1. An Investigation of Hairy Foot Wart Treatments and Associated Environmental and Public Health Risks Nicole Desnoyers Brent Frankland Micha Cetner Josh Hayford

2. Hairy Foot Wart or Papilomatous Digital Dermatitis

3. What's the deal? Caused by bacteria Caused by bacteria –Genus Treponema First reported in the U.S. 25 years ago First reported in the U.S. 25 years ago Extremely contagious Extremely contagious –31% to 89% in 3 years –30% of cows sent to U.S. slaughterhouses

4. - Wells et al. 1997

5. Associated Cost 20% of all dairy lameness cases 20% of all dairy lameness cases Milk loss Milk loss Reproductive problems Reproductive problems Premature culling Premature culling Major implications for Vermont Major implications for Vermont –$1.2 billion a year –$70 million in gross wages

6. Treatment Topical application of antibiotics Topical application of antibiotics –Not practical on large herds Medicated Foot baths Medicated Foot baths –Copper Sulfate –Formalin –Alternative Treatments What about the waste? What about the waste?

7. Copper Sulfate - 5-10% concentration foot bath - Effective for 150-300 cow passes

8. Hazards to Farm Employees General Use Pesticide General Use Pesticide –No permit required Toxicity Class 1 – Highly Toxic Toxicity Class 1 – Highly Toxic Acute Effects Acute Effects –Extremely caustic/corrosive – Burns –Ingestion Oral LD50 in rats is 472 mg/kg Oral LD50 in rats is 472 mg/kg

9. Hazards to Farm Employees Chronic Effects Chronic Effects –Liver Disease in vineyard workers –Anemia –Damage to Red Blood Cells –Kidney Disease

10. What about the waste? Used foot bath = industrial waste Used foot bath = industrial waste But….

11. What about the waste?

12. What does that amount to? Average Foot bath Average Foot bath –62 gallons of water –26 lbs copper sulfate = 6.5 lbs copper Problems? -Frequency of use -Amount of land -Soil type Soil tests Important!

13. Surface Waters Extremely toxic to fish and aquatic invertebrates Extremely toxic to fish and aquatic invertebrates 96 Hour LC50 to pond snails =.39 mg/L 96 Hour LC50 to pond snails =.39 mg/L Behavioral Changes Behavioral Changes

14. Is there Significant Risk? Hazard to employees Hazard to employees Unregulated disposal is a concern Unregulated disposal is a concern –Copper loading in soil –Danger to aquatic species

15. FORMALIN 1.37-39% Formaldehyde Solution 2.Strong, pungent hay/straw-like odour 3.Formalin - CH 2 O (Formaldehyde – CH 2 O 3 ) 4.Non-Corrosive, Biodegradable 5.Not regulated by EPA 6.Used in Footbaths in Dairy Industry – Control PDD 7.Breaks down rapidly to form formic acid and carbon monoxide 8.Disposed of in croplands 9.Human Health Risk

16. 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

17. 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 tumors 2) 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

18. The response of tumor proliferation to increasing concentrations of formaldehyde in lab rats. (Montecello et al., 1996). Formaldehyde] (mg/m3)

19. 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

20. 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 equipment Standards set for non agricultural workplaces

21. Alternatives Improved Hygiene Improved Hygiene –Flooring –Living conditions Footbaths other than formalin and copper sulfate Footbaths other than formalin and copper sulfate –Contact time with the hoof –Concentration of the chemical –Health concerns Antibiotics Antibiotics Kovex Foam Kovex Foam

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

23. Flooring Types Reduces the chance of PDD Reduces the chance of PDD –Rubber-slat flooring system –Straw yards Increases the chance of PDD Increases the chance of PDD –Solid concrete floors

24. Alternative Footbaths zinc sulfate zinc sulfate acidified sodium chlorite acidified sodium chlorite bleach bleach iodine products iodine products peroxides peroxides

25. Antibiotics Topical broad- spectrum antibiotics Topical broad- spectrum antibiotics –Tetracycline and oxytetracycline Most effective way at treating PDD Most effective way at treating PDD Issue with antibiotics Issue with antibiotics

26. Kovex Foam A new alternative A new alternative Highly accepted for easy use and effectiveness over footbath method Highly accepted for easy use and effectiveness over footbath method No seen harmful effects on cows or workers No seen harmful effects on cows or workers

27. Alternative overview Combining tactics of better hygiene along with better flooring systems and environmentally friendly PDD treatments without harming cows or workers Combining tactics of better hygiene along with better flooring systems and environmentally friendly PDD treatments without harming cows or workers

28. 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

29. 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

30. 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

31. 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