Over the past few months, the clinical team here at Farm Veterinary Matamata have been flat out inserting drycow and teatseal into both cows and heifers. Autumn has truly become one of our most labour-intensive times of year, but we are fortunate that we have had a fantastic team of both permanent and temporary staff on the job this year. Read on for our perspective on using drycow + teatseal vs teatseal only in cows, and a little on the logistics of getting teatseal into heifers.
Combination therapy (Drycow antibiotics + Teatseal) vs Selective (Teatseal alone)
Throughout the evolution of the dairy industry, we have seen no antibiotics used at dry off, whole herd use of antibiotics, selective use of antibiotics, and now with or without the use of a teat sealant. This change in practice isn’t surprising considering the demands we are putting on a cow with increased production and shorter dry periods etc. In short, the purpose of a drycow antibiotic is to both cure an existing subclinical infection (if susceptible to antibiotic) and to protect against new infection for its duration of action. A teat sealant on the other hand won’t cure anything but is very effective at protecting against new infection right up until calving when it is stripped out.
Therefore, it makes perfect sense that if we have enough evidence (herd test data etc) that a cow does not have a subclinical infection we use teatseal alone, which is much more effective than drycow in preventing new infection and spring mastitis. And we reserve the use of Drycow antibiotics for cows that are more likely to have a subclinical infection (over 150,000 for cows and over 120,000 for heifers). The obvious pros of this are that we slow the development of resistant bacteria by using less antibiotics, and we save money by not using unnecessary product. 99.9% of the time the selection criteria for a cow to get teatseal alone is correct but occasionally a cow develops post dry-off mastitis.
Post dry-off mastitis can develop under the following scenarios:
1. If the teatseal is put in without correct cleaning of the teats causing mastitis bugs to be introduced into the teat canal;
2. If the cow already has mastitis which was undetected, or;
3. If the cow’s immune system is compromised at the time of dry-off.
From the few cases of post dry-off mastitis we have investigated and further discussions with the technical vet at the company which produces Teatseal, we have determined the following:
Almost all of the cases seem to culture Staph Aureus, a contagious bug that is already present on farm
Farms at greater risk are those where there has been a recent flare up of late season mastitis, with older or high producing cows that haven’t dried down well (still producing > 5litres)
Based on this bacteriological evidence and known on farm risk factors it appears dry off mastitis in the investigated cases is less likely to be caused by unhygienic insertion of tubes.
Unfortunately, nothing is simple, especially regarding a multifactorial disease such as mastitis. What this disease triangle represents is that for a disease to occur it needs a susceptible host, sufficient pathogen load, and a conductive environment. Specific to mastitis, this means that if a cow’s immune system is down (stress from producing too much milk), there is more bacteria around (increased cases of mastitis in herd), or there is a conductive environment (very wet and muddy), then the chance of developing mastitis increases.
To summarize: What does this mean for you, the farmer?
Our recommendation is to continue use of selective drycow therapy over blanket treatment where possible. Using less drycow antibiotics saves money, saves labour to put it in, and slows down the development of resistance to antibiotics, meaning that antibiotics will still be effective in future.
But based on investigations, selective treatment should only be reserved for situations where:
Herd average BMSCC has been around 150,000 or less
Cows don’t have many teat end lesions on your cows
There is no history of Staph Aureus/ contagious mastitis in your herd
Cows are correctly selected for teatseal only based on accurate and recent herd test data
There has been no late season flare up of mastitis in your herd
Cows have been dried down well
There are no significant stressors on your cows at the time of dry off.
Finally, if you do get any cases of post dry-off mastitis following us drying off your cows, we strongly urge you to contact us so that we can provide advice on the best treatments to use and investigate the cause properly.
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