Do you have calves breaking with severe scours around 10 days of age or older? Then, it’s possible you may have a Salmonella outbreak.
“Salmonella is a fast-acting and hard-hitting organism that typically causes disease in older calves, but can hit newborns,” says John Gay, veterinarian with Washington State University College of Veterinary Medicine. Gay has studied Salmonella on dairies for many years and says calves are among the most susceptible animals to the organism on the farm.
Calves with Salmonella scours can quickly become severely ill, says Gary Neubauer, veterinarian and senior manager, Dairy Veterinary Operations, Pfizer Animal Health. “They usually do not want to drink milk or milk replacer, have high fevers, and their stools are watery and often tinged with blood. Dehydration happens quickly, and death can occur within 12 to 48 hours after the first signs of illness.
“It is important to detect this disease early and begin replacing fluids with high-energy oral electrolytes as quickly as possible, while they still can be effective,” Neubauer advises. “Antibiotic therapy also can be helpful, but only if the bacteria are not resistant to the drug, which can happen frequently in the case of Salmonella. Work with your veterinarian to perform antimicrobial susceptibility testing and to establish treatment and vaccination protocols.”
Gay notes that calves infected with Salmonella can shed the organism in feces, urine, saliva and/or nasal secretions, contaminating everything they touch, and everything that touches them. And if calves are sick, there are likely more that are shedding but have not broken with symptoms. He offers the following suggestions for helping contain the disease and helping prevent calves’ exposure to the organism:
- Thoroughly sanitize all calf equipment, including bottles, nipples, esophageal feeders, balling guns and syringes, after every use. First scrub off all organic matter before sanitizing, allow sufficient sanitizer contact time, and dry the equipment completely so that equipment looks, feels and smells clean inside and out. Make sure the sanitizer you use is labeled for Salmonella, or Gram negative bacteria, as many commonly sold products may not be effective in killing Salmonella. Follow all label instructions, including dilution, contact time required for the temperature and solution change frequency.
- Handle sick calves last to avoid transmitting the bacteria via equipment or workers’ hands and clothing. Have “clean” people handling clean items, such as putting out full nipple bottles and have “dirty” people handling contaminated items, such as picking up empty nipple bottles for washing and sanitizing.
- Feed at least four quarts of high quality colostrum within two hours after birth and 2 quarts more in the first day of life for newborn Holstein calves. Make sure the udder and the colostrum-feeding equipment are clean before harvesting colostrum, cool it quickly and store properly. Do not pool colostrum because Salmonella and other infectious agents can be transferred from one cow to multiple calves.
- Maintain clean, well-bedded calving facilities to minimize the possibility of newborn calves ingesting manure from adult animals. To control flies, do not use straw bedding in the summertime.
- Move calves to a clean, individual hutch in the first day of life so each sick animal is isolated from physical contact and the air space of healthy calves.
- Restrict exposure of calves to older animals in the herd, including manure. Workers who handle both adult cows and calves should be encouraged to wear and regularly change disposable gloves, disinfect boots between animal groups, and change soiled work clothing.
- Remember that Salmonella can be transmitted to humans. After handling sick calves, clean and sanitize boots, wash hands thoroughly if they are soiled and use an alcohol hand rub frequently. Remove and launder work clothing promptly, particularly before entering the household.
“If not exposed to direct sunshine, Salmonella bacteria lives in the environment for months,” says Gay. “If the transmission cycles aren’t broken it can become an ongoing epidemic in a herd’s calf population, but there are measures to get it back under control.”
For more information on strategies for helping control Salmonella, talk to your herd veterinarian.
Source: Pfizer Animal Health