ZOONOSES

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ZOONOSES

• One of the hazards of working with animals

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General Information

• After this session you will be able to
• Recognise the potential hazards associated with
  handling animals
• Relate personal hygiene practices to conditions
  that favour the spread of organisms harmful to
  human health
• List zoonotic diseases and their symptoms in man
• Describe precautions required when handling
  animals, especially in relation to zoonotic
  diseases

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Zoonoses

• An infection that is transmitted naturally from
  vertebrate animals to man
• Can include bacteria, viruses, fungi, internal
  parasites and arthropods
• Give new owners advice on hand washing, picking
  up faeces, maintaining internal and external
  parasite control and getting regular vet checks
• Immuno- compromised people are at special risk
• All animals leaving the shelter should be health
  checked, vaccinated, wormed and treated for fleas
• All rearers should have basic health knowledge to
  be able to recognise signs of disease

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Risks in a Shelter Environment

• High degree of turnover in animal population
• High risk of new animals contacting disease
• Stress, poor nutrition and presence of concurrent
  disease make the transmission of disease more
  likely
• Animals that enter shelters are regularly roamers
  and scavengers
• They are often infested with external parasites
• Staff are at increased risk of being bitten or
  scratched

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Control of Zoonotic Diseases in the Shelter

• Often animals may show no clinical signs
• They can shed disease after recovery
• Staff must realise any animal can be a potential
  source of infection so must maintain protective
  measures continually
• Educate staff and volunteers about zoonoses
• Staff must wear appropriate clothing and PPE
• Must wash hands between handling animals and
  before eating
• Appropriate staff should have protective
  vaccination

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Visceral Larval Migrans

• Dog and Cat Roundworm
• Soil or fomites contaminated with eggs from dog
  or cat faeces
• Ova require several weeks incubation in the soil
  before they become contaminated
• Intermediate stages migrate through the body as
  part of the life cycle
• In humans will migrate to the retina, liver,
  lungs or muscle
• Mostly in children- most common form of blindness
• Contracted through not washing hands

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Control

• Dispose of dog and cat faeces daily
• Deworm animals regularly
• Good personal hygiene
• There is no effective treatment known

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Cutaneous Larval Migrans

• Hookworm
• Source
• Contaminated soil and continually wet areas
• Larvae viable for several weeks
• Larvae penetrate through the skin
• Clinical signs
• Intense itchiness at site of entry
• Narrow elevated track along skin
• May last 50 weeks
• Treatment is through freezing and medication

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Control

• Prevent contamination of soil
• Dispose of dog and cat faeces regularly
• Deworm every 6 weeks if in an infected area
• Wash hands
• Wear gloves when working in soil

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Leptospirosis

• From pigs, cattle, rats and dogs
• From contaminated water around these animals
• Clinical signs
• Headache, malaise,renal problems, stiffness
• L Icterohaemorragia can cause severe illness
• Treatment is with antibiotics
• Control
• Protective clothing
• Cover wounds
• Rodent control
• Protect water supply from animal urine
• Vaccinate incoming dogs

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Cat Scratch Fever

• From cat nails- 17-25 of cats carry the organism
• Bacteria is transferred from cat to cat by fleas
• Bacteria
• Transmitted by scratching
• Incubation of 3-10 days
• Fever, pus, chills, enlarged lymph nodes
• Treatment by antibiotics

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Hydatid Disease

• Dog is main host
• Transmission via eating ova in dog faeces
• Eggs viable for 6 months
• Embryonic worms escape from intestine and enter
  the body
• Cysts are formed in liver,lung, brain,bones
• May take years to diagnose
• Symptoms are pain from space occupying lesion
• Rupture of cyst can cause death from anaphylaxis
• Treatment is surgery /or drugs

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Control - dont feed raw offal - dont allow
dogs to scavenge - good personal hygiene -
dont allow dogs to lick faces or hands - worm
dogs regularly
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Ringworm

• Fungus- Microsporum canis, Trichophyton spp
• Spores remain viable up to 2 years in the
  environment
• Incubation period -4-14 days
• Transmission- direct from infected animal
• - indirect from bedding and cages
• Signs- bald patches, red circular welts with
  inflamed edge
• Treatment is usually topical

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Human Ringworm lesions

• Control
• Check pets
• Wash hands- general hygiene
• 1 Halamid is effective at disinfecting the
  environment

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Psittacosis

• Parrots and cage birds, wild birds,
• pigeons, chickens
• Environment and direct contact with
• nasal, occular faecal discharge of birds
• Spread by inhalation
• Incubation 4-15 days
• Symptoms- chills, fever, headaches,pneumonia, can
  be fatal
• Treatment by antibiotics
• Control- isolate sick birds, avoid contact with
  sick birds
• Clean, air disinfect premises

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Toxoplasmosis

• Cat is the primary host- it is infected by direct
  contact with infected faeces or soil or eating
  raw meat or hunting rats, lizards etc
• From cat faeces, soil and undercooked meat
• Ingestion of under cooked meat,infected cat
  faeces or soil
• Symptoms in non pregnant people include mild flu
  like symptoms which may last months
• In pregnancy the foetus can be severely damaged

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Toxoplasmosis

• Control
• Cook all meat before eating
• Wash hands after handling raw meat
• Dont feed cats raw meat
• Keep cats in at night to stop hunting
• Collect faeces daily and dispose correctly
• Use gloves when gardening and handling faeces
• Cover sandboxes
• Have a blood test before falling pregnant to see
  if positive already- immune if have a positive
  titre

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Scabies

• Wild and domestic animals- pigs, dogs, horses,
  wombats, guinea pigs and ferrets
• Infection is through direct contact
• Intense itchiness is the main symptom especially
  at night

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Scabies
The mites burrow under the skin, laying their
eggs at the end of the burrows. This tunnelling
by the mites makes the host extremely itchy!!!
hands
belly
feet
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Bite Wounds

• 3-5 of dog bite wounds become infected
• 20-50 of cat bites become infected
• Bacteria involved are Staphs, Streps and
  Pasteurella
• Rapidly developing cellulitis pain, swelling
  and reddening
• Systemic infection may occur wounds deteriorate
  quickly

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Treatment

• Clean immediately after injury otherwise
  infection will occur
• Flush the wound thoroughly- running water is best
• Wound may need to be debrided
• May need hospitalisation, antibiotics and iv
  fluids
• Prevention is through correct handling- not
  taking risks
• Read and watch the animal carefully
• Seek supervisors help

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Tetanus

• Severe clonic convulsions and spasms
• Unable to move unable to swallow,
• eat etc
• Need ventilation
• Tetanus spores are found in soil esp where horses
  have been held ( even 20 years earlier)
• Enter body through puncture wounds
• Prevention is by vaccination- compulsory for
  animal workers

Clonic convulsions in a human case of tetanus
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Salmonella and Camphylobacter

• Naturally occurring in gut of sheep, cattle,
  pigs, birds and reptiles
• Infection can occur through indirect contact-
  food, infected water
• Or contact with sick, dead or carrier animals
• Signs include diarrhoea, vomiting, abdominal pain
• Prevention is through high standards personal
  hygiene, clean food prep areas

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Morbillivirus and Lyssavirus

• From horses and fruit bats
• Infected through aerosols and scratches
• Severe flu symptoms and death
• All bat handlers must be vaccinated against Rabies

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Q fever

• From cattle, sheep, goats, some birds, wildlife,
  domestic animals and ticks
• Occurs after contact with animal giving birth
  through inhalation of dust or through scratches
• Severe flu like symptoms
• Vaccination is best prevention

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Reducing the Risks

• Keep animal in good condition
• Worm regularly
• Dont feed dogs raw offal
• Dont feed cats raw meat
• Dont allow animals to lick your face
• Wash hands after handling animals
• Wear rubber gloves when changing litter trays
• Dispose of faeces daily
• Practice good hygiene
• Get medical advise if bitten- see supervisor
• Wear compulsory uniform and protective gear when
  required

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