Principles of Diagnostics

Question 1

What are the components of both a herd and individual diagnostic plan?

Answer 1

History, Signalment, Physical, Rule outs, treatment plan, follow-up

Question 2

What do you have to do differently on a herd basis during your physical exam?

Answer 2

Must be quick! Don’t want to waste the farmers money

Question 3

Name 5 components that are important when getting history on a dairy cow

Answer 3

Days in milk, feed intake, milk production and how it has changed, previous medical problems, treatments already performed

Question 4

What are the 6 body systems that you must check during every dairy cow physical

Answer 4

LUMMAR- Lungs, Uterus, Mammary, Metabolic, Abomasum, Rumen

Question 5

What body system is the most likely cause of fever of unknown origin in the dairy cow?

Answer 5

LUNGS

Question 6

During what time frame are problems with the dairy cow uterus most likely to occur?

Answer 6

within 2 weeks postpartum

Question 7

What is the most straightforward way to diagnose a cow with metritis?

Answer 7

Smell the discharge!

Question 8

What is the most common cause of sickness in dairy cows?

Answer 8

Mastitis!

Question 9

T/F: Milk production is one of the best indicators to determine whether mastitis is local or systemic

Answer 9

FALSE!

Question 10

When does hypocalcemia usually occur?

Answer 10

Clinical hypocalcemia (down cows) most commonly occurs in first 24 hours after calving, but infection can also be subclinical during this time

Question 10

T/F: A patient with mastitis almost always will have accompanying systemic signs.

Answer 10

False. Most mastitis infections are local and do not result in sick cows

Question 10

Which is a more common problem in dairy herds: nervous ketosis or subclinical ketosis?

Answer 10

Subclinical is much more common and is usually secondary to other conditions causing the cow to go off feed. Nervous ketosis is rare and usually more of an issue towards peak lactation

Question 11

What are the clinical manifestations of severe acidosis in dairy cows?

Answer 11

Off feed, down in milk, diarrhea, decreased rumen motility

However, acidosis is generally mild and a subclinical problem in herds due to improved nutrition

Question 12

What are the three main conditions affecting the abomasum in dairy cows?

Answer 12

Left displaced abomasum, right displaced abomasum, and right torsed abomasum

Question 13

Define subclinical, local, and systemic mastitis

Answer 13

Subclinical: cows have normal milk with elevated somatic cells
Local: abnormal milk but normal cow
Systemic: abnormal milk, abnormal cow (fever, dehydration, depression)

Question 14

What two organisms are the most common cause of systemic (toxic) mastitis? Bonus- what type of bacteria are they?

Answer 14

The coliforms: E. coli and Klebsiella
- they are gram negative environmental pathogens

Question 15

How do you determine if a herd has a problem with mastitis?

Answer 15

Epidemiology! Look at trends over time as well as treatment efficacy

Question 16

What are the causes of lack of treatment success in mastitis cases?

Answer 16

1. Superbug (rare)
2. Slow detection of disease
3. Bad treatment protocol

Question 17

What is the only thing you can do if the problem is due to a superbug?

Answer 17

Biosecurity- prevent spread through quarantine of affected animals

Question 17

How can you determine if the problem is due to superbug?

Answer 17

Rule out bad detection and treatment failure

Question 18

How can you figure out if a mastitis problem is due to lack of timely diagnosis?

Answer 18

Look at farm records such as milk weights

Question 19

What is the treatment protocol for mastitis

Answer 19

Fluid therapy: hypertonic saline IV (2-3 mL/lb), oral fluids (10 gallons)

Antibiotics: oxytet 10 mg/lb IV, Sulfadimethoxine, ceftiofur

NSAIDs: flunixin

Other supportive therapies

Question 20

T/F: Not all systemic infections result in a fever

Answer 20

TRUE- 50% of cows with peritonitis dont have a fever, and cows with severe systemic illness may have either sub/normal/elevated temps

Question 21

How many rumen contractions should occur per minute?

Answer 21

3 should occur every 2 minutes, or 1-2 per minute

*should be able to feel hand pressed outward by rumen while pressing down with stethoscope in paralumbar fossa

Question 22

A sunken paralumbar fossa may be indicative of what?

Answer 22

Being off feed or dehydration

Question 23

T/F: You can hear normal pings on the left side

Answer 23

False! a ping on the left is always indicative of something abnormal, and is most commonly LDA

Question 24

How to determine percent dehydration with skin tent?

Answer 24

1% for every second the skin stays tented
- if eyes are sunken this is automatically 7% dehydration or worse

Question 25

Where/what is the “normal ping area” on the right side of the cow?

Answer 25

it is where the spiral colon or cecum lies, and becomes more prominent in off feed cows
- it is found in the paralumbar fossa and does not usually extend up past the last rib

Question 26

What should always be assessed during a rectal palpation?

Answer 26

1. Manure quality and consistency
2. Uterus: palpate for side relative to days in milk, and check for discharge