It is the second biggest cause of involuntary culling of dairy cows, and it can infect up to 50% of all dairy herds in the US and Europe: mastitis is a constant threat among dairy herds which can have expensive repercussions. Yet the good news is, it’s preventable and treatable in almost all cases. And that means that, in the majority of examples, there is no need to replace the animal in the herd, and no reason why that animal could not go on to be productive well past the usual average 2.5 lactations.
Mastitis occurs after bacteria has invaded the teat canal, releasing toxins that inflame and damage the milk-secreting tissue. Dirt or contamination through the milking machine are the likeliest causes of the initial bacteria, though damage can also be caused by injury and chemicals.
Two categories of mastitis
The condition can be classified in two categories, with the most obvious being clinical mastitis. In this case there are visible signs: in milder cases, the milk may appear watery or have clots; in more moderate cases the udder may show signs of swelling or heat. Severe mastitis will cause pain and, if left untreated lead to gangrenous infection.
By contrast, an animal with sub-clinical mastitis may have no visible signs: the cow will behave normally and the udder and the milk will appear OK. But even mild mastitis will affect milk quality, reducing the protein and calcium content. The only effective method of detection in the case of sub-clinical mastitis is regular checking of the somatic cell value: generally speaking, the higher the cell count, the lower the quality of the milk.
It is worth remembering that for every single case of clinical mastitis in the herd, there are probably five sub-clinical cases.
Treatment of mastitis is almost always possible
Prevention is better than cure. Treatment is almost always possible – given early detection – through long-acting antibiotics, although the milk from cows in treatment is not marketable until the traces of the drug have left the cow’s body. In addition, cows may develop resistance to certain antibiotics.
Instead, a rigorous hygiene program is the best way to avoid contamination. Teats should be disinfected after every milking; and all equipment and the general environment should be kept as clean and dry as possible. Bedding should be exchanged every two days.
For more detailed advice and help with mastitis, take a look at the following: