Obviously we as herdsmen, health technicians and veterinarians only have limited tools to help us in making a correct diagnosis for diseases that affect replacement and adult animals. Unlike the human or small animal medical field that has access to radiology and many diagnostic tests, on the dairy we must rely mainly on our own senses, in addition to a thermometer, stethoscope and maybe a blood ketone (BHBA) meter.
In veterinary school, many students were reminded to keep the simple diagnoses in mind. Certainly we always need to consider the less common diseases, but as is often said, “If you hear hoof beats, it is probably a horse versus a zebra”. When we perform a physical examination on a transition cow, the same concept is valid. In reality, there are a handful of important diseases to recognize and treat. We know other diseases might be difficult to diagnose correctly, and treatment might either not be economical for the commercial animal or likely not result in a cure.
When I teach on-farm staff or veterinary students how to do a physical examination, I usually focus on five major areas:
- GI system (abomasum)
Some might argue this oversimplifies the many organ systems and diseases that can affect a cow, but let’s really keep in mind what is most common and what we can treat successfully. Sure we need to look at the eyes, skin and listen to the heart, but in terms of common transition cow diseases, if we can rule out the above systems we will likely find the cow’s issue. Let’s review.
1. The udder
The disease we are obviously concerned about is mastitis. But often times I see this overlooked in the physical exam as the thought is, "The milkers didn’t find mastitis, or they would have said so”. It’s your exam, so don’t forget to strip and look at the milk of all four quarters and also palpate the udder for firmness or swelling.
2. The uterus
If we can rule out a retained placenta or metritis, then we likely have this organ covered. Certainly we can have a uterine tear or cancer, but again, focus on what is most common.
3. GI system
This organ system can provide more difficulties in finding the correct diagnosis but, again, if we keep the most logical conclusions in mind, a displaced abomasum (DA), on either the left or right side, will be one of our important areas to rule out in the transition cow. Again, we need to be sure and actually “ping” the cow and listen for the DA. Do not assume just because she is chewing her cud that a DA cannot exist.
If the GI system gives us some uncertainty, the lungs can be more confusing. Cows with normal lung sounds can still have pneumonia, but we need to keep in mind diagnosing other findings such as an increased respiratory rate, fever and nasal discharge can be more involved than listening to the lungs.
5. Metabolic disease
The two main diseases we need to consider will be hypocalcemia (milk fever) and ketosis. Remember, both of these diseases can be either clinical (the cow shows abnormal signs that are quite obvious such as decreased appetite or weakness) or subclinical (no outward signs of disease).
Overall, if we can rule out the following diseases, we are well on the way to making a correct diagnosis for our transition cow.
Consult your veterinarian to develop a physical exam training and/or review session with your animal health team, and don’t forget to engage him or her in second opinion evaluations of sick animals. This is an important process for continued education in making the correct diagnosis.
Mark Thomas is a veterinarian and partner in Countryside Veterinary Clinic, LLP and Dairy Health & Management Services LLC in Lowville, N.Y.
Note: This story appears in the December 2017 magazine issue of Dairy Herd Management.