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