Brachyuria
As Brachyury (from ancient Greek βραχύς brachys , German , short ' and ancient Greek οὐρά Oura , German , tail' ; not to be confused with ancient Greek οὖρα Oura , German , urine ' ) is a congenital shortening of the tail in vertebrates referred. The congenital absence of the tail in animals that are normally tailed is known as taillessness or anuria . Brachy and anuria are to be distinguished from docking , in which an existing tail is partially or completely amputated by humans .
Occurrence
Brachy and anuria occur in dogs , cats , pigs , cattle , sheep and chickens . Frequency, inheritance and clinical significance vary depending on the species and race.
dog
Brachyuria in dogs is also known as stubby tail . Characteristics range from a slight shortening to complete anuria, with or without crippling of the tail ( kinked tail , "corkscrew tail " ).
Brachyuria and / or anuria are considered part of the standard in various breeds (e.g. Australian Shepherd , Entlebucher Mountain Dog , English Bulldog , English Cocker Spaniel , Pug , Bobtail , Schipperke and Welsh Corgi Pembroke ), but also occurs in those who are not systematically bred Breeds as a variant (e.g. stumpers in old German herding dogs ). Kinky tails and corkscrew tails also occur more frequently in certain breeds, e.g. B. Dachshund .
Disease value
Brachy and anuria are associated with various malformations of the spine . It can wedge vertebrae , block vertebrae or butterfly vertebrae occur; also spina bifida . This can disrupt the development of the spinal cord , leading to neurological disorders in the rear half of the body ( paraparesis , paraplegia , urinary and / or cot incontinence ).
In 17 dog breeds, brachyuria is caused by an autosomal dominant C189G mutation of the T-box transcription factor , which in its homozygous form acts as a lethal factor . In six other dog breeds ( Boston Terrier , English Bulldog , King Charles Spaniel , Miniature Schnauzer , Parson Russell Terrier , Rottweiler ) the genetic basis of brachyuria is unknown; inheritance in these breeds is probably polygenic recessive.
From a genetic and animal welfare point of view, it is not advisable to use affected dogs for breeding. In breeds in which brachy and anuria are required as standard, an x-ray examination of the spine should be carried out pragmatically before breeding in order to rule out the presence of associated malformations. In breeds with fatal brachyuria, mating with short-tailed dogs should be avoided.
cat
Brachy and anuria occur sporadically in all cat breeds. They are required in the standard for manx cats , Japanese bob tails and Kuril bob tails, as well as pixie bobs , among others .
Disease value
In cats, the tail serves both for balance when running and climbing and as a means of communication . Short-tailed and tailless cats are severely limited in their communication options. There are also disturbances in normal movement sequences. In the manx cat, brachy and anuria are often associated with malformations of the pelvis and spine , the extent of the defects appearing to be linked to the length of the tail. In addition, brain malformations ( anencephaly ) and pronounced exophthalmos can occur.
Genetically, Manx and Bobtail cats have a simply autosomal dominant inheritance with incomplete penetrance and variable expressivity, which is homozygous and fatal . The inheritance of sporadic brachy and anuria in other races has not been clarified. The conscious breeding of tailless and stub-tailed cats is what constitutes torture breeding .
pig
In pigs, brachy and anurias occur in Large White and Landrace . The malformation is occasionally coupled with adhesions in different areas of the spine, which leads to movement disorders. The inheritance is not known; affected animals should not be used for breeding.
Beef
Various German Fleckviehrassen are affected in cattle (Holstein, Red Holstein, German Fleckvieh). The phenotypic expression of the disease can be divided into four categories.
- Anuria or brachyuria
- Caudo-recto-urogenital syndrome
- Anophthalmia- anuria (brachyuria) syndrome
- Anuria as part of another malformation complex (see web links)
The defect is inherited polygenically, autosomal recessively with a threshold value, whereby significant differences in the frequency of occurrence can be determined between the offspring of individual breeding bulls.
sheep
In sheep, brachyuria and anuria are found preferentially in New Zealand Romney sheep ; however, other races can sporadically be affected. It is a simply autosomal dominant trait with variable expressivity. Homozygous embryos die at 3 to 4 weeks ( lethal factor ). Carriers of traits should not be used for breeding.
chicken
Anuria or Kaulschwänzigkeit occurs when Kaulhuhn , the Araucana and allied races. Except for the tail feathers and the rump gland , the affected birds lack the entire caudal spine and parts of the pelvic spine. Anuria is a desired breeding goal in the affected breeds.
Disease value
Tailless chickens have problems mating because of the reduced opportunities for balance . Due to the lack of the preening gland, there are problems with plumage care. The brood yield is limited by increased embryo mortality; likewise, the mortality rate during the first two months of life compared to tailed chickens is almost doubled. Tailless chicks often have problems with the droppings because the down of the cloaca plumage is stuck together with the feces and can clog the cloaca .
The inheritance is simply autosomal dominant with incomplete penetrance. Carriers of traits should not be used for breeding; The deliberate breeding of tailless chickens fulfills the criteria of torture breeding and is listed in the corresponding list of the German Ministry of Agriculture.
literature
- Th. Bartels, W. Wegner: Wrong developments in domestic animal breeding. Ferdinand Enke Verlag, Stuttgart 1998, ISBN 3-432-28131-5 .
- A. Herzog: Pareys Lexicon of Syndromes - Hereditary and breeding diseases of domestic and farm animals. Parey Buchverlag, Berlin 2001, ISBN 3-8263-3237-7 , p. 67 f.
Individual evidence
- ↑ Ludwig August Kraus: Critical-etymologisches medicinisches Lexikon . 3rd edition, Göttingen 1844. p. 100.
- ↑ MK Hytönen et al: Ancestral T-box mutation is present in many, but not all, short-tailed dog breeds. In: Journal of Heredity. 2009, 100 (2), pp. 236-240, PMID 18854372
