As a doctor, I have always been somewhat obsessive about trying to avoid giving medications to pregnant animals.  I never vaccinate any animal that is pregnant.  During my wife's three pregnancies I bugged her about even the drinking of one glass of wine.  How did I get to be this way?  What went wrong?

During my tenure at veterinary school the large animal department was doing an epidemiological study on a particularly peculiar birth defect that was occurring with alarming regularity in local sheep herds.  The lambs that were born with this defect were affectionately being called Cyclops, for the deformity that was present had effected proper fusion of the facial bones resulting in a single eye in a deeply recessed socket over a small trunklike nose, no upper lip juxtaposed with a normal lower jaw.  These lambs were viable at birth although most were euthanized by flabbergasted farmers.   Amazingly, the cause of this malady was traced to the ingestion of a certain plant, Veratrum californicum.  But what is truly incredible is the specificity of the timing of the plant's ingestion.  It turns out that there is only one day during the pregnancy when consumption of this plant would produce this abnormality -- the thirteenth day of a 150 day pregnancy – and it is at this time that the facial bones would normally be fusing, embryologically speaking.  To this day it astounds me that the ewe could dine on veratrum c. on the twelfth or fourteen day with impunity.  The implied lesson was that no matter how innocuous something seemed, by a strange quirk of nature, there could be a fleeting moment in any pregnancy where the fetus' development could be affected.  

There is a second syndrome that also deserves mention here.  Kittens born to queens that have either been infected with or vaccinated with a live virus vaccine for feline panleukopenia (cat distemper) will exhibit the Tumbler Syndrome.  Severely affected kittens are continuously rolling like beach balls because their equilibrium has been effected by a failure of the cerebellum to develop properly.  The cerebellum, the smaller lobe of the brain, controls, along with the middle and inner ear, the body's ability to balance oneself.  The virus has an affinity for cells that are multiplying rapidly and the cerebellum, which continues to develop even after birth, is the unfortunate target for the virus in the body of the fetus or the neonate.  The malfunction is proportionate to the stage of the pregnancy when the virus was introduced -- the earlier the exposure, the more severe the syndrome. 

Both of the conditions discussed here are called congenital abnormalities, which simply means that they were present at birth.  They are not hereditary conditions and have nothing to do with the genetic make up of the parents or their offspring.  These individuals were just in the wrong place at the wrong time.  As we know, timing is everything.