Mastitis is an inflammation of the udder of milking animals. It is caused by bacterial micro-organisms, mainly streptococci and the staphylococci which are common in the animal and the animal environment. The infection occurs when the micro organisms gain access to the udder through the teat canal. The infections in the udder affect the quantity and quality of the secreted milk. The disease is known to cause economic losses of up to 40 % of the herd productivity.

The disease occurs wherever and whenever the animals are bred, fed and managed with the intention to increase milk supply. Indeed the higher the level of production, the higher the occurrence unless there is very strict control measures continuously put in place. The animal is predisposed to the disease by several factors such as the age, state of lactation, milk yield, hereditary factors, trauma and lack of hygiene. Animals get most often mastitis when they have just had babies and are giving most milk. Pigs get sometimes mastitis when their teats are bitten by the sharp teeth of baby pigs.
Sheep and goats can get very severe mastitis called contagious agalactia.

Sub-clinical mastitis which can only be detected by the laboratory examination of milk drawn from the udder of affected cow. This form of mastitis is mainly caused by streptococcus agalactiae which is found in the animal. Where production of milk is meant for export market, this form of mastitis is known to contribute to a big proportion of rejected milk.

Mild clinical mastitis has distinct changes in the udder sometimes detectable by touching it. In this form, the udder becomes firm to the touch in one or more quarters. The changes in milk are, however more definite. This form of mastitis can be examined using the black plate in the strip-cup. Milk can be seen to be of watery consistence and of abnormal color, which often could be pinkish, or yellowish due to blood staining. Flakes or clots in milk may as well be noticed by the strip - cup test.

Acute or severe clinical mastitis in which, milk changes are more definite with the udder having typical inflamed signs. The milk changes consist of yellow sediment sometimes with blood clots. The milk may also appear green or yellow-green and even with foul smell especially when the infection is caused by pus forming bacteria (the Corynebacterium pyogenes). The udder changes consist of swelling and pain. The teats may reveal injury signs at closer observation. As the disease progresses, the udder becomes hard, the milk yield decreases and milk becomes thin, watery or grey in color.

Since mastitis is a management disease in a dairy farm, it will some time persist even with the most careful hygiene. With this in mind, dairy farmers are advised to adhere to the following eight control measures:

It is worthwhile for farmers to note that the most essential prerequisite to develop any control program is an accurate determination of the extent of the disease in the herd. If the above control measures are followed by the farmers, the veterinary costs of treating the disease would be minimized.

Apply antibiotics directly into the udder. The following antibiotics can be infused through teat canal:

The following drugs can be used: