Abnormal Dairy Cattle Morbidity – Current Case Definition - Cowsmo

Abnormal Dairy Cattle Morbidity – Current Case Definition

Current case definition that has been reported to this point:

**Please be advised that there are variables to these clinical signs, and more information is still being collected.**

  1. Increased dairy cattle morbidity in affected herds has been going on for several weeks and seems to be clustered in the Texas Panhandle. There have been no cases reported in Wisconsin at the time of this post release.
  2. The signalment of affected cattle has a strong link to 2nd lactation and older animals with cattle in the >150 days in lactation to be most affected. Practitioners working with these herds are estimating that 5-10% of the herd is affected. Fresh heifers and transition cows are not affected, low but not zero prevalence in these groups. Dry cows, steers, and young stock are not reported to have morbidity. There are NO reports of high mortality events, but the cows that do not recover in milk production are reported to be culled.
  3. Affected sick cattle present with anorexia and poor rumen motility as noted on physical examination or with rumination monitors. This is followed by a significant milk drop. Evaluation of milk is described as thicker in viscosity (visually consistent with the appearance of colostrum) and is trace CMT positive, but there are no other signs of mastitis. No etiological agents have been detected at this time on milk evaluation. Cattle are also presenting with hypomotility of the rumen and GI tract, fecal consistency is variable, and the most common report is not diarrhea, but rather constipation. There are also reports of secondary infections including pneumonia and mastitis. Diagnostic labs that have received submissions have not identified an etiology. Investigations are ongoing to attempt to identify the etiology.

Guidance for veterinarians:

As veterinarians, if you are faced with a significant morbidity event on a dairy with clinical disease like what has been reported in Texas, please contact WVDL for guidance on ante or postmortem sample collection. There is some guidance on sample type and number of animals to test and WVDL would like to speak to the submitting veterinarians of any case to make specific recommendations, prepare for sample receipt, and communicate with our State and Federal partner agencies.

Please be vigilant for these signs and perform the appropriate diagnostics, as directed, if these signs are observed.

Source: Wisconsin Veterinary Diagnostic Laboratory


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