Neosporosis in a Dairy Herd Jenny Cigan and Tyler Schaaf

Problem:  Herd manager for a 3000 cow dairy herd  Herd is vaccinated for a variety of different diseases and AI is used on all cows  Seeing an abortion rate of 20% in first lactation heifers after 4-6 months of gestation  Suspect Neosporosis

Neosporosis:  Caused by very small single celled protozoa called Neospora canium  Causes abortions in mid gestation in cattle, sheep, goats, dogs, and horses  Outbreaks occur in herds that may be stressed from other disease or that have never been exposed to the parasite before

Transmission:  Dog is the “definitive” host- where parasites produce infective eggs  Cow is the “intermediate” host- ingests the eggs and becomes infected

Two Modes of Transmission: 1. Ingestion of parasite eggs shed in feces of infected canines 2. Transmission of the parasite from an affected cow to her calf in utero Dogs can also be infected by ingesting placentas from infected cows, propagating the cycle

Symptoms:  No clinical signs either before or after abortion  Diagnosed through microscopic examination of placentas or aborted fetuses or through blood tests

Impact on Production:  Loss of 20% of calves from first lactation heifers is a huge economic loss  Infection lowers milk production an average of 760lbs per lactation  Mastitis is more prevalent in infected cattle

Treatment:  No vaccines or treatments for the disease are currently available  Once infected, cattle have the disease for the rest of their life

Control Measures:  Prevent canines from contaminating cattle feed or water  Do not leave placentas or aborted fetuses in the pasture for wild dogs to consume  Test any new animals coming into the herd for Neosporosis  Cull infected animals if feasible

Job Security?  Should we be fired?  No, but action should be taken to insure no more infection by canine contamination occurs

Neosporosis Questions? Jenny Cigan and Tyler Schaaf