Production diseases SBAs

Question 2

Scenario: A dairy farmer is concerned about a high incidence of clinical mastitis in his herd. You are reviewing the herd records and note that many cases occur within 30 days of calving.

Lead-in: Which of the following is the most likely cause of these mastitis cases?

Options:

A) Contagious mastitis pathogens spread during milking
B) Environmental mastitis pathogens acquired during the dry period
C) Poor milking machine maintenance
D) Inadequate teat disinfection during lactation
E) Nutritional deficiencies in lactating cows

Answer 2

B) Environmental mastitis pathogens acquired during the dry period

Question 3

A dairy cow presents with a swollen, hot, and painful udder. The milk is watery and contains clots. The cow is also showing signs of systemic illness, including fever and depression.

Lead-in: What is the most likely cause of this cow’s mastitis?

Options:

A) Staphylococcus aureus
B) Streptococcus agalactiae
C) Escherichia coli
D) Streptococcus uberis
E) Mycoplasma bovis

Answer 3

C) Escherichia coli

Question 4

Scenario: A dairy farmer wants to reduce the incidence of mastitis in his herd. He is currently using antibiotic dry cow therapy on all cows at drying-off.

Lead-in: Which of the following additional measures would be most effective in preventing new infections during the dry period?

Options:

A) Pre-milking teat disinfection
B) Post-milking teat disinfection
C) Using an internal teat sealant in all cows at drying-off
D) Culling cows with a history of mastitis
E) Increasing the frequency of milking machine maintenance

Answer 4

C) Using an internal teat sealant in all cows at drying-off

Question 5

Scenario: A dairy cow is recumbent and showing signs of severe systemic illness shortly after calving. You suspect toxic mastitis.

Lead-in: Which of the following is the most important initial treatment for this cow?

Options:

A) Intravenous antibiotics
B) Intravenous fluids and NSAIDs
C) Intramammary antibiotics
D) Oral calcium supplementation
E) Corticosteroids

Answer 5

Correct Answer: B) Intravenous fluids and NSAIDs

Question 6

cenario: A high-yielding dairy cow is diagnosed with subclinical ketosis.

Lead-in: Which of the following is the most appropriate treatment for this cow?

Options:

A) 500ml of 50% dextrose IV
B) Propylene glycol 300g orally for 3-5 days
C) Glucocorticoids
D) Vitamin B12 injection
E) No treatment is necessary

Answer 6

Correct Answer: B) Propylene glycol 300g orally for 3-5 days

Question 7

Scenario: A dairy cow is found down and unable to rise shortly after calving. She is alert but weak, with a low rectal temperature and an S-shaped bend in her neck.

Lead-in: What is the most likely diagnosis?

Options:

A) Milk fever (hypocalcaemia)
B) Toxic mastitis
C) Ketosis
D) Dystocia
E) Abomasal displacement

Answer 7

A) Milk fever (hypocalcaemia)

Question 7

Question 8

Scenario: A sheep farmer reports several ewes losing weight and exhibiting respiratory distress. You suspect Maedi-Visna (MV).

Lead-in: Which of the following diagnostic tests would be most appropriate to confirm the diagnosis?

Options:

A) Faecal PCR
B) Blood test for antibodies
C) Skin biopsy
D) Lung ultrasonography
E) Post-mortem examination

Answer 8

B) Blood test for antibodies

Question 9

Scenario: A sheep flock has a history of Caseous Lymphadenitis (CLA). You are advising the farmer on control measures.

Lead-in: Which of the following would be the most effective strategy to reduce the spread of CLA within the flock?

Options:

A) Treat all sheep with antibiotics
B) Cull all affected sheep
C) Vaccinate all sheep with Glanvac
D) Isolate infected animals and practice good hygiene
E) Deworm the entire flock

Answer 9

D) Isolate infected animals and practice good hygiene

Question 10

Scenario: A dairy cow presents with a teat laceration. The laceration is horizontal, involves the teat canal, and is more than 12 hours old.

Lead-in: What is the prognosis for this cow’s future milk production?

Options:

A) Excellent
B) Good
C) Guarded
D) Poor
E) Unpredictable

Answer 10

C) Guarded

Question 11

Scenario: A dairy herd is experiencing an increase in clinical mastitis cases. The bulk milk somatic cell count (SCC) is consistently below 200,000 cells/ml.

Lead-in: Which of the following is the most likely mastitis infection pattern in this herd?

Options:

A) Contagious mastitis infections
B) Environmental mastitis infections occurring during the dry period
C) Environmental mastitis infections occurring during lactation
D) Mixed environmental mastitis infections (dry period and lactation)
E) Not enough information to determine

Answer 11

C) Environmental mastitis infections occurring during lactation

Question 12

______________ may present with enlarged lymph nodes that are filled with thick, yellow-white pus.

Answer 12

Caseous lymphadenitis (CLA)

Question 13

______________ is a chronic wasting disease of sheep caused by a retrovirus that primarily affects the lungs, central nervous system, and mammary glands.

Answer 13

Maedi-Visna (MV)

Question 14

Scenario: A 5-year-old Holstein cow presents with a sudden onset of recumbency and an inability to rise. The cow calved three days ago and has been producing 45 liters of milk per day.

Lead-in: What is the most likely diagnosis?

Options:

a) Grass tetany
b) Hypocalcaemia
c) Ketosis
d) Toxic Mastitis
e) Johne’s disease

Answer 14

B

Question 15

Scenario: A group of 10-day-old pheasant chicks presents with high mortality, yellow frothy droppings, and ruffled feathers. The brood hut environment is malodorous.

Lead-in: What is the most likely diagnosis?

a) Yolk sac infection
b) Starve-outs
c) Salmonellosis
d) Viral enteritis
e) Spironucleosis

Answer 15

2. Answer: d) Viral enteritis

Explanation: The age of the chicks, the malodorous environment, and the yellow frothy droppings are characteristic of viral enteritis in gamebirds.

Question 16

Scenario: A 6-year-old ewe is found dead in a lush pasture. The only clinical signs are scuffing of the ground around her feet and her head pulled back on her body.

Lead-in: What is the most likely cause of death?

a) Anthrax
b) Bloat
c) Lightning strike
d) Grass tetany
e) Heart failure

Answer 16

3. Answer: d) Grass tetany

Explanation: Grass tetany is caused by low blood magnesium levels, often seen in lactating cows grazing lush pasture. The clinical signs, including the head pulled back (opisthotonos), are typical of tetany.

Question 17

Scenario: A dairy cow presents with a teat laceration. Milk is leaking from the wound.

Lead-in: What is the most appropriate immediate management?

a) Apply a teat bandage.
b) Perform a California mastitis test.
c) Clean and suture the laceration.
d) Administer prophylactic antibiotics.
e) Perform teat amputation.

Answer 17

4. Answer: c) Clean and suture the laceration

Explanation: Immediate repair of a teat laceration is crucial to minimize contamination and inflammation, and to optimize healing and milk production.

Question 18

Scenario: A dairy cow that has had several lactations has a pendulous udder that almost touches the ground.

Lead-in: What is the most likely cause of this condition?

a) Treading injury
b) Barbed wire injury
c) Bite wounds
d) Rubbing injury
e) Stretching of the suspensory apparatus

Answer 18

5. Answer: e) Stretching of the suspensory apparatus

Explanation: The suspensory apparatus supports the udder. With repeated lactations, it can stretch, leading to a pendulous udder that may eventually touch the ground.

Question 19

Scenario: A group of lambs presents with poor weight gain, ill thrift, and scouring. Some lambs have died from suspected pasteurellosis. The lambs are grazing on a permanent pasture with high levels of molybdenum.

Lead-in: What is the most likely cause of these signs?

a) Copper deficiency
b) Selenium deficiency
c) Cobalt deficiency
d) Parasitism
e) Milk fever

Answer 19

Answer: c) Cobalt deficiency

Explanation: Cobalt deficiency can lead to poor growth, ill thrift, and increased susceptibility to infections in lambs. High levels of molybdenum in the soil can further exacerbate cobalt deficiency.

Question 20

Scenario: A 4-week-old calf presents with a small, fleshy growth on its teat.

Lead-in: What is the most likely diagnosis?

a) Supernumerary teat
b) Teat spider
c) Teat polyp
d) Viral wart
e) Milk calculus

Answer 20

d) Viral wart

Explanation: Viral warts are common in young cattle and can occur on the teats. They are often small, fleshy growths that may bleed or cause discomfort during milking.

Question 21

Scenario: A dairy cow presents with a teat laceration that is more than 12 hours old.

Lead-in: What is the prognosis for this condition?

a) Excellent
b) Good
c) Fair
d) Poor
e) Grave

Answer 21

e) Grave

Explanation: The prognosis for teat lacerations worsens significantly with time. Lacerations more than 12 hours old have a very poor prognosis due to increased contamination and inflammation.

Question 22

Scenario: A dairy cow presents with a tight teat sphincter that is causing difficulty with milking.

Lead-in: What is the most appropriate surgical intervention?

a) Teat amputation
b) Open teat surgery
c) Removal via the streak canal
d) Cutting or stretching the teat sphincter
e) Teat bandage

Answer 22

d) Cutting or stretching the teat sphincter

Explanation: This surgical intervention aims to relieve the tightness of the teat sphincter, allowing for easier milking and reducing the risk of further trauma and mastitis.

Question 23

Scenario: A ewe presents with a clinical picture suggestive of pregnancy toxemia.

Lead-in: What is the most important aspect of the history to confirm this diagnosis?

a) Age of the ewe
b) Breed of the ewe
c) Stage of gestation
d) Parity of the ewe
e) Vaccination status of the ewe

Answer 23

c) Stage of gestation

Explanation: Pregnancy toxaemia typically occurs in ewes carrying multiple foetuses in late gestation. The stage of gestation is a crucial piece of information to confirm this diagnosis.

Question 24

Scenario: A dairy cow presents with a high-pitched metallic ping on the left side of the abdomen and elevated blood beta-hydroxybutyrate (BHB) levels.

Lead-in: What is the most likely diagnosis?

a) Type I ketosis with a left displaced abomasum
b) Type II ketosis with a left displaced abomasum
c) Subclinical ketosis with a left displaced abomasum
d) Pregnancy toxaemia with a left displaced abomasum
e) Milk fever with a left displaced abomasum

Answer 24

a) Type I ketosis with a left displaced abomasum

Explanation: The high-pitched ping suggests a left displaced abomasum, and the elevated BHB indicates ketosis. Since the cow is in peak lactation, it’s most likely Type I ketosis.

Question 25

Scenario: A dairy cow presents with a swollen udder and teats. The skin of the udder is warm and tender to the touch.

Lead-in: What is the most likely diagnosis?

a) Photosensitisation
b) Chorioptic mange
c) Ringworm
d) Mastitis
e) Foot-and-mouth disease

Answer 25

d) Mastitis

Explanation: Mastitis is an inflammation of the mammary gland that causes swelling, heat, and tenderness in the udder. The skin is often warm to the touch due to the inflammation.

Question 26

Scenario: A flock of sheep is experiencing an outbreak of Border disease.

Lead-in: What is the most likely route of transmission?

a) Contaminated feed
b) Contaminated equipment
c) Contact with an infected animal
d) Contact with a persistently infected ram
e) Vaccination

Answer 26

d) Contact with a persistently infected ram

Explanation: Persistently infected (PI) rams are a major source of Border disease transmission. They shed the virus in their semen, infecting ewes during mating.

Question 27

Scenario: A herd of cattle is experiencing an outbreak of pseudocowpox.

Lead-in: What is the most important preventative measure to prevent further spread?

a) Vaccination
b) Quarantine of new animals
c) Antibiotic treatment
d) Culling of infected animals
e) Teat dipping

Answer 27

b) Quarantine of new animals

Explanation: Quarantining new animals helps prevent the introduction of pseudocowpox and other infectious diseases into a herd

Question 28

Scenario: A cow presents with a teat injury that is causing a large amount of swelling. The farmer wishes to keep the cow in the herd.

Lead-in: What is the most appropriate management strategy?

a) Teat amputation
b) Drying off the affected quarter
c) Machine milking
d) Manual milking
e) No intervention

Answer 28

b) Drying off the affected quarter

Explanation: Drying off the affected quarter reduces milk production and swelling, allowing the teat injury to heal more effectively and minimizing the risk of wound breakdown.d.

Question 29

Scenario: A lactating dairy cow presents with clinical mastitis in one quarter. You have performed a clinical examination and collected a milk sample for culture and sensitivity.

Lead-in: Which of the following antibiotics is the most appropriate treatment to commence while awaiting culture results?

Options:

a) Amoxicillin - intramuscular injection.
b) Cefoperazone -intramammary infusion.
c) Enrofloxacin - administered by subcutaneous injection.
d) Oxytetracycline - intramuscular injection.
e) Ampicillin - an intramammary infusion.

Answer 29

D - Intermammary and a Cat D antibiotic.

Question 30

Scenario: A group of 20 replacement ewe lambs, approximately four months old, is due to be purchased at a local market. The purchaser intends to breed from them as shearlings (yearlings) next year.

Lead-in: Which of the following actions is most appropriate to reduce the risk of introducing disease?

Options:

a) Isolate the purchased ewes until next tupping season.
b) House the purchased ewes for 3 days and then turn them out with the main flock.
c) Blood test a sample of the purchased ewes for Border Disease antibodies.
d) Blood test all the purchased ewes for Maedi Visna antibodies.
e) Perform post-mortem examinations on any fallen stock from the group of purchased ewes.

Answer 30

Answer: a) Isolate the purchased ewes until next tupping season.

Explanation: This is the most effective way to prevent the introduction of diseases. By isolating the new ewes, you minimize the risk of them spreading any potential infections to the main flock. While the other options have some merit, they are not as comprehensive in preventing disease introduction.

Question 31

Scenario: A dairy cow presents with a supernumerary teat that is interfering with milking.

Lead-in: Which of the following methods is the most appropriate for removal of the supernumerary teat in this cow?

Options:

a) Crushing the base of the teat with artery forceps.
b) Crushing the base of the teat with a Burdizzo emasculatome.
c) Surgical removal using a combination of sharp dissection and ligation of blood vessels.
d) Teat amputation using a tourniquet and three-layer suture closure.
e) No intervention.

Answer 31

c) Surgical removal using a combination of sharp dissection and ligation of blood vessels.

Explanation: This method offers the most precise and controlled removal of the supernumerary teat, minimizing the risk of complications like bleeding or incomplete removal. Crushing techniques can be less precise and may lead to complications. Teat amputation is a more invasive procedure reserved for cases where the supernumerary teat is significantly large or diseased.

Question 32

Scenario: A group of gamebird chicks presents with a high mortality rate and the presence of caecal cores on post-mortem examination.

Lead-in: Which of the following diseases is the most likely diagnosis?

Options:

a) Yolk sac infection
b) Salmonellosis
c) Viral enteritis
d) Spironucleosis
e) Coccidiosis

Answer 32

e) Coccidiosis

Explanation: Coccidiosis is a parasitic disease that commonly affects young gamebirds. The presence of caecal cores on post-mortem examination is a hallmark sign of coccidiosis. While the other diseases listed can cause mortality in gamebirds, they do not typically result in caecal core formation.

Question 33

Scenario: A ewe is diagnosed with pregnancy toxemia, and you administer treatment.

Lead-in: What is the single most important preventative measure to advise for the future?

Options:

a) Vaccination against clostridial diseases
b) Trace element supplementation for the ewe
c) Anthelmintic treatment for the ewe
d) Improved nutrition to ensure a rising plane of nutrition in late gestation
e) Early pregnancy scanning to determine litter size

Answer 33

Answer: d) Improved nutrition to ensure a rising plane of nutrition in late gestation

Explanation: Pregnancy toxaemia is primarily caused by inadequate nutrition in late gestation, especially in ewes carrying multiple foetuses. Ensuring a rising plane of nutrition during this critical period is the most important preventative measure to reduce the risk of pregnancy toxaemia. While the other options may be beneficial for overall flock health, they do not directly address the primary cause of pregnancy toxaemia.

Question 34

Aetiological agents of mastitis can be divided into two groups based on their source: ________ and ________ .

Answer 34

Aetiological agents of mastitis can be divided into two groups based on their source: contagious and environmental.

Question 35

Two diagnostic tests that can be used to detect subclinical ketosis in dairy cows are BLANK and BLANK.

Answer 35

hypocalcaemia and ketosis.

Question 36

A dairy cow in her second lactation is 14 days post-calving. She has a body condition score of 1.5/5 and is producing 35 litres of milk per day. A blood sample is taken, and the BHB value is 2.1 mmol/L.

Lead-in: What is the most likely diagnosis?

Options:

a) Subclinical Type I ketosis
b) Clinical Type I ketosis
c) Subclinical Type II ketosis
d) Clinical Type II ketosis
e) No ketosis present

Answer 36

c) Subclinical Type II ketosis

Explanation: The cow’s BHB value is above the threshold for subclinical ketosis (1.2 mmol/L) but below the level for clinical ketosis (3 mmol/L). As the cow is early post-calving, it is more likely to be Type II ketosis.

Question 37

Scenario: A dairy cow is found down and unable to rise. She calved yesterday. She is hypothermic and her rumen is static. You perform a cow-side blood test and find that her blood BHB is 5.4 mmol/L.

Lead-in: What is the most appropriate interpretation of the BHB result?

Options:

a) The result is consistent with clinical Type II ketosis.
b) The result is consistent with subclinical Type II ketosis.
c) The result is consistent with clinical Type I ketosis.
d) The result is not consistent with ketosis.
e) The result is not reliable due to the cow being recumbent.

Answer 37

Answer: a) The result is consistent with clinical Type II ketosis.

Explanation: The cow’s BHB value is above the threshold for clinical ketosis (3 mmol/L), and the clinical signs are consistent with ketosis. As the cow is early post-calving, it is more likely to be Type II ketosis.

Question 38

Scenario: A high-yielding dairy herd is experiencing a higher than expected incidence of displaced abomasum in early lactation. The herd is housed all year round and fed a TMR. You are asked to investigate. You take 12 blood samples from cows between 10 and 25 days in milk. The results show that 5 of the 12 cows have a BHB of >1.4 mmol/L.

Lead-in: What is the most appropriate interpretation of these results?

Options:

a) The results suggest a herd problem of subclinical ketosis.
b) The results suggest a herd problem of clinical ketosis.
c) The results suggest a herd problem of milk fever.
d) The results suggest a herd problem of Johne’s disease.
e) The results do not suggest a herd problem.

Answer 38

Answer: a) The results suggest a herd problem of subclinical ketosis.

Explanation: More than 3 of the 12 cows have elevated BHB levels, indicating a herd problem. The BHB values are consistent with subclinical ketosis.

Question 39

Scenario: A beef suckler cow is in late gestation and is due to calve in 3 weeks. She is housed with the rest of the herd and fed a TMR. You perform a clinical examination and take a blood sample. Her BHB is 1.6 mmol/L.

Lead-in: What is the most appropriate interpretation of this BHB result?

Options:

a) The result is consistent with subclinical Type I ketosis.
b) The result is consistent with clinical Type I ketosis.
c) The result is consistent with subclinical Type II ketosis.
d) The result is consistent with clinical Type II ketosis.
e) The result is not consistent with ketosis.

Answer 39

e) The result is not consistent with ketosis.

Explanation: Although the BHB value is above the threshold for subclinical ketosis, it is important to consider the cow’s signalment. Type II ketosis is associated with early lactation. Type I ketosis is associated with peak lactation, which would be several weeks after calving. Therefore, this result is more likely to be artefactual, and not a true representation of ketosis.

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