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Congenital and Neonatal Disease - Pathology (view source)
Revision as of 19:58, 13 August 2009
, 19:58, 13 August 2009New page: {{review}} {{toplink |linkpage =General Pathology |linktext =General Pathology |maplink = General Pathology (Content Map) |pagetype =Pathology }} <br> ==Introduction== * Changes in the p...
{{review}}
{{toplink
|linkpage =General Pathology
|linktext =General Pathology
|maplink = General Pathology (Content Map)
|pagetype =Pathology
}}
<br>
==Introduction==
* Changes in the patterns of growth and differentation result in growth disorders.
** These changes may be in single cells, tissues or organs.
* There are two types of growth disorders.
*# '''Malformations'''
*#* Occur during gestation.
*# '''Congenital'''
*#* Detected at birth.
* Some growth disorders have a heriditary input.
** Occur as a result of genetically transmitted disease.
* Some growth disorders occur as a sequl to a variety of insults to the foetus during gestation.
* Only a few malformations are readily accessible to surgical correction.
==Causes of Malformations==
* There are many causes of malformations in animals.
* If the insult occurs early in gestation and is sufficiently severe, it will result in foetal death, resorption and infertility.
* If the insult occurs late in gestation, the malformation will be more limited and the foetus usually survives.
===Chromosomal Defects===
* Although malformations can be caused by chromosomal abnormalitis, these often result in early abortion or resorption.
===Viral Diseases===
* Some viruses are able to cross the placenta and cause damage to foetal tissues.
* For example:
** Border Disease Virus in lambs.
** Cerebellar hypoplasia in kittens caused by parvovirus.
===Toxins===
* For example, toxic plants ingested by the dam during pregnancy.
** ''Veratrum californicum''
*** May produce cyclopia in lambs when ingested by the dam in early pregnancy.
===Drugs===
* Griseofulvin
** Used to treat "ringworm" (dermatophytosis). ( for the treatment of dermatophytosis - 'ringworm' )
** Can cause serious malformations in kittens if administered to a pregnant queen.
* Oestrogens and Actinomycin D have also been associated with malformations.
===Ionising Radiation===
* For example, X-rays.
===Nutritional Deficiencies===
====Copper Deficiency====
* Copper deficiency in the pregnant ewe can result in "''swayback'''" in lambs.
** Due to white matter degeneration in the central nervous system of prenatal and neonatal lambs.
* The degeneration is thought to be a mixture of both hypomyelination and demyelination.
* The central nervous system of the lambs is affected.
** Neonatal lambs show an ataxia in the first few weeks of life.
*** Due to demyelination of dorsolateral and ventromedial tracts in the white matter of the spinal cord.
** More severe lesions can be present in lambs affected prenatally.
*** Destruction of subcortical white matter in the brain.
**** The extent of this varies.
* It is unknown how copper deficiency exerts this effect.
** Supplementation in pregnancy prevents the prenatal form.
** Supplementation in the first few weeks will alleviate the neonatal form.
====Vitamin Deficiencies====
* Vit. A and D deficiency can result in skeletal malformations.
===Physical Factors===
* For example, adhesions between foetal membranes or umbilical cord.
** Can result in amputation of skeletal segments.
*** Especially around limbs.
===Anoxia===
* Lack of oxygen in gestation can result in malformations.
==Malformations==
===Cyclops===
* The presence of a single central eye as a result of facial deformity.
===Bulldog Calf===
* A well recognised deformation in Dexter calves.
* Related to [[Bones Developmental - Pathology#Chondrodysplasia|defective cartilage matrix and abnormal ossification]].
* The calf is born with short and crooked limbs and the facial bones are short.
===Cleft Palate===
* A very common malformation in many species.
* Due to failure of the [[Skull and Facial Muscles - Anatomy & Physiology#Palatine Bone (os palatinum)|palatine bones]] to fuse in the midline.
* The animal:
** Fails to suckle properly
** Can develop an aspiration pneumonia.
* Caused by:
** Administration of griseofulvin to queens during pregnancy.
** Certain viral infections.
** Ingestion of toxic plants.
===Cystic Kidney===
* Also known as polycystic kidney.
* Can be seen in many different species.
* Can have a hereditary basis.
* The cysts may be single or multiple.
* Results from the failure of development of the tubular system in nephrons.
* Severely affected animals may die of renal failure early in life.
** The affected kidney does not have enough functional reserve, and so small infections can have a serious effect on renal function.
===Spina Bifida===
* A failure of closure of the vertebral arch.
* May result in herniation of the meninges and /or spinal cord.
** There may be a direct communication between those structures and the skin surface.
===Hydrocephalus===
* Not uncommon in dogsand cats.
* Abnormal drainage of cerebrospinal fluid (CSF) results in dilation of the ventricles of the brain.
** Is a result of either stenosis of:
*** The aqueduct between the 3rd and 4th ventricle, or
*** The foramina further back in the brain stem.
** May also be acquired as a result of compression by tumours or infectious processes.
* Dilation of the ventricles with CSF causes pressure atrophy of the overlying brain tissue.
* Hydrocephalus can be seen at birth.
** Characterised by a dome shaped skull and open fontanelles.
* Hydrocephalus may also be hidden and detected later in life.
===Cerebellar Hypoplasia===
* The cerebellum is smaller than normal and oftenrudimentary.
* Microscopy shows a highly disorganised architecture.
* The animal shows tremors and ataxia.
* Usually associated with viral infections during gestation.
===Skeletal Malformations===
* There are numerous skeletal malformations.
* Include:
** Absence of bones
** Deformation
** Shortening
** Duplication
** Hypoplasia
===Skin Defects===
* E.g. Epitheliogenesis imperfecta.
** There is absence of portions of the epidermis.
*** Results in ulcers.
===Muscular Defects===
* E.g. defects in the thoracoabdominal walls resulting in exterioration of internal viscera.
** Called "shistosoma".
===Cardiac Defects===
* There are several possible types of cardiac defects.
** These include:
*** Patency between chambers
*** Persistent right aortic arch
*** Tetrology of Fallot.
===Sexual Organ Malformation===
* E.g.:
** Hermaphrodites
** Pseudohermaphrodites
** Freemartinism in females calves.
===Metabolic Diseases===
* "Storage" diseases.
** Vital enzymes are missing or defective within all cells.
* These diseases express themselves as storage of intermediate products within cells.
* Because neural tissue is a very sensitive tissue and cannot repair, these diseases usually express themselves as disease of the Central Nervous System.
{{toplink
|linkpage =General Pathology
|linktext =General Pathology
|maplink = General Pathology (Content Map)
|pagetype =Pathology
}}
<br>
==Introduction==
* Changes in the patterns of growth and differentation result in growth disorders.
** These changes may be in single cells, tissues or organs.
* There are two types of growth disorders.
*# '''Malformations'''
*#* Occur during gestation.
*# '''Congenital'''
*#* Detected at birth.
* Some growth disorders have a heriditary input.
** Occur as a result of genetically transmitted disease.
* Some growth disorders occur as a sequl to a variety of insults to the foetus during gestation.
* Only a few malformations are readily accessible to surgical correction.
==Causes of Malformations==
* There are many causes of malformations in animals.
* If the insult occurs early in gestation and is sufficiently severe, it will result in foetal death, resorption and infertility.
* If the insult occurs late in gestation, the malformation will be more limited and the foetus usually survives.
===Chromosomal Defects===
* Although malformations can be caused by chromosomal abnormalitis, these often result in early abortion or resorption.
===Viral Diseases===
* Some viruses are able to cross the placenta and cause damage to foetal tissues.
* For example:
** Border Disease Virus in lambs.
** Cerebellar hypoplasia in kittens caused by parvovirus.
===Toxins===
* For example, toxic plants ingested by the dam during pregnancy.
** ''Veratrum californicum''
*** May produce cyclopia in lambs when ingested by the dam in early pregnancy.
===Drugs===
* Griseofulvin
** Used to treat "ringworm" (dermatophytosis). ( for the treatment of dermatophytosis - 'ringworm' )
** Can cause serious malformations in kittens if administered to a pregnant queen.
* Oestrogens and Actinomycin D have also been associated with malformations.
===Ionising Radiation===
* For example, X-rays.
===Nutritional Deficiencies===
====Copper Deficiency====
* Copper deficiency in the pregnant ewe can result in "''swayback'''" in lambs.
** Due to white matter degeneration in the central nervous system of prenatal and neonatal lambs.
* The degeneration is thought to be a mixture of both hypomyelination and demyelination.
* The central nervous system of the lambs is affected.
** Neonatal lambs show an ataxia in the first few weeks of life.
*** Due to demyelination of dorsolateral and ventromedial tracts in the white matter of the spinal cord.
** More severe lesions can be present in lambs affected prenatally.
*** Destruction of subcortical white matter in the brain.
**** The extent of this varies.
* It is unknown how copper deficiency exerts this effect.
** Supplementation in pregnancy prevents the prenatal form.
** Supplementation in the first few weeks will alleviate the neonatal form.
====Vitamin Deficiencies====
* Vit. A and D deficiency can result in skeletal malformations.
===Physical Factors===
* For example, adhesions between foetal membranes or umbilical cord.
** Can result in amputation of skeletal segments.
*** Especially around limbs.
===Anoxia===
* Lack of oxygen in gestation can result in malformations.
==Malformations==
===Cyclops===
* The presence of a single central eye as a result of facial deformity.
===Bulldog Calf===
* A well recognised deformation in Dexter calves.
* Related to [[Bones Developmental - Pathology#Chondrodysplasia|defective cartilage matrix and abnormal ossification]].
* The calf is born with short and crooked limbs and the facial bones are short.
===Cleft Palate===
* A very common malformation in many species.
* Due to failure of the [[Skull and Facial Muscles - Anatomy & Physiology#Palatine Bone (os palatinum)|palatine bones]] to fuse in the midline.
* The animal:
** Fails to suckle properly
** Can develop an aspiration pneumonia.
* Caused by:
** Administration of griseofulvin to queens during pregnancy.
** Certain viral infections.
** Ingestion of toxic plants.
===Cystic Kidney===
* Also known as polycystic kidney.
* Can be seen in many different species.
* Can have a hereditary basis.
* The cysts may be single or multiple.
* Results from the failure of development of the tubular system in nephrons.
* Severely affected animals may die of renal failure early in life.
** The affected kidney does not have enough functional reserve, and so small infections can have a serious effect on renal function.
===Spina Bifida===
* A failure of closure of the vertebral arch.
* May result in herniation of the meninges and /or spinal cord.
** There may be a direct communication between those structures and the skin surface.
===Hydrocephalus===
* Not uncommon in dogsand cats.
* Abnormal drainage of cerebrospinal fluid (CSF) results in dilation of the ventricles of the brain.
** Is a result of either stenosis of:
*** The aqueduct between the 3rd and 4th ventricle, or
*** The foramina further back in the brain stem.
** May also be acquired as a result of compression by tumours or infectious processes.
* Dilation of the ventricles with CSF causes pressure atrophy of the overlying brain tissue.
* Hydrocephalus can be seen at birth.
** Characterised by a dome shaped skull and open fontanelles.
* Hydrocephalus may also be hidden and detected later in life.
===Cerebellar Hypoplasia===
* The cerebellum is smaller than normal and oftenrudimentary.
* Microscopy shows a highly disorganised architecture.
* The animal shows tremors and ataxia.
* Usually associated with viral infections during gestation.
===Skeletal Malformations===
* There are numerous skeletal malformations.
* Include:
** Absence of bones
** Deformation
** Shortening
** Duplication
** Hypoplasia
===Skin Defects===
* E.g. Epitheliogenesis imperfecta.
** There is absence of portions of the epidermis.
*** Results in ulcers.
===Muscular Defects===
* E.g. defects in the thoracoabdominal walls resulting in exterioration of internal viscera.
** Called "shistosoma".
===Cardiac Defects===
* There are several possible types of cardiac defects.
** These include:
*** Patency between chambers
*** Persistent right aortic arch
*** Tetrology of Fallot.
===Sexual Organ Malformation===
* E.g.:
** Hermaphrodites
** Pseudohermaphrodites
** Freemartinism in females calves.
===Metabolic Diseases===
* "Storage" diseases.
** Vital enzymes are missing or defective within all cells.
* These diseases express themselves as storage of intermediate products within cells.
* Because neural tissue is a very sensitive tissue and cannot repair, these diseases usually express themselves as disease of the Central Nervous System.