An app that predicts the cure rate of clinical mastitis.

An app that predicts the cure rate of clinical mastitis.
Each year, more than 700,000 dairy cows across New Zealand are treated for clinical mastitis. However, the success rate of these treatments varies between 20% and 90%. This means that a significant amount of money is being spent treating cows, with no guarantee of success.

This huge variation in cure is partly predictable if four key factors are known; the cow’s age and stage of lactation, the gland and bacteria causing mastitis.

Extensive New Zealand research studies of over 1,200 mastitis cases collected key information on cow age, breed and days in milk, gland position and bacterial species at the time of treatment. Importantly, follow-up milk samples were also collected to determine whether treatment had been successful (i.e. whether the bacteria causing the mastitis was no longer present in the gland).

Based on analysis of this data and with funding from the Sustainable Farming Fund, Dr Scott McDougall has developed a smart phone app, which allows herd owners and veterinarians to estimate the cure rate of clinical mastitis cases. Dr Scott McDougall is a registered specialist in bovine reproduction, has been involved in the dairy industry for over 25 years and is the Managing Director of Cognosco, the Research Division of Anexa FVC. .

So where might this app be useful?

“There are some cows in which the probability of cure is sufficiently low that treatment may not be a viable option.”

“For example, a cow that has had recurrent cases of clinical mastitis across the lactation, is infected with Staphylococcus aureus, is an older cow, and/or has multiple glands involved, is likely to have a very poor cure rate. In these cases, if mastitis is diagnosed in later lactation, drying off or culling the cow may be the best option. However, where such cases occur earlier in lactation, then drying off the quarter may be an option. Alternatively, in discussion with your vet, high-value cows with a likely poor cure rate may be treated with alternate/longer duration therapy which may improve the outcome,” says Dr McDougall.

This free and simple app offers the opportunity to make smarter and quicker treatment decisions about cows with clinical mastitis.

The app is available from the Play Store, by searching “bovine mastitis cure calculator” or pasting in the URL below:

How does the app work?

The app calculates the likely bacteriological cure rate following input of data via drop-down boxes of four factors; cow age, number of weeks in milk, gland position and, if known, bacterial species.

In many cases, the clinical cure rate or percentage of cows in which the milk and the gland return to normal with no signs of clots, heat or swelling will be higher than the bacteriological cure rate.

What this means is that some cows will remain infected despite having milk and glands of normal appearance. This is particularly important in the case of contagious bacteria, such as Staphylococcus aureus. These bacteria are hard to cure and, if cure fails, the cow may act as a source of infection for other cows in the herd.

Also the app does not account for those cows that are apparent clinical failures and so are re-treated. Generally, this represents approximately 10% of cases; hence the overall cure rate is likely to be about 10% lower than the number indicated by the calculator. The calculator assumes treatment on-label with a ‘normal’ duration of treatment.

The app is only a guide and the actual cure rate will depend on individual farm- and cow-level factors.

“It is going to be interesting to get farmer feedback on the usefulness of the tool. Our vets see it as a great opportunity for farmers and their vets to work together to minimise use of antibiotics and to reduce the cost of mastitis treatment on-farm,” says Anexa FVC head vet Andy Collier.

Date Added: Tuesday, 30th June 2015