9. Diseases Flashcards
What can the temperature of an animal be like with bacterial disease
Pyrexic, normal or sub temperatures
Only ever get as high as 40 degrees, and more would suggest viral infection
Give some types of fluid to test for white cell and neutrophil counts
Tracheal wash
Peritoneal fluid
Pleural fluid
joint fluid
Biopsies
In salmonella infection, would peripheral neutrophil count be increased/normal/decreased and why
Decreased - neutrophils have travelled to the site of infection (GIT) and been expelled in diarrhoea
In sepsis, would white cell and neutrophil count be increased or decreased
Increased
Degenerate neutrophils and toxic change
Give 3 examples of acute phase proteins
Fibrinogen
Serum amyloid A
C reactive protein
Would peripheral acute phase proteins be increased/decreased/normal in bacterial infections
Slightly increased
What 2 fluids do not culture well for culture and sensitivity of bacterial infections
Cerebrospinal fluid
Joint fluid
Type of bacterial infection:
Old, unspayed dog, pyrexic, drinking lots, off food
Pyometra
Type of bacterial infection:
Cow, unwell, low temp, not eating, loose faeces
Echogenic portions on the liver
Hepatic abscesses
secondary to ruminal acidosis
Type of bacterial infection:
Heart ultrasound with echogenic fluid surrounding it
Septic pericarditis
What would pleural pneumonia look like on an ultrasound
Fluid in pleural space
lung consolidation
strands of fibrin connecting lung surface to parietal pleura
How best to treat bacterial infection of body cavity
Lavage with high volumes of sterile saline
Systemic antibiotics
example of exotic viral disease
avian influenza
example of endemic viral disease
Calf respiratory disease
3 examples of feline sporadic diseases
feline parvovirus
calicivirus
herpesvirus
What is feline infectious peritonitis secondary to
Feline enteric conoravirus
What virus causes malignant catarrhal fever In cattle
Ovine herpes virus 2
crosses species barrier
common clinical signs of malignant catarrhal fever in cows
Sever pyrexia
corneal oedema
marked discharge from eyes and nose
Economic importance of viral disease
Costs of loss of production, culling, banning of imports and exports, costs of control
3 examples of viral zoonoses
Hantavirus
Louping ill virus
European bat lyssavirus
example of notifiable disease
Foot and mouth
Highly pathogenic avian influenza
Definition of pathogenicity
The ability of a microbe to damage a host
Definition of degree of virulence
The relative capacity of a pathogen to damage a host
Definition of virulence factors
The bacterial traits that confer pathogenicity
3 things a microbe must do to act as a pathogen
Compete with normal flora to gain a foothold
Must evade or overcome normal host defences
Must express genes that encode for factors that cause disease
How bacterial infection can cause tissue damage (3 ways)
Bacterial toxins
Inflammatory response
Immune response
Changes associated with inflammatory response to bacterial infection
Systemic - pyrexia, HR, RR increase
Local - heat, swelling, pain, redness
Pus
Granulomas
2 Cardiovascular consequences of bacterial infection
Congested mucous membranes
Toxic line - horses
difference between degenerate neutrophils and toxic change of neutrophils
degenerate = how neutrophils are dying
toxic change = how they are being made
3 steps for cells leaving vessels
- marginalisation
- adhesions
- migration
3 Signs of neutrophil toxic change
foamy cytoplasm
diffuse cytoplasmic basophilia
Dohle bodies
why lactate builds up in sepsis
Blocks normal pathways that lactate would be eliminated through
Increased lactate coming into circulation
How coagulopathy develops in sepsis
Inflammation is a pro-coagulators state
Microthrombi will build up in vasculature
Low platelet count
Low coagulation factors
Which 2 viruses cause cat flu
calicivirus and herpesvirus
clinical signs of cat flu
nasal and ocular discharge
pyrexia
anorexia
lethargy
Clinical signs of calf respiratory disease
cough
nasal and ocular discharge
pyrexia
depression
clinical signs of canine parvovirus
Vomiting, bloody diarrhoea
Pyrexia
Neutropenia
Villus stunting, crypt dilation and necrosis
Why does parvovirus cause neutropenia
Virus also affects the bone marrow
What is an example of lentiviruses in cats
FIV
Name 3 viruses which cause cancer
Retroviruses
Herpes Viruses
Papillomaviruses
2 immunological effects from viral infections and examples
Immune suppression - FIV, BVDV
Immunopathology - FIP
Which viruses cause prenatal infections (name 2)
BVD
Schmallenberg
which pathogen causes greasy pig disease
Staphylococcus hyicus
which pathogen causes strangles in horses
strep equi equi
what is the gold standard test for bacterial infections
culture and sensitivity
How can you use cytology to confirm bacterial infection
look for intracellular bacteria in neutrophils
what colour will gram stain stain gram positive and negative bacteria
Gram positive = purple
gram negative = pink
when should you use prophylactic antimicrobials
surgery where contamination is high e.g. colic or joint surgery
3 ways to detect a virus
Detection of antigen, nucleic acid or antiviral antibodies
diagnostic tests for canine parvovirus
SNAP test or lateral flow
Neutropenia
PCR
Diagnostic tests for cat flu
Virus isolation and PCR
diagnosis of FIP
Detect FeCoV antibody - not FIP specific tho
Rivalta test - effusion of liquid from abdomen
samples to take and diagnosis of avian influenza
samples - tracheal, oropharyngeal and cloacal swabs, fresh tissue sample
diagnosis by RT-qPCR
3 aspects of disease control
Biosecurity
Husbandry
Vaccination
3 ways in which fungi grow
Yeast (unicellular)
Mould (multicellular filamentous hyphae)
Both (dimorphic)
What are fungi cell walls made from
Chitin
Other polysaccharides
How to fungi reproduce
Spore formation
Are dermatophytes commensals or pathogens
pathogens
Fungi classification by habitat - 3 categories
Geophilic - found in soil/environment
Zoophilic - found on animals
Anthropophilic - found on man
3 ways in which fungi cause disease
Tissue invasion (mycosis)
Toxin production (mycotoxicosis)
Induction of hypersensitivity
3 categories of tissue invasion of fungi (mycosis)
Superficial mycoses
Subcutaneous mycoses
Systemic mycoses
What predisposes to tissue invasion of fungi (mycosis)
Immunological deficits
Immunosuppression
Prolonged antibiotic therapy
Traumatised tissues
Persistent moisture
2 types of superficial mycosis
Dermatophytosis - caused by dermatophytes
Dermatomycosis - caused by non-dermatophytic fungi
What organisms cause Dermatophytosis
Microsporum spp.
Trichophyton spp.
What organisms cause Dermatomycosis
Malassezia
Candida
(commensals)
How subcutaneous mycosis occur and what are the lesions like
Follow foreign body penetration
Chronic lesions, remain localised
What organism causes systemic mycosis
Cryptococcosis (cryptococcus neoformans and gatii)
How systemic mycosis occurs and how it spreads through the body
Inhalation of fungus in dust => nasal infection => invasion via cribriform plate => CNS or spread to other sites via blood or lymphatics
Definition of chromomycosis
If lesion caused by pigmented fungus
Definition of hyalohyphomycosis
If lesion caused by non-pigmented fungi
Definition of mycetoma
Organism in granules/grains within lesion, associated with swelling and draining sinus
Definition of a pseudomycetoma
Have different granule formation to mycetoma
What fungi are commonly associated with toxin production (mycotoxicosis)
Penicillium
Aspergillus (=> aflatoxicosis)
Fusarium
Claviceps ( => ergotism)
How do animals become affected by mycotoxicosis
Fungi on crops, pasture or stored feed produce toxins which animas ingest
Why is mycotoxicosis an issue in food producing animals
Accumulation in tissues of food-producing animals can result in human exposure
What disease is associated with induction of hypersensitivity by fungi in cattle and horses
Chronic pulmonary disease
3 pathological changes associated with tissue mycosis
- Acute suppurative inflammation + micro abscess formation
- Chronic inflammation - (pyo)granulomatous
- Necrosis
clinical changes with superficial mycoses
alopecia, erythema, ulcers
clinical changes associated with subcutaneous mycoses
papules or nodules
Ulceration
Discharging tracts
Regional lymphadenopathy
clinical changes associated with systemic mycoses
Granulomas
Pyogranulomas
Necrosis
Systemic illness
What species of fungi has more than one manifestation of tissue invasion
Aspergillus
Mame 4 diagnostic tests for fungal infections
Direct microscopy
Fungal culture
Histopathology
PCR and woods lamp
How to diagnose mycotoxicosis
Epidemiological features
Clinical signs
Confirmation of mycotoxin
Which type of hypersensitivity is most commonly associated with fungal infection
Type 1
Define an outbreak
Occurrence of more cases of a disease than expected in a given region, community or group; evidence of disease spread within a facility
Define endemic disease
Disease commonly found in, or restricted to a particular region, community or group
Define epidemic
A level of disease in a population significantly greater than usual
Define pandemic
Epidemic that affects multiple regions/areas
Define index case
First known infected animal
What are the 3 main contributing risk factors to a disease outbreak
Hygiene
Biosecurity
Water source
key elements of prevention of a disease outbreak
Good hygiene and biosecurity
Good facility design
Stress reduction
Good nutrition
Preventative treatment
Define a zoonotic disease
Animal diseases that can pass between animals and humans
Reportable vs Notifiable disease
Reportable - report once case is confirmed
Notifiable - report if you suspect
what is the difference between PrPSc and PrPC
PrPc is host-encoded and has high levels of expression in the CNS, not infective
PrPSc is produced by the misfolding of PrPc - infective
3 ways in which a host can be infected with PrPSc
Spontaneous
Inherited
Acquired
Name the most common prion diseases in: sheep, cattle, cats, goats, deer
Sheep - Scrapie and atypical scrapie
Cattle - BSE
Cats - FSE
Deer - Chronic wasting disease
Goats - BSE
Clinical signs of prion disease
Weight loss
Behavioural changes
Licking lips
Grinding teeth
Pruritus
Ataxia and tremors
Death
What cell types is predominantly associated with granulomatous disease
Macrophages
If neutrophils are found in granuloma, what is it classified as
Pyo-granulomatous
Name 3 causes of granulomatous disease
- microbial agents
- autoimmune disease
- foreign bodies
Name 5 bacteria that cause granulomatous disease (ABBMR)
Actinobacillus spp.
Burkholderia mallei
Brucella spp.
Mycobacterium spp.
Rhodococcus equi
What class of fungi cause granulomatous disease
dimorphic fungi
Name 6 species of fungi which cause granulomatous disease (ABCCCH)
Aspergillus fumigatus
Blastomyces dermatitidis
Cryptococcus neofromans
Coccidioides immitis
Candida albicans
Histoplasma capsulatum
Name features of Rhodococcis equi and how it causes granulomatous disease
Intracellular, Gram positive bacteria
Proliferates inside macrophages
Inhibits phagosome-lysosome fusion
Young foals - acquire by inhalation
Causes pyogranulomatous bronchopneumonia and ulcerative enteritis
Name features of Mycobacterium spp. and how it causes granulomatous disease
Johnes Disease and Tuberculosis
Acid-fast, weakly gram-positive, intracellular, non motile
Requires iron for growth
Ingestion is main route of infection
Causes chronic enteritis in cattle
Name features of Actinobacillus lignieresii and how it causes granulomatous disease
Wooden tongue disease
Aerobic, non spore forming, gram negative
Commensal in oral cavity - invades when mucosal trauma
Causes pyogranulomatous lymphadenitis
Name features of Burkholderia mallei and how it causes granulomatous disease
Glanders disease
Non motile, non spore forming, weakly gram negative
Zoonotic and NOTIFIABLE
Name features of Brucella spp. and how it causes granulomatous disease
Transmission by contact with infected tissues/secretions/excretions
Causes bacteraemia
Name 3 examples of dimorphic fungi
Candida albicans
Aspergillus fumigatus
Histoplamsa capsulatum
Cryptococcus neoformans
Which bacteria causes bTB
Mycobacterium bovis
describe the aspects of the 25 year eradication strategy for bTB
3 management zones (high risk, edge, low risk)
Increased frequency testing
Badger culling and vaccination
Biosecurity advice
name 3 ways of testing for bTB
Skin testing (SICCT)
Blood testing - interferon gamma
Post mortem inspection
