Infectious Diseases Flashcards
Which virus is responsible for >80% of cat flu cases?
List another virus responsible for cat flu
Feline calici virus (FCV)
FHV-1
List 3 bacterial causes of cat flu
- Mycoplasma felis
- Pasturella spp.
- Streptococcus equi (zooepidemicus)
List 3 ways you can diagnose cat flu
- Isolation & culture
- PCR
- Serology (limited)
Which antibiotic is most appropriate to treat cat flu?
Doxycycline
What is the carrier status of FHV-1 in cats?
80% are life long carriers (intermittent shedders)
What is the carrier status of FCV in cats?
100% shed at 30 days
50% shed at 75 days
10-25% shed long term
*No real latency, carriers will shed the virus while infected
How long can FHV-1 survive in the environment?
< 24 hours
How long can FCV survive in the environment?
8-10 days
List 3 possible treatments for FHV-1 cat flu
- L-lysine
- Famcycovir
- Polyprenyl immunostimulant
Describe a general treatment course for cat flu
Antibiotics and fluid/nursing support
How is cat flu spread
Via aerosols
List 5 ways to manage the spread of cat flu
- Decrease stocking density
- Increase air flow
- Provide sneeze barriers
- Disinfection
- Stop breeding
Which virus causes acute cat flu
How is the infection classified?
Highly pathogenic vascular systemic FCV (VS-FCV)
Severe systemic haemorrhagic fever like vascular systemic disease
Which group is more affected by acute cat flu (VS-FCV)
Adult cats
List 2 clinical signs of acute cat flu (VS-FCV)
Provide 3 additional general clinical signs
- SQ oedema / ulcerative dermatitis
- Coagulopathy / systemic vasculitis (DIC)
Pyrexia, mouth ulcers and nasal discharge
Why is VS-FCV so prevelent in crowded, high stress environments (i.e., resuce centres)?
There is a lot of FCV biodiversity in large groups (different strains, persistent/coinciding infections), meaning the virus is likely to keep re-infecting animals in the centre and recombine with other strains to make a highly pathogenic and virulent strains
There is also lots of non-neutralizing immunity, which means cats in these centres will not present with VSD, just cat flu
What happens when you take a cat with VS-FCV out of a resuce centre and introduce it to a non-exposed cat, and why?
The non-exposed cat will develop VSD from the highly pathogenic FCV, because the virus will have an altered cell tropism and basically infect everywhere
List 3 ways you can diagnose VS-FCV
- Epidemiology
- Isolation & culture
- Post mortem
Serology is of limited value
List a treatment option for VS-FCV
High dose interferon
Or remdesivir
Is vaccination effective against VS-FCV?
No
List 3 viral causes of feline infectious peritonitis
Which causes more severe disease?
- Feline coronaviruses
- Feline enteric coronaviruses
- Feline infectious peritonitis viruses
FIPVs
Good MCQ
Describe the pathogenesis of FIP
- Oral infection
- Replication in pharynx & intestines
- Invades enterocytes
- Systemic infection & immune response
- Widespread dissemination
Why is there such a high risk with FIP?
They are RNA viruses so they can readily mutate - when they infect & replicate in macrophages they can mutate to an even more pathogenic strain
List 3 factors affecting the host’s response to FCoV
- Dose of the virus
- Age of the cat
- Genetics of the cat
What is the majority outcome of infection with FCoV?
Transient infection
How many cats infected with FCoV develop FIP?
5-10%
Describe the pathological progression of wet FIP
Inflammation of blood vessels causes protein rich fluid to leak into the body cavity causing ascites and/or pleural/pericardial effusions
Wet FIP: acute or chronic
Acute
Dry FIP: acute or chronic
Chronic
List one clinical sign of dry FIP for each tissue affected: eye, abdomen, liver, kidney and CNS
Eye: uveitis
Abdomen: diarrhoea
Liver: jaundice
Kidney: renomegaly
CNS: ataxia
List 3 changes you would see on a serum biochem for FIP
- Increased alpha-1 acid glycoprotein (an inflammatory mediator)
- A:G ratio less than 0.4 (indicates an inflammatory process)
- Increased globulins (indicates inflammatory process)
An AGP greater than __ is indicative of FIP
1500 ug/mL
Which diagnostics tests for FIP can confirm infection
Immunohistochemistry, immunocytochemistry, and quantitative RT-PCR
Which diagnostic test for FIP can identify FCoV but not FIPV
RT-PCR
List 3 possible treatment options for FIP
What are their success rates?
- Polyprenyl immuno-stimulant (dry FIP) - 10%
- Nucleoside analogue GS (increase dose for wet & neuro FIP) - 77-96%
- Remdesivir (GS prodrug) - 85-90%
How can you control the spread of FIP?
Reduce the number of cats in one place, and proper hygiene (disinfection & litter boxes)
Describe Canine Distemper virus
Enveloped, single stranded RNA virus
Describe the pathway of transmission to clinical disease for CDV
Aerosol spread, infects tissue macrophages, infects tonsils and local lymph nodes, clinical disease manifests in the:
- eyes
- cutaneous epithelium
- GI epithelium
- CNS
- respiratory epithelium
Where is CDV excreted
From the resp and GI epithelium
List 3 GI clinical signs of CDV
- Vomiting
- Diarrhoea
- Anorexia
List 3 respiratory clinical signs of CDV
- Coughing
- Bronchopneumonia
- Oculo-nasal discharge (key feature)
List 3 ocular clinical signs of CDV
- Bilateral muco-purulent conjunctivits
- Dry eye
- Retinal degeneration
List 3 dermatological clinical signs of CDV
- Pustular dermatitis
- Nasal & digital hyperkeratosis
- Hard pad (KEY! feature)
List 3 CNS clinical signs of CDV
- Vestibular dysfunction
- Seizures
- Myoclonus (twitching)
List 3 specific tests you can perform for CDV, and what each one tests for
- IFA on conjunctival smears (viral antigen)
- ELISA for Anti-CDV IgG (antibody)
- qRT-PCR on CSF (viral DNA)
Which test for CDV is best for testing in the acute phase of disease?
IFA
Why are ELISA and qRT-PCR not always the best for confirming CDV?
ELISA can only tell you about previous exposure (false positive)
qRT-PCR can’t discriminate between vaccine and natural infection
Describe Canine Adenovirus-1
Non-enveloped, double stranded DNA virus
Describe the pathway of transmission to clinical disease for CAV-1
Oro-nasal infection, infects tonsils & regional lymph nodes, viraemia, clinical disease manifests in the:
- Liver
- Vascular endothelium
- Eye
- Kidney
Where is CAV-1 excreted and for how long?
In the urine, for up to 9 months
List 3 hepatic signs of CAV-1
- Hepatocellular necrosis
- Hepatomeagaly
- Abdominal distension
Jaundice is surprisingly uncommon
List 3 vascular clinical signs of CAV-1
- Petechiation
- Ecchymoses
- Epistaxis
List the prinicple clinical sign of CAV-1 in the eye
Corneal oedema (blue eye)
What is the clinical presentation for per-acute infectious canine hepatitis
Within 6-24 hours of infection, collapse, coma and death
What is the clinical presentation for acute infectious canine hepatitis
Within 48-72 hours, it is very variable
What is the clinical presentation for chronic infectious canine hepatitis
Chronic hepatits, glomerulonephritis and uveitis
List 3 specific diagnostic tests for CAV-1 (ICH), and what each one tests for
- PCR (viral DNA)
- Anti-CAV-1 serology (antibodies)
- Histopathology
List 3 viral causes of canine viral enteritis
- Canine parvovirus
- Canine rotavirus
- Canine coronavirus
Describe Canine Parvovirus
Non-enveloped, DNA virus
What is the clinical incubation period for parvo?
4-14 days
Describe the pathway of transmission to clinical disease for parvo
Oro-nasal exposure, infects the tonsils, lymph nodes and thymus, viraemia, clinical disease manifests in:
- Lymph nodes
- Bone marrow
- GI epithelium
- Eyes
- Myocardium
Where is parvo excreted and for how long?
In the feces, for 3-10 days post infection
List 2 specific diagnostic tests for parvo
- Fecal antigen test
- PCR
What is another DDx for a dog presenting with parvo, and what could be the cause?
Infectious diarrhoae - caused by distemper, campylobacter, toxoplasmosis, giardia, leptospirosis, etc.
How would you generally treat canine infectious diseases?
Supportive care (fluids, anti-emetics, analgesia, nutrition, and antibiotics for secondary infections)
List 2 tertiary supportive therapies for parvoviral enteritis
- Interferon gamma (cytokine)
- Hyperimmune plasma transfusion from a previously infected survivor