What you don’t know can hurt you, and it could hurt your cows, too. As an associate professor with the University of Wisconsin School of Veterinary Medicine, Dr. Gary Oetzel is training the next generation of food animal veterinarians.
During the Professional Dairy Producers of Wisconsin Business Conference in March, he shared the same best practices he is teaching vet students for identifying and treating fresh cow problems like milk fever, toxic mastitis and metritis, including some tips and tidbits of information that may surprise you.
Milk fever
- Identifying the illness: While prevalence of milk fever has been on the decline, the occasional case may arise. Most commonly, it strikes cows in their second lactation or later, just prior to calving or up to 48 hours afterward.
General observation can pick up on the early symptoms. Cold ears, shuffling feet and wobbliness may give it away, coupled with a rapid heart rate, muscle tremors and shivering on the backside of the shoulder. Once a cow has reached stage two of milk fever, she is down.
She may either be upright (sternal recumbency) or flat on her side (lateral recumbency). At this point, she has lost tone in her anal and tail areas. Classically, these cows are hypothermic, registering a body temperature below 100ºF.
- Treatment: Prepare the cow for an I.V. by slipping a halter over her head and tying it back to her hock on the same side of her body. Take a moment to pull a pre-treatment blood sample from the vein. This sample may come in handy later, but it must be done prior to administering an I.V. because the solution will alter her phosphorus and mineral levels.
“If she gets up, throw the sample away,” Oetzel instructed. “If she doesn’t, then you have the only possible diagnostic information to help your vet solve that cow’s problem.”
After pulling the blood sample, administer I.V. calcium. Oetzel uses calcium gluconate. Certain products may advertise additional ingredients that sound beneficial to the cow but, in fact, can be deceiving. Some contain phosphorus, but the form included in these bottles is entirely unavailable to the cow.
Magnesium does not do any good either, he added, because a cow with milk fever already has an elevated level of the mineral. The same goes for high levels of glucose.
“Every cow has high blood glucose close to calving,” Oetzel said. “All you are going to do is slow the gut down, cause her to shift electrolytes and have to urinate out extra glucose.”
One 500-mL bottle of straight calcium gluconate (23 percent) is all it takes. “That’s it,” he added. “We do not give two bottles to down milk fever cows.”
The reason one bottle is sufficient is because the cow’s total body calcium deficit cannot be more than about 6 grams. One bottle provides 10.5 grams, which is already an overdose, Oetzel noted. While some people may believe they have better luck with cows responding from two bottles, he insisted this is likely because the cow had more time to get up while she received the second bottle.
“I can never figure a scenario where [giving the second bottle] can do anything but harm,” he said. “It’s just too much for the cow.”
The calcium gluconate I.V. is to be given slowly over 12 to 20 minutes. Oetzel teaches veterinary students to slide a stethoscope under the sternum or find the carotid pulse on the neck of the cow and feel just below the jugular vein. In a classic milk fever case, the pulse will be fast and shallow, but as the calcium runs into the cow, it will slow down to 90 beats per minute, then 80 and so on.
“If it drops to 60 [beats per minute], pull the needle out because that is one way cows die – the heart slows down too much,” he said.
Of course, not every cow follows the rule. Some will have an adverse reaction to the calcium, responding with a pulse increase. If this occurs, pull the needle out of the vein at 140 beats per minute.
- Prevent a relapse: According to Oetzel, as many as 40 percent of cows successfully treated I.V. for milk fever will relapse within 12 to 18 hours. He recommended giving a slow-release, easily absorbed calcium product orally after the I.V. If the cow is not up and alert, this may need to be done subcutaneously. A dose of oral calcium should follow these treatments 12 hours later to reduce the chance of a relapse.
Toxic mastitis
- Identifying the illness: “Be careful not to confuse clinical milk fever with an early lactation toxic mastitis,” Oetzel warned. Cows with severe infections may go down, a symptom that can easily be mistaken for a milk fever case.
Determining whether it is toxic mastitis or milk fever ailing the cow is important because there are serious consequences with a misdiagnosis. Giving intravenous calcium to a cow with toxic mastitis can be fatal. “They need a little calcium, but if you give it to them I.V., it could be euthanasia,” Oetzel explained. In these instances, oral calcium is the way to go.
To determine if toxic mastitis is ailing the down cow, Oetzel palpates the udder for hot, hard quarters and checks for watery milk. He also looks at her eyes.
“Sunken-in eyes are not typically associated with milk fever,” he noted. “That is dehydration.”
“Dehydration is a hallmark of toxic mastitis, and it is not common with milk fever,” he added.
A skin-tenting test can validate whether or not the cow is dehydrated. On the neck of the cow, pinch up a piece of skin, give it a little twist and let it go. It should snap back in a couple of seconds. If that doesn’t happen, that means she is dehydrated and her skin has lost elasticity.
- Treatment: Oetzel recommends treating toxic mastitis cases with 2 liters of hypertonic saline, administered I.V., followed with offering large amounts of fresh water.
Metritis
- Identifying the illness: Metritis will occur within five to 10 days in milk. Because the first symptom is abnormal vaginal discharge, it is helpful to define what is normal discharge, and what is not normal.
“If it is whitish or clear, I don’t worry about it,” Oetzel said. Large amounts of fluids don’t bother him either; he considers that part of the cow’s normal process of clearing her uterus after giving birth.
On the other hand, a red flag goes up for the “stinky stuff” – the brown, watery, foul-smelling discharge.
“This is not good, but it is not treatable metritis yet,” Oetzel stated, adding that a lot of cows will clear the infection on their own. In fact, he teaches herds to be conservative about treating cows without multiple symptoms of this disease of immune disfunction.
“You still need at least one more sign to go with it,” he said. That second symptom could be elevated body temperature, decreased appetite or decreased milk yield.
- Treatment: Once a cow is diagnosed with metritis, Oetzel typically recommends ceftiofur products. However, he reminds that these medications need to be used in accordance with labeled instructions for dosage and route of administration.
Oetzel discourages intrauterine treatments because infusing or inserting boluses can traumatize tissue and carry infection into the uterus. For severe and non-responsive cases, call a veterinarian. PD
Photo by PD staff.
Peggy Coffeen
Editor
Progressive Dairyman
