Vet Pharm Theme II session 2

• Pathogenic disease


  Diseases caused by pathogens

  
• Pathogen


  A biological agent of disease
• Disease causing


  • Bacteria
  • Viruses
  • Fungi
  • Protozoa
  • Helminths
  • Prions
  • Arthropods

  
• Transmission of infectious diseases


  • Blood-borne: Blood/ body fluids
  • Airborne (respiratory droplets): Pox, Newcastle disease, Kennel Cough
  • Faecal-oral: Eating, drinking, licking contaminated food, water, objects
  • Vector-borne: Bloodsucking arthropods
  • Direct contact

  
• Host


  Any organism that another organism live in or on
• Primary host/ definitive host


  Organism / parasite gains maturity
• Secondary/intermediate host


  Organism/parasite is in a larval stage
• Transport host/ vector


  A carrier in which the organism remains alive but does not develop
• Vector


  Any agent (person, animal or microorganism)that carries and transmits an infectious pathogen into another living organism

  
• Carrier


  Person/animal that harbors an infectious agent with no signs of disease
• Reservoir of infectious agents


  Any person, animal, etc. in which an infectious agent normally lives and multiplies

  
• Zoonosis


  Disease that can be transmitted between animals and human beings
• How do diseases occur in animals?


  • Sporadic: isolated incident in a single animal
  • Enzootic: disease occurs repeatedly in a particular locality
  • Epizootic: disease that effects a large number of animals in a short period of time in a particular area (larger area than enzootic)
  • Panzootic: disease that spreads rapidly over a very large area and effects many animals in a short period of time (foot & mouth disease)

  
• Methods Of Disease Prevention

  • Quarantine
  • Vaccinations
  • Hygiene
  • Adequate nutrition
  • Intentional breeding
  • Rotational grazing
  • Isolation
• DISEASE CONSIDERATIONS - OUTLINE

  • Affected animals
  • Causal organism
  • Signs
  • Method of transmission
  • Method of control

  
• ANIMAL BACTERIAL INFECTIONS


  • Staphylococci
  • Streptococci: Strangles
  • Bacilli (rods): Anthrax
  • Spirochetes (spiral): Leptospirosis
  • Endospore(oval): Clostridium
  • Rickettsia (rod): Ehrlichia

  
• The most common infections treated are bacterial infections
• Bacterial infections have the most antimicrobial agent approvals for animals
• Bacterial infections can be zoonotic – transmittable from animals to humans (& vice versa)
• Bacterial infections by body system

  • Respiratory
  • Gastro Intestinal
  • Reproductive
• Anthrax


  • Affected animals: Cattle, sheep, goats & pigs
  • Causal organism: Bacillus anthracis
  • Signs: High fever, depression, blood oozes from natural orifices (nose, mouth & anus of carcass)
  • Method of transmission: Contaminated feed, water, equipment & infected animal
  • Method of control: Regular vaccination, proper sanitation & isolation of infected animals
• Brucellosis / Contagious Abortion/ Bang Disease

  • Affected animals: Female cattle, sheep, goats & pigs
  • Causal organism: Brucella abortus / Brucella species
  • Signs: High fever, depression, premature abortion, still-birth, retention of the after birth (placenta), inflammation of the uterus (womb)
  • Method of transmission: Contaminated feed, water, & infected animal
  • Method of control: vaccination, proper sanitation & isolation of infected animals
• Brucellosis is zoonotic - Transmittable through direct contact with infected animals or consumption of contaminated raw animal products
• Tuberculosis


  • Affected animals: Cattle, Poultry birds, pigs & Sheep
  • Causal organism: Mycobacterium tuberculosis
  • Signs: Difficulty breathing, constant coughing, soft & moist cough, emaciation/loss of weight and appetite
  • Method of transmission: Inhalation of contaminated air, contact with contaminated droppings/faeces/litter
  • Method of control: vaccination, environment sanitation, isolation & slaughter of infected animals
• Tuberculosis is zoonotic - Transmittable through direct contact with infected animals or consumption of contaminated raw animal products
• Common animal bacterial infections (1)


  • Dermatitis
  • Pyoderma
  • Keratoconjunctivitis
  • Otitis Externa
  • Rhinitis and Sinusitis

  
• Common bacterial infections (2)

  • Pneumonia
  • Gastroenteritis
  • Metritis
  • Contagious Abortion
  • Mastitis
  • Anthrax
• Infectious bacterial diseases by species

  • Swine: Yersinia
  • Cattle: E Coli, Mastitis, Anthrax
  • Horse: Tetanus, Strangles
  • Canine: Leptospirosis (Lepto), Ehrlichiosis (Tick Fever), Bordatella Bronchiseptica (kennel cough)
  • Cat: Enteritis, Cystitis

  
• Foot & Mouth Disease (FMD)

  • Affected animals: Ruminants – Sheet, pigs, cattle & goat
  • Causal organism: Aphthovirus
  • Signs: Fever, vesicles on the mouth mucous membrane, skin & and hoof; inflammation of teats and udder; Salivation; Lameness & weight loss
  • Method of transmission: Contact with infected animals or their excretions (urine/faeces). Respiratory secretions and through milk, semen, and ingestion of feed from infected animals (meat and offal)
  • Method of control: Isolate infected animals, burn & bury contanimated material (feeders/drinkers), vaccinate
• Newcastle Disease


  • Affected animals: Poultry birds
  • Causal organism: Avian paramyxovirus type 1
  • Signs: Sudden death, lethargy, and respiratory distress. Respiratory (acute respiratory disease) – sneezing, coughing, nasal discharge, difficulty breathing. Nervous – Paralysis, Somersaulting, cycling movement, depression, nervous signs. Digestive – loss of appetite and diarrhoea
  • Method of transmission: contaminated material feed, water & litter (wood shaving & saw dust)
  • Method of control: Vaccination and strict biosecurity. Culling, burn & bury ill birds there is no treatment. Sanitation change litter every 3-7 days

  
• Vaccines prevent clinical signs but not infection, and the control of Newcastle disease is challenging in enzootic regions

  
• List common animal viral infections

  • Hepatitis, Pneumonia, Meningitis & Encephalitis
  • Anaemia, Warts, Pox, Rabies
• Symptoms of Hepatitis

  Vary from slight fever to death
• what are the signs of Anaemiain an animal?

  Fever, weight loss, abortion, low iron level in blood
• Vaccines prevent clinical signs but not infection, and the control of the disease is challenging in enzootic regions
• Warts


  • Fibrous tumors of the skin an mucous membranes
• Pox


  • Skin lesions-bumps, blisters, pustules, and crusts
• Abortion


  • Loss of fetus
• Meningitis and encephalitis


  • Inflammation of the brain covering causing blindness, paralysis, wobbling, seizures, coma and delirium
• Rabies


  • Throat paralysis
  • Behavior change
  • Change in bark (dog)
  • Aggression in later stages
  • Lack of fear