F500
Mastitis

clinical signs | contagious | environmental | other causes of mastitis

Causes: Mastitis is an infection of the udder caused by two major categories of bacteria. These categories include bacteria that are

  1. Highly Contagious - These are passed from cow to cow, usually during milking.
  2. Environmental - These bacteria are usually found in a manure contaminated environment.

Clinical Signs: These are also broken down into two major categories:

  1. Clinical mastitis: (Based on physical exam, cow shows evidence of disease.)
  1. Abnormal milk (watery to thick or even custard-like consistency)
  2. The udder or quarter feels warm, swollen, or firm and appears to cause the animal pain
  3. Fever >103.5°
  4. Sick looking, weak cow with possible signs of dehydration (sunken eyes)
  1. Subclinical mastitis: (Cow does not show signs of disease without additional tests.)
  1. Low milk production on an individual cow or entire herd basis
  2. Increasing somatic cell counts
  3. Positive California Mastitis Test (C.M.T.)
  4. Positive Hy-Mast or culture and sensitivity tests
  5. On strip test the milk looks thin and/or has flakes in it

Diagnosis: There are many different types of tests that can identify a cow with mastitis. Some tests can also identify the bacterial cause of the mastitis. The following are some of these tests:

  1. C.M.T.
  2. Strip test
  3. Hy-Mast test
  4. Culture and sensitivity on the milk

(See section D for additional information on the above tests.)

Treatment: Proper treatment of mastitis depends on the type of organisms causing the problem. It is essential that the bacteria causing the infection be identified and the appropriate treatment, based on findings, be initiated. To begin with, any case of mastitis should be placed in one of the following two categories:

  1. Highly Contagious
  2. Environmental

Understanding the source of infection, the producer can then begin appropriate treatment and take steps to correct the conditions causing the infections. The organisms associated with each category are found on the following pages.

  1. Contagious: Treatment of CONTAGIOUS bacteria depends on the specific organism causing the problem. Most of these infections are subclinical, therefore, additional testing is required to detect the problem. Most of these infections tend to be gram positive bacteria.

    There are three major bacteria in this category:
  1. Streptococcus agalactiae - This organism must live in the mammary gland.
  • Treatment for this bacteria is usually done one cow at a time with an appropriate antibiotic based on the culture and sensitivity. Many intramammary products are effective (Today, Tomorrow and Pirsue). Some injectable antibiotics may include penicillin and Gallimycin, with consideration of withholdings. This is one of the only bacteria that can be SUCCESSFULLY REMOVED from a herd.
  • Control of this problem centers around the milking parlor and milking procedures (teat dipping, milking machine surveillance, milking hygiene, and dry cow treatment).
  1. Staphylococcus aureus - This organism is found on workers’ hands and equipment that are contaminated with milk from infected cows.
  • Treatment for this organism can include intramammary tubes and other injectable antibiotics. However, this bacteria is extremely difficult to eliminate because it causes micro abscesses in the mammary tissue that prevent the antibiotics from reaching the bacteria.
  • Control of this problem includes teat dipping, washing hands/equipment properly, and a good dry treatment program. Infected cows should be grouped together and milked last.

* Because this organism is so difficult to eradicate, it is recommended that culling of affected animals be an essential part of herd management.

  1. Mycoplasma - This organism is usually introduced into a herd through replacement cows, generally not through a heifer. The respiratory tract of young calves can also be a hiding place for the organism. Infection with this bacteria often causes joint swelling and a yellow/grainy discharge from the quarter.
  • Treatment with antibiotics DOES NOT WORK!! Culling of affected animals is the ONLY means of eradication.

* Special culture techniques for Mycoplasma are not routinely used unless requested. Therefore, the laboratory should be informed each time a milk sample suspected of containing Mycoplasma is sent.
  1. Environmental: Environmental bacteria are more likely to cause clinical signs and even death. Following are two major categories of bacteria to be concerned about:
  1. Environmental streptococci
  • Treatment of these bacteria usually involves intramammary, dry treatment tubes and/or injectable antibiotics.
  • Use a combination of injectable and intramammary antibiotics. Some research indicates this is necessary for total elimination of this problem.
  • Control of this problem involves keeping stalls and sheds as clean as possible (manure free).
  • Proper hygiene is beneficial, although control of this organism is difficult because it is found in the environment.
  1. Coliforms - These include E. coli and Klebsiella and are generally gram negative. The milk is generally watery and serous (slightly blood tinged and sticky).
  • Treatment involves controlling the side effects of the infection throughout the cow:
  • Frequent milking, with oxytocin given just prior to milking, is very beneficial.
  • Anti-inflammatory agents such as Banamine are also recommended. These reduce the fever and have an anti-endotoxin effect.
  • Administration of oral or IV fluids may be required if dehydration is a concern. See page B115 and F145.
  • Antibiotics can also be implemented to prevent systemic or whole cow infections. See section G.
  • J-5 Strain E. coli bacterin vaccines can be given to prevent clinical mastitis. See sections C.
  • In cases of severe infection, Dexamethasone may be necessary.
  1. Other Causes of Mastitis:
  1. Actinomyces pyogenes - This usually results in a very foul smelling, custard like discharge from the quarter. This disease is usually not very contagious and affects only one cow at a time.
  • Treatment may involve penicillin and frequent milkings.
  1. Gangrenous mastitis - This can be caused by many organisms. The milk is usually watery and the teat itself can be cold to the touch. Many times gas is present when milking out the quarter. At this point, the cow is often very sick and/or down.
  • Treatment is very aggressive and involves anti-inflammatory agents, fluids, and injectable antibiotics like penicillin. The use of steroids, under the direction of a veterinarian, may also be necessary in severe cases.

* Before initiating any treatment, CONSULT A VETERINARIAN!

Mastitis Prevention:

  1. Ensure the cows and the environment are clean.
  1. Be emphatic about corral and free-stall cleaning and maintenance (Clean each area as often as 3 times a day if necessary.)
  1. Maintain regular milking machine maintenance.
  1. Have a routine check of the entire milking system at least every 6 months by a qualified technician
  2. Use high quality inflations and change them regularly
  1. Insist on good milking procedures.
  1. Use gloves
  2. Forestrip each quarter
  3. Pre-dip
  4. Wipe teat, especially teat end with individual towels
  5. Do not over-milk or under-milk
  6. Post-dip
  7. Have fresh feed in the mangers after the cows leave the milking parlor
  • This will keep the cows standing until the teat sphincter constricts and the post-dip has dried
  1. Have a written dry cow program that is followed.
  1. Utilize intramammary antibiotic infusions based on culture and sensitivity results (see page D135 for additional information on cultures)
  2. Maintain clean conditions, particularly in the calving areas
  1. Realize that nutrition can play a significant role in preventing mastitis
  1. Supplements such as zinc, vitamin E, selenium and biotin are helpful for mastitis prevention. Consult a nutritionist to ensure that these components are properly included in the dry and lactating cow rations.