|Annual Report 1999|
The Division of Animal Health maintains disease control programs to protect the health and well-being of livestock in New Jersey. As part of its regular operations throughout the year, the Division of Animal Health conducts epidemiological investigations of diseases and drug residues, operates an animal health diagnostic laboratory, manages a contagious equine metritis quarantine facility for imported horses, and supports a vigorous Johne's disease control effort.
1999 saw the decade's highest incidence of Eastern equine encephalitis (EEE) in the Garden State, brought about by the convergence of numerous factors - a mild winter, an early northward wild bird migration, a wet spring and a burgeoning mosquito population. The division worked closely with the veterinary community and horse and poultry owners to alert them to the prevalence of this insect-borne disease and the availability of vaccines which could prevent EEE fatalities in equine. By the time mosquito season had ended, EEE had claimed nine equine and infected several bird flocks around the state. The disease also killed more than a dozen emu in Cumberland County, as well as quail on an Atlantic County farm, pheasant on farms in Ocean and Warren Counties, and a racing pigeon in Middlesex County.
Equine infectious anemia (EIA), a viral disease transmitted by biting insects and contaminated needles, debilitates the immune system and eventually causes death. With no vaccine to prevent EIA infection, the discovery of an EIA case this year was troubling. The division's investigation revealed that the infected horse had been brought in after purchase out of state. The division worked closely with veterinary officials in the state of origin to insure that the disease had not spread to other horses in the same shipment. Fortunately, the remainder of the imported horses proved to be free of the disease.
New Jersey is one of 18 states approved by the USDA to quarantine and test stallions and mares imported from countries known to be endemic for contagious equine metritis, a serious equine venereal disease not found in the United States. This year the facility in Long Valley housed 31 mares and seven stallions during their required quarantine and testing period. Many of the horses come to the Garden State from Germany, the Netherlands, Ireland and Great Britain and will eventually be used for breeding. Importing these valuable horses safely into the United States improves the bloodlines of these breeds and frequently leads to the birth of outstanding equine athletes who stand out in both domestic and foreign competitions.
The last unusual equine health issue that faced NJDA this year required the Division of Animal Health to assist an equine veterinarian who was trying to determine the cause of a neurological disease in five horses at a stable in Bergen County. The symptoms exhibited, including lack of coordination and severe weakness of the hind limbs, could have had many causes. Ultimately, the animal health laboratory was able to diagnose the disease as equine herpes virus for which there is no effective vaccine. These were the only reported cases of the disease in the Garden State this year.
NJDA's three-year-old voluntary Johne's disease control program for New Jersey dairy farmers focused this year primarily on herd testing and identification of Johne's-positive animals using a blood test and a fecal culture, both of which are processed in the department's laboratory. More than 20 percent of the state's dairy herds have participated in the Johne's control program. Because the causative bacteria results in severe diarrhea, weight loss and eventual death, it is estimated that farmers with Johne's-infected herds could lose up to $200 per cow every year due to decreased milk production and early culling losses.
A secondary, but equally important, focus is the development of an individual herd plan for each participating dairy producer based on a farm walk-through by Rutgers Cooperative Extension and NJDA personnel. The walk-through can help pinpoint high-risk practices for Johne's transmission, such as inadequate manure management, and enable dairymen to incorporate improvements into the herd plan. Moreover, dairy producers participating in the NJDA program will have a head start on compliance with USDA's Johne's control program guidelines which are expected within the next few years. In addition, the positive herd management changes dairy farmers institute for Johne's control also help them control other important diseases such as E. coli and salmonella.
Although this region of the United States has been alert to the potential for more frequent cases of rabies in wild animals and domestic pets, the disease is not generally associated with livestock. However, the vulnerability of farm animals to the disease was underscored this year when the division's animal health laboratory was called upon by the New Jersey Department of Health & Senior Services to confirm a suspected case of rabies in a Holstein heifer yearling from Warren County. This was the only confirmed case of rabies documented in New Jersey's livestock herds this year.
Because of the devastation avian influenza (AI) virus can cause to the state's poultry industry, the division continued its annual monitoring visits to the live-kill poultry markets in the tri-state area to determine which strain of the AI virus is circulating in the bird population. This year, following USDA's official recognition of the markets as indicators, rather than sources, of AI, the Division of Animal Health brought together officials from Delaware, Pennsylvania and New York to begin the process of establishing uniform rules and procedures for live-kill poultry markets to minimize the occurrence of AI.
During the fall, the discovery of AI at a game poultry farm in Somerset County led to a more conservative, yet very effective, alternative to depopulation. The affected farm raised 60,000 pheasants and quail sold for slaughter. Since USDA indemnity funds for AI were scarce and the market for the expensive birds was unique, the Division of Animal Health devised a system to bring the birds out of quarantine. The process entailed placing sentinel birds free of the AI virus in strategic areas near the remaining game birds, with the assumption that, if the AI virus were still present, the sentinel birds would succumb and test positive. In this case, test results were negative. With the continuing shortage of federal indemnity funds to cover AI losses, the division's method of "testing" farms out of quarantine should prove to be an economical way to protect poultry farmers in the Garden State.
NJDA's animal health laboratory conducts a wide variety of tests to support domestic livestock disease control programs, including veterinary bacteriology, virology, serology, pathology and histology. Equine veterinarians in New Jersey rely on the laboratory for required Coggins tests for equine infectious anemia (EIA) as well as tests for Eastern equine encephalitis, equine influenza, Lyme disease, Potomac horse fever, herpes virus and equine viral arteritis.
Bovine practitioners in New Jersey rely on the laboratory for tests such as bovine viral diarrhea, parainfluenza, infectious bovine rhinotracheitis, brucellosis and Johne's, among others. In addition, the laboratory prepares specimens and coordinates testing for some foreign animal diseases and zoonotic diseases.
In FY99, the laboratory added a diagnostic test for leptospirosis, a bacterial disease of both large and small animals. The laboratory also successfully completed required certification testing administered by the National Veterinary Services Laboratories. Such regulatory test certifications included EIA, bluetongue and pseudorabies. Through these and other services, the laboratory supports New Jersey's livestock industry by providing private veterinarians with an in-state source of disease testing that provides fast, accurate, convenient and economical animal health testing services.
In addition to its regular programs to safeguard the health of New Jersey's livestock, the division also focused this year on a variety of serious livestock diseases with the potential for disastrous economic impact on the industry: Eastern equine encephalitis and equine infectious anemia, both spread by insects, and avian influenza, a recurring problem for the region. In addition, the division dealt with isolated cases of both rabies and equine herpes virus.
The Division of Animal Health played an important part in a variety of industry outreach efforts this year, including:
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