Many farmers have never heard of Mycoplasma Bovis infections, while those who have heard of it never want to hear or see of it again. From talking to over 10 dairy farmers in the last number of days, it is clear that a number of herds are suffering with the disease. I talked to a number of farmers that had the disease over the last number of years and most didn’t know why cows were affected or why it disappeared. The problem can occur in beef and dairy herds. Respiratory problems can occur in purchased weanlings, joint ill (arthritis) type problems in milking cows, ear infections/pneumonia in young calves and mastitis in milking cows.
Many farmers have never heard of Mycoplasma Bovis infections, while those who have heard of it never want to hear or see of it again. From talking to over 10 dairy farmers in the last number of days, it is clear that a number of herds are suffering with the disease. I talked to a number of farmers that had the disease over the last number of years and most didn’t know why cows were affected or why it disappeared.
The problem can occur in beef and dairy herds. Respiratory problems can occur in purchased weanlings, joint ill (arthritis) type problems in milking cows, ear infections/pneumonia in young calves and mastitis in milking cows.
Cattle that have been infected can become nasal carriers of Mycoplasma. Beef and dairy cows can also transmit M. bovis to their calves either via respiratory secretions or milk. The prevalence of Mycoplasma infections in Ireland is unknown.
Unlike respiratory disease, joint infections may be caused by Mycoplasma on its own. Clinically, not only are joints hot, swollen and painful, but tendons above and below may also be affected.
Both mycoplasmal arthritis and pneumonia are frequently associated with an underlying suppression of the immune system, e.g. from concurrent BVD infection or stress from mixing animals, overcrowding or inclement weather.
Respiratory disease is usually followed approximately one week later by joint involvement, though arthritis may occur without any prior evidence of pneumonia. It has also been found that Mycoplasma is capable of causing immuno-suppression and worsening the course of disease caused by other agents.
Diagnosis
Culture and detection using PCR testing from joint fluid is the best for confirming a diagnosis.
Joints remain positive to the culture for a week or more after initial signs. It is best to request your vet to take samples of joint fluid within the first two to three days of clinical disease. Blood samples can also be analysed for antibodies. A negative result in advanced disease probably rules out Mycoplasma involvement. However, a positive result may not confirm a diagnosis as non-pathogenic strains of M. bovis limits the value of the results.
While diagnosis can be confirmed effectively, treatment is still subject to significant limitations. Once disease becomes chronic, treatment is likely to be unrewarding. This means — like our farmers suggest (page 31) — no matter what they treat the cows with it has little or no effect on managing the disease.
Prevention
While there are some reports of effective use of specially manufactured autogenous vaccines in young calves in other countries, these products are not available in Ireland.
As no mycoplasmal vaccine exists, protecting against respiratory viral and bacterial diseases and other management factors that predispose to respiratory disease is essential to curb losses.
Because environmental contamination with Mycoplasma has been reported, cleaning of the environment, particularly water troughs, after removing groups of affected cattle is recommended.
In beef weanlings, preventive use of antibiotics in cohort animals, where a diagnosis has been confirmed, has also proved to be useful in restricting losses.
Treatment and prevention of Mycoplasma infections are not always rewarding. Early intervention is a key success factor.
CASE STUDIES
“I feel very sorry for anyone that has this problem. I had a serious problem with swollen knees and hocks in 2010 and I found treatment with any antibiotics almost worthless. We were treating with long-term antibiotics (six week meat withdrawal products) and, if I were back again, I would put the cows straight up on a trailer and factory them. We treated them and spent thousands on drugs, isolated them and milked them once a day for six weeks and nothing worked for us. To this day, we have no idea why it came or went. We sampled blood and milk and samples from the infected joints which showed up positive. We had 15 to 20 seriously infected from 110 cows milking.” – North Cork dairy farmer
“We have 10 from 100 milking cows in trouble this week — mostly first and second calvers. We haven’t confirmed Mycoplasma Bovis just yet but, already, I can see the knock-on effects will be significant.” – Laois dairy farmer
“This week, we have 25 cows from 80 cows in trouble with swollen hocks and knees. I have some cows in the sick bay on straw that can’t put a leg under themselves. One cow has two swollen knees and a hind leg. We have used all type of drugs but to no avail. Cubicles are well stocked but cows have lots of feeding space. There are no definitive test results back yet.” – West Cork dairy farmer
“We started off with a couple of milking cows having a problem in February 2012. This quickly spread to a few dry cows with swollen joints. I rang the vet — a very good vet — but he didn’t know what was the problem. We took blood samples but numbers affected got worse and worse. We got swelling in calves which seemingly has a disastrous effect on young animals because they are growing. Our best success for testing was taking milk samples — everything else seemed to be a bit hit and miss. Our vet now tells us it is present in every herd but a challenge on the herds immunity can make the problem more pronounced than other herds. Because the bacteria has no cell wall seemingly antibiotics or any drugs has little or no effect.” — Limerick dairy farmer
“We had 50 out of 100 cows with very swollen knees and hocks, some cows were completely crippled. We didn’t do any testing but we used a product in the feed (50g/day) that soaks up Mycotoxins (Actisaf/Mycosorb) and the herd was a different herd four weeks later. No amount of drugs worked for us either so we were very happy when we found this solution.” – Armagh dairy farmer
“Read your article on Mycoplasma Bovis with much interest. Unfortunately, we also had this disease in our bull beef herd and we lost three bulls with it before it was correctly diagnosed. It does not respond to the usual antibiotics. Tylovet is the only thing it will respond to, but you have to hit it early. In bulls, symptoms include secretions from nose and eyes, drooping ears and lameness. If not treated quickly swelling happens in the legs exactly as you described it. This is a terrible disease and can cost thousands if not diagnosed quickly. Our vet told us that due to stress, for example, being at the mart, the animal will develop the disease three weeks later. We buy in all our bull weanlings and, sure enough, three weeks after being bought this disease showed up. I hope that this may be of help to someone as we were looking for answers for a long time.” — Sligo beef finisher
“We had 50 cows out of 200 affected by the Mycoplasma Bovis disease with roughly 30 lameness cases from swollen hocks and 25 mastitis cases. Our vet lab cultured Mycoplasma in the milk but he tells me that to identify this bug, milk must be cultured for six days, longer than what would needed to identify standard mastitis bugs, such as Staph aureus. My problems started on 1 February in a dry cow and I am only now seeing a slowdown in infections with only two cows infected in the last seven days. I have tried several antibiotic treatments and found none to be effective. I’ll have to dry off the 30 worst affected cases but I hope that these will recover enough to allow me fatten them for slaughtering.” — Roscommon dairy farmer
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