170 likes | 511 Views
Case 6: Neosporosis. Linda Behling Sarah Galdi Jamie Jergenson. Case Summary. Herd manager for a 3,000 cow dairy located in Southern California Abortions in 20% of first lactation heifers during first 4-6 months of pregnancy and cows aborting at 5 months
E N D
Case 6: Neosporosis Linda Behling Sarah Galdi Jamie Jergenson
Case Summary • Herd manager for a 3,000 cow dairy located in Southern California • Abortions in 20% of first lactation heifers during first 4-6 months of pregnancy and cows aborting at 5 months • Blood test is being run, but results not back yet • Suspected cause of abortions is Neosporosis
Cause and Transmission • Caused by protozoan Neospora Caninum • Transmitted two ways • From cow to calf (across placenta) • From host to cow (ingestion of contaminated feed)
Results of Neospora • 3 possibilities for fetus: • 1.) Fetus becomes infected early and is aborted • 2.) Fetus is infected late, pregnancy maintained but calf is born with neurological diseases • 3.) Fetus is infected late, pregnancy is maintained, calf is born normally but is more likely to abort during first gestation than heifers not infected
Economic Impact on Dairy Herd • Cows with Neospora have: • Decreased milk yield • Decreased reproductive efficiency • Decreased weight gain and feed efficiency • Decreased value as breeding stock • In California, the approximate economic loss from both abortion and other factors (semen, breeding, vet costs, open/not milking) is $35,000,000/yr
Treatment • No effective drug or vaccine available • Suggestions to reduce incidence: • Remove all cows infected with Neospora • Test replacement heifers and newborn calves • Reduce stressors (low quality feed stuffs, overcrowding and excessive heat) • Prevent horizontal transmission by preventing fecal contamination of cattle feed
Diagnosis • ELISA test • Blood samples
Likely Situation at CA Dairy • Wildlife infected with Neospora by consuming an infected aborted fetus • Wildlife are contaminating feed supply • First lactation heifers and cows (that are housed together) are ingesting the feed • Cattle are passing disease on to fetus (some of which survive and carry the disease to their offspring)
Should the herdsman be fired? • No, Neospora is not tied directly to his or her herd management responsibilities • He just began this past year and the initial infection would have started with the later lactation cows before he was hired. • Improved pest control methods must be implemented to control the presence of wildlife around the dry lot Coyote/Dog FencingLive Traps
Sources • Washington State University College of Veterinary Medicinehttp://www.vetmed.wsu.edu/depts_waddl/Neosporosis.asp • United States Department of Agriculture Agricultural Research Servicehttp://www.ars.usda.gov/Main/docs.htm?docid=11007 • The Merck Veterinary Manualhttp://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/51600.htm