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Eye and Ear - Coggle Diagram

- - - - loc
        
        parasites of conjunctival sac, lacrimal duct, sometimes aq humor
      - DH: horses, but also cattle, buffalo, dogs
      - IH: face fly (musca autumnalis), house fly (fannia)
      - descrip: small milk-white worms
      - common in N Am, S Am, Euro, Asia
        
        esp CA, MD, KY
      - life cycle
        
        females produce larvae (viviparous) -> larvae picked up by fly feeding around eye -> mature to infec L3 in fly -> larvae departs the mouthparts as fly feeds -> worm mature in or on eye at 3 mo
        
        seasonal w flies
      - CS
        
        most horses are asymp
        
        may have profuse lacrimation, plugging of lacrimal duct, conjunctivitis, photophobia, keratitis, corneal opacity
      - diag
        
        CS, worms in lacrimal fl or surf of eye
        
        examine underside of 3rd eyelid
        
        flush lacrimal duct
      - EYE
    - - DH: dogs, cats
      - IH: muscid flies
      - same life cycle as T. lacrymalis
      - loc
        
        found in lacrimal ducts and conjunctival sac
      - found in W US
      - CS
        
        worms in eye, corneal ulcer
      - EYE
  - - - found in chickens and turkeys under nictitating memb
    - - eggs laid by female -> pass down lacrimal duct -> are swallowed -> passed out in feces -> eggs inges by cockroaches and dev into L3 -> bird eats roaches -> larvae escape and migr -> esophagus -> pharynx -> lacrimal ducts -> eyes
        
        most common in free ranging poultry
    - - mild conjunctivitis to severe ophthalmia, blindness, globe destruc, watery eyes, white cheesy material under eyelids
    - - adult spirurids in the eye, spirurid type eggs in feces
        
        eggs are 45 um, ovoid, larvated, thin shell
        
        direct smear or sedimentation technique
    - - control roaches, common in outdoor birds
  - - - adults live in SQ tis of horses -> produce microfilariae that are found in skin and lymphatics on ctx tis (may also be in periph blood, urine, sputum) -> blackfly takes blood meal -> microfilriae penetrate blackfly's midgut and migr to thoracic musc -> L1 larvae -> L3 larvae -> micr to fly mouth -> blackfly takes blood meal and L3 enter SQ tis thru bite wound
    - - adults cause few problems
        
        skin lesions
      - microfilariae may cause dermatitis from migr of larvae, eye lesions, accum of microfilariae, uveitis from widespread immu response
    - - CS, microfilariae on skin biopsy - soak vs H&E
        
        soak = full thickness biopsy, macerate tis in saline = larvae intact
    - - neck threadworm
      - adults in ligamentum nuchae
    - - leg threadworm
      - flexor tendons
    - - insecticides and repellents, no trtmt effective against adults
      - ivermectin/moxidectin effective against microfilariae
      - may cause edema and inflamm when killed
  - - - eggs -> larvae -> nymph -> adult = 2-3 wks
    - - direct contact
    - - coffee ground ears -> waxy dk brown dry parchment life material that sheets, pruritis, outer pinnae scabbed
        
        ear canal: hyperkeratosis and hyperplasia
    - - observe mites w auroscope, microscopic examin
  - - - spiny integument causes severe trauma to ear canal
      - lay eggs in crevices, walls, and feeding troughs
      - not vectors for any vet dz
    - - live deep in ear canal
    - - severe otitis, waxy ear canals, severe infes may cause anemia or rupture eardrum
        
        secondary bact infec from tis trauma
- - - - exists in biofilms -> resis mech
      - plankton form - unicellu
      - highly resis to disinfec
        
        quat ammonium, weak soap soln, weak antiseptics
      - ubiquitous in body (skin, GI) and environ
      - easy to grow -> simple nutri req
      - survives in high salt, grows at wide temp range (42C), and water faucets
      - 3 forms
        
        natural: rough colonies
        
        clin: fried egg
        
        respir or urinary tract: mucoid
    - - opportunistic (immunocomp), nosocomial
        
        predisp factors: corneal injury, immunusupp drugs, burns, wounds
    - - pigments
        
        pyocyanin: blue green
        
        blue pus = typ feature of suppur infec
        
        inc bioavail of iron and enh virulence via oxidative stress
        
        contrib to persis of Pa in lungs of CF ptx
        
        interferes w mammalian c func
        
        ciliary beating, epidermal c growth, Ca homeostasis
        
        pyoverdin: yellow green, fluor
        
        pyorubin: red brown
        
        pyomelanin: brownish black
    - - ear infec
        
        otitis externa and media
        
        most common cause of dz in dog
      - abscess forma
      - ulcerative keratitis
        
        eye infec in horses: dirt and sand flying into eye during race = damage protective epith = lead to corneal ulcers
      - urinary and genital infec
      - mastitis and abortion
      - sepsis, shock and death (from endotoxin)
    - - pus, affect tis, swabs -> microscope
      - cytology, culture and PCR is definitive
    - - suscep test bact
      - vax -> formalin killed bact
      - disinfect: phenolics
    - - flagellum and pili
        
        motil, host invasion, spread, adh properties
      - endotoxin
        
        can lead to sepsis, shock, DIC
      - exotoxin A
        
        impairs prot synth, causes tis necrosis and wound infec
      - thick biofilm
        
        protects bact from phago, makes bact MDR
      - pyocyanin and pyoverdin
        
        maint fitness of bact c and forma
      - MDR
        
        beta lactamases and aminoglycosides modif enz makes sig #s of Abs useless on Pa
      - type 2 and 3 secre sys
        
        responsi for toxin invasion in host c = c injury and death
  - - - differen into reticulate bodies (the inclusion)
      - after sev rounds of replic, reticulate bodies re-differen into elementary bodies -> released from host c, ready to infect neighboring c
    - - Gm neg, oblig IC rod
      - lack machinery for autonomous survival and replic
    - - endemic among domestic cats
      - not able to survive long in environ
      - conjunctiva = PRIMARY TARGET
      - infec most common in multi-cat households
    - - bact multiples in host epith c = causes c to lyse = release more infec particles
    - - spread via direct contact, specifically w ocular secre
    - - conjunctivitis, corneal scarring, red eye, watery discharge, pawing at eyes, VERY CONTAGIOUS
    - - oral/topical abx for 4 wks
      - TREAT ALL CATS IN HOUSEHOLD
    - - inactivated and MLV vax
    - - culture (nasal or conjunctival)
      - PCR (ocular or nasal secre)
      - Giema stain/conjunctival scrape to check for intracytoplasmic inclusion bodies
      - fluor Ab test
      - ELISA for Ab detec
  - - - cattle only known reservoir
      - Gm neg, oblig aerobe, non motile rods
        
        beta hemolytic on BA
      - mort is low, morb is high
    - - house flies and stable flies (mech vector), fomites contamin w ocular secre, direct contact, spread rapidly in herd
        
        cattle w little eye pigment more severely affec
    - - keratitis, vary degree of corneal opacity and ulceration, profuse lacrimation, conjunctival swelling
    - - fimbriae
        
        aid in attachment to corneal epith
        
        secre beta hemolytic, corneotoxic, and leukotoxic cytotoxin
      - hydrolytic and proteolytic enz
        
        brkdn junc btwn corneal epith and c
        
        init inflamm response
    - - clin signs + culture (lacrimal secre on BA plates), FA on smears
    - - bacterins, live vax, fimbrial vax, insecticides
    - - abx, topical powders, topical sprays, shuteye patches to protect eye while healing