An Investigation of Hairy An Investigation of Hairy Foot Wart Treatments Foot Wart Treatments

and Associated and Associated Environmental and Environmental and Public Health RisksPublic Health Risks

Nicole DesnoyersNicole DesnoyersBrent FranklandBrent Frankland

Micha CetnerMicha CetnerJosh HayfordJosh Hayford

Hairy Foot WartHairy Foot Wartoror

Papilomatous Digital Papilomatous Digital DermatitisDermatitis

What's the deal?What's the deal?

Caused by bacteriaCaused by bacteria– Genus Genus TreponemaTreponema

First reported in the U.S. 25 years First reported in the U.S. 25 years agoago

Extremely contagiousExtremely contagious– 31% to 89% in 3 years31% to 89% in 3 years– 30% of cows sent to U.S. 30% of cows sent to U.S.

slaughterhousesslaughterhouses

- Wells et al. 1997

Associated CostAssociated Cost

20% of all dairy lameness cases20% of all dairy lameness cases Milk lossMilk loss Reproductive problems Reproductive problems Premature cullingPremature culling Major implications for VermontMajor implications for Vermont

– $1.2 billion a year$1.2 billion a year– $70 million in gross wages$70 million in gross wages

TreatmentTreatment

Topical application of antibioticsTopical application of antibiotics– Not practical on large herdsNot practical on large herds

Medicated Foot bathsMedicated Foot baths– Copper SulfateCopper Sulfate– FormalinFormalin– Alternative TreatmentsAlternative Treatments

What about the waste?What about the waste?

Copper SulfateCopper Sulfate-5-10% concentration foot 5-10% concentration foot bathbath-Effective for 150-300 cow Effective for 150-300 cow passespasses

Hazards to Farm EmployeesHazards to Farm Employees General Use PesticideGeneral Use Pesticide

– No permit requiredNo permit required Toxicity Class 1 – Highly ToxicToxicity Class 1 – Highly Toxic Acute EffectsAcute Effects

– Extremely caustic/corrosive – BurnsExtremely caustic/corrosive – Burns– IngestionIngestion

Oral LD50 in rats is 472 mg/kgOral LD50 in rats is 472 mg/kg

Hazards to Farm EmployeesHazards to Farm Employees Chronic EffectsChronic Effects

– Liver Disease in vineyard workersLiver Disease in vineyard workers– AnemiaAnemia– Damage to Red Blood CellsDamage to Red Blood Cells– Kidney DiseaseKidney Disease

What about the waste?What about the waste?

Used foot bath = industrial wasteUsed foot bath = industrial waste

But….

What about the waste?What about the waste?

What does that amount to?What does that amount to?

Average Foot bathAverage Foot bath– 62 gallons of water62 gallons of water– 26 lbs copper sulfate = 6.5 lbs copper26 lbs copper sulfate = 6.5 lbs copper

Problems?-Frequency of use

-Amount of land

-Soil type

Soil tests Important!

Surface WatersSurface Waters

Extremely toxic to fish and aquatic Extremely toxic to fish and aquatic invertebratesinvertebrates

96 Hour LC50 to pond snails = .39 96 Hour LC50 to pond snails = .39 mg/Lmg/L

Behavioral ChangesBehavioral Changes

Is there Significant Risk?Is there Significant Risk?

Hazard to employeesHazard to employees Unregulated disposal is a concernUnregulated disposal is a concern

– Copper loading in soilCopper loading in soil– Danger to aquatic speciesDanger to aquatic species

FORMALINFORMALIN1. 37-39% Formaldehyde Solution2. Strong, pungent hay/straw-like odour3. Formalin - CH2O (Formaldehyde – CH2O3)4. Non-Corrosive, Biodegradable5. Not regulated by EPA6. Used in Footbaths in Dairy Industry – Control PDD7. Breaks down rapidly to form formic acid and carbon monoxide8. Disposed of in croplands9. Human Health Risk

Formaldehyde dissolves rapidly in water Half-Life of 2-20 days in clean fresh water Decomposed in ~30 hours in lake water (aerobic) and 48 hours (anaerobic)

Formaldehyde in Water

Formaldehyde in Air Formaldehyde molecules react with hydroxyl radicals:

1)hydrogen and carbon monoxide stable molecules, or 2) formyl (HCO) radicals and hydrogen atoms

Half-life of 7-71hours, limiting long range distribution HCO radicals important in smog generation – Urban areas

Formaldehyde and Wildlife

No build up of contaminant residues in plants and animals Marine algae sensitive to formalin Fresh water algae slightly more tolerant Bioaccumulation in fish – no significant results Initial toxic effects in fish – variable (striped bass most sensitive) Formalin kills larvae of terrestrial invertebrates and nematodes No data on mammals, bird and reptiles Animals in lab – enhanced sensitization to inhaled allergens Rats – 1)cell proliferation in nasal and respiratory tract → inflammation

and ulceration → increased tumors2) Gastrointestinal tract → lowered food and liquid intake

Animals exposed to high levels – shortened lifespan, reproductive problems, lowered fertility, changes in appearance or behaviour

No carcinogenic effects from formalin given orally

The response of tumor proliferation to increasing concentrations of formaldehyde in lab rats. (Montecello et al., 1996).

Formaldehyde] (mg/m3)

Formaldehyde and Human Health

Formalin cause irritation of eyes, nose, throat, and burning of skin

Ingested – severe abdominal pain, vomiting and possible death

People exposure to formaldehyde – cancer of nose and throat Allergic reactions from household and personal products Symptoms may only occur long after exposure Formaldehyde and all bi-products (incl. formalin) possible

carcinogens Evidence of tumors in upper respiratory tract No evidence of abortion associated with maternal and

paternal exposure Known to cause insomnia, lack of concentration, memory loss

or loss of appetite

State Regulation Governing Formaldehyde

Vermont – standards in workplace, mainly in industrial and commercial settings, disallowed on farms

Agricultural businesses rarely visited, random inspections carried out periodically

New York – no stringent regulations in agricultural use, but use with caution and with safety equipmentStandards set for non agricultural workplaces

AlternativesAlternatives

Improved HygieneImproved Hygiene– FlooringFlooring– Living conditionsLiving conditions

Footbaths other than formalin and copper Footbaths other than formalin and copper sulfatesulfate– Contact time with the hoofContact time with the hoof– Concentration of the chemicalConcentration of the chemical– Health concernsHealth concerns

AntibioticsAntibiotics Kovex Foam Kovex Foam

Living ConditionsLiving Conditions

Keep dairy cows out of locations which Keep dairy cows out of locations which harbor the potential for bacterial growth harbor the potential for bacterial growth by promoting exposure to sun, air flow, by promoting exposure to sun, air flow, and dry conditionsand dry conditions

Flooring TypesFlooring Types

Reduces the Reduces the chance of PDDchance of PDD– Rubber-slat flooring Rubber-slat flooring

system system – Straw yardsStraw yards

Increases the Increases the chance of PDDchance of PDD– Solid concrete Solid concrete

floorsfloors

Alternative FootbathsAlternative Footbaths

zinc sulfate zinc sulfate acidified sodium chloriteacidified sodium chlorite bleach bleach iodine productsiodine products peroxides peroxides

AntibioticsAntibiotics

Topical broad-Topical broad-spectrum spectrum antibioticsantibiotics– Tetracycline and Tetracycline and

oxytetracyclineoxytetracycline Most effective way Most effective way

at treating PDDat treating PDD Issue with Issue with

antibioticsantibiotics

Kovex FoamKovex Foam

A new alternativeA new alternative Highly accepted for Highly accepted for

easy use and easy use and effectiveness over effectiveness over footbath methodfootbath method

No seen harmful No seen harmful effects on cows or effects on cows or workersworkers

Alternative overviewAlternative overview

Combining tactics Combining tactics of better hygiene of better hygiene along with better along with better flooring systems flooring systems and and environmentally environmentally friendly PDD friendly PDD treatments without treatments without harming cows or harming cows or workersworkers

Recommendations PDD infections - large financial impact on dairy industry Loss of approx. $190 million ± $130 million Farmers main concern - Financial feasibility, practicality, and most

rapid recovery results Only half cows affected show signs of lameness

GENERAL CARE:-

Wetter yearly climate - very important Well ventilated Barns Housing Facility – Clean and Dry Cleaning tools and footbaths after use – hoof-trimmer Automatic mechanized Alley-Scraper

Prevention:

Neither Formalin nor Copper Sulfate treat PDD lesions, only preventative Copper sulfate – expensive @ ~$80/ 50lb bag (~$1.60-$2.00/lb) and 1 bag

/footbath/200 cows/weekly – environmental problems Zinc sulfate – expensive @ ~$42/50lb bag (~$0.84/lb) and 1 bag/footbath/200

cows/weekly - efficient preventative but dissolves poorly – environmental problems Formalin – inexpensive @ ~$250/55 gallon barrel (~$4.50/gallon) and 1gallon

/footbath/~120 cows/weekly Vermont - copper sulfate in footbath more common New York - Formalin more common Prevent burning of cow feet Formalin most cost effective whole heard preventive treatment - CARCINOGENIC Caution and correct safety equipment

Treatment:

Clean infected area Scrape lesion Antibiotic topical application – oxy-tetracycline powder Not practical for large herds and expensive Wrap in conjunction with footbath preventative program Spraying of feet is affective but not practical – dilution, disturbance,

contamination