ingleside, Jervis Bay, Kembla Grange, Lurnea, Marrickville, Medowie, Newcastle, Newtown, Old Erowal Bay, Paddington, Potts Point, Randwick, Rangari, Redfern, Robertson, Sanctuary Point, Speers Point, South Coast, St Georges Basin, Sanctuary Point, Surry Hills, Sussex Inlet, Tomerong, Tuggerah, Trunkey Creek, Vincentia, Wallsend, Waterloo, Woollamia, Worrowong Heights.
Despite assurances from the manufacturers last June that vaccines would be readily available, supplies dried up late in 2022 and no stock has been available for the first 6 months of 2023. Gungahlin Veterinary Hospital vaccinated some 1263 dogs against Leptospirosis from June to December 2022, and these dogs are now coming due for their first annual vaccination. We received 200 doses in June, with the expectation of further supplies in September 2023. The manufactures have now advised that vaccine will not be available until First Quarter 2024.
Because there have been no further cases in the Canberra region (the only case occurred in Jerrabombera in June 2022), we no longer regard Canberra as an “at risk” area
Therefore, we are sorry to say that we will not be able to provide booster doses to all the dogs that received vaccine last year, and nor to all the dogs that haven’t yet been vaccinated against this disease. We have been able to vaccinate dogs that are definitely visiting the South Coast or other “at-risk” areas but unfortunately this is no longer possible
The manufacturers have provided specific advice that, although boosters are preferred at around 12 monthly intervals, a delay of up to 6 months is acceptable. Therefore, if your dog was vaccinated in, say, August 2022, it can be given the booster vaccination any-time before March 2024 without needing to restart the primary course (a primary course is two vaccinations, 2-4 weeks apart).
We thank you for your patience and understanding as we navigate this difficult supply issue together.
Michael Hayward BVSc FAVA
for all the staff at Gungahlin Veterinary Hospital