FDA Fails to Assess Data or Draw Conclusions on Impact on Human Health of Sickly Clones Carrying Disease or Requiring Extra Drugs, Especially Antibiotics
It is clear from studies FDA reviewed on animal health that clones have higher rates of illness and death than non-clone comparators, particularly at the younger ages. This could lead to greater use of drugs on clones, which in turn could exacerbate antibiotic resistance. FDA’s Risk Assessment failed to assess this risk.
In both cloned cattle and sheep, one of the biggest health problems is large offspring syndrome (LOS). As the name implies, LOS refers to offspring that are abnormally large at birth, but they also have a range of other abnormalities. FDA lists 11 clinical signs associated with LOS, including fetus weight more than 20% larger than average for the breed, deformities of limb and/or head, disproportionate or immature organ development, increased susceptibility to infection, and cardio vascular problems. Since cattle with LOS tend to have increased susceptibility to infection, there would be a greater need for antibiotics and other drugs to help fight the infections in those LOS cattle. Although LOS doesn’t appear to happen normal reproduction or AI, it does happen with some of the ARTs, such as in-vitro fertilization (IVF), embryo culture, as well as with SCNTs.
The incidence of LOS in SCNT clones is very high. FDA has identified 13 studies that look at rate of LOS in SCNT cow clones; 12 were published studies and the other was data supplied by industry (Cyagra). Of the 13 studies, 10 only look at SCNT clones while 3 also looked at transgenic cattle produced via SCNT. In the studies, incidence of LOS in SCNT clones varied from 8% (1 in 12) (Miyashita et al. 2002) to 100% (8 of 8, 6 of 6) (Batchelder 2005, Kubota et al. 2000). If the studies are pooled together, then 54.6% (239 of 438) of clones suffer from LOS (Table V-4 in FDA 2006). Excluding the 3 studies that also included transgenic clones hardly changes the result: 51.2% (151 of 295) of these clones suffer from LOS.
Since LOS basically doesn’t happen with normal reproduction or AI, having an incidence of over 50% of the animals having LOS, and thus being potentially more susceptible to diseases than regular animals is a big problem. Unfortunately none of these studies reported the actual amount of antibiotics and other drugs used in treating LOS animals. If the embryos are large enough, this can also cause problems for the dam and may require cesarean section and other medical interventions, which could include drugs and hormones.
Another important health risk associated with SCNT clones is hydrops, which refers to abnormal fluid accumulation in parts of the placenta and/or fetus itself, which can lead to complications with the pregnancy and potential health problems in the fetus. Hydrops is a very rare condition in cattle and is estimated to occur at the rate of 1 in 7,500 pregnancies in general cattle population (Hasler et al. 1995).