Back From the Vet: Pregnancy Toxemia
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Spring is coming, and so are kids. If you are a spring kidder, it is time to begin preparing to have little tykes bouncing about the farm.
As does head into late-term pregnancy, they become at risk for pregnancy toxemia, or pregnancy ketosis. Growing fetuses can cause this metabolic condition which is life-threatening to does as well as the growing kids. Does most at risk for developing for pregnancy toxemia are those with low body condition, 2 BCS or less, and high body conditions, 4 BCS and over. Does carrying multiple kids are also at increased risk of developing pregnancy toxemia. While late pregnancy is the primary time for onset of pregnancy toxemia, high production milking goats are also at risk early in milk production due to their high energy demands.
Pregnancy toxemia occurs most commonly in the last one to three weeks of gestation. Early signs include lethargy and decreased feed intake, especially of grain. As the disease progresses, does will become ataxic (abnormal movement), recumbent, and finally comatose and dead. This progression can be fairly rapid, occurring over the course of only a few days.
The cause of pregnancy toxemia is inadequate nutritional intake. Does are unable to meet the growing demands of late-term fetuses, which are substantially higher than early pregnancy. Does that are thin, either from lack of feed or concurrent disease, mobilize more body fat to sustain the pregnancy. The resultant metabolism of fat causes ketosis, liver damage, and subsequent hepatic lipidosis (fatty liver). Similarly, over-conditioned animals mobilize fat rapidly during times of decreased feed intake, which quickly overwhelms the liver. Overfat animals will have decreased intake due to space limitations. Fat within the abdomen and the growing fetuses limit the space for feed intake within the rumen. Animals with early or subclinical disease may also show illness after times of stress. Special care should be taken of animals in late-term pregnancy, as any handling, illness (such as foot rot), or changes in weather may be enough stress to decrease feed intake induce acute illness.
Does exhibiting early clinical signs such as decreased feed intake and energy can recover well with rapid treatment on the farm. Propylene glycol can be given orally, 60ml twice daily. Electrolyte drenches are advised as well. Increasing the quality of nutrition, such as adding alfalfa and increasing grains, is also imperative. Any concurrent illness, such as foot rot or pneumonia should be treated at this time. Does showing more severe clinical signs, such as ataxia or blindness will require more aggressive treatment from your farm veterinarian.
There are several other conditions that may cause neurologic signs, such as polioencephalomalacia, listeriosis, and hypocalcemia, so it is important to involve your herd veterinarian in any treatment choices to ensure the right condition is being treated. Does may respond to drenching with oral calcium, electrolytes, further propylene glycol, and some may require insulin injections to maintain blood glucose. Those does that are too thin or fat and unable to continue with the pregnancy will require induction of parturition, or abortion. This can be done with injection of dexamethasone, although does may also benefit with the addition of prostaglandin F2alpha. Does that are within three days of expected due date may be considered for emergency cesarean section to save alive fetuses. This choice should be reached carefully, as induction of parturition with dexamethasone may be less stressful on the doe, and should be used to save valuable alive fetuses. In does that are severely ill, it should be acknowledged that even extensive treatment is unlikely to be successful.
Pregnancy toxemia can be prevented by careful management of does throughout their reproductive cycle. As indicated by the at-risk categories, body condition plays an important role in contracting pregnancy toxemia. Nutritional management is the key to healthy pregnancies. Prior to breeding, does should be assessed and ensure that they are in the proper body condition. Care should especially be taken to ensure that pet or show animals are not over-conditioned and pasture or range animals are not thin. The ideal breeding BCS is 3. Does should not be less than a BCS of 2.5 when entering the last six weeks of gestation, and ideally be 3-3.5. (The American Dairy Goat Association has a helpful body condition scoring article and video at https://adga.org/dairy-goat-
Does carrying multiples are at exponentially increased risk due to the increased energy demands of multiple growing fetuses. Ultrasound may be used early in pregnancy to identify does carrying multiples. To successfully identify multiples, an ultrasound should be performed between 40-60 days of pregnancy. Thin does and does with multiples can then be separated and fed according to their increased energy needs.
There are also several tests available to assess the risk or presence of pregnancy toxemia. BHB, or beta hydroxybutyrate testing can be used to asses risk within a flock as they near kidding season. Testing 10-20% of the flock can give an idea of the extent of risk of development of toxemia. Should the average BHB of these animals be 0.8mmol/L or greater, then there is a risk of pregnancy toxemia. This is a fairly simple blood test that can be performed by your veterinarian. Urine dipsticks may also be used to monitor for ketones, which are indicative of abnormal fat metabolism. Animals exhibiting early signs with ketones in their urine should be treated immediately. These tests can also be utilized by your veterinarian when determining the cause of a sick doe’s clinical signs.
Pregnancy toxemia occurs at a small percentage even in healthy flocks, however, careful management ensures much less risk. Breeding does should be kept in good health and at an appropriate body condition. When nearing kidding it is important to monitor does closely for any signs of early pregnancy toxemia. Early identification of this disease greatly increases the chances of survival.