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Health Testing

What is Johne's?

Johne’s disease is caused by the bacteria Mycobacterium Avium subspecies paratuberculosis (MAP). Infection results in a thickening of the intestinal wall, which prevents the animal from successfully absorbing nutrients and water through the gut.

The disease causes considerable production losses in both dairy and beef herds worldwide. It can often go unnoticed in herds for many years as animals are culled before showing overt signs of Johne’s.

Testing Options

Clinical Signs

  • Weight loss
  • Scour
  • Sub-clinical disease can be evident several years before the classic clinical signs are shown. This can include:
    • High SCC.
    • Mastitis.
    • Lameness.
    • Yield reduction.

Prevention & Management

  • Careful purchasing from herds with good Johne’s management, or ideally are CHECS accredited low risk.
  • Identifying Johne’s infected cows as early as possible in the course of the disease and managing them to prevent spread.
  • Good calving management with excellent hygiene, provision of clean colostrum, and swift removal of calves into clean calf housing.

Read our Intro to Johne's leaflet for more information on the disease and how it is spread.

What Testing Options Are Available?

Testing for Johne’s is split into

  1. Testing for surveillance (monitoring to see if Johne’s is present in the herd)
  2. Testing for control/management (identifying infected cows to facilitate risk management).

All testing can be carried out on blood or milk samples (milk recording samples can be used).

Please note bulk milk testing is not available for Johne’s disease due to the poor sensitivity of this testing option.

You should always consult your vet about your Johne’s strategy and what testing options are appropriate for your herd.

Surveillance Options

Targeted 30 Cow Screen

This option is a great way to establish herd status if no previous testing has been carried out.


This option provides good surveillance for herds with no evidence of Johne’s disease.

Control/Management Options


This option provides you with Johne’s results four times per year and includes the new Johne's Progress Tracker and Priority Cull Reports on Herd Companion.

Johne's 1-2-3

This option is suitable for both recording and non-recording herds wanting to test the whole herd once, twice or three times per year.

Johne's Essential Sampling (JES)

JES by NMR is a simplified Johne’s testing service for farmers who do not fully milk record.

Ad Hoc

Ad Hoc individual cow testing is also available

Request a Quote

Once you have spoken to your vet about the testing option suitable for your herd, contact us for a free quote.

Frequently Asked Questions

Milking cow

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