Cattle 3 Flashcards
(100 cards)
1
Q
What questions to ask on the phone for a calving call and on arrival
A
○ Is she a heifer/ how many calves has she had before
○ How long has she been presenting those signs
○ What have you tried with her
○ Why do you think she is calving and what makes it different
On arrival
○ Where is the cow
○ Has anything changed since we last spoke
○ Previous history of the cow
2
Q
Schistosomus reflexus what is it, how generally present, cause, treatment and future for cow
A
§ Generally come out guts and viscera first or head and legs first
□ If 2 front feet and 2 back feet present -> may think it is twins so try to push and pull but nothing happening
Cause - don’t know - failure of body to zip up at the beginning of gestation
What do you do now
○ Kill the calf humanely asap -> captive bolt, lethabarb
○ Check cow for possible trauma -> foot through uterus?
○ Check for a twin
- Should we cull her?
○ Not a reason to cull the cow - sporadic
○ If a good cow then no, but if a bad cow then maybe the tipping point
3
Q
What are the 4 main supplementary tests for diagnosing skin disease
A
- Swabs for microbiology
- Skin scrapings
- Biopsy or impression smears
- Haematology/biochemistry
4
Q
Ringowrm significance, what common in, findings, diagnosis and treatment
A
○ Zoonotic - especially for young/old - not much of an issue
○ Fungal and common
○ Esp in young animals in close contact
○ Findings - Grey, circular crusts… may coalesce
○ Diagnose - skin scraping show hyphae/spores
○ Treatment - Often resolve spontaneously but treatment sometimes requested (iodine - twice a day for 2 weeks)
5
Q
Papillomatosis appearance, when issue, diagnosis, treatment and control/prevention
A
○ Appearance is highly variable
§ Proliferative, hairless, on head, teats, penis
○ Only an issue if in a spot where interfering with normal processes such as teat, eye, penis, show animals
○ Diagnosis on appearance
○ Treatment not usually required as generally go away by itself
§ Excision, autogenous vaccine
○ Control/prevention - immunotherapy (BCG)
6
Q
Dermatophilosis cause, presentation and treatment
A
○ Dermatophilus congolensis
○ Damaged, broken or macerated skin - diffuse
○ Sporadic in temperate areas - warm climates
○ Scabs are tenacious - hair growing through
○ Can become infected with other bacteria
○ Not usually pruritic - unlike manage
○ Treatment - antibiotics (penicillin, tetracycline) and predisposing factors
7
Q
What are the 3 main lice of cattle, generally what animals present on and treatment
A
pediculosis
○ Sucking lice - haematopinus eurysternus, linognathus vituli
○ Biting lice - bovicola (Damalinia) bovis
○ Host specific with site preferences
○ Generally underlying reason ->
○ Esp in young animals, often “secondary”
○ Treatment - spray, pour-on, injection in autumn/winter
8
Q
Mange mites how host specific, diagnosis, the 3 main types in Australia and what do they lead to
A
○ Not as species specific ○ Diagnose - via skin scraping a. Chorioptic (Chorioptes bovis) § Ugly but often not itchy - thickened wrinkles skin § Bad cases can get very itchy b. Demodectic (demodex bovis) § Species specific § Little irritation.. Brisket, neck, withers § Often asymptomatic - not usually diagnosed clinically c. Ear mites (raillietia auris) § Otitis externa § Unsure on whether pathogenic
9
Q
What are the 2 main exotic mites and what they do to the cattle
A
a. Sarcoptic (sarcoptes scabei var bovis) § Fairly host specific § Annoying, brisket, neck and groin b. Psoroptic (psoroptes ovis) § Primarily a parasite of sheep § Notifiable in Australia § Can lead to high sensitivity
10
Q
What are the 3 main ticks of cattle
A
1) boophilus microplus
2) haemaphysalis longicornis (NZ cattle tick)
3) ixodes holocyclus (paralysis tick)
11
Q
Boophilus microplus lifecycle, significance and 3 control strategies
A
§ One host tick (3 weeks on host, 1 month egg laying)
§ Heavy infestations > “tick worry” - they hurt, annoyed, depressed
§ Important vector of disease
□ Babesiosis and anaplasmosis - diseases of the blood that will kill, anaemia, decrease production
® Real issue when naïve cattle are exposed to ticks -> DEATH
§ Control
1. Chemical control of ticks
2. Resistance of cattle (bod indicus)
3. Vaccine (expensive, repeated)
12
Q
Haemaphysalis longicornis and ixodes holocyclus lifecycle, where found and effect
A
Haemaphysalis longicornis (NZ cattle tick)
§ Three host tick
§ Found in relatively low numbers in Australia
□ Queensland, NSW, Victoria
§ Less significant
Ixodes holocyclus (paralysis tick)
§ Can cause ascending paralysis, esp in calves
- Sporadic, in wetter coastal regions of eastern Australia
13
Q
Photosensitive dermatitis what are the primary causes
A
- Exogenous PDAs absorbed
® Ingested, then PDAs circulate in periphery
® Pale, hairless skin then exposed to UV light
® UV light alters PDA to cause cellular damage - Plants - e.g. St John/s Wort, Brassica spp
® Esp. immature plants, infected with fungi - Drugs - phenothiazine, corticosteroids
14
Q
Photosensitive dermatitis secondary cause pathogenesis
A
- Chlorophyll converted to phytoporphyrin
® Phytoporphyrin previously known as phylloerythrin
® Produced by bacteria in the rumen
® Usually conjugated in liver and excreted in the bile - Reduced excretion in bile allows build-up
- Hepatotoxins impair hepatobiliary excretion
® Sporidesmin (pithomyces chartarum), lantana - leads to fascial eczema
15
Q
Photosensitive dermatitis clinical signs and what can lead to with result
A
○ Clinical signs vary in severity
§ Behavioural -> may not see lesions but hypersensitive skin
§ Physical -> sloughing, bleeding, ulcerations
- found underside of tongue, lateral aspect of teat (problems when milking), backs, nose
- Acute bovine liver disease
® Autumn or early winter
® Mortality 10-20%
® Pyrexia, depression, milk drop, severe photo
16
Q
Facial eczema how occurs, how common, where, pathogenesis
A
- a disease manifested via secondary photosensitisation
○ Quite common and serious in Australia (Gippsland) and NZ
○ Pithomyces chartarum grows on pasture
§ Dead lead litter in warm, humid weather
§ Sporulation after 4 days of >12 degrees with moisture at ground level
○ Fungal spores contain sporidesmin -> necrosis of bile ducts
17
Q
Facial eczema clinical signs, diagnosis and treatment
A
○ Typical photosensitisation signs - Signs occur 10-14 days after exposure
○ Diagnosis
§ Clinical signs and epidemiology - multiple animals in late summer early autumn
§ Serum GGT >70IU/L mild, >300 moderate, >700 severe - may need to cull if severe
○ Treatment
§ Protect from sunlight - lock in a shed (will not stay there willingly)
§ Anti-inflammatories (and antibiotics) as support
§ Zinc is not effective after exposure or once clinical signs become apparent
18
Q
Facial eczema what are the 3 main control methods
A
1) Monitor paddocks by spore counts >100,000/g is dangerous (less if grazing harder)
- Find information on websites such as dairy Australia
- Farms can do there on spore counts
2) Provide zine early (prior to exposure)
- Zn sulphate in water using automated dispensers - cows can taste, will choose to drink different water if available
- Zn oxide as an oral drench - everyday
- Metallic Zn oral bullets (FaceGuard in NZ)
- Zn toxicity is a significant danger
® ↓ therapeutic margin
® Gastroenteritis, anorexia; ↓milk production
3) Pasture fungicides available in NZ
19
Q
Squamous cell carcinoma how common location and character
A
○ Common ○ Esp in white skin of cows § Muco-cutaneous junctions - eyes, vulva, anus § Along back or on udder ○ Locally invasive, locally metastatic
20
Q
Ocular carcinoma how common, where present, treatment options
A
○ Common in beef and dairy cows
○ Eye pigment. Sunlight, viral agents
○ On eyeball or third eyelid
○ May regress but may also invade or metastasize (locally)
Several treatment options
§ Surgery (easy with third eyelid), cryotherapy, radiotherapy (not common)
21
Q
Ocular carcinoma when salvage slaughter is important
A
§ Illegal to send cattle with malignant tumors of the eye larger than 2cm to saleyards
§ If not bleeding or discharging up to 2cm may be sold
§ If between 2-3cm go to abattoir at owners risk of non-payment
§ If send large tumors to abattoirs or saleyards may lead to animal cruelty fines
22
Q
Cutaneous angiomatosis and lymphosarcoma what are they, location, results
A
Cutaneous Angiomatosis ○ Usually on back or flanks ○ Often only noticed due to trauma -> LOTS OF BLOOD -> tie off the bleeder Cutaneous lymphosarcoma ○ Uncommon ○ A form of sporadic bovine leukosis § Also occurs as multicentric and thymic forms ○ Usually in younger animals (<3 years)
23
Q
What are the 5 main skin diseases of calves
A
- Inherited epidermal dysplasia aka. “baldy calf syndrome”
- Neonatal alopecia
- Inherited congenital hypotrichosis
- Iodine deficiency
- Curly coated cardiomyopathy
24
Q
Baldy calf syndrome cause, effect and treatment
A
○ Inherited as autosomal recessive trait
○ Progressive changes in skin after birth
§ Patches of alopecia
§ Overgrown hooves
§ Also excessive lacrimation, poor appetite
- May respond to Zn supplementation
25
Pseudo-lumpy skin disease what differential for, cause, effect and treatment
```
○ Differential for lumpy skin disease (exotic -> deep lesions in the skin)
○ Bovine herpes virus type 2
§ Also causes bovine herpes mammillitis
§ Multiple firm cutaneous nodules
§ Resolve spontaneously
```
26
Subcutaneous emphysema what occurs and treatment
○ Traumatic, can suck air into subcutaneous tissues
| ○ Treatment - penicillin (just in case), will resolve by itself
27
Enzootic bovine leukosis (EBL) cause, significance, presence in australia and risk factors
- Infectious - retrovirus
- An important disease of cattle - notifiable
○ Decrease prod, restrictions (trade, semen sales, milk etc)
- Eradicated from Australian DAIRY herd through regular testing
- Beef bulls introduced to dairy herds should be EBL tested!
Risk factors
- Older animals (<5)
- Less than 5% infected animals show clinical signs of lymphosarcoma
○ Approx. 30% develop non-neoplastic lymphocytosis
28
Enzootic bovine leukosis clinical signs, transmission and diagnosis
Clinical signs - progressive - weight loss, decrease production (peracute if heart/adrenals involved = catastrophic events)
Transmission - Vertical and horizontal transmission - instruments contaminated with blood
Diagnosis - serology or milk vat tests
29
Sporadic enzootic bovine leukosis cause, how common, 3 types and diagnosis
- Not related to BLV
- Uncommon but fatal
- Cause unknown - genetics
- More likely to see this in practice
- Young animals
- Sporadic
Types
1. Juvenile, multicentric form: symmetrical LN enlargement, weight loss, death
2. Thymic form: mass around thoracic inlet, dysphagia, resp distress
3. Cutaneous form (rarest): grey/white hyperkeratotic plaques -sometimes appears to get better, typically recurs and animals diet due to infiltration of other organs
Diagnosis
- Presence of leukaemia, anaemia, serology to rule out EBL
30
Symmetry of the head what looking for and differentials
○ Drooping ears
§ Differentials - otitis external, listeriosis
○ Swelling (unilateral vs bilateral)
§ Differentials - abscess, actinomycosis, tumours
○ Excessive licking or chewing, irritability
§ Differentials - hypomagnesaemia, lead poisoning
31
Listeriosis cause and important characteristics of organism and significance
- Listeria monocytogenes
- Can grow in temps 3-45 degrees, pH 5.6-9.6
- Can survive environmental conditions for long periods (hay, silage, faeces, straw)
Can live and multiple inside
macrophages
ZOONOSIS - food poisoning and abortion in humans
32
Listeriosis clinical signs and treatment
Clinical signs
- Encephalitis, abortion, iritis in cattle, paralysis
- Unilateral facial paralysis - no menace reflex, droopy ear, tongue weakness, depressed, inappetant
- Progresses to recumbency
- Depends on which nerves the bacteria infiltrates within the head
Treatment
- Eliminate infection (Ab's - penicillins), supportive care
33
Otitis externa how common, mite involved and treatment
- Especially old hot northern cattle, sporadic in temperate env
- Raillitia mites - importance unknown
Treatment
- Antibiotics
- Flush
- drain
34
Otitis media spread, result, clinical signs and treatment
- Eustacian tube or homogenous spread
- Exudate, pressure increase, tympanic rupture
Clinical signs
- Tilted head - affected ear down, milk circling - dirft towards affected side, purulent discharge
- Droopy ear - involvement of facial nerve
Treatment
- Antibiotics - broad spectrum for several weeks
35
Anaphylaxis general cause, clinical signs and treatment
- Generally in response to something you or farmer has given them -> vaccines, blood transfusion, LA corticosteroids
Clinical signs
- Generalised oedema with respiratory signs, dyspnoea, cyanosis, death
Treatment
- Need adrenalin quickly!!
36
What are the 4 main reasons for licking of chewing
1. Foreign body
2. Phosphorus deficiency (pica, lactating beef cattle)
3. Ketosis (chewing) - nervous ketosis as a result of poor nutrition in late pregnancy
4. BSE (bovine spongiform encephalopthy) (nose licking, flehmen, head tossing)
37
When checking the eye and eyelids in cattle what are you looking for
- Discharges - uni or bi-lateral
- Sunken eyes - hydration
- Protrusive eyes
- Movements (nystagmus)
- Menace reflex - slight/motor function
- Pupillary light reflex (optic vs oculomotor vs central) - dark env, bright light source
- Conjunctiva and eyelids - colour, lesions and pain
- Cornea (ulcers, opacity, vascularisation, scarring)
- Anterior chamber (hypopyon)
38
Eye lesions what are the 3 main conditions that cause this
1) Infectious bovine keratoconjunctivitis (pink eye, IBK)
2) Squamous cell carcinoma (cancer eye)
3) Inflammation associated with systemic disease
○ Bovine herpesvirus type 1 (infectious bovine rhinotrachetitis)
○ Malignant catarrhal fever
○ Septicaemia
○ Anaphylaxis
39
Bovine herpes virus what are the 2 forms, predisposed for and clinical signs
- Highly infectious - discussed under respiratory
○ Genital form - vulvovaginitis
○ Respiratory form - mild respiratory, profuse oculo-nasal discharge
- Predisposes to more severe respiratory disease (enzootic pneum, pneum pasteurellosis)
○ Calves: severe systemic disease in neonates, respiratory dz and diarrhoea
- Nasal signs as well as occular signs (white necrotic plaques)
40
Malignant catarrhal fever main presentation, 3 forms, clinical signs, treatment and what need to differentiate from
- Acute, fatal, sporadic (1-3y) - contact with sheep
3 forms
○ Head/eye - most common and described below
○ Peracute
○ Milk
Clinical signs
- Conjunctivitis, copious ocular and mucopurulent nasal discharge, eyelid oedema
- corneal opacity starts at the limbus and progresses centrally sometimes - pathognomonic
- Also severe mouth lesions, nose lesions and severe pyrexia (fragile MMs)
Treatment
- Untreatable, euthanasia
Differentiate from - exotic vesicular disease and BVD
41
Septicaemia what common in and cause
- Particular in calves - hypopion/scleral injection
Cause - post-septicaemic localisation 5-7 days following coliform septicaemia
Also associated with arthritis, meningitis
42
Bovine iritis where present, cause, result, clinical signs, diagnosis and treatment
- A disease of the northern hemisphere - recognised in NZ
- Silage eye - listeria monocytogenes
- Not much conjunctival or corneal ulceration -> beneath the surface of the eye
Clinical signs
- Iritis, uveitis, keratitis - profuse lacrimation, blepharospasm, vascular engorgement, corneal opacity (temporarily blind)
Diagnosis
- Condition score and silage feeding +/- bacterial isolation
Treatment
- Topical Cloxacillin
43
Hyphaemia most common causes if uni or bilateral and treatment
- Bleeding into anterior chamber of the eye
- Unilateral - trauma
- Bilateral - thrombocytopenia, sepsis, spontaneous
- Treat the underlying condition otherwise will resolve by itself
44
Cataracts how common, cause and autopsy
- Rare and sporadic
- Congenital - associated with pestivirus when in the womb
- Beware - at autopsy, cataracts combined with clear corneas can be an artefact due to cooling
45
Muzzle and nostrils causes of discharge, lesions and smell
```
- Discharges
○ Unilateral or bilateral
○ Blood vs purulent vs gut contents
- Lesions
○ Necrosis (patches - IBR, diffuse - MCF)
○ Granulomas
○ Crusting
- Smell
○ Pneumonia
○ Gangrenous lesions
```
46
Nasal granulomas/foreign body what leads to, clinical signs and treatment
- Chronic allergic rhinitis: nasal granulomas
- Cow cannot pick their nose so they rub them against stalky plants
Clinical signs
- Bilateral, profuse mucopurulent nasal discharge, partial obstruction, irritation
- Often secondary to foreign bodies
Treatment
- Remove foreign bodies - NSAIDS
47
Other nasal signs for intestinal phytobezors, respiratory disease and if unilateral what more likely
- Intestinal phytobezoars often have green rumen contents discharge
- Respiratory disease is often associated with a mucopurulent discharge
- More likely a granuloma or foreign body if unilateral
48
Mouth main clinical signs and structural and functional causes
- Dysphagia - structural or functional? -- trouble swallowing
○ Structural -> obstruction, fractures
○ Functional - nerve issue due to listeria
49
What are 6 important things to look for when examining teeth
1) malocclusion of incisors
2) eruption of incisors
3) incisor wear - decrease ability to eat
4) molar abscesses
5) aging cattle
6) flurosis
50
Aging cattle on teeth at what point can you do this
§ Cows are born with 8 temporary "milk incisors"
§ At 22-34 months - 2 permanent incisors erupt
§ At 27-40 months - 4 permanent incisors erupt
§ At 33-42 months - 6 permanent incisors erupt
§ At 40+ months - 8 permanent incisors (full mouth)
§ ABOVE THIS YOU CAN'T TELL
51
Fluorosis how common, causes, clinical signs, treatment and diagnosis
§ Not common
§ Chronic intake of fluoride
□ Pollution, Deep wells, Fertilizer
§ Clinical signs
□ Excess wear of teeth = chalky enamel, difficulties chewing, ill-thift, yellow, dark brown or black discolouration
□ Osteoporosis
§ Treatment
□ Irreversible but important to diagnosis - herd base problem so need to address to prevent in the future
§ Diagnosis
□ Elevated fluoride concentrations in blood, urine, feed or drinking water, excess periosteal bone formation (adults)
52
Gums what looking for and diseases associated
- Look at gum colours
- Pale - anaemia
- Yelloe - jaundice
- Ulcers - foot and mouth disease
53
What are some important disease/injuries of the jaw and tongue
1. Actinobacillosis - woody tongue
2. Actinomycosis - lumpy jaw
3. Other trauma, infections, foreign bodies of soft tissue
- Salivary gland infections
- Blocked salivary ducts
- Phlegmonous cellulitis
- Propionibacterium infection
4. Fractures of mandible
54
What are the 3 main reasons for subcutaneous oedema around the jaw
- Celluitis with heat and pain (infection/trauma)
- Oedema of the head and neck only (interference with venous or lymphatic return)
- General oedema (low protein, increased hydrostatic pressure)
55
Actinobacillosis what also called, cause and presentation
WOODY TONGUE
- Glossitis/stomatitis due to actinobacillus lignieresi - found worldwide
- Opportunistic infection of soft tissue (not bone) secondary to trauma
- Characteristics pyogranulomatous lesions
- Hard, yellow
- Inappetence, salivation, submandibular swelling
56
Actinobacillosis treatment
- They look terrible but respond well to treatment
- Streptomycin WAS drug of choice NOW ILLEGAL
- Oxytetracycline most commonly used
- Sodium iodide
- Often use sodide IV, then systemic antibiotics
§ Not really an antibiotic but used instead of antibiotics in:
□ Woody tongue
□ Ringworm in valuable animals
□ Peritonitis, septic arthritis □ Long acting - single dose - repeat in 7-10 days
57
Actinomycosis other name, cause, result, clinical signs, treatment and prognosis
- LUMPY JAW
- Actinomyces bovis - uncommon
- Osteomyelitis of mandible post trauma, destruction of bone, deformity of jaw and molars
Clinical signs
- Pain, difficulty chewing, unilateral swelling, discharging sinuses, yellowish sticky pus
- Atypical infections of soft tissues
Treatment
- Sodium iodide and oxytet
Prognosis - depends on bone damage
58
Trauma of the mouth common causes, clinical signs and diagnosis
- Often iatrogenic
- Drench gun injury (irritant solution)
§ Fibrous capsule
§ Abscess, cellulitis, possibly death
- Also from eating foreign objects
- Unselective grazing behaviour
- Cows do not spit
Clinical signs
- Abscess, difficulties, with prehension, pain, stertorous respiration, dysphagia, salivation, swellings
Diagnosis
- Detailed mouth exam
59
Salivary glands what are the two main diseases and causes
1. Infection/abscessation of the salivary glands
- Trauma, grass seeds
- Clinical signs: associated with pressure/pain
- Hard to differentiate from lymph nodes
- Drainage/antibiotics (7 days)
2. Blocked salivary ducts
- Sublingual salivary gland has only one duct
- Grass seeds occasionally block
- Need to remove the blockage
- Congenital atresia in young animals
60
Phlegmon called, cause, result, clinical signs, treatment and prognosis
- More properly "phlegmonous cellulitis"
- "footrot of the mouth" - fusobacterium necrophorum
- Can extend down the brisket if untreated, become toxaemic
Clinical signs
- Sub mandibular swelling, purulent fluid not oedema, temp >40.5 degrees, increase HR
Treatment
- Drainage - find the dependent point
- Antibiotics
- Penicillin high dose
- Early cases respond well
- Poor prognosis if advanced
- Abscesses may develop in area
61
Define vesicle, erosion, ulcer, crusting and plaque
- Vesicles = a fluid filled, cellular, circumscribed elevated lesion up to 1cm in diameter
- Erosion = is a shallow or superficial loss of epidermal layers
- Ulcer = a deeper form of erosion that penetrates the epidermal basement membrane
- Crusting = the reaction of mucosal surfaces to chronic irritation/discharges
- Plaque - a raised area
62
What are the 6 things that cause mucosal lesions
1. Foot and mouth disease - exotic - many affected
2. Vesicular stomatitis - exotic
3. BVD/mucosal disease - erosions rather than vesicles
4. Malignant catarrhal fever - other signs are pathognomonic
5. Bluetongue - tends to be erosions rather than vesicles
6. Bovine popular stomatitis - plaques - often subclinical - calves
63
Squamous cell carcinoma what susceptible, results and treatment
- Known to farmers as ‘cancer eye’
- increased in incidence in cattle with unpigmented skin surrounding the eyes (i.e. eyelids but even the cornea - occurs more in breeds such as Herefords
- Tumour can invade underlying tissues and become ulcerated, creating a significant animal welfare issue
- Dairy breeds more susceptible to third eyelid cancers
Treatment
1. Immediate sale for slaughter (if the tumour is less than 2 cm)
2. Removal of the tumour with a view to subsequent sale and slaughter
- Not for long term treatment as may grow back
3. Surgical eye ablation
4. Euthanasia
64
Squamous cell carcinoma what occurs at the beginning and advice at this stage
- Solar keratosis around the eyelids
- Increase redness and raising of the third eyelid
Removal of the third eyelid at this stage is feasible and easy
- Advise to cull at end of lactation as can recur
65
What are the 6 steps in surgical eye ablation
1) preparation of skin, sedation, restraint
2) local anaesthetic infiltration around upper and lower eyelid then deep into orbit tissues
3) first incision around the upper eyelid
4) dissection of orbital tissues and musculature - blunt
5) optic nerve severed and eye removed
6) post-operative treatment
66
Surgical eye ablation what is important about the incision around eyelid
- You need to remove enough eyelid tissue to be certain of no ingrowing eyelashes etc remaining, and of removing tumour tissue.
○ On the other hand, you need to leave sufficient skin to be able to close the wound!
- Second incision is around the lower eyelid.
- Some practitioners suture the eyelids closed before commencing the first incision
Haemostasis -> better off progressing through the surgery and getting to the skin
If major (squirting into face) put haemostats on
67
What is involved with post-operative treatment of surgical eye ablation
- The dead space left in the orbit constitutes a significant infection risk.
- Antibiotic eye ointment (e.g. cloxacillin ointment used for pink eye treatment) is liberally placed in the empty orbit before closure.
○ (Some practitioners may also include some sterile packing material (tape) that is removed a few days later via the medial canthus.)
- Removing excess blood from the skin and applying anti-fly topical spray may also be indicated.
68
Infectious bovine keratoconjunctivitis in cattle what known as, cause, pathogenesis and clinical signs
PINK EYE
- moraxella bovis - Toxins produced by the organism cause inflammation and ulceration of the cornea (and conjunctiva), giving the disease its characteristic appearance
Clinical signs
- corneal opacity increased, ulcer present
- photophobia, blepharospasm
- puss and necrotic material within teh centre
- if chronic corneal scarring (reduce sight)
- if severe eyeball can rupture
69
Infectious bovine keratoconjunctivitis epidemiology and diagnosis
- Outbreaks can occur in hot, dusty conditions, particularly if animals have been yarded
- Flies also aid in the spread of the disease
- Pink eye commonly affects young cattle
- Recovering cattle exhibit non-permanent immunity to the disease
Clinical signs, +/- swabs for bacteriology
- Need to distinguish between
○ Active lesions
○ Scar (no inflammation, smooth surface)
70
Infectious bovine keratoconjunctivitis prevention and treatment (3 options)
- Predisposing factors
○ Fly control
○ Fly repellents
- Vaccination
○ Against 3 strains of M. bovis
○ Seems to work well in herds HOWEVER some herds have M. bovoculi (not in vaccine)
○ Single vaccination, 3-6 weeks before pink eye season
Treatment
1) cloxacillin eye ointment - repeart at 48 and 72 hours, treat BOTH eyes
2) inject procaine penicillin into bulbar conjunctiva
3) third eyelid flap or temporary tarsorrahaphy
71
Lameness prevalence in dairy cows, most cases associated with and which locations
- Around 10% of the dairy cows in Australia suffer from at least one cause of lameness
90:90:90
- Most cases (90%) associated foot lesions
- Back feet much more commonly affected
○ Hind leg used more for propulsion - hence friction
- Lateral claw more commonly affected
72
List 6 economic losses due to lameness and other main issue
1) reduced milk production
2) cost of treatment
3) weight loss
4) reduced reproductive efficiency -> milk 56% 6 week in calf rate aim for 70%
5) premature culling
6) replacement costs
Animal welfare and lameness
73
What are the 5 main causes of lameness
1. Environment
○ Moisture softens horn , Concrete abrasive - wears the sole down, Dryness may lead to fissuring
○ Incidence may be higher in large herds - track maintenance, walking longer distances
2. Management - human factors - MOST IMPORTANT
○ Cows should not be hurried on farm tracks - patience of farmer
○ Bail feeding = lower incidence lameness
○ USE OF A BITING DOG -> pushing the cows up
3. Hereditary - animal factors
○ Cork screw claw - DO NOT BREED FROM
4. Nutrition
○ Rumen acidosis (maybe not as big of a risk) and laminitis
5. Infectious
○ Fusobacterium necrophorum - responds to penicillins
Treponema spp - causes digital dermatitis in cows - emerging - ISSUE
74
What are the 3 main risk factors for lameness
1) track - maintenance, patience of farmer, motor bikes, BITING DOGS
2) shed - use of biting dogs, cow density in yard, AGGRESSIVE use of backing gate
3) animals - higher in friesians
75
What are the 5 important things involved in the examination of the lame cow
1) observe standing free in yard
2) history
3) 8 point exam
4) lifting hing foot
5) lifting front foot
76
What are the situations of the 8 point exams
1. Which leg is the cow lame in
§ Head down - hind limb - to bring weight forward and take pressure off back
§ Head up - forelimb - to bring weight backwards and take pressure off front
2. Is the leg swollen and obviously
3. Are cracks present in external surface of the hoof wall of lame leg
4. Is there soft tissue swelling with foul smelling discharge and dead and damaged skin in the interdigital space
5. Is there abnormal discolouration in the sale horn? Do not confuse with normal pigment
6. White line - expanded and filed with mud and gravel, especially towards heel area
7. Are there any sensitive areas which cause withdrawal reflex
8. Seek veterinary advice as lameness may be associated with upper leg abnormality
77
What are the 5 steps in lifting a hind and front foot
- Lifting hind foot
1. Slip knot above hock - IMPORTANT
2. Rope over rail
3. Then back around above hock
4. Then up to rail on other side
5. Secure foot with soft rope
§ Needs to be held as if goes down could dislocate hip
- Lifting front foot - should only be 10% of lameness cases
1. Loop around leg at level of dewclaw
2. Over rail and back under axilla
3. Then back over rail and lift
4. Secure front leg with soft rope
5. Tie the back leg away - so doesn't kick
○ WATCH THE BACK LEG
○ If extensive may need to sedate
78
Examination of the foot what are the 7 steps
1. Clean with scrubbing brush, water
2. Look for swelling at coronary band
3. Look for defects or penetrations of the sole
4. Use hoof testers to check for pain
5. Clean sole with hoof knife, rasp or angle grinder
6. Examine for axial, abaxial wall cracks
7. Thoroughly explore any defects detected
79
What is important to consider with angle grinders
○ Angle grinders are potentially dangerous
§ Electricity and water - use circuit breaker
§ Only use on well restrained animal
§ Must wear safety goggles
§ Can generate excessive heat - proceed slowly
§ Not recommended for use on front feet of standing animal unless very well restrained
80
Anaesthesia of bovine digit what can use, when
1) Xylazine an excellent sedative - always for a bull
2) Interdigital nerve block - 20 cc lignocaine injected between the digits
3) Intravenous regional anaesthesia - use for claw amputation (embryotomy wire) - REMOVE ALL BONE, bandage, antibiotics)
81
What are the 4 main causes of lameness and 10 other causes
1) white line disease
2) axial wall crack
3) sole penetration/abscess/under run sole
4) foot rot
Other
1) bruised sole
2) excess hoof wear
3) inter-digital dermatitis
4) hair heelwart or digital
5) inter-digital skin hyperplasia
6) aseptic laminitis
7) sand crack
8) abnormal hoof growth
9) septic arthitis of distal interphalgneal joint
10) fracture of third phalanx
82
White line disease what is it, pathogenesis, location, lameness and treatment
○ Disintegration of the junction (white line) between the sole and the wall - normal
- BUT -> Penetrate dirt, stones can get stuck in this gap -> cannot come back together
○ May track up to coronary band - or may go systemic -> septic arthritis
○ Usually lateral claw hind digit
○ Variable lameness
○ Treatment -> need to open up and remove the foreign bodies
83
Axial wall crack location, lameness and when generally occur
○ Occur adjacent to axial groove of medial claw of hoof
○ Often no lameness
○ Lameness often follows heavy rain
84
Sole penetration/abscess/under-run sole what occurs, lameness, swelling and what is important to do
○ Infection through foreign body or horn defect
○ Acutely lame
○ Characteristic "sliding" lameness
○ Swelling above coronary band (may be very slight)
○ Careful search for hoof defect
85
Foot rot cause, results and signs
```
Infectious necrobacillosis
○ Footrot - Fusobacterium necrophorum
○ Necrotising infection interdigital dermis, cellulitis of digital area
○ Signs
§ Sudden onset lameness* VERY PAINFUL
§ Swelling affected area
§ Responds antibiotics
- Often stone is the primary issue which allows for penetration of fusobacterium
```
86
Excessive hoof and inter-digital dermatitis cause and presentation
Excess Hoof wear
○ Feet kept moist due to environmental conditions
○ On concrete at time of milking
○ Plus time walking laneways
- very soft and thing - elongated
Inter-digital dermatitis
○ Cause - bacteroides nodosus
○ Can produce benign footrot sheep
○ Inter-digital dermatitis, but little swelling -> looks like footrot but not as necrotising and smelly
Often affects more than one foot, calves particularly susceptible
87
Hair heelwart or digital dermatitis, presentation, prevalence, cause and the 2 types
○ Very painful, contagious disease causing wart-like areas on the back of the hind feet, on the bulb of the heel or near the interdigital cleft
○ Relatively uncommon in Australia -> now increasing - most common in northern hemisphere
○ Cause is unknown - bacteroides species and an invasive treponema spirochaete have both been implicated
○ Clinical features - two distinct types
1. erosive/reaction
2. proliferative (wart-like)
88
Hair heelwart/digital dermatitis describe the two main clinical presentations
1)The erosive/reactive (strawberry-like)
□ Cleansing exposes reddish granulation tissue (strawberry) with a concave profile
□ Lesion is very sensitive and easily bleeds, but the soft tissue is not swollen
2) The proliferative (wart-like) forms
□ May give rise to papillomatous type - mass of hard, fine tendrils which can be several centimetres in length and cover a considerable area - chronic
□ Can then go back to the erosive phase
89
Hair heelwart/digital dermatitis diagnosis and treatment
○ Diagnosis
§ Often based on history of an epidemic onset of discomfort and lameness in the herd
□ Commonly seen as shifting lameness
○ Treatment
§ Lesions affecting individuals animals should be treated topically
§ After cleaning and drying, the lesion should be sprayed with an aerosol containing a solution of oxytetracycline
§ Herd outbreaks are treated with a footbath containing antibiotic
§ In general, parenteral antibiotics have not shown any affect on either the erosive or proliferative form of digital dermatitis
90
Inter-digital skin hyperplasia what occurs, location, lamness and treatment
```
○ Excess epidermal, hypodermal tissue
○ More common in hind feet
○ Appear as protuberance of skin
○ Degree of lameness varies
○ Treatment surgical
○ Often grows back, need to remove the fibroma, wire the claws together
```
91
Laminitis define and result and the 3 types
○ Inflammation of the soft tissue between the hoof wall and sole and the underlying pedal bone within the claw
○ Inflammation results in a reduction in the quantity and quality of hoof material produced
1) acute laminitis
2) subclinical laminitis
3) chronic laminitis
92
Acute laminitis how common, clinical signs, affected animal presentation
○ Not common in cattle in our environment - may follow acute illness
○ Clinical signs similar to signs seen in horse, but more variable
○ Affected animals
§ Move slowly, arched back
Stand with hind legs extended forward, fore legs forward
93
Subclinical laminitis how common, predisposes to, signs, possible sign
○ Occurs much more commonly than acute laminitis
○ It's an important factor in the development of other hoof disease, for example, white line disease, sole abscess, sole ulcer and claw deformities
○ Produces no immediate signs, but is recognised by the changes in the hooves which occurs several months after episodes of sub clinical laminitis
○ The changes are a deterioration in hoof horn quality and haemorrhages in the sole of the hoof
○ The white line develops a yellow colour and has small red dots of haemorrhage along it
94
Chronic laminitis what occurs to the foot
○ The claw changes shape
- Becomes longer, front wall of the hoof is concave when viewed from the side
○ The sole becomes flatter and wider
○ The wall develops horizontal ridges or ripples due to partial interruptions in its production
95
Sand crack what occurs, and the types of cracks
○ Vertical split in hoof wall, extending from coronet to a variable distance along the direction of growth
○ Large incomplete sandcracks often not associated lameness
○ Two distinct vertical fissures
§ Fissures of coronet
§ Fissures of wall
○ Horizontal fissures of hoof wall
§ Discontinuity of wall of hoof in a plane parallel to coronet
§ Often occurs in all hooves
§ Related to severe upset of metabolism - mastitis, metriti
96
Abnormalitis of hoof growth causes and result in
○ Inherited and environmental factors
○ Abnormal hoof conformation result as a primary hoof lesions
○ Eg - beak claw, cork screw claw
97
Septic arthritis of distal interphalangeal joint what occurs and result
○ Pus in joint may discharge through a sinus near site of entry of infection
○ Sinus formation may develop along the abaxial coronary region where joint is superficial
○ Severe pain distal digital area, severe lameness
98
Fracture of third phalanx location, presentation, prognosis
○ More common in front feet
○ Stance, gait changes so that fractured distal phalanx bears little weight
○ If both fore limbs affected, cross limbed stance characteristic
○ Not a good prognosis especially in a bull
99
Amputation of digit indications and 3 steps
```
Indications
- Septic arthritis
- Severe tenosynovitis
- Osteomyelitis of third phalanx
Steps
1. Anaesthesia - Local IV
2. Amputate at end of P1
3. Bandage
```
100
What are 5 principles of treatment bovine hoof
1. ADQEUATE RESTRAIN
2. Suitable local anaesthesia where necessary
3. Under-run areas opened to allow drainage
4. Avoid exposing to much corium when trimming claw cracks - otherwise granulation tissue
5. In painful conditions, raised affected claw
