Averting future terrorism requires open eyes, diligence

Dallas-The lingering threat of terrorism prompted ACVIM to devote a half-day symposium on its biological, chemical and agricultural aspects, during its annual forum concluded June 1.

Dr. E. Murl Bailey, Jr., Ph.D., DABVT, consultant in College Station,Texas, and Dr. Tam Garland, Ph.D., DABT, a consultant in Greenfield, Ind.,co-hosted the program.

"Awareness is the first step in preventing agricultural terrorism- recognition of the vulnerability, and disease potential and clinical signsof disease in animals and people," says Garland.

Bioterrorism is defined as use of a microorganism derived from livingorganisms to induce death or disease in people, animals or plants. The mostsignificant bioterror threats, according to Garland, are smallpox, botulinum,anthrax and the plague.

Botulinum

"Botulinum is the most toxic of known toxins," she says. Itis produced by anaerobic bacteria Clostridium botulinum.

A primary sign of botulism intoxication, says Garland, is flaccid muscularparalysis, as well as difficulty swallowing or breathing, urinary complications,and inability to stand.

"One of the most obvious signs in cattle is loss of the abilityto retract the tongue, so the animal's tongue hangs out of the mouth,"she says.

Antitoxins for botulinum are available from CDC.

Anthrax

Anthrax, or Baccillus anthracis, is believed to be one of the plaguesof Egypt. Although a threat to many species, it affects ruminants most profoundly,and presents in three forms: cutaneous, pulmonary and inhalation.

The disease spreads among grazing animals, says Garland, via contaminatedsoil and feed, by blowflies and by contaminated meat or feed.

"Penicillin is the antibiotic of choice for cattle, horses and petanimals," says Garland.

Plague

Although the prairie dog is the most sensitive species to plague or Yersiniapestis, the cat is the most sensitive domestic sentinel.

There are two forms of plague: bubonic and pneumonic. Primary signs ofBubonic plague are swollen lymph nodes, or buboes. In pneumonic form, respiratorysigns predominate, according to Garland.

Primary signs of plague in cats are buboes, accompanied with a high fever.

"Cats more rarely develop pneumonic plague, passing the agent throughthe air as they cough or sneeze," Garland says.

Flea control and strict isolation of infected animals can help preventnatural occurring plague. Also, animals can be treated with doxycycline,amoxicillin, streptomycin or tetracycline.

Chemical terrorism

Don't underestimate the abuse of chemicals to cause disease and deathin a target population such as animals via a contaminated feed supply, advisesBailey of Texas A&M.

"Most chemicals rapidly cause a disease syndrome, but some chemicalsmay induce a slow insidious disease," he says.

The red-flag chemical agents are: nerve agents, irritating agents, chokingagents and blister agents.

Chemical agents are classified in the following categories: lung irritant(i.e., phosgene, chlorine gas); vesicant (mustard gas, Lewisite); sensoryirritants (riot control agents); blood agents (cyanide agents, HCN, cyanogenchloride); nerve agents; and incapacitating agents.

"A nerve agent could be the most likely chemical agent to be usedby a terrorist; they are nothing more than very toxic organophosphate insecticides,"says Bailey.

A normal treatment regimen for nerve agents is atropine.

Vesicants would most likely affect an animal's exposed skin, or eyesor be ingested. Prognosis is bleak to grave.

"Incapacitating agents, while not normally lethal could cause adiagnostic nightmare," says Bailey. Terrorists may attempt to contaminatea food or water supply with such chemicals. Clinical signs induced in animalscan be managed pharmacologically.

Government on red alert

"The threat of biological weapons and potential for terrorists todisrupt economies and societies by introducing pathogens into the food supplyand livestock is now being taken seriously by government agencies,"says Garland.

The USDA has established a biosecurity system to prevent introductionof dangerous plant and animal pathogens into the agricultural system. (Seerelated story, page 17.)

For security, it is advised to isolate sick animals, avoid other farms,and disinfect. Watch for signs of salivation, lameness and unusual swellings.

"Veterinarians should be alert to any of these situations and reportthem as soon as possible to the appropriate official responsible for investigatingoutbreaks," Garland says.