Preventing Animal Preventing Animal DisordersDisorders on Pasture

Patty Scharko, DVM, MPHPatty Scharko, DVM, MPHLivestock Disease Diagnostic CenterLivestock Disease Diagnostic Center

University of KentuckyUniversity of Kentucky

Animal Disorders on Pasture

Bloat Acute Bovine Pulmonary

Emphysema (fog fever) Nitrate Toxicity Cyanide/Prussic Acid Toxicity Poisonous Plants Mineral deficiency

Grass TetanyTrace mineral- copper, selenium

Animal Disorders on Pasture

not coveredBlacklegJohne’s diseasePinkeyeFootrotSalmonellosisLeptospirosisand more

Grass Tetany

Dec Apr Jun Aug Oct DecFeb

NitrateNitrateNitrateNitrate

Bloat

AIPABPEFog fever

AIPABPEFog fever

NitrateNitrateNitrateNitrate

CyanideCyanideCyanideCyanide

Dec

Bloat

BloatWhat is

it? gas accumulates in the rumen animal unable to eructate (belch up

gases) can result in sudden death

Pasture bloat

(legume)

Legumes favor frothy bloat; winter wheat

Frothy bloatStable protein foam in rumen traps gas from fermentation

Pressure on lungs

Causes of Bloat Animal inheritance for

susceptibility

High susceptible cattle

have larger rumen

volumes and slower

passage rate Bloating cattle consume

18 to 25% less alfalfa than non-bloaters

Causes of Bloat

Adaptation to pasture/rationRumen microflora need to adapt

Time of dayDew does affect bloatCattle were 2-17 times at higher

risk when fed between 7 - 8 AM compared to 11 AM - noon

Causes of Bloat

Plant maturity

Soluble protein content in plant

Lush, young plants produce bloat

Alfalfa < 10 inches caused bloat 2

times compared to alfalfa > 19 inches

Treatment

Do NOT remove from pasture

at first signs of bloat

Continuous grazing gives less

bloat than removal and return

Effect of feeding on incidence of bloat on

alfalfaGrazing System

Continuous Graze 6hrs/da-----Number of cases----

Week 1 1 25

Week 2 4 16

Total 5 41

J. Anim. Sci. 1995. 73:1493-1498

Treatment Foam reducers- drench or tube

Bloat-PacBloat treatment

Dish detergent: 1 oz in 1 L water Vegetable oil- tube only Beware of turpentine

Treatment Last resort/ emergency

hole in rumen

left side

trochar, cannula, or knife

needs to be sutured by veterinarian

antibiotics

Effect of feeding treatment products on alfalfa pasture bloatTreatment Dose, mg/lb ReductionMonensin 0.3a 71

Rumensin 0.6 72Lasolacid* 0.3 30

Bovatec 0.45b 120.6a 16

Polaxalene 20a,b 100 Bloat Guard

* Not approved in lactating dairy cattle* Not approved in lactating dairy cattlea JAS 1983. 56:1400; b JAS 1986. 63:1246

Prevention Bloat Guard

Pre-mixMolasses-mineral block

IonophoresRumensin- approved in stocker,

feeder, beef & dairy cows, dairy & beef replacement heifers & calves; goats

Bovatec Must be consumed on the same day

that bloating may occur

Prevention

1. Do NOT remove at first signs of

bloat

2. Provide grass-legume mixture for

pasture

3. Do NOT turn hungry cattle on lush

immature alfalfa or clover

Acute Bovine Acute Bovine Pulmonary Pulmonary

EmphysemaEmphysema

Acute Bovine Acute Bovine Pulmonary Pulmonary

EmphysemaEmphysema Aka: Fog Fever or Atypical Interstitial Pneumonia

Nutritional disorder, resulting in sudden onset of acute respiratory distress

Caused by formation and metabolism of 3-methylindole (3MI)

“Fog Fever”/ABPE “Fog fever” occurs often when moving

from grazed down area to lush succulent

growth

The better quality the pasture moved to,

the greater occurrence of ABPE

Death may be sudden, average 30%

Signs:

Open-mouth breathing

Frothing at mouth

Labored breathing with expiratory

grunt

“Fog Fever”/ ABPE

Atypical Interstitial Pneumonia

LDDC Necropsy Case Diagnosis

0

1

2

3

4

5

LD

DC

Nec

rop

sy C

ases

Jan

Feb

Mar

Apr

Jun

Jul

Aug

Sep Oct

Nov

Dec

1996199719981999200020022003

ABPE Prevention withRumensin (monensin) or Bovatec

(lasalocid) *a

Clinical LungGroup Trt./Dose Signs Lesions Deads

1 M 100 mg0/4 0/4 0/4 2x

2 M 200 mg0/4 0/4 0/4 1x

3 L 100 mg 2/4 4/4 1/4 2x

4 Control 4/4 4/4 1/4

* Boavatec is not approved in lactating dairy cattle* Boavatec is not approved in lactating dairy cattlea Vet Record 107:322

Effect of Bovatec (lasalocid*)

on ABPE Prevention Dose Clinical

Groupmg/hd/da Signs Deads

1 0 5/5 3/5

2 200 0/5 0/5

3 400 0/5 0/5

4 600 0/5 0/5

* Not approved in lactating dairy cattle* Not approved in lactating dairy cattle a J. Anim. Sci. 60:232

Nitrate Toxicity SIGNS:

Depression, staggering, incoordination

Excess salivation

Brownish discoloration of mucous membranes

Drought N fertilization Grazing &/or hay

Sorghum, Sudan, Johnson grass Stable in hay

Nitrate Toxicity LDDC Necropsy Cases

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1

2

3

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5

LD

DC

Nec

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ases

Jan

Feb

Mar

Apr

Jun

Jul

Aug

Sep Oct

Nov

Dec

199619971998199920002002200320042005

Nitrate Toxicity Nitrite is the toxic entity; 10x more toxic

than nitrates

Nitrite combines with hemoglobin to

form methemoglobin; prevents oxygen

transport

Chocolate brown blood

Death from asphyxiation

Nitrate Toxicity (2)

Young cattle are more susceptible

Hungry cattle more susceptible

Cattle can adjust to higher levels

given enough time

Nitrate Toxicity (3) Nitrite crosses into fetus; can lead

to abortion

Prevention

Ensiling reduces 40 to 60%

Dilution

Increase tolerance

Cyanide (Prussic Acid) Toxicity

SIGNS: Severe respiratory difficulty, sudden

death Sudan, sorghum-sudan, sorghum (Johnson

grass), wild cherry tree Frost/stress Do NOT graze frosted plants!

Wait 10-14 days after non-killing frost

Wait 48 hours after killing frost

Cyanide (Prussic Acid) Toxicity

Ingest cyanogenic glycosides that yield

hydrocyanic (prussic) acid in rumen

Hydrocyanic acid stops cellular respiration;

death from respiratory paralysis

Bright red blood

Toxic Plants

Japanese Yew (Taxus)

Oak/Acorns

Buckeye

Osage orange

(hedgeapple)

Mineral Deficiency

Magnesium

Selenium

Copper

Grass Tetany Hypomagnesemia, magnesium deficiency,

grass staggers, winter tetany

Affects only ruminants

� Primarily in lactating beef cows in spring

� Within 60 days of calving

� Pastured on cool season grasses

Spring grasses are high in potassium

Heavily fertilized (nitrogen &/or potash)

Magnesium Deficiency

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5

10

15

20

25

LD

DC

Nec

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ases

Jan

Feb

Mar

Ap

r

Jun

Jul

Au

g

Sep Oct

Nov

Dec

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

Grass Tetany Cows need 20 grams of Mg daily or 4

oz/day of 15% Mg mineral mix Consumption important, individual cows may not

consume adequate free choice minerals

For spring calving, start Dec/Jan and continue

until daytime temperatures above 60o F

PREVENT!!

Copper Deficiency

Selenium Deficiency“white muscle disease”