Fa Med - Bovine Ophthalmology

Front 1

Unique eye anatomical structures of the bovine

Back 1

-upper and lower lacrimal puncta
-horizontal pupil
-dorsal and ventral pupillary ruff
-tapetum w/ "stars of Winslow"
-holangiotic fundus with tapetum

Front 2

Anophthalmia/Microphthalmia
-causes

Back 2

-congenital

-generally unknown cause
-BVDV major concern****
-Infection, Toxin, Nutrition, environment, inherited

Front 3

Anophthalmia/Microphthalmia
-other ocular anomalies likely present

Back 3

-microcornea
-corneal opacity
-cataracts
-aniridia
-retinal changes/detachment

Front 4

Most common maternal infection causing ophthalmic defects

Back 4

-BVDV

Front 5

When does BVDV usually cause ocular defects during gestation?

Back 5

-76-150 days

Front 6

BVDV
-ocular defects caused

Back 6

-wide range of defects

Front 7

Coloboma
-define

Back 7

-tissue absence

Front 8

Dermoid
-define

Back 8

-plaque of differentiated skin in an abnormal location

Front 9

Dermoid
-type of condition

Back 9

-congenital

Front 10

Dermoid
-most common location

Back 10

-temporal limbus

Front 11

Dermoid
-breed predilection

Back 11

-inherited in herefords

Front 12

Dermoid
-treatment

Back 12

-none if small, hair-free
-superficial keratectomy if painful or impairs vision

Front 13

Diagnose

Back 13

-dermoid

Front 14

Diseases of globe position and movement

Back 14

-Esotropia
-Exotropia

Front 15

Esotropia
-define

Back 15

-convergent strabismus

Front 16

Exotropia
-define

Back 16

-divergent strabismus

Front 17

Estropia
-causes

Back 17

-Bilateral Convergent Strabismus and Exophthalmia (BCSE)
-Polioencephalomalacia (PEM)
-Listeriosis

Front 18

Bilateral Convergent Strabismus and Exophthalmia (BCSE)
-cause

Back 18

-inherited

Front 19

Bilateral Convergent Strabismus and Exophthalmia (BCSE)
-effects

Back 19

-blinding
-abducent nerve (V) motor nucleus defect

Front 20

Polioencephalomalacia
-effects

Back 20

-dorsomedial direction
-blind and exhibiting episthotonus

Front 21

Listeriosis
-effects

Back 21

-Ipsilateral neurologic signs
-brain stem inflammation impinging on abducens nerve

Front 22

Exotropia
-causes

Back 22

-hydrocephalus when bilateral
-anomaly when unilateral

Front 23

Orbital disease
-most common clinical sign

Back 23

-exopthalmia

Front 24

Orbital disease
-prognosis

Back 24

-depends on etiology (neoplasm, inflammatory)

Front 25

Orbital disease
-most common neoplastic cause

Back 25

-Bovine Lymphosarcoma Virus (BLV)




-Squamous cell carcinoma

Front 26

Orbital disease
-effects of neoplasia

Back 26

-unilateral or bilateral exophthalmos +/- strabismus

Front 27

Orbital disease
-physical exam findings with a neoplastic cause

Back 27

Systemic abnormalities
-lymph nodes
-melena
-cardiac

Front 28

Orbital disease
-effects of cellulitis/abscess

Back 28

-exophthalmus

Front 29

Orbital disease
-cause of cellulitis/abscess

Back 29

-trauma
-foreign body
-chronic frontal sinusitis

Front 30

Chronic frontal sinusitis
-caused by

Back 30

-Dehorning (Actinomyces pyogenes)
-Respiratory dz (Pasteurella multocida)

Front 31

Orbital disease
-treatment for cellulitis/abscess

Back 31

-treat underlying cause

Front 32

Entropion
-define

Back 32

-inward rolling of the eyelids

Front 33

Entropion
-effect

Back 33

-skin/hairs irritate the eye
-squinting, tearing, ulceration
-can lead to blindness

Front 34

Entropion
-lid normally affected

Back 34

-lower lid

Front 35

Blepharitis
-bacterial cause

Back 35

-Dermatophilus congolensis (rain scald)

Front 36

Blepharitis
-D. congoliensis initial areas affected

Back 36

-distal extremities
-muzzle
-dorsum

Front 37

Dermatophilus congoliensis
-treatment

Back 37

-dry environment
-bathe with iodine/chlorhexidine shampoo (except head)
-bathe head with dilute betadine solution

-Penicillin +/- Streptomycin (IM) 3-5 days
or
-Long acting oxytetracycline injection

Front 38

Why not bathe the head in chlorhexidine shampoo?

Back 38

-toxic to the corneal epithelium

Front 39

Blepharitis
-fungal cause

Back 39

-Trichophyton sp. (all animals)
-Candida albicans (Jersey cattle)

Front 40

Blepharitis due to fungal
-treatment

Back 40

-infection self-limiting
-treat to affect spread to other animals and humans

-topical/systemic antifungal
-iodine shampoo
-dry environment
-good nutrition
-Vaccination

Front 41

Blepharitis
-parasitic cause

Back 41

-Sarcoptes scabiei (reportable)
-Demodex sp.

Front 42

Differentiate between Demodex sp. and Sarcoptes scabiei

Back 42

Sarcoptes scabiei
-pruritis
-papules
-erythema

Demodex sp.
-invade hair follicles and sebaceous glands of face, limbs, back
-skin gets thick

Front 43

Blepharitis due to parasitic infection
-treatment

Back 43

-lime sulfur dip
-amitraz dip
-ivermectin SQ

Front 44

Blepharitis
-Photosensitization causes

Back 44

Primary
-ingestion of photodynamic pigments

Secondary
-hepatitis
-colicystitis

Front 45

/major sites for important ophthalmic disease in food-producing animals

Back 45

-conjunctiva
-cornea

Front 46

Conjunctivitis/Keratitis
-causes

Back 46

-Infectious bovine keratoconjunctivitis (IBK)
-Squamous Cell Carcinoma (Cancer eye)
-Malignant Catarrhal fever
-IBR, Chlamydophila sp., M. bovoculi
-Thelazia spp.
-Environment (pollen, dust, fumes)

Front 47

Infectious Bovine Keratoconjunctivitis (IBK)
-aka

Back 47

-Pink Eye

Front 48

IBK
-etiology

Back 48

Moraxella bovis
-gram (-)
-multiple serotypes

Front 49

Moraxella bovis
-transmission

Back 49

-fomites, contact, handlers
-vectors: face fly (Musca autumnalis)

Front 50

IBK
-contributing factors

Back 50

-sunlight
-dry environment
-shipping stress
-face flys

Front 51

IBK
-susceptibility

Back 51

-Bos Taurus > Bos indicus
-Herefords/Hereford crosses
-Young animals

Front 52

IBK
-pathophysiology

Back 52

Moraxella bovis
-pathogenic strains are pilated (Q pili bind to cornea)
-release proteolytic enzymes (beta-hemolysin)
-proteases --> progression of ulcer

Front 53

Moraxella bovis
-effect of beta-hemolysin

Back 53

-damage corneal epithelium
-allow access to corneal stroma

Front 54

IBK
-epidemiology

Back 54

-acute dz (rapid spreading)
-occurs in summer (M. bovis, face flies, UV radiation)
-dec in fall (less calves, less vectors)

Front 55

IBK
-clinical findings

Back 55

-unilateral/bilateral
-photophobia, blepharospasm, epiphora
-conjunctivitis
-central corneal lesion
-corneal vascularization
-secondary uveitis
-corneal rupture w/ continued ulceration
-anorexia due to blindness --> can't compete with herd for food

Front 56

What is occurring?

Back 56

-neovascularization to repair ulcerated region

Front 57

IBK
-treatment

Back 57

-self-limiting but takes 4-6 wks (lose $$$)

Minimize production loss
-prevent spread (isolation, vector control)
-reduce exposure to enhancing factors
-antibiotic
-Pain control with atropine and NSAIDs

Cover affected eyes
-some king of patch

Front 58

IBK
-why should the affected eye be covered

Back 58

-provides shade
-protects from flys

-NO ulcer healing

Front 59

IBK
-medicinal therapy

Back 59

Antibiotics
-Topical ointment (not practical)
-Subconjunctival penicillin/ampicillin injection
-Systemic oxytetracyclin

Topical atropine for uveitis

Systemic NSAIDs for discomfort/uveitis

Front 60

IBK
-strategies for prevention

Back 60

-fly control
-shade
-temporary isolation of new animals
-vaccination protocol (question efficacy)

Front 61

Most economically important neoplasm of large animals
-why

Back 61

-bovine ocular squamous cell carcinoma

-large part of slaughterhouse condemnations

Front 62

Bovine ocular squamous cell carcinoma
-aka

Back 62

-cancer eye

Front 63

Bovine ocular squamous cell carcinoma
-associated with

Back 63

-bovine papilloma virus

Front 64

Bovine OSCC
-risk factors

Back 64

-periocular depigmentation (Hereford, Ayrshire, Simmental)
-UV radiation (latitude, altitude, season)
-Age
-Genetics (bos Taurus; Herefords)

Front 65

Breeds with periocular depigmentation

Back 65

-Hereford
-ayrshire
-simmental

Front 66

Bovine OSCC
-clinical findings

Back 66

-ocular/periocular location (bulbar conjunctiva & cornea with most on the limbus)
-single or multiple lesions
-unilateral/bilateral

Front 67

Bovine OSCC
-lesion progression

Back 67

-hyperplastic plaque
--papilloma noninvasive carcinoma (in situ)
---invasive carcinoma

-extensive keratosis (keratoma)

Front 68

In situ
-definition

Back 68

-has not penetrated the basement epithelial membrane

Front 69

Diagnose

Disease associated with

Back 69

-keratosis (keratoma)

-Bovine OSCC

Front 70

Bovine OSCC
-pathophysiology

Back 70

-progression of premalignant stages to invasive
-rare metastasis
-common local invasion with eyelid and nictitating membrane tumors

Front 71

Bovine OSCC
-diagnosis

Back 71

-appearance
-biopsy (histopath)

Front 72

Bovine OSCC
-treatment

Back 72

Practicality important
-surgical excision
-Cryotherapy/laser therapy
-enucleation
-euthanasia

*When there are multiple possible treatment, it means none are very good

Front 73

Bovine OSCC
-recurrence rate

Back 73

-30-40%

-culling is probably most effective option

Front 74

Bovine OSCC
-prevention

Back 74

-genetic selection for pigment around eyes
-select agains animals with high dz incidence

Front 75

Infectious Bovine Rhinotracheitis
-etiology

Back 75

-Bovine herpes virus - 1

Front 76

IBR
-Ocular signs linked with

Back 76

-shipping fever

-conjunctivitis: MC ocular manifestation
-keratitis
-discharge (mucopurulent)
-+/- anterior uveitis

Front 77

IBR
-possible concurrent with what other ocular disease

Back 77

-IBK

Front 78

IBR
-treatment

Back 78

-course 2-4 wks

-vaccines available

Front 79

Malignant Catarrhal Fever
-etiology

Back 79

-herpes virus

Front 80

Malignant Catarrhal Fever
-clinical signs

Back 80

-"head-and-eye"
-pyrexia
-profuse ocular/nasal discharge
-hyperventilation
-death

Front 81

Malignant Catarrhal Fever
-ocular signs

Back 81

-photophobia
-excessive lacrimation
-episcleral injection and scleritis
-keratitis (perilimbal edema, bullous keratopathy, corneal erosions)
-anterior uveitis (if cornea clear)

Front 82

Malignant Catarrhal Fever
-diagnosis

Back 82

-PCR

Front 83

MCF
-Prognosis

Back 83

-poor

Front 84

MCF
-prevention

Back 84

-no vaccines or treatment
-keep cattle away from sheep

Front 85

Uveitis
-Cause

Back 85

Septicemic neonates
-umbilical infection
-pneumonia
-scours

Systemic adults
-mastitis
-metritis
-traumatic reticuloperitonitis
-MCF
-IBK
-listeriosis
-neoplasia
-trauma

Front 86

Uveitis
-clinical signs

Back 86

-pain
-photophobia
-flare
-hypopyon
-miosis
-swollen iris
-peripheral corneal edema

-Glaucoma
-cataract
-phthisis bulbi

Front 87

Uveitis
-treatment

Back 87

-topical steroids
-topical atropine
-flunixin

-address underlying cause

Front 88

Ocular surgeries in cattle

Back 88

-Enucleation (blind/painful eyes)
-Exenteration (neoplasia)

Front 89

Ocular surgery in cattle
-procedure

Back 89

-standing sedation with adequate restraint
-periocular nerve blocks
-transpalpebral

Front 90

Cattle ocular surgery
-how long do sutures stay in

Back 90

-2-3 wks

Front 91

Auriculopalpebral nerve block
-purpose

Back 91

-ocular exam/surgery
-eyelid akinesia

Front 92

Articulopalpebral nerve block
-procedure

Back 92

-inject lidocaine SQ where nerve crosses zygomatic arch (caudal to supraorbital process)

Front 93

Local lidocaine block
-purpose

Back 93

-eyelid anesthesia during surgery

Front 94

Four-point block
-purpose

Back 94

-enucleation
-retrobulbar block

Front 95

Four-point nerve block
-procedure

Back 95

-insert needle transconjunctivally adjacent to the globe
-inject lidocaine

Front 96

Peterson nerve block
-purpose

Back 96

-enucleation
-retrobulbar injection
-block nerves II, III, IV, V, VI