NADIS disease forecast – Cattle (August)

ADULT CATTLE

Fertility
As the autumn calving season gets properly underway, the number of calving difficulties is going to increase. Planning and preparation now can save significant amounts of time, effort and money in the future. As always good hygiene is essential. Endometritis levels are currently around 30% above average and are only going to get worse as calving begins indoors. Dirty calving yards don’t just increase the risk of diseases such as endometritis or toxic mastitis, they significantly increase the severity of the disease as well. Having regular post-calving checks and keeping records of treatment of endometritis can be a useful method of identifying whether calving hygiene is good enough.

The number of abortions remained high last month. Brucellosis still remains a threat as we are still importing cattle from countries that have the disease even though mainland UK is still officially Brucellosis free, so it is important to remember that all abortions should be reported to your local veterinary office. Additional investigation on top of the Brucella tests is always valuable, try and get as much material as possible, particularly the membranes as they can be very helpful in the diagnosis of bacterial abortion.

Keeping cows outside can reduce calving-associated diseases, provided fields remain relatively dry, but this significantly increases the risk of milk fever and grass staggers. The risk of staggers or milk fever can be reduced by very tight stocking of the dry cows so that they are mainly eating provided rations rather than an unknown quantity of grass of uncertain quality. This will also prevent dry cows getting fat, which is one of the commonest causes of calving problems. However the tight stocking rate required can only be achieved on dry, well-drained pasture; a wet muddy field is as bad for endometritis and toxic mastitis as a poorly maintained calving yard. If September is like last year in most areaa, continued calving outside will be a viable option on many farms

Pregnancy rates were too low last month, particularly for dairy cows.  Much of this is due to vets only being called in if the owner considers that there are problems.  Such problems can only get worse as herds become larger and labour more scarce. This will also lead to a higher number of farms where problems are missed and the vet isn’t even called in.  Good fertility is vital and should be at the top of any management plan. Getting cows checked for pregnancy at an early stage can save considerable amounts of money

Lameness
So far this summer the weather has meant that levels of most of the major causes of lameness have been seen at below average levels.  Hopefully a dry September will mean that cows enter housing without too many lameness problems.

Now is the time to tackle lameness problem. For the claw horn diseases (sole ulcer and white line problems) foot trimming before housing will get the feet right before they encounter concrete for 24 hours a day. For digital dermatitis, check your cows. If there are any signs of digital dermatitis plan a daily footbath regime of copper sulphate, formalin, or similar product for at least the two weeks prior to housing. This will treat many of the cows with active lesions and may also eliminate the infection in ‘carrier’ cows that are not showing disease.

Mastitis
So far this year the pattern of summer mastitis has followed the average seen in previous years. However even with August nearly over it is important to remember that one third of summer mastitis cases occur in September, so, particularly if it’s warm, maintain fly control, keep a close eye on your dry cows and heifers for the signs of disease and, if possible, avoid using fields where you’ve had more than the occasional summer mastitis case in the past.

Like endometritis the number of cases of toxic mastitis has been much higher this year than average, which suggests that even though in many areas the environment has looked good, environmental infection is still continuing. This may be because in warm dry weather cows lie down more which increases the risk of infection even though the numbers of bacteria about are lower. If September remains dry and warm this problem may persist.

Metabolic disease
The risk of milk fever and staggers is high if we get warm wet weather and cows remain outdoors. In such circumstances grass can be just like green water in appearance and texture. Imbalances in nutrients, particularly magnesium, cannot be avoided if such forage is the main source of minerals.  Grass staggers problems are likely to be high this month in cattle out at grass; indeed NADIS vets reported some large outbreaks this time last year. Plan your strategy now and ensure that your cows at grass in September have a guaranteed daily intake of magnesium and are not relying on grass alone.

Other Disease Problems
September and October are usually the peak months for lungworm so there could be a large number of husk outbreaks in adult cattle and heifers this year, particularly if September turns warm and wet. It is important to remember that one of the first signs of lungworm problems is drop in milk yield which can occur before coughing is seen. If you do get lungworm in adult cattle, you should discuss your vaccination and worming regime with your vet.

Fog fever is a problem to look out for in September. This disease is seen in cattle moving from relatively bare field to a fresh relatively lush pasture (often a silage aftermath). Affected cattle have severe difficulty breathing and froth at the mouth. Pasture management is the best method of prevention

Growing Cattle
Look out for increase cases of husk in unvaccinated youngstock in September. Summer mastitis is also likely to be a potential problem particularly if the weather is warm and humid, as will New Forest Eye. Both of these diseases are much easier to treat if caught early so regular checking of heifers, combined with fly control, can save you money and prevent significant losses. Poor fertility is a perennial problem in heifers at grass at this time of year, particularly when the quality of grass is variable. If heifers receive poor quality food they’ll have low fertility.

Calves
Previous NADIS data suggest that the number and severity of scour problems is likely to get worse as autumn progresses. Early prompt treatment is essential, getting fluids into calves as soon as possible will save time and money. If problems do not respond to nursing care get your vet involved as soon as possible. In severe outbreaks a sacrifice calf is the best way to get an effective diagnosis that can be used to plan a control strategy

Respiratory problems have been normal low levels so far this summer but some farms still had but there severe outbreaks. Usually cases of respiratory disease are low in September, provided the weather remains relatively fair and the animals are not stressed from management or other changes. Now is a good time to plan your vaccination strategy for the coming winter. New vaccines have come onto the market at the moment so discuss vaccination with your vet to ensure that you are using the best vaccine for your situation.

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