How to stop summer mastitis wreaking havoc on your herd

This fly-borne disease can be nasty if not diagnosed and treated quickly — but there are ways to keep the flies away

The recent heat and humidity has led to a welcome flush of grass, but it has also led to some unwelcome visitors flies.

Flies are responsible for the development and spread of conditions such as pink eye in calves and fly strike in sheep.

The most common condition we have seen over the past few days associated with the increased number of flies is summer mastitis.

What is summer mastitis?

It is a bacterial infection that causes dry cows and sometimes maiden heifers to develop a severe mastitis in one or more quarters.

It is a very nasty condition. The affected animal will have a high temperature and a reduced appetite.

The affected quarters will be quite swollen and painful. When the quarter is drawn, it will be full of pus or foulsmelling discoloured fluid.

The animal will seem very stiff and slow to move. When lying down, she will often ‘lie off ’ to take the pressure off the affected side of the udder.

In-calf cows run the risk of aborting.

Summer mastitis is highly contagious within a group of cows/heifers. Flies are attracted to the swollen quarter(s). When they fly off to another cow, they can transfer the bacteria.

On farms where heifers calve down with blind teats, there is a strong possibility that summer mastitis could be a cause.

How can we diagnose it?

The first step is to try to spot a sick cow/heifer before the mastitis gets too severe. Dry stock should be checked daily.

It isn’t enough to have a quick look over the hedge and do a head count.

A close walk around each animal should be done, paying close attention to all four quarters. Any swelling of a quarter or abnormality of a teat should warrant immediate attention.

When examining an animal with suspected summer mastitis in the crush, take precautions. She will probably not have had her udder and teats checked in some time and the affected quarter could be quite sore. A kick is almost guaranteed.

It is worth having someone with you to hold the tail, or else tie one leg to the crush.

We have seen a few cases lately where very sick animals have become aggressive. They are agitated, sore and probably scared.

From a safety point of view, we need to be extra vigilant. A trip to A&E is definitely not anyone’s to-do list.

How do we treat it?

This is one of the cases where a call out from the vet is worthwhile.

Antibiotics and antiinflammatories are the first port of call. Fluid therapy may also be needed as dehydration can set in quickly.

The affected quarter needs to be stripped out a number of times each day. In cases where the teat is damaged or if the animal is particularly difficult to handle, the vet may surgically open the teat to let it drain.

Chances of saving a badly affected quarter are very low. Saving the animal’s life is the main priority.

How do we prevent it?

In the case of summer mastitis, prevention is definitely better than cure. If we can stop the flies from landing on the animals, we can stop the infection from developing and spreading.

There are a number of pour-on or spot-on products that have fly repellent activity. Read the label carefully to see where on the animal the product should be applied, at what rate and how long it has activity for.

Fly tags have been found to be useful. These look similar to a regular ear tag but with the added bonus of containing a fly repellent.

Topical preparations such as Stockholm tar can be applied to the udder and teats of any at-risk animals. Again, with regard to safety, take special care when doing this. A second pair of hands to hold the tail and restrain the animal should be mandatory.

It is a messy job so wear arm-length gloves on both hands.

Products such as Stockholm tar need to be applied regularly.

I have heard some farmers claim to have gotten good results using garlic licks.

In reality, a combination of a number of products is necessary to give a decent level of protection.

If you see a cow swishing her tail or kicking at her flank, she is quite possibly being irritated by flies. It’s time to put a plan in place to prevent this irritation developing into a very nasty condition.

Eamon O’Connell is a vet with the Summerhill Veterinary Clinic, Nenagh, Co Tipperary Summer scourge:

Increased numbers of flies can cause summer mastitis, a bacterial infection which can turn into a nasty and contagious condition in dairy herds