Beef - Cow-Calf Diseases

What is the first stage of the beef industry?

cow-calf operations

What is the business goal of cow-calf operations?

to sell as many pounds of calves as possible

* Pounds of calf - a good beef farm should sell at least one calf off of every cow they own


* Calves should be weaned + backgrounded

The amount of calves a cow-calf operation sells is dependent on what?

* Cow and bull fertility
* Calving success
* Weaning success (can cow raise calf until weaning)

Describe a cow year.

* Goals: every cow has a calf every year and to have cows calf early in breeding season with enough time for calves to grow (if selling in Oct, want to have calves in March)
* Shorter breeding time = older, larger calves 

What are the optimal statistics every cow-calf operation aims for?

* 95% + cows pregnant within 63 day breeding season
* 90%+ heifers pregnant within 45 day breeding season
* Bull capable of impregnating 1 cow per month of age beginning at 15 months of age (up to 48 months)

Optimum fertility is dependent on what factors?

* Nutritional status
* Positive energy balance
* Correct balance of energy and protein
* Appropriate mineral balance including trace minerals
* Genetics (Fertility is moderately heritable)


* Healthy status of herd
* Timing of herd-level events (breeding, etc)

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Heifers should be regularly cycling at how old?

12-123 months of age at 55-65% of mature body weight

Heifers should have minimum of ______ pelvic canal area at 12 months of age

140 cm^2

Cows should be regularly cycling how long post-calving?

45-60 days

What are common diseases that affect bulls on a cow-calf operation?

* Vibriosis
* Trichomoniasis
* Bovine Papillomatosis (Warts)

Vibriosis Organism

*Campylobacter fetus venerealis* Bacteria

Vibriosis Pathogenesis

Venereal disease - Bull gets bacteria, bacteria infects penis and sheath. Vibrio spreads to cow while breeding and causes pregnancy loss

Vibriosis Effects

* Cause of infertility
* EED
* Irregular estrous cycles
* Repeat breeding
* Elongated calving seasons
* Decreased calf crop - increased # of lost pregnancy
* Interferes w/ cow-calf - delays when cow will have calf (less days to grow)

Trichomoniasis Organism

*Tritrichomonas foetus foetus* Protozoan

Trichomoniasis Pathogenesis

Venereal disease

Trichomoniasis Effects

* Cause of infertility
* EED
* Irregular estrous cycles
* Repeat breeding
* Elongated calving seasons
* Decreased calf crop
* Interferes w/ cow-calf - delays when cow will have calf (less days to grow)

How does vibrio and trich affect bulls?

* Once infected, always infected - will ALWAYS be spreader
* Susceptibility increases with age

How does vibrio and trich affect cows?

* Showing clinical signs = infection
* Can recover and clear infection
* Carriers rare - chances increases as cow ages
* Vibrio: uterus is clear, but cervix/vaginal vault may harbor bacteria for >6 mon after pregnancy
* Trich: infection cleared in 3 mon, but can be reinfected

Define venereal disease

* a disease typically contracted by sexual contact with a person already infected; a sexually transmitted disease
* Spread by bull in group of cows
* Can also be spread through nonsterile AI equipment and untreated semen

How do carrier states develop for vibrio/trich?

* Bulls may (will) become permanent carriers
* Susceptibility increases with age
* Bulls more than five years of age are highly susceptible to permanent infections
* Attributed to increased number and size of epithelial crypts in the penis and prepuce of older bulls

Describe the common clinical findings for vibrio and trich.

* Both result in
* Early embryonic loss (abortions not seen)
* Low % pregnant
* Scattered calving season/spread calving windows (due to termination of original pregnancy during proper time)
* Returns to cycling during breeding season

How do you differentiate between vibrio and trich?

Often, you cannot clinically distinguish between the two 

* Trich has an increased incidence of pyometras
* Investigate infertility problems simultaneously 
* Can’t do anything without regular herd management!!

Vibriosis control

* Vaccinate susceptible animals > 4 weeks prior to breeding season 
* Culture older bulls and cull positives 
* AI (sterile) for 2 years after diagnosis to clear cows 
* Use virgin bulls only 
* Cull open cows: treatment difficult and success variable 

Trichomoniasis control

* Test and cull positive bulls > 2 yrs old 
* Cull open cows 
* Use virgin bulls only 
* AI (sterile) 

Is there an effective vaccine for vibrio/trich?

* Older vaccines not effective, but a new research vaccine (unpublished) is promising 


* No treatment/cure for bulls
* Most likely to use virgin bulls + vax or test older bulls (trich)

Bovine Papillomatosis Organism

*Papillomavirus* virus

Bovine Papillomatosis Pathogenesis

Is a CONTAGIOUS DISEASE!

* Abrasions to epithelium allow entry of virus
* Eg. rubbing up against one another in pasture
* Can live on taggers, fenceposts, etc. and spread to other animals
* Rejection from livestock shows
* Breeding concerns - spread to bulls = cannot breed
* Low morbidity
* Common in young animals (especially large groups of young bulls) or immunosuppressed

Bovine Papillomatosis Clinical Signs (external)

Cosmetic disease

* Dry, scaly growths
* 2-10 mm diameter usually
* Non-pruritic
* Non-painful

Bovine Papillomatosis Clinical Signs (Penile)

* Bleeding from prepuce
* Avoidance of breeding
* Inability to retract penis into sheath
* Inability to urinate
* CANNOT BREED A COW!
* Delays breeding window = delays breeding season
* Part of check to ensure that bull is fertile

What is a lesion caused by Bovine Papillomatosis?

* Moist cauliflower-like growth
* Can be necrotic, gray to tan
* Pyogenic

Bovine Papillomatosis Treatment

* Self-limiting - bulls will get over it and become immune
* Still messes up current breeding season
* Surgical removal if extreme - severe cases where normal functions are restricted by growths require more aggressive therapy

Bovine Papillomatosis Control

* Segregate affected
* Vaccination - not common, older not as effective

What are common diseases that affect breeding/pregnant cows on a cow-calf operation?

* Leptospirosis
* Neospora
* Bovine Viral Diarrhea Virus (BVD)
* Infectious Bovine Rhinotracheitis (IBR)

Leptospirosis Organism

Contagious bacterial infection

Leptospirosis Contamination

* Spreads among every warm-blooded mammals
* Host-adapted strains and non-host-adapted strains (wildlife)
* Wet environments (Lives in the kidney - spreads through urine)
* Can contaminate food/water supplies through saliva

Leptospirosis Clinical Signs

* Abortions (stage of pregnancy loss dependent on strain)
* Usually aborted during third trimester
* Major cause of pregnancy loss in breeding herds
* Renal disease
* Anemia

What are the most commonly cultured strains from cattle abortions in US?

* Pomona
* Hardjo (bovis)
* Grippotyphosa
* *L. borpetersenii* hardjo bovis = cattle-adapted strain
* Carrier state

Leptospirosis Pathogenesis

* Survives 6 months in wet soil and ponds, 15 days in moving water
* Cow exposed, penetrates mucous membranes (eyes, mouth, genitals, open wounds in skin)
* Spread via bloodstream
* Lodge in liver, kidney, spleen, nervous system
* Can cross placenta to infect developing fetal organs
* Antibodies develop - host can fight off easier

What is a **maintenance host** concerning lepto?

No signs/have mild disease symptoms -> bacteria sets up in kidney, repro tract, eye -> Long-term shedding of bacteria

What is a **incidental host** concerning lepto?

Have disease -> Recover after short-term urinary shedding

Leptospirosis - Abortive Form

* Non-host adapted strains = mid to late 3rd of gestation
* 7 months of gestation most common
* Host adapted strains = early to mid gestation (resorption)
* “Abortion storm” - several cows abort at once due to lepto outbreak
* Symptoms vary greatly and clinical diagnosis often difficult

How does a farmer prevent an abortion storm from lepto?

* Culture urine from recently aborted
* Submit fetus for necropsy
* Immediate herd vaccination
* Takes 3-6 weeks for immunity to develop
* Mass medication of herd with antibiotics
* Treatment in “storm” often too little, too late

Leptospirosis Vaccination

* Effective - usually found in combo pre-breeding vaccines (L5)
* L5 = 5 serovars of leptospirosis pathogens 
* All non-host adapted
* L. hardjo bovis not always included

How long does a lepto vaccination last?

* Generally only effective for 90 days
* Vacc commercial beef herds twice a year
* Practical: Pre-breeding and at pregnancy exam
* Some dairies vacc herd 4x/year (ease of animal contact)
* Lepto is not a good antigen, so vaccine does not last long
* Depends on level of exposure individual farm has

What strains of lepto are found in a 5-way lepto vaccine?

* Strains of *L. interrogans*:
* Canicola
* Grippotyphosa
* Hardjo prajitno
* Icterohemorragica
* Pomona

How often should breeding animals have the lepto vaccine?

* Should vax commerical beef herds twice a year (pre-breeding and at pregnancy exam)
* Some dairies vacc herd 4x/year (ease of animal contact)
* Replacement heifers - at weaning
* All cows - 30-60 days prior to breeding season
* Two initial doses 2-4 weeks apart

Leptospirosis Biosecurity Measures

* Biosecurity = IMPORTANT
* Have a closed herd
* Quarantine and test purchased replacements
* Purchasing open replacements not helpful in preventing introduction of lepto
* Difficult to control because of environment/wild animals

Leptospirosis Control

* Management practices
* Rodent control
* Limit wildlife contact with herd (impractical)
* Control water access (restrict access to ponds, wet areas of pasture; have cows drink from wells/troughs)

What are some public health concerns when it comes to lepto?

* Human infections with *hardjo* common in some areas
* Flu-like disease most common
* Prolonged recovery possible
* Can pass through breast milk to nursing infants

Neospora Organism

Protozoan parasite *N. caninum* 

Neospora Pathogenesis

Dogs are carriers - spread by dog feces, contaminates pasture

* Infection inapparent in dogs/wild animals through eating from feed or contaminating pasture

Neospora Effects

Common cause of abortion in intensively raised cattle

* Abortions occur in mid to late gestation in cattle
* Live calves may be born, but are weak and often have neurological deficits

Epidemic vs. endemic abortions

* Epidemics associated with contamination of TMR
* Widespread in cattle herds, not commonly diagnosed in eastern US

Neospora Treatment

* No treatment available
* No vaccine approved

Neospora Control

* Restrict dog access to feed sources/pasture
* Clean up aborted fetuses/membranes immediately - prevent pasture contamination
* Test cows, do not keep heifers from seropositive cows or cull

Bovine Viral Diarrhea Virus (BVD) Effects

Cause of early embryonic death -> late-term abortions

* Interferes at any stage of development - Can cause very early pregnancy loss, lack of fertility, or late-term abortions
* Significant potential for reduction in calf crops
* Can also cause pneumonia/respiratory disease

BVD Transmission

* Contact with infected cattle
* Saliva
* Nasal discharge
* Urine
* Feces
* Semen
* Milk
* Basically, ANY SECRETION!
* Invades the membranes, kills embryo

BVD Clinical Signs

* Highly dependent on what type of infection/age of infection we are talking about!
* Poor reproductive performance 
* Increased morbidity and mortality from other agents 
* Congenital defects

Persistently Infected Carriers

Calf will get infected with BVD and become a carrier for life if cow is infected between 60-125d (1-4m) of gestation

* 93% of all PI’s produced this way 
* PI’s produce PI’s 100% of the time - should euth any PI calves

Why are PI calves bad?

Spread BVD like wildfire!

* ONE PI in a feedlot pen can substantially increase the rate of illness and death in not only that pen, but other pens around it!
* One PI calf = spread to entire herd = more PI calves
* Can spread both abortive and respiratory forms to any and all cows
* Interferes with and degrades infected cow’s immune system, too

Exposure to BVD at 100-150 days gestation can result in…

* Abortion
* Congenital Defects
* Cerebellar hypoplasia - cerebellum deformities
* Unable to stand
* Intention tremors
* Abnormal eyes/blindness
* Abnormal hair coats

How will I know if my cows get BVD?

You probably won’t notice anything is abnormal… for a while 

* Importance of calving season 
* Importance of regular herd diagnostic work

BVD Control

* Maintain closed herd
* Quarantine and test all purchased additions
* Buy only from sources that test calves, test yourself too
* Avoid commingled cattle sales - know history!
* Vaccinate
* Fomites
* Spread within the herd with needles, sleeves, trailers, etc.
* Individual use only!

BVD Vaccination

* Modified live given to cows PRIOR to gestation
* Includes both types of BVD (cross-protection)
* Killed vaccine to pregnant cows
* Live virus works better for immunity, but the MLV BVD vaccine causes abortion in pregnant cows
* Cannot make PI b/c MLV is not PI strain of BVD

Is wildlife a concern when spreading BVD?

Not a major problem

* Deer can be experimentally infected and shed BVD virus (3/5)
* Questionable as to whether can spread to cattle from wildlife - main spread is cattle-to-cattle

Infectious Bovine Rhinotracheitis (IBR) Forms

* Three Forms:
* Ocular
* Respiratory in most classes, especially young and/or stressed cattle
* Abortions and IPV
* Abortions usually occur 1-2 months after initial infection of cow
* Remains in nerve tissue until triggered to replicate again

Infectious Bovine Rhinotracheitis (IBR) Vaccination

Vaccination in face of outbreak will *not* help - months too late

Infectious Bovine Rhinotracheitis (IBR) Control

* Vaccination is effective
* Modified live vaccines can be very effective in causing abortion - do not give to pregnant cows!
* MLV safe for open cows, more effective
* Killed virus used for pregnant cows

Does vaccination = disease prevention?

* NO! Answer is not in a bottle - The bottle is only an adjunct to proper health maintenance.


* No core vaccines for beef cattle.
* Generally accepted combo vaccines most popular (BVD, lepto, vibrio, IBR)
* Plenty of animals that never see them and are healthy.
* Problems arise when animals move or are stressed.
* For breeding stock, most center around pregnancy protection.


* Buy from a herd that has been vaccinated, has good biosecurity

Herd Health Plan Components

* Defined production cycle
* Nutrition plan
* Pasture maintenance/renovation: forage availability, water, sanitation
* Genetic development
* Vaccinations
* Parasite control, deworming
* Disease surveillance/management (biosecurity)
* Annual plan evaluation: year in review and year forward

You can’t manage what you don’t measure. What should you keep track of?

* Pregnancy diagnosis 
* Records analysis 
* Production calendar 
* Targeted interventions 
* Professional involvement

What are common diseases that affect brood cows on a cow-calf operation?

* Lameness
* Interdigital Necrobacillosis
* Digital Dermatitis
* Calf Loss
* Dystocia
* Prolapse

Bovine Lameness Welfare

* HUGE area of animal welfare concern
* Public often reports lame animals
* Proper diagnosis is key to effectively treating lameness.

What is the biggest flaw when it comes to lameness treatment?

Large area for improvement in judicious use of antibiotics among veterinarians and cattle producers

* promotes resistance, concerns of use of antibiotics in food animals/contamination
* Not every cause of lameness is infectious, and therefore does not necessitate antibiotics!

How does bovine lameness affect bulls? Cows?

* If cows are lame, they are less likely to be proper caregivers to calves/give birth = no calves or smaller calves
* If bulls are lame, they can’t mount females to breed = no calves
* Lameness is much more common in older cattle. 

How can we prevent bulls/cows from going lame?

* Check for proper conformation before buying/selling cattle
* Perform frequent checks and watch for limping
* Keep pastures dry

Bovine Lameness Causes

* Genetics - Poor confirmation 
* Injury - Broken bones, frostbite 
* Nutritional issues 
* Laminitis 
* White line 
* Sole ulcers 
* Infection

Interdigital Necrobacillosis (Footrot)

Characteristic foul-smelling necrotic process involving tissue between claws

* Major cause of lameness in many sectors of beef industry
* 1+ feet may be infected at any given time

Footrot Organism

*Fusobacterium necrophorum*

* Soil-borne organism - infect from wet environments
* Once on farm, there for good -> likely already there

Footrot Pathogenesis

* Disease most prevalent during wet seasons OR during prolonged periods of dry weather
* Cattle congregate in small, shallow muddy areas near water sources
* Continuously wet feet -> skin swells and cracks -> soil organisms invade

Footrot Clinical Signs

* Raw sore between toes
* SYMMETRICAL swelling and redness of interdigital region
* NO FOREIGN BODIES
* Severe lameness
* +/- elevated body temperature
* Decreased production (milk, weight gain, breeding ability)

Footrot Treatment

* Clean and Debride, Floss - remove infected/dead tissue
* Systemic Antibiotic - injected, get in bloodstream to reach tissue
* Oxytetracycline (most common)
* Pain Mitigation - Banamine
* Not many pain relief drugs for cattle
* Topical Treatment +/- Keep Dry

What is Banamine?

IV NSAID-like anti-inflammatory/pain reliever

* Also available in a “pour-on” version that is poured on the back and absorbed

Footrot Control

* Individual animal treatment and isolation
* Footbath preparations - Formalin or copper sulfate preparations
* Feed additives - improve hoof health/resistance to infection
* Oral iodides
* Zinc compounds (zinc methionine)
* Vaccine available
* KEEP OUT OF EXCESS MUD

Digital Dermatitis (aka Hairy Heel Wart)

Contagious erosive Infection on heel

* Associated with Spirochete: *Treponema sp.*
* Originally and commonly found on Dairy farms
* Now observed in beef cattle


* VERY painful!

Hairy Heel Wart Pathogenesis

Commonly infects those in wet environments - doesn’t remain as long as foot rot

* NOT FOOT ROT, but can look similar - Hoof does not swell as much, but much more painful

Hairy Heel Wart Clinical Signs

* Raised Red Sore +/- elongated hairs (overgrowth of certain tissues)
* Skin and hoof erosions
* Walk or stand with toe on ground - too painful to fully put down
* Poor response to injectable antibiotic therapy

Hairy Heel Wart Treatment

* Clean & Debride Lesion
* Oxytetracycline powder or liquid under bandage
* Repeat bandaging
* Injectable does not work - topical more effective
* Antibiotic spray or foot bath
* Recurrence Likely

What is another common cause of lameness?

Hole in foot - acute affected area from stepping on nail or other object

* Lots of bruising around area
* Abscess forms - usually will heal if treated early
* May have to amputate infected claw if too severe

How do we diagnose lameness?

Early diagnosis and early treatment is vital for preventing long-term damage from infection

* Disease Identification
* Requires Examination
* Antibiotic Stewardship

When do the most calf losses occur?

69% of perinatal losses occur w/i 96 hours after birth

What are the most common reasons of calf loss?

1. Dystocia (difficulty calving) - late to colostrum, death during birth
2. Scours
3. Respiratory disease
4. Bloat/Digestive (Parasites)
5. Unknown


1. Maternal issues?
2. Unreported
3. Carnivores

Dystocia

Action (mechanical or physiological) that delays or interferes with normal birth

Stats on Dystocia

* Calves born to cows with dystocia were 5x more likely to die neonatally - too weak to nurse, usually require human intervention
* 6.4% of US calves die before weaning (3% born dead) 
* 2/3 of those die before 3 weeks 
* 50% of

Intrinsic factors that influence incidence of dystocia

* Age, weight, parity, pelvic size of cow (prevent having too big of calves)
* Breed and size
* Calf weight, gender, and conformation
* Gestation length
* Sire affect
* Malposition - not preventable

Extrinsic factors that influence incidence of dystocia

* Diet - overweight or underweight, lack strength
* Should maintain good BCS
* Supervision - lack thereof can cause issues
* Disease
* Induced parturition
* Inappropriate bull/genetic selection - can’t breed a tiny cow with a massive bull because calves would be too big

Fetal Causes of Dystocia

75 % of all dystocia cases

* Large Fetus
* Position
* Multiple Births
* Deformed fetus

Maternal causes of dystocia

25% of all dystocia cases

* First-time mothers - more prone to dystocia
* Abnormal birth canal
* Uterine inertia
* Primary - metabolic
* Secondary - exhaustion

Other causes of dystocia

Calf birth weight

* Genetics
* Environment
* DO NOT attempt to decrease calf size by starving dam

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Fetal Malposition - not preventable

* Normal presentation Calf is ‘diving’ out
* Abnormal presentation Any other presentation
* Common with twins

How do we prevent dystocia in the heifer?

* 65 % of mature cow weight at breeding
* Newer research suggests 55% mature weight is acceptable given appropriate genetic selection
* 85 % of mature cow weight at calving
* Newer research would then put this at 65-75% of mature weight at calving
* Calve (30 days) prior to cows
* Use of EPDs (bull stats) - pick bulls based on predictions that will give a properly-sized calf
* Pelvic measurement
* Appropriate selection pressure?

How do we prevent dystocia in the cow?

* Observe animals regularly during calving season (2x day min)
* Why a “calving season” is important - can watch all cows at once instead of having scattered births
* Not practical in all management systems
* This ain’t Australia…
* Calve in groups
* Feed in the evening - more likely to calve the next day (instead of the middle of the night)
* Select appropriate sires for herd
* Know when to assist and when to call for help!