Feline Infectious Diseases Flashcards
What organisms make up the Feline Upper Respiratory Disease (FURD) complex?
Viral:
Feline herpesvirus (FHV-1)
Feline calicivirus (FCV)
Bacterial:
Chlamydia felis
What is the transmission method of each organism of FURD?
FHV-1 & FCV:
Shed in ocular, oral + nasal discharge of infected cats
Direct contact with infected cats
Fomites on food bowls, hands etc
Aerosolisation 1-2m
Chlamydia Felis:
direct contact or aerosolisation
How do you diagnose FURD?
Often based on clinical signs and which predominate
Chlamydia - can swab ocular secretions for culture, often treated by CS
FHV-1: almost all cats become latently infected. Stress = reactivation, shed virus, may show CS
FCV: almost all become persistent carriers. Stress or glucocorticoid treatment = shedding + CS
PCR may detect FHV-1 or FCV if actively shedding, but can also be found in healthy cats
A cat presents with intermittent upper respiratory signs. On examination you notice oral ulceration. What is your top differential?
Feline calicivirus
A cat presents with conjunctivitis, chemosis, and ocular discharge. What is your top differential?
Chlamydia felis
A cat presents with nasal discharge, sneezing, and corneal ulceration. What is your top differential?
Feline herpesvirus (FHV-1)
What is the treatment for Chlamydia felis?
Doxycycline 5-10mg/kg BID for 3-4 weeks
What is the treatment for viral rhinitis?
No consistently effective treatment available, will help lessen Cx but not cure.
Famciclovir 125mg PO q8-12hr used as long term therapy to help lessen Cx
AB - ONLY judiciously if secondary bacterial infection present
A cat presents with severe nasal discharge, ocular secretions and is showing signs of respiratory distress. What are your top differentials, and what will your treatment plan be?
Hospitalise - isolation/barrier nursing
Feeding - warm up food + syringe feed + appetite stimulant (mirtazapine)
May require NG/NO tube
IV fluids depending on hydration
Nebulising (NaCl steam)
Good nursing! - clean secretions
What secretions have the highest viral concentrations of FeLV?
Saliva
Less in: blood, semen, milk, faeces
What cats are most at risk for infection with FeLV?
Multi-cat environments, young cats, outdoor access
How is FeLV transmitted?
Mostly social contact: shared litter trays, food bowls, mutual grooming
Less common: bite/fight wounds
What are the 3 possible outcomes for FeLV infection?
Abortive: virus elimination before spread, lifelong protection against infection. May test positive in first 1-2 weeks, then negative on POC test
Progressive: spread + viraemia, death within a few years due to neoplasia, BM suppression, or opportunistic infection. Persistently positive on POC test
Regressive: partial control by immune system with spread + transient viraemia (2-8 weeks). Persistence of virus with rare cases. Positive for first 2-8 weeks, then may be positive or negative.
What tests are used to diagnose FeLV?
Point of care - tests for p27 antigen
If positive on POC, send blood to lab for PCR
PCR 100% sensitivity + specificity but $$
How are progressive and regressive cases of FeLV managed?
Treat presenting disease i.e. opportunistic or refractory infection
Keep separate, vaccinate all in-contact cats for FeLV
Recombinant feline interferon omega - may reduce recurrent infections + prolong survival
What secretions have the highest viral concentrations of FIV?
Blood and saliva
How is FIV most commonly transmitted?
Bite + fight wounds
Less commonly: vertical transmission, social contact
FI = fighting
Describe the duration of infection with FIV and its different stages
Lifelong infection due to integration into cats genome
Primary: viraemic, malaise, may have lymphadenopathy (weeks - months)
Secondary: asymptomatic, limited viral replication. May last years or be indefinite for some cats
Tertiary: usually terminal. Viral replication increases -> clinical disease. CD4+ lymphocytopenia, lymphoma, opportunistic infections, gingivostomatitis
What tests are used to diagnose FIV?
Anigen or Witness antibody point of care test
Always confirm positive test with second different POC test
- snap combo idexx cannot differentiate FIV vaccination and natural infection - don’t use
What is the life expectancy of a cat with FIV?
Equivalent to non-infected cats
What is the management/treatment for FIV?
Asymptomatic:
Confine to avoid spreading virus and exposure to pathogens
Avoid immunosuppressive drugs
Continue core vaccines
Symptomatic:
Diagnose + treat as for any other cat -> may require longer treatment due to immunosuppression
Gingivostomatitis + viraemia may respond to recombinant feline interferon-omega
What is FIP?
Feline infectious peritonitis/Feline coronavirus
How is FIP spread?
Faeco-oral transmission
What percentage of cats with feline coronavirus go on to develop FIP?
10% - virus mutates within infected cat to cause FIP
What does “wet” or “dry” FIP mean?
Wet - effusive form
Vasculitis, ascites, pleural or pericardial effusion
Dry - non-effusive form
Granulomas, ocular, and neurological signs
What is the prognosis and treatment for FIP?
Prognosis: poor, usually fatal within weeks to months
Treatment:
Remdisivir - available online but not licensed
Prednisolone - may provide palliation
How is Toxoplasma transmitted?
Ingestion of sporulated oocytes (faeces)
Tissue cysts (meat)
Vertical: placenta or milk
Contaminated food + water sources
How does Toxoplasmosis in cats present?
Clinical disease rare.
Young cats - diarrhoea
Immunosuppressed cats - serious disease depending on location of parasite e.g. uveitis/ocular, CNS signs
How would you diagnose Toxoplasmosis?
Clinical suspicion (ocular/neuro signs) and rising serology LCAT titres (4 weeks apart)
What is the treatment for Toxoplasmosis?
Clindamycin BID 4 weeks
