Increase in cases of Salmonella Bovismorbificans: please complete laboratory sample submission forms

The Ministry for Primary Industries (MPI) has noticed an increase in the reported incidence of Salmonellosis in livestock since 2015, most notably involving the serotype Bovismorbificans.

Sporadic cases and outbreaks have been reported predominantly in dairy cattle (both adults and calves), although there have also been cases in beef cattle and sheep.

Case presentations include diarrhoea and late-term abortion/stillbirth.

Cases of Salmonellosis are reported year round, but there appears to be some seasonal variation (main peak in spring and a smaller peak in early autumn).

Most regions of the country have experienced cases, but most cases have been reported from Waikato, Manawatu-Whanganui and Taranaki. Case reports are also increasing from Canterbury and the Bay of Plenty.

Unfortunately, alongside the increasing trend in animal cases, ESR is reporting an increase in cases of S. Bovismorbificans in humans over the same time period. It is important to remember this organism (and Salmonellae generally) is zoonotic and therefore a potential health and safety risk to those working with animals.

MPI's ability to understand and interpret animal disease data relies heavily on information provided by clinical veterinarians on laboratory sample submission forms. But MPI is finding it difficult to estimate the impact of S. Bovismorbificans on outbreak farms, because of incomplete sample submission forms.

To help MPI better understand the impact of S. Bovismorbificans on animal and human health, please complete all fields on laboratory sample submission forms. It is really important to note a full clinical history of the whole herd/mob - including number of animals at risk, number affected and number dead.

We would also like to remind you of the recent guideline from ACVM about Magnesium supplementation in dairy cows.

MPI will also work with agriculture industry bodies to communicate the situation to farmers and others who handle livestock. Key messaging to the primary sector will include:

• Encouraging farmers to seek advice from their veterinarian about Salmonella and increase awareness of livestock vaccination against it.
• Reminding livestock handlers about the need for good hygiene practices.
• Highlighting the risk of Salmonellosis from consuming raw (unpasteurised) milk.

If you have questions or comments, please contact us at nzva@vets.org.nz.