Unser Haushund: Eine Spitzmaus im Wolfspelz? - Wolf-Ekkehard ...

84and diabetes and are somewhat protected against aging. This is consistent with findings in mice with adefective growth hormone receptor gene.” 146Eine Deletion im insulin like growth factor 1 (IGF1)-Gens selbst hat beimMenschen schwerwiegende Folgen (siehe den vollständig abrufbaren Bericht zueinem Patienten mit einer homozygoten partiellen Deletion des IGF-1-Gens).Woods et al. berichten (1996, p. 1363) u. a.:"IGF-I knockout mice also have defects in neurologic development, indicating that IGF-I may have specificroles in axonal growth and myelination. In addition, neonatal mortality is substantial, suggesting that thisdefect may be lethal in humans. In this report, we describe a 15-year-old boy with severe prenatal andpostnatal growth failure, sensorineural deafness, and mental retardation who had a homozygouspartial deletion of the IGF-I gene.” 147Deficiencies auf der genetischen und/oder organismischen Ebene dürftenjedenfalls auch für die Miniaturisierung bestimmter Hunderassen im Vergleichzum Wolf verantwortlich sein – was auch immer schließlich an genauen Ursachen(causal mutations) erkannt werden wird (es wäre natürlich für meine Analyse derDeficiencies sehr zweckdienlich, wenn man jetzt schon sagen könnte, was genauauf der DNA-Ebene passiert ist).Werfen wir zu den Deficiencies noch einem Blick auf den von Dawkins undanderen Autoren als Argument für die Makroevolution viel zitierten Chihuhua.Zum Thema Health Disorders lesen wir 148 :"This breed requires expert veterinary attention in areas such as birthing and dental care. Chihuahuas are alsoprone to some genetic anomalies, often neurological ones, such as epilepsy and seizure disorders.Chihuahuas, and other toy breeds, are prone to the sometimes painful disease hydrocephalus. It is often diagnosedby the puppy having an abnormally large head, or hydrocephalus, during the first several months of life, but othersymptoms are more noticeable since "a large head" is such a broad description. Chihuahua puppies exhibitinghydrocephalus usually have patchy skull plates rather than a solid bone and typically are lethargic and do not grow atthe same pace as their siblings. A true case of hydrocephalus can be diagnosed by a veterinarian, though the prognosisis grim.Chihuahuas have moleras, or a soft spot in their skulls, and they are the only breed of dog to be born with anincomplete skull. The molera fills in with age, but great care needs to be taken during the first six months until theskull is fully formed. Some moleras do not close completely and will require extra care to prevent injury. Manyveterinarians are not familiar with Chihuahuas as a breed and mistakenly confuse a molera with hydrocephalus.[17]Chihuahuas can also be at risk for hypoglycemia, or low blood sugar, which is especially dangerous for puppies. Leftunattended, hypoglycemia can lead to coma and death but can be avoided with frequent feedings, such as every threehours for very small or young puppies. Chihuahua owners should have a simple sugar supplement on hand to use inemergencies, such as, Nutri-Cal, Karo syrup or honey. These supplements can be rubbed on the gums and roof of themouth to rapidly raise the blood sugar level. Signs of hypoglycemia include lethargy, sleepiness, low energy,uncoordinated walking, unfocused eyes and spasms of the neck muscles or head pulling back or to the side.Chihuahuas are prone to eye infections or eye injury due to their large, round, protruding eyes and their relativelylow ground clearance. Care should be taken to prevent visitors or children from poking the eyes. The eyes also waterfrequently to remove dust or allergens that may get into the eye. Daily wiping will keep the eyes clean and prevent tearstaining.Collapsed trachea is a health concern that is characteristic of the chihuahua breed.[18]Chihuahuas have a tendency to tremble but it is not a health issue. Instead, it occurs mainly when the dog is stressed,excited or cold. Cold can also present a problem for these small animals. They often enjoy wearing coats or sweaterswhen outside and enjoy digging and snuggling in blankets when sleeping.Although figures often vary, as with any breed, the average lifespan range for a healthy Chihuahua is between 10 and18 years.Chihuahuas are sometimes picky eaters and care must be taken to provide them with adequate nutrition. Sometimeswet or fresh food can have the most appealing smell to these constant eaters. Chihuahuas are prone to hypoglycemiaand could be at a critical state if allowed to go too long without a meal. At the same time, care must be exercised not tooverfeed them.146 http://en.wikipedia.org/wiki/Laron_dwarfism147 Es fehlen die Exons 4 und 5: http://www.nejm.org/doi/pdf/10.1056/NEJM199610313351805Woods, K., Camacho-Hübner, C., Savage, M. O. and A. J. L. Clark (1996): Intrauterine Growth Retardation and Postnatal Growth Failure Associated withDeletion of the Insulin-Like Growth Factor I Gene, New England Journal of Medicine, 1996148 http://en.wikipedia.org/wiki/Chihuahua_(dog)http://www.dog-illnesses-n-symptoms.com/chihuahua-health-problems.html