Farm animal 4 Flashcards
1
Q
Outline the management of a possible complications of teat laceration repair in cattle
A
- Teat fistulas:if unsuccessful repair or left untreated
- perform surgery on granulated tissue at least 2-4 weeks after injury, and after daily cleaning and steps taken to prevent mastitis
- Fistulous tract dissected out all the way to teat cistern to expose healthy teat mucosa
- Close resulting hole with 3 layer closure
2
Q
When is open teat surgery indicated?
A
For mid-teat obstructions or teat spiders
3
Q
Outline open teat surgery in cattle
A
- Vertical incision on opposite side to lesion
- Do not enter teat sphincter or rosette of Furstenberg with incision
- Granulation tissue masses excised, correct mucosal deficits by undermining adjacent mucosa and sliding over defect
- If >30% mucosa affected, can use prosthetic implant
- Close in 3 layers
4
Q
Discuss the value of open teat surgery in cattle
A
- Fresh, non-contaminated, usually elective: good success rate
- Use in place of other methods e.g. teat knives or spirals
5
Q
Discuss possible complications and their management following open teat surgery
A
- Haemorrhage: locate and ligate
- Blood clots: may require surgical removal
- Incisional leakage following surgery: close incision again
- Failure to milk from affected quarter: no milk within 24 hours, place sterile teat cannula into teat, lavage with warmed sterile saline and drain teat using cannula until suitable for machine milking
6
Q
Discuss the management of teat fistulas in cows
A
- Usually secondary to trauma
- If no effect on normal teat drainage allow to heal self
- can be trimmed and sutured if needed during dry period
7
Q
What are the indications and contraindications for the use of teat prosthesis?
A
- Indications: defect in mucosa >30% of mucosa
- Contra: infection, remove if chronic or frequent mastitis cocurs
8
Q
Outline the management of irreversible trauma and severe gangrenous mastitis in cows
A
- Teat amputation under local anaesthesia or lumbosacral epidural
- Allow milk to drain and give prophylactiv intramammary antibacterial therapy
- Place rubber tourniquet at base of teat, trim out milk sinus, close defect with 3 layers of sutures
- If necrotic or infected, trim/crush and remove devitalised tissue with burdizzo, then leave open to drain
- Leave tourniquet on for 24-48hours to prevent haemorrhage
9
Q
Outline the management of supernumerary teats in cattle
A
- Ideally remove <4 weeks old
- If >3months old must be removed by vet
- Local anaesthetic always recommended
10
Q
What are the possible complications resulting from supernumerary teats in cattle?
A
- Interference at milking
- Risk of mastitis
- Cosmetic appearance
11
Q
Outline the management of conjoined teats in cattle
A
- Must be removed
- Surgical intervention
- Elliptical incision parallel to long axis of primary teat, dissect down to annular ring to isolate sinus of accessory teat, transect it, close wound in 3 layers
- Care not to enter teat cistern of primary teat
- Good prognosis but consider heritability
12
Q
Outline the management of atresia of the teat in cows
A
- Often not seen until first lactation
- Treat as for obstructive lesions
- Consider cause: may be congenital, or as a result of trauma from suckling and infection from flies
13
Q
List the risk factors for teat hyperkeratosis in cattle
A
- Long pointed teats
- Slow milking cows
- Higher producing cows
- Peak lactation
- Cluster on before milk let down
- Low threshold for ACRs (automatic cluster release)
- Over-milking
- high vacuum
14
Q
Describe a teat scored as “N”
A
- No ring
- Teat end smooth, small even orifice
- Typical appearance for many teats soon after start of lactation
15
Q
Describe a teat scored as “S”
A
- Smooth or slightly rough ring
- Raised ring encircles orifice
- No fronds of old keratin evident
16
Q
Describe a teat scored as “R”
A
- Rough ring
- Raised, roughened ring with isolated fronds or mounds of old keratin extending 1-3mm from orifice
17
Q
Describe a teat scored as “VR”
A
- Very rough ring
- Raised ring with rough fronds/mounds of old keratin extending 4mm or more from orifice
- Rim of ring is rough and cracked, often giving teat-end a flowered appearance
18
Q
Briefly outline the steps in a clinical examination of a cow’s teats
A
- All 4 teats and glands
- Examine milk/secretion
- Look and palpate for signs of acute/chronic inflammation (heat, swelling), injury/trauma, coldness
19
Q
What are cold teats indicative of?
A
Gangrene
20
Q
List the methods that can be used for the detection of abnormal milk
A
- Clinical examination/fore milking
- Conductivity (electrical)
- Chemical tests e.g. acute phase proteins, NAGase
- California Milk test
- Individual cow somatic cell counts
21
Q
Explain the importance of fore-milking
A
- Detect abnormal milk
- Legal requirement during milking
- Look for clots, watery consistency, colour change
- May use inline filters to detect clots in milk
22
Q
Describe the use of conductivity for the detection of abnormal milk
A
- Charge passed through milk, affected by mastitic changes
- Need to compare over time and between quarters
- Often found in robotic milkers
23
Q
Describe the california milk test for the detection of abnormal milk
A
- Detects elevation in SCC
- Crude but useful indicator of subclinical mastitis
- Test kit reagent or Fairy liquid, mix at 50/50 ratio
- High SCC leads to coagulation of solution (changes >400,000 cells/ml)
24
Q
Describe the use of individual cow somatic cell counts for the detection of abnormal milk
A
- Useful for detecting sub-clinically affected cows
- Composite sample from all 4 quarters, send to lab for analysis
25
Explain the difference between clinical and subclinical mastitis
- Clinical: cases detected by farmer during milking e.g. clots, swelling, sick cow
- Subclinical: only detected by SCC >200,000 cells/ml
26
In a clinical mastitis, what might a low bulk milk cell count be indicative of?
Environmental organisms
27
In a severe clinical mastitis, organisms are likely to be implicated?
Coliforms
28
How is the causative pathogen of a clinical mastitis determined?
- Impossible to determine at clinical exam, need to collect sample and send to lab
- Cow side petrifilm available but rare in UK, possibly useful on farms with lots of G-ve infections
- Newer methods: mass spec aka Molditoff, strain typing, not commercially available
29
What are the steps required to collect a milk sample for bacteriology?
- Clean udder
- Disinfect teat
- Spirit swab teat end
- Collect sample
- Store (can be frozen)
30
Discuss the value of bacteriology in the investigation of mastitis
- Useful, but sensitivity limited value
- Good decisions can be made without
- Herd patterns often more valuable (timing of infection, SCC, prevalence of infection)
- Important to have bacteriology for Strep. agalactiae
31
What is lactation new infection rate defined as?
The proportion of cows acquiring new intramammary infections between milk recordings
32
Explain what is meant by the bulk milk somatic cell count
- Overview of herd
- Calculated from individual cow recordings
- But circumvents on-farm management of bulk tank by withholding cows
33
What rate of lactation new infections triggers intervention?
5%
34
Explain what is meant by, and the importance of, the proportion of herd infected and chronically infected
- Provides indication of cows currently infected, as well as those persistently infected
- Can allow insight into potential dynamics within the herd
35
What would be the most likely cause of mastitis if the proportion of herd infected, and proportion of chronically infected cows is both rising and converging?
Suggests cause is pathogens that are more likely to cause persistent infection, and less likely to be cured i.e. contagious pathogens
36
What would be the most likely cause of mastitis if the proportion of herd infected, and proportion of chronically infected cows are both rising but diverging?
Suggests cell counts are being driven by pathogens less likely to cause persistent infection and more likely to be cured i.e. environmental pathogens
37
Define dry period infection rate
The proportion of cows moving from below to above the SCC threshold between the end of one lactation and the beginning of the next (incl. heifers)
38
Define dry period cure rate
The proportion of cows moving from above to below the SCC threshold between end of one lactation and the beginning of the next i.e. indication of proportion of cows curing during dry period
39
Define the putative dry period origin mastitis rate and give the target
- The rate of clinical mastitis cases occurring in the first 30 days of lactation
- Only includes first index cases of each cow
- 1 in 12 cows
40
Define the putative lactating period origin mastitis rate and give the target
- The rate of clinical mastitis cases occurring after the first 30 days of lactation
- 2 in 12 cows
41
What are the principal aims of mastitis control?
- Prevent new infections
| - Remove existing infections
42
Identify the areas likely to be most important with respect to mastitis control in dairy cattle
- Parlour routine
- Cubicle comfort
- Dry cow therapy
- Straw bedding management
- Hygiene of dry cow shed
- Gloves during milking
- Ventilation of dry cow shed
- Pasture management
- Treating high SCC cows
- Internal teat sealants
43
List the features of the 5 point mastitis control plan
- Post-milking teat disinfection
- Blanket antibiotic dry cow therapy
- Treat clinical cases promptly
- Cull chronically infected animals
- Milking machine maintenance
44
Which point of the 5 point plan may need amending and why?
- Blanket antibiotic dry cow therapy
| - Non-antibiotic therapy now available and very effective, now aim for selective dry cow therapy
45
What is the national average for the number of clinical mastitis cases?
~55-65 cases/ 100 cows, aim for 25-30
46
What is the national average for bulk milk cell count?
~160,000cells/ml
47
What origin of mastitis would the following features of a herd be indicative of?
High incidence rate of clinical mastitis, low BMSCC, high incidence of dry period origin cases, low incidence rate of lactation origin cases, seasonal variation
Environmental dry period origin mastitis
48
Explain why environmental origin mastitis may lead to a low/normal BMSCC
Short lived infections easily cleared by the cow, so only a small number of cows at a time are above the target SCC
49
What mastitis disease profile commonly results from contagious pathogens?
- Increased prevalence of subclinical infections
| - Increased prevalence of chronic infections
50
Explain the disease profile that results from contagious pathogens
- Increased prevalence of subclinical and chronic infections
- Contagious pathogens passed from cow to cow in milking process
- Pathogens adapted to live in udder, difficult to get rid of
51
What origin of mastitis would the following features of a herd be indicative of?
High incidence rate of clinical mastitis, high BMSCC, high prevalence of subclinical and chronic infections, low dry period cure rate, many recurrent infections
Contagious lactation period origin
52
In an outbreak of abortions in a cattle herd, list the questions that may help in the diagnosis of the underlying cause
- Vaccination status and what/when used
- Appearance of aborted material
- Age groups affected
- Clinical status of dams
Previous repro problems
- AI or natural breeding?
- Open or closed herd?
- Proportion aborted?
- Other animals on farm?
53
List the most important bacterial causes of abortion in cattle, and indicate which of these may be zoonotic
- Brucella abortus (Z)
- Campylobacter foetus venerealis
- C foetus foetus, C jejuni
- Leptospira interrogans (multiple serovars) (Z)
- Trueperella pyogenes
- Listeria monocytogenes (Z)
- Coxiella burnetii (Z)
54
List the most important viral causes of abortion in cattle
- BVD
- Bovine herpesvirus I
- Bluetongue
- Epizootic bovine abortion
55
List uncommon infectious causes of abortion in cattle
- Chlamydophila abortus
- Ureaplasma diversum
- Salmonella spp.
- Bacillus (extremely rare in UK
- Schmallenberg
56
List the infectious causes of abortion in cattle that may be transmitted venereally
- Brucella abortus
- Campylobacter foetus venerealis
- Tritrichomonas foetus
- BHV-1
- Bluetongue
- (Ureaplasma diversum
57
What is a fungal cause of abortion in cattle?
Aspergillus spp
58
Give the protozoan causes of abortion in cattle?
- Tritrichomonas foetus
| - Neospora caninum
59
List the infectious causes of abortion in cattle that can be vaccinated against in the UK
- Campylobacter (but no licensed vaccines)
- Leptospira (uncommonly done)
- Tritrichomonas
- BVD
- BHV1
- Bluetongue
- Epizootic bovine abortion
- Schmallenberd (rarely done, currently not available)
60
Outline the transmission of Brucella abortus
- Ingestion of contaminated feed, bedding, water (also skin/eye mucosa)
- Venereal (vaginal discharge)
- Birth products
- Lots of shedding at calving
61
Describe the typical abortion outbreak profile for Brucella abortus (proportion, timing)
- Up to 80% of unvaccinated animals infected in 1st/2nd trimester
- Abortions generally 6-9months gestation
- Abortion or stillbirth 2weeks - 5 months after infection
62
Describe the pathology of the placenta, calf and dam/adults seen with Brucella abortus
- Placenta: retained, red-yellow coloured necrotic cotyledons, thickened area between
- Calf: normal or autolytic, bronchopneumonia
- Adults: retained foetal membranes, swollen testicles in bulls
63
What samples should be sent to a laboratory where Brucella abortus is suspected? How is a diagnosis made?
- Placenta, foetus, uterine discharge
- Maternal serum sample
- Diagnosis: Maternal serology, IFAT on placenta, bacterial isolation
64
Outline the control of Brucella abortus
- Notifiable in UK, not present
- vaccine not available in UK
- Slaughter of affected and in contacts
65
Outline the transmission of campylobacteriosis causing abortion in cattle
- Venerealis: venereal, both ways
| - Foetus foetus/jejuni: venereal, may be ingested
66
Describe the abortion outbreak profile seen with Campylobacteriosis in cattle (proportion, timing)
- >10% abort with venerealis, sporadic with foetus foetus and jejuni
- Venerealis abortion 5-8 months
- Others: 4-9 months
67
Discuss the risk of abortion recurrence with Brucella abortus
Majority only abort once, but can remain infected for life
68
Discuss the risk of recurrence of abortion outbreak with Campylobacteriosis in cattle
- Uncommon
| - Convalenscent cows resistant t infection
69
Describe the pathology of the placenta, foetus and dam seen with abortion due to campylobacteriosis
- Placenta: mild placentitis, haemorrhagic cotyledons, oedematous intercotyledonary area
- Foetus: fresh or autolysed. Mild fibrinous pleuritis, peritonitis, bronchopneumonia
- Dam: dirty white discharge 1-2 weeks after infection
70
What samples are of particular appearance where campylobacter abortion is suspected and how is a diagnosis made?
- Placenta, foetal abomasal contents, vaginal flushing
| - Diagnosis: microscopic detection, isolation
71
Discuss the control of campylobacteriosis abortion in the UK
- No licensed vaccine available
- Biosecurity main aspect
- Do not use natural service until 2 years after initial outbreak
- Consider quarantine of new animals, consider antibiotic treatment of older bulls pre-breeding
72
List the serotypes of Leptospira interrogans that may cause abortion in cattle
- Grippotyphosa
- Pomona
- Hardjo
- Canicola
- Icterohaemorrhagiae
73
How is Leptospira transmitted in cattle?
- Rodents
- Wet conditions
- Ingestion of contaminated food/water
74
Describe the typical abortion outbreak profile in cattle resulting from Lepto (proportion, timing)
- 5-40% affected
- Last trimester
- Abortion 2-5 weeks after infection
75
Discuss the recurrence of abortion due to Lepto in cattle
Immune to serotype causing previous abortion, but sensitive to other types
76
Describe the pathology and clinical signs seen with Lepto abortion in cattle
- Placenta: diffuse placentitis, avascular light tan cotyledons, oedematous yellowish intercotyledonary areas
- Foetus autolysed
- Acute: pyrexia, dullness, drop in milk yield, haemorrahge under MM
- Subacute: milder version of acute signs
- Chronic: abortion
- Hardjo: causes udder form (sudden milk drop, pyrexia, thickened clotty milk) and abortion form (abortion and milk drop)
77
Give the samples required and diagnostic tests for Lepto abortion in cattle
- Placenta, foetus
| - Diagnosis: IFAT (for Abs), PCR
78
Outline the treatment of leptospira abortion in cattle
- Antibiotics e.g. dihydrostreptoycin, tetracyclines
| - Can use blood transfusion
79
Outline the control of leptospira abortion in cattle
- Vaccination possible (but sporadic cases, uncommonly done)
- Rodent control
- Remove brackish water
- Isolate infected cows
- Improve drainage
80
How is Trueperella pyogenes transmitted in cattle?
Environment
81
Describe the abortion profile and recurrence of Trueperella abortion in cattle (proportion, timing)
- Sporadic causes
- Abort at any stage
- Unknown whether abortion may recur
82
Describe the pathology seen with Trueperella abortion in cattle
- Placenta: diffuse placentitis reddish brown to brown colour, endometritis
- Foetus auolysed, fibrinous pericarditis, pleuritis, peritonitis
- No clinical signs in dam
83
What samples are required and how is Trueperella abortion diagnosed in cattle?
- Placenta, foetus
| - Diagnosis: identification in bacterial culture from placenta or abomasal contents
84
Outline the prevention and treatment of Trueperella abortion in cattle
- No vaccine available
| - Treatment: procaine penicillin, long course (21-42 days)
85
How is Listeria causing abortion spread in cattle?
Contaminated feed, in via conjunctival membranes
86
Describe the abortion profile seen with listeria in cattle (proportion, timing, recurrence)
- Usually sporadic but can reach 50%
- Last trimester
- May recur
87
Describe the pathology/clinical signs seen with Listeriosis abortion in cattle
- Retained placenta
- Dam: pyrexia, inappetance, may show neuro signs (facial paralysis, stargazing, salivation)
- Foetus: autolysed, fibrinous polyserositis and white necrotic foci in the liver and/or cotyledons
88
Give the samples required and method for diagnosis of listeriosis in cattle
- Placenta, foetus
| - diagnosis: identification in bacterial culture from placenta or abomasal contents
89
Outline the treatment and prevention of listeriosis abortion in cattle
- Treatment: antibiotics if identified early (ampicillin, amoxicillin, gentamicin+amoxicillin)
- Prevent by lowering feed, do not spread silage from high up
- Do not feed poor silage
90
How is Coxiella burnetii transmitted in cattle?
- Aborted material
- Milk
- Urine
91
When does abortion resulting from Coxiella burnetii typically occur?
- Late pregnancy
| - May also produce live weak offspring
92
Describe the pathology and clinical signs seen with Coxiella abortion in cattle
- Dam: no clinical signs
- Placenta: visibly thickened
- Foetus: no characteristic findings
93
Give the samples required and method for diagnosis of Coxiella abortion in cattle
- Foetal and placental samples
| - Ziehl-Neelsen staining - stain red (may be intra or extra cellular)
94
Outline the treatment and prevention of Coxiella burnetii in cattle
- Treatment: tetracyclines to in contact animals (prevent further abortions)
- Prevention: isolate new animals, dispose of aborted material and anything contaminated by this
- Warn of zoonotic potential
95
List the Aspergillus species that may cause abortion in cattle
- Mucor
- Absidia
- Rhizopus
96
How is Aspergillus causing abortion in cattle spread?
- Mainly respiratory from mouldy feed/bedding
| - Haematogenous spread to placenta takes 1-2 months
97
Describe the abortion profile seen with aspergillosis in cattle (proportion, timing, recurrence)
- Usually sporadic but can reach 5-10%
- From 4 months to term (most common in winter)
- May recur
98
Describe the pathology and clinical
| signs seen with Aspergillus abortion in cattle
- Placenta: severe necrotising placentitis., Cotyledons enlarged and necrotic, intercotyledonary areas thickened and leathery
- Foetus: autolysed, ~30% have grey ringworm-like skin lesions mainly involving head and shoulders
- Dam: spontaneous recovery, no clinical signs before or after abortion
99
Outline the treatment and prevention of Aspergillus abortion in cattle
- No treatment known
| - Treat hay with fungicides during hay making to prevent mould growth
100
What is the main source for Tritrichomonas foetus in a cattle herd?
Bulls - are infected for life
