Recommended Disease Definitions

The following recommended disease definitions identify the minimum signs to diagnose 9 common diseases of dairy cattle.  Whatever criteria are used on a particular dairy to diagnose disease, it is important that those criteria are consistent.  Criteria to make treatment decisions should be separate from those to diagnose a disease.  That is, a cow may have disease but not meet the criteria for treatment.

All disease episodes should be recorded regardless of severity or treatment decisions criteria.  Severity scores are provided where commonly used criteria exist.

 

Clinical Mastitis (Severity Score)

At a minimum: 

Abnormal milk (1): flakes, clots, watery to varying degrees.

May have:

Abnormal gland (2): firmness and/or swelling, discoloration of the skin

Abnormal cow (3): varying degree of dehydration, fever, signs of depression

 

Metritis

All cows with abnormal uterine contents should be recorded even if the cow is ‘normal’ and treatments are not given.

At a minimum:

Abnormal uterine contents: watery discharge of varying color, with a foul odor

May have:

Abnormal cow: varying degrees of dehydration, fever, signs of depression

 

Retained Placenta

Placenta is visible at the vulva or identified in the uterus/vagina >24 hours after calving (practical timing will be the day after the cow calves at next routine examination, which may be less than 24 hours).

 

Milk Fever

Stage should be recorded.  Stage 1 milk fever is likely the most inaccurately diagnosed (ie. standing, shaking and weak but normal blood calcium levels)

Cow >1st lactation, ≤3 DIM

Stage 1: Standing but shaking/twitchy/weak

Stage 2: Unable to rise, rapid heart rate (100+), decreased rumen movement, dry firm feces

 

Displaced Abomasum

High pitched “Ping” on percussion with fluid ‘sloshing’ sound when abdomen is ‘bumped’ with a fist on the right or left side.  Most are ‘off-feed’ and are positive on urine ketone test.

 

Diseases causing Lameness

Clinical Lameness = Locomotion score of ≥3 out of 5: Arched back standing and walking with abnormal gait (3/5) or obviously favoring affected limb (4-5/5).

  • Footrot – Symmetrical swelling of foot.
    • Early: Claw separation due to swelling of tissue between them.  Sensitive to squeezing toes together.
    • Later: Swollen skin broken open with protruding dead and decaying tissue and a foul odor present.
  • Sole abscess – Paring sole reveals grey-white puss and gas, sound of gas escaping may be heard as abscess is pared into.
    • Early: Sensitive to pressure on sole of affected claw, softness in sole may be present.
    • Later: Asymmetrical swelling of foot, swelling above the coronary band of affected claw.  Sensitive to pressure on sole and softness may be present on affected claw.
  • Sole ulcer – Hole in the sole of the claw with corium (sole producing soft tissue) exposed, often bleeding.  Most commonly found on the outer claws of the hind feet.
  • Heel wart – Lesions present between the claws just above the level of the heels on the back or on the front side of the foot at the cleft between the claws.
    • Erosive lesion: rough, reddened, depression in the skin of the foot
    • Proliferative lesion: raised lesion with fine finger-like projections