Poor hygiene and handling are the number one accelerator for most cases of mastitis at the farm. This is because mastitis is a bacterial infection and bacteria tend to thrive in unhygienic conditions.
Mastitis in cows is manifested as the inflammation of the cow's mammary gland and udder tissue. This disease/condition is a major endemic disease of dairy cattle but can affect all other lactating mammals as well (including humans).
When the bacteria gain entry into the udder through the teat canal, they find nutrients in the udder and multiply rapidly. Their metabolic byproducts cause poisoning of the udder tissues resulting into an inflammation. The inflammation is due to the cow’s autoimmune response to the toxic metabolites released by the bacteria.
In this post, we highlighted some sources of bacteria that you may need to check if you have to control bacterial infection at the farm level. It is important to take note that mastitis can also occur due chemical, mechanical, or thermal injury to the cow's udder.
The bacterial metabolites released in the udder tissue can damage the milk-secreting tissues and ducts throughout the udder. In some situations, the damage is permanent and the udder loses its functionality. Acute cases can lead to fatalities while cows that recover will be incapacitated for the rest of their lactation lives.
Mastitis in cows can be a very complex illness since the farmer may not be able to detect it during its subclinical phases. This is to say that the herd may have mastitis without showing any signs and symptoms. At this stage, the disease can spread very fast to the rest of the herd if proper handling is lacking in the farm.
To manage the situation, you should consider paying a very close attention to the milking hygiene to avoid cross contamination. You should couple this with good housing and proper nutrition to promote general good health of the animals. In extreme cases, you may need to cull the severely infected cows.
Given the gravity of the effects of mastitis in cows, it is important to take precautions to ensure that you do not end up with mastitis in your farm. Dairy cows have many predisposing factors to mastitic infections such as the risk of contamination from the milking equipment, hygiene of the milking equipment handlers, and cleanliness of the cleaning water.
Since farmers tend to milk their animals at predetermined hours, their udder sphincters tend to be under stress than beef cows whose calves nurse regularly. The stress may lead to loosening of the teat canal through which the bacteria will gain entry into the udder to cause mastitis.
There are occasions when incidences of mastitis may qualify to be a public health concern. When this is the case, farmers must do all they have to do to ensure that their animals are not infected. At the same time, they must manage the already infected animals to prevent any further spread of the disease.
Consequently, it is not uncommon to see the farmers to procure intramammary antibiotics due to its low risk of administration.
Organic dairy farmers on the other hand prefer to use limited antibiotics and prefer to use alternative therapies, e.g. homeopathy, to treat mastitis. Such farmers also prefer to take a more holistic approach in their farms to prevent mastitis.
While applying any treatment method you prefer to use, you must be sure that you know what you are doing. If in doubt, consult your veterinarian or animal health care expert. There have been incidences of prescription abuse, which puts us on the precipice of losing the war against bacteria.
When the bacteria have developed sufficient resistance to the antibiotics, you will be forced to look for a more potent alternative, which could be very expensive or non-existent. Whenever you treat a bacterial infection in your herd, it is important not to go for the strongest medication first because if it fails to deliver, you will not have an alternative.
Characterized by an extremely ill cow that may die if untreated. The udder becomes gangrenous and the milk may look normal even the though the cow is sick in the early stages. Soon enough, the milk becomes abnormal.
Here, the cow may not necessarily be sick but the udder is visibly swollen, painful, and hot. The cow produces abnormal milk with clots and blood.
The cow looks indifferent and the udder does not show any observable changes. You will notice abnormalities in the milk.
The cow looks fine and the udder does not have any abnormalities. You will notice a few clots or flakes in the milk.
The cow looks very fine but you may feel lumps in the udder tissue. You will also observe changes in milk e.g. the milk can be very watery. This could be the reason why your milk is always rejected at the dairy despite feeding your cow well and treating it from all diseases.
Your cow looks fine and the udder is well. You may not make out any observable changes in the milk but a chemical analysis of the milk will show significant changes in the milk composition.
There are many scientific methods for testing and confirming mastitis in cows. Some of the tests are straight out simple while others are complicated and require sophisticated equipment, e.g. DNA testing method.
The most common method for mastitis testing is the California Mastitis Test (CMT). This cow-side testing method works by disrupting the cell membranes of the somatic cells present in the milk sample and exposing the DNA of the cells to the reagent.
Upon touching the reagent, the mixture turns into a gelatinous mass, which confirms the presence of mastitis in cows.
To perform this test, you will need the CMT test kit. You can get one from Amazon at a reasonable price and it will be shipped to you.
You can have a look at this short video to see how it actually works.
(Source: NBC Field Service).
Correctly diagnosing and controlling mastitis pathogens in a dairy herd is important because it helps to reduce associated economic losses, in particular subclinical mastitis, because of less milk yield and poor milk quality. Mastitis causes a cow’s udder tissue to become inflamed and painful. Reducing its occurrence helps produce more high-quality milk and increases your herd’s saleable milk yield. Mastitis treatment and control is one of the largest costs to the dairy industry and is a significant factor in dairy cow welfare.
The best way to control mastitis is to protect cows from getting new infections, which can come from the environment or from other infected cows. Working out when cows get infected and the source of infections is the first step. You can then focus on preventing new cases of mastitis in your herd.
The tavle below lists some common pathogens that can wreak mastitis havoc in your dairy herd. Included are manifestations and how to manage each case.
Where found |
Manifestation |
Management |
1. Pseudomonas aeruginosa – Causes subclinical mastitis |
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Found in soil-water environments in dairy farms. |
Severe mastitis with toxaemia and high mortality results in some herds. May also lead to subclinical infections. |
Ensure clean feeds and water for the cows. Clean the milking equipment and aseptically clean the udders. |
2. Mycoplasma spp. Causes severe mastitis that spreads quickly |
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M bovis is the most common cause. Other species include M. californicum, M. canadense, and M. bovigenitalium |
Carriers are asymptomatic. Shed the bacteria through the intrammamary or respiratory disease transmissions. |
Take a lot of care when introducing animals into the farm because carriers do not show symptoms. |
3. Trueperella pyogenes. Causes characteristic mastitis in heifers and dry cows |
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Common in dry cows/heifers that graze in the pastures and access water from the ponds. |
Produces an inflammation with a foul-smelling exudate. |
Therapy is rarely successful; do not milk infected quarters. |
4. Nocardia asteroids. Causes destructive mastitis |
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Characterized by high fever, loss of appetite, loss of weight, udder inflammation. |
The udder inflammation exhibits extensive fibrosis with palpable nodules. |
Practice aseptic intrammamary treatment to prevent infections. |
5. Serratia spp. |
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Infections arise from contaminated cleaning water, dirty hoses, contaminated teat dips and other milking equipment. |
The bacteria are resistant to disinfectants but infected cows show clinical signs of mastitis. |
Cull cows that continue to show clinical signs of mastitis. |
6. Yeasts and molds |
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Common in cows with prolonged antibiotic/penicillin treatment. These fungi are introduced during preparation of infusions. |
Severe infection, high fever. |
Reduce contact between the teat dip container and the teats when treating the cows |
7. Prototheca spp |
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These bacteria tend to inhabit wet and humid environments. |
Chronic and asymptomatic. |
Hard to predict and therapy does not work with this pathogen. |
Milk the cow dry and apply an intrammamary antibiotic. Do not add the affected cow’s milk into the batch tank until the drug clears from the cow’s system. You can only use such milk to feed the calves, otherwise, just drain the milk.
It is illegal and unethical to sell milk with antibiotics in it. You can use a physical marker (e.g. leg bands) to mark out sick cows in a large herd. Keep health records of the herd.
Clean the teat and disinfect with ethanol, after which you allow it to dry for a few seconds. Partially insert the cannula containing the infusion onto the teats to reduce contact, which can introduce fungi that will cause a different form mastitis.
Once the teat comes into contact with the antibiotic infusion, streak the teats by pinching and palpate a little bit to make sure that the antibiotic treatment enters the mammary gland.
Effective treatment of mastitic cows depends on complete removal of milk from the teat cisterns. You can achieve this by increasing the intervals of milking.
Bacteria thrives in milk because it gets nourishment from the milk. When you empty the teat canal, the bacteria will not find nourishment and the antibacterial drugs will be more effective.
If the cow is a high producer, you may need to streak it in between the milking times. You can inject the cows with oxytocin to increase milk let down so that you can achieve complete milking.
In some instances, the bacteria may fail to go away despite regular streaking and application of the antibacterial drugs. This will lead to chronic infections, which is associated with Staphyloccocus aureus, bacteria that naturally exist on the skin.
In such cases, the cow will remain a constant source of contamination for the rest of the herd. You will have no option but to cull such a cow if you must protect the herd.
Given the magnitude of the effect of mastitis in a dairy enterprise, it is important to look for ways to prevent the spread of this disease in the farm.
Having a firsthand knowledge of mammary anatomy and physiology, the defense mechanisms, microbial behaviors, aetiology and manifestations, farm and equipment hygiene, and antibiotics/germicides will be very helpful in controlling the spread of mastitis.
There are several intervention methods that can help a farmer to achieve this and they include:
Researchers have been able to develop bacterins from E. coli and Salmonella that can help reduce the severity of mastitis caused by coliforms. They also observed that repeated application of these vaccines during the dry period can significantly reduce clinical coliform mastitis in the early lactation.
The effectiveness of these vaccines reduces after 50 days; therefore, large herds may warrant extended immunizations.
Sadly, the researchers have not yet developed an effective vaccine for Staphyloccocus aureus, which is a big pathogen for mastitis in cows.
Environmental pathogens pose a special challenge to the farmer in terms of control. They are not specific to the cow or the farm; therefore, the farmer must find the source/habitat and control it from the source. Usually, one can achieve an effective control of the pathogens by eliminating their habitat.
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