Biochemical Warfare Agents: What you need to know for your companion animal

With anthrax scares as a heightened national and international concern, it is important to recognize if your companion animal has been exposed to deadly biochemical agents. Questions such as how exposure affects non-human animals and what to do in case of exposure are primary concerns. Although it is unlikely that anyone’s companion animals will be affected, early diagnosis and therapy is crucial. The following information on potentially deadly biochemical agents is critical for animal lovers everywhere.

1. Anthrax: Anthrax is caused by Bacillus anthracis, soil-borne bacteria. It is ubiquitous in the environment. Herbivores (for example, cattle) get it from ingesting contaminated soil. Carnivores (for example, dogs and cats) get it by ingesting raw meat of contaminated carcasses or animal byproducts. Dogs are relatively resistant. Anthrax will cause inflammation and damage to the gastrointestinal tract. It can also cause the head and neck to swell, and then spread to lymph nodes and internal organs. Penicillin and other antibiotics can treat it. Animals suspected to have anthrax should be taken to a veterinarian immediately. Dead animals can spread the disease and should be handled by professionals.
2. Plague: Plague is caused by Yersinia pestis. It is maintained in wild rodents and transmitted by fleas. Dogs and cats can get it by fleabites. They can also get it from contact to a mucus membrane (the inside of the nose and mouth), broken skin, or inhalation. Cats have a similar susceptibility to people. Dogs, however, are very resistant. Cats and dogs get the disease by eating an infected rodent or rabbit, or from bites from plague infected fleas. Dogs develop a high fever and swollen lymph nodes. Cats develop fevers, swollen lymph nodes, and depression. Lymph nodes may abscess and drain pus. Sometimes, discharge from the eyes, vomiting, diarrhea, facial sores, and weight loss are present. The infection can become systemic and spread to the liver, kidney, spleen, brain and lungs. Collecting tissue samples from affected organs and tonsils is critical for diagnosis. The bacteria are very slow growing so treatment may be instituted before a confirmed diagnosis if plague is strongly suspected. Several antibiotics are effective including streptomycin, gentamicin, doxycycline and fluoroquinolones. Humans need to be treated too.
3. Tularemia: Tularemia is caused by Francisella tularensis. It is spread by ticks, and carried by Dermacentor andersoni, Dermacentor variabilis, Dermacentor occidentalis and Amblyomma americanum. There is a localized infection at the site where the tick attached. Cats are more susceptible than dogs, and young animals are more susceptible than older animals. Fever, discharge from the eyes and nose, enlarged lymph nodes, and pustules at the tick bite site are present. Experimentally, cats have become sick from eating purposefully infected guinea pigs. Dogs are relatively resistant, but may show a decreased appetite, fever, draining abscesses, and sudden death. Cats become depressed, have enlarged lymph nodes, oral ulcers, jaundice, and draining abscesses. There is no definitive treatment but fluoroquinolone antibiotics may be helpful. People can get it from being bitten or scratched by a cat. Prevention of tick bites and ingestion of wild mammals will decrease chances of exposure. There are excellent tick control products such as Frontline and Preventic collars. Preventic collars are not suggested for use in cats.
4. Q fever: Q fever is caused by Coxiella burnetti. Infected ticks transmit it. It may also be inhaled or ingested. Animals get it from eating infected animals such as cattle, sheep and goats. Wildlife animals can also be infected. Dogs and cats that eat wildlife can then become infected. Infected animals shed organisms in feces, urine, milk and placentas. Fortunately, dogs and cats usually have mild infections, manifesting in fever, loss of appetite, and lethargy. Q fever may be treated with tetracycline or chloramphenicol.
5. Botulism: Botulism is caused by Clostridium botulinum. Animals get it from ingesting preformed toxin in contaminated food. Honey is a major source of botulism toxin. There have been no natural cases reported in the cat. Most dogs are relatively resistant, however it is seen in the dog. Dogs with botulism become progressively weaker and weaker until they are unable to stand. They have decreased jaw tone (so the jaw drops), salivate excessively, and have a weak bark. The disease can be diagnosed by finding toxin in blood, feces or organs. Therapy consists of antitoxin and supportive care. Fortunately, dogs can recover. Botulism toxin can be inactivated by heating food to high temperatures (80 degrees Celsius for 30 minutes or 100 degrees Celcius for 10 minutes.) Also, prevent your pet from eating carcasses.
6. Anticholinesterase agents: These nerve agents work by inhibiting the breakdown of acetylcholine, a major neurotransmitter of the body. Clinical signs are related to over stimulation of the nervous system. Minutes to hours after exposure-affected animals will salivate, vomit, and have diarrhea, experience changes in heart rate and pupil size. They may also have muscle twitching and seize. Cats are more sensitive than dogs. The condition is diagnosed by measuring cholinesterase levels. Several emergency drugs such as atropine and 2-PAM can be lifesaving.
7. Nitrogen mustard: Nitrogen mustard is a vesicant or blister agent. It is used as a chemotherapy agent in dogs. It can cause skin blisters, but also gastrointestinal, liver, kidney, and bone marrow damage. The outer layer of the eye can also blister. Supportive care can be lifesaving.

For further information on these biochemical agents, please contact:

Jennifer Chaitman, VMD, Diplomate ACVM

Veterinary Internal Medicine and Allergy Specialists

Internal Medicine

207 East 84th Street

New York City, New York 10028

T 212-988-4650

http://www.vimany.com