Mastitis in the Beefies


Mastitis is often thought of as a disease of dairy cattle. However, it has become a growing problem in the beef industry and we have seen many cases in local beef herds lately.

Mastitis is the inflammation of the cow’s mammary gland, most commonly secondary to bacterial infection of the udder. It is the costliest disease of the dairy industry where economical losses occur due to reduced milk production, culling of high value cows and veterinary costs. On the Beefy side, mastitis has been shown to decrease calf growth rates and weight gain by 7 to 12.5 %, leading to economic losses.


How do I know if my cows have mastitis ?

Milk from mastitis udders is often abnormal in consistency and reduced in volume. It can be discoloured, bloody, and have flakes or clots. In some cases it can be very watery. In acute cases, the affected quarter is often swollen, hard and hot to touch. Cows are usually painful when the udder is palpated. Certain types of bacteria can also cause the skin of the udder to die and slough off. In on-going, chronic cases of mastitis the udder tissue may be replaced with scar tissue and the quarter subsequently shrink in size. Milk production from such quarters is eventually reduced to absent.

Whether the cow herself will be unwell depends on the bacteria causing the disease. Some cows may look completely normal while others can be off their food, dehydrated, down and have a fever. In severe cases, cows may die.


What factors predispose cows to mastitis ?

In Beef cattle, the main source of infection is the environment with dirty, muddy areas such as a shaded spot under trees or wet patches near water/feed troughs being commonly implicated. Dams and other water sources contaminated with faeces may also be a problem. Therefore, fencing off problem areas when practical and repairing leaky water troughs is beneficial. Overcrowding paddocks, especially under wet and rainy conditions is also a significant risk factor in the development of mastitis so keep that in mind.

As a rule, the older the cow and the greater the number of calves, the higher the risk of mastitis. This is because they have had greater exposure to bacteria than heifers and also tend to have more pendulous udders which increases contact with bacteria in the environment. Clinical mastitis is more common around calving time or within the first 2 months of calving so particular attention should be paid to your calving paddocks to make sure they are as clean as possible !!!

Trace minerals and vitamins are important for udder health, especially Selenium and Vitamins A and E. Deficiencies in those can predispose cattle to mastitis so consider supplementing your cows prior to calving.



Antibiotics, either intramammary, injectable or a combination of both, play an important role in treating mastitis. The route used to give the drugs will depend on the clinical status of the cow and how bad the mastitis is. . Anti-inflammatory drugs can also come in handy to reduce pain and discomfort. The udder needs to be stripped as often as practically possible to encourage drainage. Fluids either orally, or into the vein may be needed as well to flush out the toxins that mastitis bacteria release into the blood stream. The bottom line is: Any cow with mastitis that is SICK and/or DOWN REQUIRES A VET VISIT !!!

Remember that prevention is better than cure. While complete environmental control is unrealistic it is worth paying close attention to your paddocks and reduce sources of contamination as much as possible, particularly dams, especially around calving time.