Announcements - Tufts Veterinary Field Service

 TVFS HPAI Federal Order Guidance

April 28, 2024  
References:

Federal Order Requiring Testing for and Reporting of Highly Pathogenic Avian Influenza (HPAI) in Livestock dated April 24, 2024

APHIS Requirements and Recommendations for Highly Pathogenic Avian Influenza (HPAI) H5N1 Virus in Livestock For State Animal Health Officials, Accredited Veterinarians and Producers dated April 26, 2024

Clarification Regarding Movement of Cattle Through Markets or Auctions to Slaughter, Under the April 24 Federal Order issued April 27, 2024

Principles:

• Dry cows, youngstock (non-lactating dairy heifers) and male cattle do not require certificate of veterinary inspection to move to sale barns / abattoirs per current regulations.
• Lactating dairy cows going to a dealer will require a CVI
  • Papers cannot be written for sick lactating cows (GI, respiratory or generalized illness); this would include lactating cows with grade 2 or higher mastitis.
  • Healthy lactating cows require a certificate written at farm of origin or at consolidation point if hauler and farm are in the same state.
  • Destination for CVI will be abattoir location.
  • Destination of cattle (Full name and address) required per federal order and to be provided by producer.
• Bovine Influenza A Virus Infection Case Definition
  • Infected cattle may be asymptomatic (subclinical) or symptomatic (clinical) and virus is predominantly found in milk and mammary tissue regardless of symptoms.
  • Clinical signs: Decrease in feed consumption with a simultaneous decrease in rumination and rumen motility; respiratory signs including clear nasal discharge; and subsequent acute drop in milk production. Additional clinical signs may include abnormal tacky or loose feces, lethargy, dehydration, and fever. Severely affected cattle may have thicker, concentrated, colostrum-like milk or produce no milk at all.
• All lactating dairy cattle moving for any other purpose outside of slaughter are required to receive a negative test for Influenza A virus at an approved National Animal Health Laboratory Network (NAHLN) laboratory using an NAHLN approved assay prior to movement
  • UCONN veterinary diagnostic lab, Cornell Animal Health Diagnostic Center and Wisconsin Veterinary Diagnostic Laboratory are among those offering this service
    • Eligible samples are 3-10 mL of milk (preferred) or deep nasal swab
    • Samples MUST be collected by an accredited veterinarian and submitted within 7 days of movement.
  • All cattle in a group of 30 or less must be tested, if group is larger than 30 then only 30 total must be tested.

 Highly Pathogenic Avian Influenza Updates in Cattle in the US

April 24, 2024  
Highly pathogenic avian influenza (HPAI) H5N1 has infected cattle in Texas and Kansas recently, likely due to wild bird exposure. A Michigan dairy also reported HPAI in their herd after cattle were moved from a different state that had previously reported HPAI in cattle. There are presumptive positive cases in three other states at this time. We may eventually see HPAI in New England in cattle and wanted to share some information with you.  

Clinical Signs Observed in Cattle:  
Impacted animals were primarily older cows in mid-lactation, while dry cows, heifers and youngstock did not appear to be affected. Signs are relatively non-specific; however, the most significant finding is thicker, concentrated, colostrum-like milk. Other signs include:

• decreased milk production
• acute, sudden drop in production
• decrease in feed consumption
• abnormal manure (tacky or loose)
• low-grade fever

Testing:  
We are still waiting on guidelines and recommendations from our state veterinarians in CT, MA and RI and we will share these with you as soon as we are made aware. Criteria for testing would be having sick cows with signs as described above, dead birds, and potentially dead cats or other mammals as well. If illness or deaths cannot be ruled out through other diagnostic means, HPAI sampling may be warranted.

Precautions and Biosecurity:  
Precautions for Cattle:

• Delay or stop incoming or returning animals from herds with unknown or suspect health status
• Separate (quarantine) all new or returning animals for a minimum of 21 days
• Use trailers just for your own cattle
• Clean and disinfect trailers – most quaternary ammonium disinfectants are effective against HPAI: https://www.epa.gov/pesticide-registration/epas-registered-antimicrobial-products-effective-against-avian-influenza
• Limit non-essential visitors to the farm and consider limiting outside vehicle access to the farm (i.e., picking up veterinarian at the end of the driveway/property line)
• As unpasteurized milk seems to be the most likely mode of disease transmission, consider switching to milk replacer or ensuring colostrum is heat-treated and milk is adequately pasteurized before feeding to calves. Acidification is not enough to inactivate HPAI.
• Consider cleaning and disinfecting water sources more frequently and do so especially if your dairy becomes infected.
• Report findings of odd behavior in wild birds or small mammals and minimize chances for birds and small mammals to nest or scavenge. Limit bird entry into the barns if possible (netting, screens, curtains, sound decoys, etc.). Cover compost piles and feed sources as well.

Precautions for Humans:    
Initial testing of cattle samples did not find any evidence that would make this strain of H5N1 more transmissible to humans, so the current risk to the public remains low. Precautions are still warranted as there is a lot still unknown at this time. Most importantly, do NOT consume unpasteurized milk, unpasteurized (raw) cheeses, uncooked or undercooked meat from animals with suspect or confirmed H5N1.

Based on poultry worker recommendations:

• Self-monitor for new signs of respiratory illness, including conjunctivitis for 10 days after potential exposure.
• Wear gloves (at a minimum) and avoid touching eyes, nose, and mouth when working with sick animals
  • Poultry workers exposed to HPAI wear PPE that includes an N95 filtering facepiece respirator, eye protection, and gloves.
• Wash hands with soap and water (preferred) or alcohol-based hand rub after contacting sick animals or their areas and before eating and drinking.
• Avoid eating, drinking, or smoking in areas with animals.
• Remove clothing that contacted sick animals – leave at work to launder or place in a garbage bag and transport to a washing machine.
• Shower at the end of the work shift.