PHC 2 - Feline respiratory disease

Question 1

What are the primary agent for feline URTI?
What are the secondary agents

Answer 1

• Primary: Feline Herpes virus (FHV-1) and Feline Calicivirus (FCV)
  ○ Usually occur together
  Secondary: Bordetella Bronchiseptica, Chlamydophila felis, and Mycoplasma

Question 2

What are the clinical signs of FHV-1 aka __________?

Answer 2

• Sneezing; nasal congestion; serous or mucopurulent nasal discharge; ocular changes
  
  • Ocular changes: blepharospasm and blepharitis (eyelids); conjunctivitis (inflammation of conjunctiva), serous or mucopurulent discharge.
  • Herpes keratitis that may cause corneal ulceration (dendritic ulcers), chemosis (swelling of conjunctiva)
    ○ More common in shelter medicine population

Feline Rhinotracheitis

Question 3

Feline Calicivirus (FCV) clinical signs:

Answer 3

• Sneezing; serous nasal discharge; ocular discharge; limping syndrome; oral changes, inappetence/anorexia, pyrexia.
  ○ Limping syndrome: Transient fever and lameness, multiple limbs, sometimes noted as shifting lameness from limb to limb. Can sometimes also be seen post vaccination with modified FCV vaccine - it is transient
  Oral changes: Ptyalism (drooling), halitosis (bad breath), oral ulceration (tongue, gingiva, thin red line just above the teeth, hard palate).

Question 4

How are the viruses shed/carrier states?

Answer 4

• Sick cats will shed virus through oral nasal and conjunctival secretions
  
  • For both viruses, clinically recovered cats can become carriers
  • Cats with FCV may shed continuously for at least 1 month post infection
  • Cats with FHV-1 may shed intermittently for at least 3 weeks

Question 5

What is the incubation period of FHV1?
Where does it remain latent?

Answer 5

Incubation period of virus is 2-6 days, disease generally runs its course in 10-20 days.

Once infected, FHV-1 remains latent in the trigeminal nerve ganglia

SO all cats infected become chronic carriers

Question 6

What is recrudescence?

Answer 6

Recrudescence - describes reactivation of a latent virus. Stressful events are often the reason for a recrudescence. For FHV-1, recrudescence can occur 4-12 days after stressful event. Recrudescence may or may not be associated with clinical signs. Obviously easier to clinically detect when they show clinical signs.

Question 7

What are the clinical signs of B. Bronchiseptica?
What is research saying about this bacteria?

Answer 7

• Sneezing coughing conjunctivitis, nasal or ocular discharge
  
  • Research is still undecided on the relevance of B. Bronchiseptica in cats. Once thought to be a secondary or opportunistic invader but research is accumulating that it may be a primary agent and more widespread than initially thought.
  • Coughing may occur but not a hallmark of as it is in canine infectious respiratory disease complex.

Question 8

Clinical signs of chlamydophila felis?

Answer 8

• Sneezing; serous nasal discharge; ocular discharge and conjunctivitis (often unilateral to begin then progress to bilateral). Occasionally decreased appetite
  Often considered to be a ‘co infection’ with FHV-1 and FCV. Clinical signs are not much different from FHV-1 and FCV but suspicion of Chlamydophila arise clinically when URTI signs are getting worse or not responding to supportive care

Question 9

What are the clinical signs of Mycopalsma?

Answer 9

• Non-specific clinical signs of sneezing, coughing, ocular or nasal discharge
  
  • May be implicated or cultured as secondary or opportunistic bacterial pathogen in upper or lower respiratory tract infections in cats.

Question 10

How do you treat URTI?

Answer 10

• Supportive and symptomatic. Goal = control clinical signs associated with the viruses and (secondary) bacterial infections, maintain comfort and appetite
  
  • Fluid therapy if dehydrated
  • In clinic treatment will require isolation of URTI patient from other cats and dogs
  • Treat secondary bacterial infections when suspected: doxycycline for mycoplasma, B. bronchiseptica, and chlamydia
  • Topical eye preps to treat conjunctivitis, blepharitis, and ulceration when present.
    ○ Antibiotics such as chloramphenicol, tetracycline, tobramycin.
    ○ DO not use topical corticosteroids in cases where corneal ulceration are present
  • Anti-mucolytic agents (Bromhexine, Bisolvon oral power)
  • Room humidification/vaporizer treatment to help nasal congestion
  • Wipe away nasal ocular discharge
  • L-lysine may help with severity of FHV-1 conjunctivitis clinical signs. Works much better as a prophylactic than a cure (1000mg/day recommended dose).
  • Fresh, warm, palpate, soft food (esp. in cases with oral ulceration)
  • Appetite stimulant can help (Mirtazapine)
  • NSAIDs if persistently pyrexic and/or severely depressed
  • Feeding tubes may be indicated to bypass oral/pharyngeal passages in cases of severe oral ulceration and or in cases of anorexia
  • Antiviral drugs may be considered
  • Support and management often required for 2-4 weeks while herpes viruses run their course

Question 11

What is the prognosis and outcome of URTI?

Answer 11

• Unless very young or severely compromised individual, prognosis for clinical recovery is very good
  
  • Chronic rhinitis, stomatitis, and/or conjunctivitis can occur - these are generally medically manageable
  • Stress is a known trigger factor for latent FHV-1 and can cause recrudescence - warn client
  • Preventing or putting stress mitigation/behavioural modification practices in place may be the best prophylactic for recrudescence.