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ZOONOSES
or
Everything I Didn't Want To Know About Wildlife Diseases


Zoonoses are diseases that can be transmitted from animals to humans. The causative agents are bacteria, viruses, parasites, and fungi. Possible zoonotic exposure can be eliminated by good personal hygiene and handling of animals in a prescribed manner. Frequent hand and glove washing with an approved disinfectant such as NOLVASANâ surgical scrub must be a priority that is strictly adhered. Good hygiene will also prevent cross-contamination of non-zoonotic diseases from animal to animal. Do not have hand-to-eye or hand-to-mouth contact while working with animals or soiled animal caging, bedding, and accessories. Handling animals in the prescribed manner for that species can prevent zoonotic exposure through bites, scratches, and abrasions.

BACTERIA


TULAREMIA ("rabbit fever"):
Scientific name: Francisella tulerensis
Transmission:
-Through broken skin.
-Undercooked infected meat.
-Inhalation.
-Bite of mosquito, tick, and horsefly.
-Eye conjunctiva touched by contaminated hands.
Host animals: Predominately rabbits and to a lesser extent over 100 mammals and 25 avian species.
Incubation period: One - 10 days
Clinical symptoms:
-Through broken skin: flu-like in nature with skin ulceration at point of organism entry.
-Ingestion: diarrhea and vomiting.
-Inhalation: pneumonia.
Treatment: Tetracyclines or dihydrostreptomycin.
Prognosis: Ranges from complete cure to rare but possible death.
Prevention:
-Exam gloves when exposed to animal blood, particularly that of rodents and lagamorphs.
-Tick control.
-Properly cooked contaminated meat.
-Avoid urine contaminated water.
-Good personal hygiene.

LEPTOSPIROSIS:
Scientific name: Leptospiras spp.
Transmission:
-Direct contact with infected animal.
-Indirect via urine infected soil, water, or food.
-Through intact skin, mouth, or nostrils.
Host animals: Rodents, mustalids, and marine mammals.
Incubation period: Two to 14 days.
Clinical symptoms:
-Icteric type (Well's disease): includes fever, nausea, headache, vomiting, diarrhea, constipation, skin hemorrhages, and jaundice.
-Anicteric type: similar to icteric type but less severe symptoms.
-Stiff neck.
Treatment: Penicillin, tetracyclines, or dihydrostreptomycin.
Recovery time: Icteric, one-two months; Anicteric, one month.
Prognosis: Good.
Prevention:
-Good personal hygiene.
-Proper waste disposal.
-Rodent proofing food supplies and buildings.
-Vaccine is available but seldom prescribed.

LYME DISEASE:
Scientific name: Borrelia spp.
Transmission: Bite of nymph-stage tick.
Host animals: All, including domestics.
Incubation period: One or more weeks. (Exception is a visual ring-shaped lesion or "bull's-eye" which appears at site of bite within 48 hours in approximately 30% of exposures.
Clinical symptoms:
-Fever with chills, sweating, headaches, vertigo, fatigue, and diminished concentration.
-Chronic, reoccurring arthritis.
-Neurologic or cardiac problems.
Treatment: Megadoses of prescribed antibiotics, orally or intravenous.
Prognosis: Good with early intervention; Chronic symptoms possible with delayed treatment.
Prevention:
-Lyme vaccine protection.
-Tick control in animals as well as in the environment.
-Avoid bite wounds and saliva of tick infested animals.
-Personal tick inspections.
-Immediate medical consultation if exposed.

CHLAMYDIOSIS (psittacosis or ornithosis):
Scientific name: Chlamydia psittaci.
Transmission: Inhalation of aerosolized feces.
Host animals: Over 100 avian species including pigeons, raptors, and finches.
Incubation period: Four to 15 days.
Clinical symptoms: Flu-like symptoms which can develop into bronchopneumonia. May be severe in persons over 50.
Treatment: Chlortetracycline.
Prognosis: Good; very low mortality rate.
Prevention: Control of avian fecal matter.

SALMONELLOSIS (A common, worldwide zoonose):
Scientific name: Salmonella spp.
Transmission:
-Fecal-oral.
-Fecal contaminated food and water.
Host animals: Common in opossums but can be found in all vertebrates.
Incubation period: Six to 48 hours.
Clinical symptoms: Diarrhea, vomiting, dehydration, and low-grade fever.
Treatment: Supportive care, bed rest, and electrolytic fluids. Antibiotics are contraindicated unless salmonella group is identified.
Prognosis: Recovery in two-four days.
Prevention: Personal hygiene to prevent fecal-oral exposure.

TETANUS (Lockjaw) (Not zoonotic but worthy of mention):
Scientific name: Clostridium tetani
Transmission: Puncture wound
Host animal:
-Skin punctures by claws or teeth
-Skin punctures with rusty wire or nails.
Incubation period: Up to one week.
Clinical symptoms:
-Stiffness of the jaw (lockjaw), the esophageal muscles, and muscles of the neck. Facial muscles contract, and hysteria is produced.
-Descending trauma develops in the back and extremities.
Treatment:
-Intensive care hospitalization.
-Wound debridement.
-Tetanus immune globulin injection.
-Intense medication regiment.
Prognosis: Depends on severity but usually fatal.
Prevention: Tetanus vaccine protection. A booster shot if inflicted with a bite or other puncture wound.
 

MYCOSES (Fungi)


ASPERGILLOSIS:
Scientific name: Aspergillus fumigatus.
Transmission: Inhalation of fungal spores.
Host animals: Captive birds, mainly waterfowl and raptors.
Incubation period: Undetermined.
Clinical symptoms: Respiratory disorder. (Except for persons debilitated by disease, illness, or on long term medication, most persons are resistant to infection.)
Treatment: Antifungal drugs.
Prognosis: Good with proper treatment.
Prevention:
-Personal hygiene.
-Do not house waterfowl on wood shavings.
-Dispose of moldy waterfowl food or bedding.
-Use of masks during necropsies of suspect animals.
 

HISTOPLASMOSIS (Not zoonotic but worthy of mention):
Scientific name: Histoplasma capsulatum.
Transmission: Inhalation of spores.
Host animals: Indirectly through avian feces.
Incubation period: Undetermined
Clinical symptoms: Mild, self-limited respiratory infection. If severe: fever, anemia, enlargement of spleen and liver, leukopenia, pulmonary distress, adrenal necrosis, and ulcers of the gastrointestinal tract.
Treatment: Intravenous medication.
Prognosis: Good except occasionally in debilitated elderly or pulmonary patients.
Prevention: Routine disposal of bird droppings in roost areas. (Histoplasmosis occurs naturally in the soil. Long term accumulation of avian feces can enrich the soil to favor development of the airborne spores.)
 

VIRUSES


RABIES:
Scientific name: None. Also known as LYSSA or HYDROPHOBIA.
Transmission: Injection of virus via bite wound. Also possible transmission through wounds which have bled within 24 hours, and mucous membrane invasion.
Host animal: All mammals. Seldom diagnosed in small rodents and lagamorphs (rabbits). Viral serotypes are relatively species-specific and do not pass easily from animal to animal in "spill-over" species.
Incubation period: Usually four-six weeks; seldom as short as one week or up to one year.
Clinical symptoms:
-Site of viral entry is painful, tingles, and sensitive to temperature changes.
-Fear of water (hydrophobia, a human symptom only).
-Restlessness.
-Convulsions produced by sensory stimuli.
Treatment: Critical intensive medical care.
Prognosis: Death in almost all cases.
Prevention:
-Pre-exposure rabies vaccine and timely boosters.
-Post-exposure vaccine regiment if you suspect direct exposure.
-Glove use when working with wild mammal species or stray companion animals.
-Use of appropriate disinfectants.
-Sun/air drying of contaminated surfaces.
 

PARASITES


RACCOON ROUNDWORM:
Scientific name: Baylisascaris procyonis. (Baylisascaris columnaris, the skunk roundworm, has the same life cycle and effect on intermediate hosts but is not as prevalent.)
Transmission: Ingestion of egg (ova).
Host animal: Raccoons (skunks for columnaris).
Incubation period: Variable. Once ova is ingested it must mature to larval stage and enter intestinal wall to prevent elimination from the digestive system.
Clinical symptoms: Varies with number of active larva and body tissue damaged (see Prognosis).
Treatment: At onset of symptoms, use of prescribed anthel-mintics may destroy larval migrans but cannot repair previous damage.
Prognosis: Varies with number of active larva and body tissue (mainly organs) damaged. Baylis larva are drawn toward brain tissue and sometimes, the retina of the eye.
Prevention:
-Personal hygiene (fecal-oral contamination).
-Proper and timely fecal removal from cage. (Egg isn't infectious in the environment for approximately 30 days.)
-Active worming program for incoming wildlife. (Parasite in neonatal intakes is same age of host. Shedding of eggs begin at 6 weeks, host orphan can be wormed at approximately 5 weeks.)

IMPORTANT NOTE: Eggs may remain viable in the environment for a year or more. They have a high resistance to decontamination procedures due to dense cell walls and sticky surface. The only sure methods of elimination, once established, is by autoclave, torching with propane, gasoline, or fuel oil, or boiling in lye or LYSOLâ . Small children are most at risk and should be discourage from playing with firewood when brought indoors if fecal deposits have been found on woodpile. Handling firewood with latex gloves should be a strong consideration.

CRYPTOSPORIDIOSIS (Protozoa):
Scientific name: Cryptosporidia spp.
Transmission: Fecal-oral route.
Host animals: Most vertebrates.
Incubation period: Five to 21 days
Clinical symptoms: Nausea, mild fever, abdominal pain, body aches, chills, sweating, watery diarrhea.
Treatment: Supportive care including ample intake of hydration fluids. No microbial drugs against the parasite has been proven safe and effective.
Prognosis:
-If otherwise healthy: recovery by 9-14 days.
-Reduce normal activity for an interval following clinical recovery.
-Immunosuppressed: Diarrhea may be prolonged for up to two years withwasting as well as above symptoms.
Prevention: -Personal hygiene (fecal-oral contamination).