Leptospirosis – Increased risk of infection

MPI (Ministry for Primary Industries) has warned that there is an increased risk of leptospirosis infections but what does this mean for you and your pets?

This warning for animals and humans comes after all the adverse weather conditions experienced this year. Post cyclone Gabrielle, an increase in human leptospirosis has been noted. This indicates that there is an increase in the bacteria that is circulating in animals, as humans are infected due to contact with infected animals’ urine, directly or indirectly (through flood water for instance). Initially focus was placed in the flood affected areas but focus on awareness is now shifting to a wider area.

What is Leptospirosis?

This is a contagious disease and potentially life-threatening bacterial infection, most commonly spread via urine, where the bacteria is excreted in large numbers. Leptospirosis is a zoonotic disease which means it passes between animals and humans. Other forms of transmission can be through bite wounds or ingestion of infected tissue etc. Bacteria can enter the bloodstream through a cut in the skin or penetrate the mucous membranes of the eyes and rapidly multiply, spreading to other tissue including kidneys, liver spleen, nervous system, eyes and genital tract. The main animal host in New Zealand is the rat.

Leptospirosis is prevalent in rural, suburban, and urbanised areas. Young dogs can be more severely affected, but it is more common in mature dogs as their outdoor activity is more likely to put them in contact with rat habitats.

The bacteria can also be present in any stagnant surface water, moist soil and recreational water sources such as ponds and lakes and dogs can become infected with Leptospirosis by drinking, swimming in or walking through contaminated water. Even water troughs can present a risk. Exposure risk increases during the summer and early autumn months, and other periods of high rainfall. Additionally, natural disasters such as floods and earthquakes present an increased risk of exposure to this disease.

What should I look out for?

Infected pets should be treated as soon as possible as severe illness can rapidly result in death with only a few symptoms such as lethargy, muscle tenderness and shivering. Some signs to look out for:

  • Fever
  • Loss of appetite, vomiting and diarrhoea
  • Abdominal pain
  • Dehydration
  • Weakness
  • Depression and lethargy
  • Yellow colour in gums and whites of eyes

Usually, an examination of a blood sample will assist in making a diagnosis.

Treatment options

The more quickly the disease is diagnosed and treated, the more likely a positive outcome becomes. The leptospirosis organism can stay in the kidneys and be shed for several months in the urine. Usually within 7-8 days the dog will start recovering, as long as the damage to the kidneys or liver is not too severe. Aggressive treatment with a combination of intravenous fluids and antibiotics and supportive hospital care may save some dogs but death due to Leptospirosis is not uncommon.


  • Vaccination of dogs is the simplest prevention technique. This vaccine can be administered as part of the pups routine vaccinations and then given annually.
  • Avoid water that may be contaminated with the bacteria (especially stagnant water)
  • Practice good sanitation ie washing your and your children’s hands, especially when handling anything that may have dog urine on it
  • Protective clothing can be worn where routine exposure to standing water is required
  • Try to limit rats in your environment ie remove potential food sources and seal entry points etc


If you are concerned in any way, your veterinarian is the best source of information. Contact Otaki Vets to book a leptospirosis vaccination.