Every year there are a number of significant flooding events which strike the country, and despite our best efforts to plan, it is inevitable that stock may be caught out in the rising waters.

For dairy cattle there are a number of serious conditions which can occur during and in the aftermath of these events. It is useful to be aware of diseases which may develop in order to get stock through the event and out the other side in the best shape possible.

Safety – People first, Stock second

Removing stock from flooded areas into safe paddocks needs to be done as soon as possible, however regardless of animal welfare, human safety should always be the highest priority and a serious risk analysis should be taken of the situation before considering entering flood waters. Never work alone and if there are any doubts about the safety of the situation, never enter the water.

Lifting down or trapped animals may be required – hip lifters and a supporting strop under the chest, just behind the front legs, is the least damaging way to move cows that cannot walk, over small distances.

The strop can be passed easily through the “armpit” area on one side, then around the front of the brisket and under the opposite “armpit. Just make sure to slide it under the brisket/sternum before lifting the cow.

Hypothermia

While cows have a substantial internal heating unit in the form of their rumen, if they are in water for a prolonged period, low core body temperature will affect them. Low body temperature will make it far harder for a recumbent cow to stand again, and so this needs to be addressed before trying to get her to rise. Place hypothermic animals out of the wind where possible, and make use of empty sheds for shelter if practical.

Once an animal has been extracted to a safe area, warming them up will help them to regain the use of their muscles. Stomach tubing with warm water and electrolytes is an effective way to start raising the core body temperature.

The use of lined and waterproof covers helps to insulate them. Packing them with hay or straw can also help. Twenty-litre buckets or drums filled with warm water can provide a heat source. Any water used as a heat source should not be so hot as to scald the animal.

If any metabolic diseases are potentially contributing to the situation, such as flooding during the calving period, then treatment with calcium and magnesium is warranted.

Water aspiration

Aspiration pneumonia is a risk when an animal’s head has gone under the water. Flood water is full of all sorts of nasty bacteria, and the consequence of aspirating it can be life-threatening.

The antibiotics most farmers have on-hand are of little use against the type of bacteria found in floodwaters – gram-negative bacteria such as E. coli. In addition, aspiration pneumonia does not necessarily develop immediately – it is something to monitor individuals for, for at least 48-72 hours after the event.

A veterinary examination would usually be required to get the right type of drugs on board for the cow, so if there is any concern then about a cow having gone under the water, get a vet involved early on.

Gram negative mastitis

Lactating cattle are at high risk of developing mastitis after exposure to flood waters.

Gram-negative mastitis is the most common type to develop. This can be debilitating in itself, so be sure to check all four quarters thoroughly at every milking for a few days after a flood, or if the cow shows signs of becoming sick.

Therapy for this type of mastitis, most especially if the cow is sick, should involve oral fluid therapy as well as the use of anti-inflammatories for the duration of illness.

Cellulitis and skin infection

While trapped in water, cattle may receive injuries to their limbs which can then become infected. When infection establishes in the connective tissues under the skin, this is known as cellulitis – these infections can spread extensively under the skin and result in a very sick animal.

Skin infections are common when the skin has been abraided and wet for a prolonged time.

Monitor animals for signs such as swelling on a limb and significant lameness, and call a vet for advice at the earliest opportunity.

COW #64 CASE STUDY:

COW #64 WAS AN 8Y/O CROSSBRED cow on day 2 in the colostrum mob. She was one of the top producing cows in the herd. The colostrum mob were grazing a paddock with a known flood plain, however there was plenty of access to safe ground and the forecast for rain was not enough tocause alarm.

During the night, the rain arrived much heavier than expected, with 50mm falling in the early hours of the morning. At 5am, when the colostrum mob were being checked, the whole mob were on the high ground, but #64 was found down with milk fever in 1m deep floodwater.

A phone call was made to get a second person to help, while the tractor, hip lifters and strop were retrieved. The hip lifters were attached and the strop passed blindly under the front legs and chest.

She was lifted from the water and moved 100m away into a flood-safe paddock. A trip back to the shed was made to collect a cow cover, thermometer, two buckets of warm water, electrolytes, anti-inflammatories, penicillin, and metabolic bags.

The cover was put over #64 to insulate her against further heat loss as her rectal temperature was very low. The metabolic bags were given into the vein, along with an anti-inflammatory. Penicillin was administered into the muscle. She was drenched with 30L of warm water with cow electrolytes and propylene glycol. She was then left to recover for a few hours while the rest of the herd was taken care of.

The vets came out first thing to check her for aspiration pneumonia, and luckily her lungs sounded fine so no extra antibiotics were needed. #64 was able to rise later that morning. The cow cover was left on for a few days due to the cold weather.

The day following the flooding #64 had mastitis in 2 quarters. She had milk samples taken and was treated with intramammary penicillin. Luckily the milk samples grew Strep uberis, and the mastitis responded well to 3 days of treatment.

#64 had a rough few days, but went on to recover fully and was back in the herd after the drug withholdings had elapsed.

• Lisa Whitfield is a production animal veterinarian in the Manawatu