The spring and summer of 2008 was hard on Midwest livestock producers. In addition to the high price of corn, widespread flooding damaged and still threatens livestock operations. This isn’t the first time flooding has im-pacted cattle herds, however. The USDA states that several thousand dairy cows perished during floods in Snoho-mish Valley, Wa. in 1991, approximately 1,200 dairy cows perished during floods in Tillamook, Ore. in 1996 and during 1997, and approximately 90,000 beef cows died during floods in Minnesota, North Dakota, and South Dakota.

Just three years ago when hurricanes Katrina and Rita rolled through the Gulf Coast, thousands of cattle were also affected. Observers estimate producers lost at least 80% of the cattle in Plaquemines Parish, La., alone.

Common hazards to livestock during flooding include:

  • Contaminated food and water supplies
  • Standing, stagnant water
  • Mosquitoes
  • Livestock carcasses
  • Sharp objects transported or blown into pastures
  • Sick/diseased animals
  • Wild animals displaced by floodwaters
  • Damaged barbed wire fences and gates
  • Weakened barns and other structures
  • Eroded and unstable creek beds

    (David W. Smith, Texas Extension Disaster Education Network)

Louisiana State University Extension veterinarian Christine B. Navarre, DVM, MS, Dipl. ACVIM, says flooding issues caused a variety of immediate problems for cattle. “Cattle were stranded on levees with only brackish/salt water to drink without enough food,” Navarre says. “There were some injuries and thousands drowned.”

Navarre saw a rise in infectious abortions (infectious bovine rhinotracheitis and Leptospira hardjo, both diagnosed) from commingling cattle. “We also had reports of respiratory disease.” She notes that some mastitis problems occurred on dairies from lack of power and having to milk erratically.

Severe flooding in the 1990s helped many of the Oregon Coast dairymen prepare for smaller-scale flooding in the past several years. Former dairy practitioner and vice president of Quality and Member Services for Tillamook County Creamery Association, Tillamook, Ore., Mark Wustenberg, DVM, says in the last two years the number of animal mortalities due to flooding has been relatively low and usually related to producers not reacting fast enough as the water is rising. In most cases the dairies are moving their animals to a neighbor’s temporarily or moving them onto “cow pads” (elevated areas created with fill) that allow the animals to temporarily get up out of the barns.

Wustenberg says, “This last winter we had one herd that lost milking animals and heifers because they chose to leave their animals on the dairy while the neighbors took theirs to other farms. They did have a cow pad and put the animals on this but they failed to fence or restrain the animals and some decided to leave the elevated pad.”

Increased mastitis

More recently in the Midwest, Mike Knoll, DVM, River Valley Veterinary Clinic, S.C., Plain, Wis., had clients affected by the spring and summer flooding. He says though they didn’t see many cases of drowning or lightning strike in livestock, they have seen some increase in environmental mastitis cases. “We’re concerned about potential diseases such as foot rot/hairy heel warts and clostridial diseases,” Knoll says. “We’re recommending initiating or boostering J5 and clostridial disease vaccinations.”

Wustenberg notes that somatic cell count (SCC) will increase even in low SCC herds with irregular or missed milkings. “In herds where SCC typically runs low, the counts will come back down rapidly as regular milkings are re-established,” he says. “In herds where there is significant subclinical mastitis, it may take a while for the counts to come down. Re-establishing a regular feeding, milking schedule and getting animals a dry place to lie down is really the best medicine.”

Erratic milking and milk-hauling was also a problem for dairies along the Oregon Coast that flooded in 1996 and subsequent years. “Many dairies have generators that will allow milking but don’t have the added ability to keep the milk cooled properly. Our biggest logistical issue is figuring out how to get the milk off the dairies and to the plant,” says Wustenberg. “Roads are flooded and blocked by downed trees because we get flood and wind together. Power is out so milking times vary. We need to pick up milk right after milking because cooling is inadequate. The milk haulers are probably the biggest ‘unsung heroes’ in this situation.”

Post-flooding problems

Diseases aren’t the only livestock problems that can happen subsequent to disaster issues. Flood-damaged feeds and mycotoxins are a real concern for Knoll and his clients. “We are advising clients to watch for moldy feed. If moldy feeds are fed, producers should test for mycotoxins, monitor for feed refusal or illness and dilute with safe feeds. Mycotoxin-absorbing products may be helpful. Mycotoxins can be especially problematic in young stock and pregnant animals.”

Wustenberg adds that when exposed to flood waters, the bottoms of hay stacks begin to heat and commodity piles do the same, and there is usually some damage to silage piles, “although if they are packed well it’s surprising how little penetration into the piles you get,” he says. “You can get changes in parts of stacks that continue to take place post-flooding relating to moisture, pH changes and contamination with things like Listeria, Bacillus, and clostridials.”

“The degree of feedstuff destruction will depend on the relation of moisture, time and temperature; and, of course, how rapidly drying occurred to suboptimal levels for microbial proliferation,” says Gavin Meerdink, DVM, Veterinary Diagnostic Investigations, Inc., Mahomet, Ill. “About any of the agents listed under mycotoxin production would be suspect and depending on aerobic/anaerobic conditions, clostridial and other anaerobes would have to be included.” Meerdink says in addition to potential bacterial and mycotoxic problems, veterinarians should be aware of the potential contamination of flooded feedstuff from adjacent materials such as petroleum tanks, chemical storage facilities, etc.

Many of Knoll’s clients were also affected to varying degrees based on topography and run-off. “Crop losses are by far more significant than direct animal losses,” he says. “Both corn and soybean land have either been lost or damaged by flooding/soil saturation. Some replanting has been done but some land was too wet to allow that. High feed costs are going to make it very difficult for farmers who have had significant crop losses.”

In Louisiana, Navarre says one huge problem in beef herds was the lack of working facilities, fences and barns that took time to rebuild, especially when most families were dealing with having to rebuild/repair their houses. “The dairies also had many fences destroyed and downed trees in pastures in the way of planting winter grazing. That affected production as we rely heavily on winter grazing for nutrition.”

An 18-month drought following Katrina and Rita compounded the problems. Salt from the Rita storm surge in southwest Louisiana remained in the soil which affected some ryegrass planting for beef cattle. Economic costs to replace animals and pay for the labor to re-fence (despite donations of amount of fencing materials) were huge.

Wustenberg says re-establishing pasture productivity and the impact on additional purchased feed costs was significant in that the impact can extend in some cases for months to even years depending on the extent of damage. “It can be really difficult for folks because assistance is usually focused on the immediate issues and not the longer-term impacts to productivity and cost.”

Louisiana producers also had some problems with rustling of beef cattle. “People showed up with trailers saying they were here to help rescue stranded cattle,” Navarre notes. “They loaded them up and were never seen again, and tags were cut out.” As a result, many of the producers have gone back to branding.

Though she doesn’t know if it’s related, Navarre has seen an increase in reports of clostridial diseases in both adult and young cattle this spring. “We have no way of knowing if this is a delayed effect of hurricanes/drought or both,” she says.

How to be prepared

Knoll believes veterinarians can be key players in disaster preparedness. “Flooding like we’ve experienced this summer has reminded us how important contingency plans are. The State of Wisconsin has been recruiting veterinarians to join the Wisconsin Veterinary Corps. This is a group of veterinarians that undergo training and volunteer to help out in the case of disease outbreaks or natural disasters. An event like this year’s floods provides incentive for us to put more emphasis on disaster preparedness.”

Navarre agrees. “Veterinarians need to be ready to respond to their producers’ needs, or more importantly, help the producers prepare in advance. They also need to know how to prepare their practices. Those were very hard times for our veterinarians’ businesses during and after the hurricanes.”

Navarre adds that an important area in emergency preparedness is having a well-vaccinated herd. “We want them to be ready if they have to be moved or commingled. We don’t want to wait until the event is under way.”  Another aspect of preparedness, she says, is having premises identification.

Wustenberg suggests helping clients develop emergency plans for moving animals, getting facilities cleaned up and sourcing feed and bedding post-flooding. “It is important to involve the state department of agriculture, including the state veterinarians and the local emergency and relief agencies,” he says. “We have been working with the local 911 folks to see if there is a way to coordinate folks who need animals moved with folks that have trailers and can get there to help.”

Last year Wustenberg says they were able to identify areas where they were under the most pressure to re-establish milking and milk delivery to the plant. “We were able to communicate this to the road crews and folks working on establishing power so that they could better focus their activities. They, in turn, could give us information on when they were going to have power and roads re-established so we could better coordinate the milk hauling and producer activities.”