Mastitis in Dairy Cattle – Causes, Types, Symptoms & Treatment

‘Mastitis’ is an inflammation of the udder tissue caused commonly by bacteria. It is a common and major problem in the dairy cattle causing economical loss to the farmers. Mastitis is also caused by physical damage to the udder or teats by improper milking practice and mechanical injuries to the udder.

What are the common bacteria that produce mastitis?

  • Staphylococcus sp S.aureus is a major organism responsible
  • Streptococcus sp
  • Pseudomonas aeriginosa
  • Brucella meletensis
  • Mycoplasma sp
  • Corynebacterium sp
  • E.coli
  • Pasturella sp
  • Proteus sp

What are the common causes?
Mastitis is usually caused by poor sanitation in the sheds like unclean floorings, bedding, animals and the milking surroundings. Unhygienic conditions favor multiplication of bacteria and infect the animals.

Poor milking practice, not washing the animal’s udders before milking, not practicing the dipping of teats in antiseptic solution and incomplete milking of animals are also responsible for mastitis.

Infection also spreads through milking machines if they are not cleaned well before use
Infection also spreads through milking persons if their hands are contaminated and not cleaned well with a disinfectant before milking.

Improper milking methods like milking using thumb and pressing or pulling the teat causes a mechanical injury to the teat.

Injuries to the udder or teats also cause mastitis.

Subclinical form of mastitis in the herd infects other healthy animals. Hence screening of milch animals for presence and count somatic cells and strip cup test should be done frequently to detect the same.

Types of mastitis
Two types of mastitis are generally seen. Acute and sub clinical form of mastitis. The acute form is characterized by classical symptoms of inflammation like swelling of the affected quarter and teat, pain, redness and hot to touch. The quality of the milk also changes. Therefore easy to detect and treat. On the other hand sub clinical form of mastitis does not show any symptoms to detect and acts as a source of infection to other healthy animals. Detecting subclinical form of mastitis is a major task of the dairy managers.

Pathogenesis:
After entry through the teat canal the bacteria enter into the udder tissue multiply and produce toxins causing inflammation of the udder or the affected quarter and the corresponding teat. Due to the inflammation the body releases leucocytes and the quality of the milk will be affected. The milk becomes watery or curdled sometimes blood streaks may also be present depending on the severity of infection.

Symptoms:

  • Swelling of the udder and teat
  • Redness and pain of the udder
  • Milk gets curdled becomes watery with blood streaks in some cases
  • Fever, listlessness and anorexia Reduced milk production
  • In chronic and sub clinical cases the teat canal gets thickened, when the teat is palpated it appears like a thread inserted in the teat canal.
  • In subclinical cases the milk is not affected and appears normal but the somatic cell count increases and the milk yield is decreased. If the subclinical cases are more in the farm it becomes a problem to control the disease.

Diagnosis of mastitis:
The acute form of mastitis can be diagnosed easily due to the presence of classical signs of inflammation (Swelling, pain, redness and heat). Milk also becomes watery, and curdled. A strip cup test can be done to detect the curdled milk pieces.

Since majority of cases are subclinical mastitis without any visible change in the milk quality a somatic cell count helps to detect it. A count of more than 50,000 cells /ml of milk can be taken as positive for mastitis.

Strip cup test: This test is easy to conduct and should be practiced every day at the time of milking. This helps to detect the changes in the milk and to eliminate first few strips since the fore milk contain more bacterial load. By doing this method the quality of milk improves. A wide mouthed mug made of plastic or aluminum can be taken and a black cloth is placed on it and tied tightly with a thread. The milk can be stripped on it and examine for the presence of streaks of curdled milk.

Milk also can be cultured for diagnosing the causative organism.

Diagnosis also can be done by mixing the milk with a colored reagent to detect the extent of infection. The milk reacts with the reagent and forms a gel if the infection is high. If negative it remains in the same condition.

Treatment:
One thing should be kept in mind is that mastitis cannot be completely eradicated from the herd. If proper hygienic practices are followed in the farm besides treatment mastitis can be controlled to a great extent. Frequent testing for subclinical mastitis helps for controlling the disease.

Dry animal treatment: This is the best method to control mastitis in a herd. Once the animal dried an antibiotic is infused into all the quarters once. Before infusion the udder and the teats are cleaned with a soap solution cleaned with a towel and dried. The teats are then cleaned with alcohol and allowed to dry. After drying the antibiotic is infused into the udder through the teat canal. Then the antibiotic solution is worked out so that it spreads well. While working the teat opening should be closed by means of pressing. Similarly the antibiotic should be infused into all the teats.

In acute clinical mastitis antibiotic infusions can be given along with injecting antibiotics into the body. Before infusing, the animal should be milked completely.

Preventing measures:
A good sanitary condition along with better management practices helps a lot in controlling the mastitis in a herd.

Identification of sub clinical form of mastitis by counting the somatic cells and treating them is a good practice to prevent mastitis spread.

Teat dipping and dry animal treatment is also a good practice to prevent mastitis.