Leptospirosis – Update March 2024

Leptospirsis is a very serious infectious (bacterial) disease of dogs, with a high mortality rate (as many as 3 in 4 dogs who contract the disease will die despite treatment). The source is primarily the urine of rats and mice, although hunting (eating) rats and mice, and the urine of other animals including livestock and wildlife are all potential sources of infection. The most common way of contracting the disease is by drinking (playing in, swimming in) water contaminated with infected urine.

There has been a steady stream of cases of Leptospirosis in dogs for the last 7 or so years. Cases were initially found in central Sydney, and over time cases have appeared in other parts of Sydney, around Newcastle, then around Wollongong , Shellharbour and the escarpment, and then in the first half of 2022, around Jervis Bay on the south coast of NSW.

A single case in Jerrabomberra in June 2022 prompted local vets, with the advice of experts , to recommend vaccination for ACT and district dogs. In the next 9 months, Gungahlin Veterinary Hospital vaccinated more than 1000 dogs. However, in the second half of 2023, vaccine supply dried up, and has only just become available again.

There have been ongoing cases on the South Coast, most in the area around Jervis Bay. There have been no further cases in or around the ACT.

1. We no longer regard the ACT as an area of risk for Leptospirosis, and if your dog does not leave this area, vaccination against this disease is probably not required unless your dog has exposure to wild rodents.
2. The University of Sydney now recommends “vaccination against leptospirosis in dogs living at the South Coast area, Eastern suburbs, Inner South and Inner West (of Sydney) or in any area if the dog is in contact with rats or other rodents”.
3. While dogs living in these areas are clearly at higher risk, vaccination is likely wise for dogs visiting these areas.
4. There is only one registered vaccine against Leptospirois in dogs in Australia – Protech C2i. This is the vaccine that we have used, and which has just become available again. This vaccine contains only one serovar of Leptospira (L copenhageni).
5. Cases on the South Coast have predominantly been caused by another serovar – L. autralis. It is not known how much protection is conferred against this strain by the available vaccine.
6. There is a vaccine against L australis, which may be used under certain conditions (by vets at the coast for dogs living at the coast). However, it is not currently available.
7. Anecdotal advice for the University of Sydney is that “any vaccine is better than no vaccine” for dogs at risk.
8. In the last 7 years, vaccinated animals which contracted Leptospirosis have been much more likely to survive than non-vaccinated animals. 15 dogs contracted Leptospirosis in NSW in 2023, none had been vaccinated, and 40% of them died.
9. Vaccination against this disease requires two doses of vaccine, 2-4 weeks apart, followed by annual boosters. We have received advice that if a booster is less than 6 months overdue, a single booster dose is satisfactory. If the booster is more than 6 months overdue, the primary course (two doses) needs to be repeated. As of today, about 250 dogs previously vaccinated against Leptospirosis by this hospital could be boosted with a single dose, more than 750 would need to have a repeat primary course (two visits and doses).
10. We have been able to secure 100 doses of vaccine at this stage, and ongoing supply is uncertain. Therefore, we are unlikely to be able to boost the Leptospirosis vaccination of all the dogs we have vaccinated in the past.

So, should you get your dog vaccinated against Leptospirosis? we recommend vaccination for dogs which:-

1. Visit Sydney (particularly the inner city, Eastern Suburbs, Inner South and Inner West), Newcastle and Hunter regions, Wollongong, Shellharbour and escarpment regions, and the South Coast of NSW. While we are unaware of cases south of Jervis Bay, the University of Sydney recommends vaccinating dogs living in this area.
2. May have exposure to wild rats or mice. The biggest risk factor in International studies is exposure to free standing  water (puddles, pools, lakes, dams, creeks or rivers), especially if there is a rodent problem or proximity of livestock (especially dairy cattle) of perhaps wildlife.
3. May we stress again that there have been no cases in the ACT or district since mid 2022.

Please discuss the need to vaccinate with your veterinarian. Advice on protection for your pet, regardless of vaccination, is available in the article linked above. If your dog was vaccinated less than 18 months ago, you have a limited time to boost the vaccination with a single dose. Otherwise, two doses would be required.

If you are planing to visit an “at risk” area, please have your dog vaccinated a month before you expect to arrive in that area (allows for two doses of vaccine two weeks apart, and a two week period for the vaccine to become effective).