AABP Update: Disease Outbreak on Dairy Farms in Texas and Southwest

PVMA received the following statement from the American Association of Bovine Practitioners last week about an emerging disease syndrome in dairy cattle occurring in the southwestern US.

I wanted to update you on a situation that has occurred on dairy farms in Texas and potentially other parts of the southwest. AABP leadership is involved in discussions with local veterinarians and diagnostic laboratories and will do our best to keep our membership updated on this situation.  Unfortunately, there is a significant amount of misinformation being circulated.  It is important that AABP members not become part of disseminating this misinformation and rely on official statements from diagnostic laboratories and individuals directly involved in managing this disease event.

Veterinarians are on the front-lines of preventing the spread of disease and I ask that each of you review this email in the event that you observe, or your clients report, these symptoms. The clinical case presentation that has been reported is:

1. Sudden reduction in feed intake with decreased ruminations evident on physical exam and rumination monitors.
2. Sudden decrease in milk production on a herd level. Individual cows that are more severely affected have milk that is yellow and concentrated with the appearance of colostrum.
3. Variations in manure consistency with the most common finding being tacky to dry manure, although some cows appear to have diarrhea.
4. Secondary infections such as pneumonia and mastitis.

The affected cases appear to be in lactation 2 or greater animals that are more than 150 days in milk. Calves, heifers, and dry cows appear not to be affected. Morbidity is around 10% of the animals. Cases present over a 7-10 day time period and the first herds report a return to near normal production in 3 weeks. Mortality is very low, however individual cows who do not return to production are being culled. Diagnostic labs that have received submissions have not identified an etiology. Investigations are ongoing to attempt to identify the etiology.

We are encouraging all AABP members to be aware of this disease syndrome. If the above presentation is seen, we encourage you to immediately address it with your clients and submit samples to your diagnostic laboratory. The American Association of Veterinary Laboratory Diagnosticians (AAVLD) has been notified and we are working with a group of AABP members and diagnosticians in a collaborative effort.

It is important to submit a complete set of samples to the laboratory. This should include red top and purple top blood, feces, urine and milk from at least 10 affected and 10 non-affected animals. The negative control samples are critically important to be able to identify a causative agent. If there are any animals that can be sacrificed, a complete necropsy should be performed with submission of all tissues to the diagnostic laboratory, both fixed and fresh, along with a complete case description. Please contact your veterinary diagnostic laboratory prior to sample collection to make sure that there are no additional samples recommended and for assistance with collection of samples, preservation, and shipping.

AABP will continue to provide timely updates regarding this disease event as new information surfaces.  Please be vigilant for these signs and perform the appropriate diagnostics if these signs are observed.

Thank you

Fred

K. Fred Gingrich II DVM

Executive Director

American Association of Bovine Practitioners

1130 East Main St Suite 302

Ashland, OH  44805