Both the conditions which you've mentioned are very serious. The term
"secondary infarction" is used in several different ways, but most
commonly it involves an embolism or thrombus (clot) in a blood vessel,
or refers to a vascular disorder caused by occlusion of blood flow.
"Necrosis" means "tissue destruction." "Hemangiosarcoma" is a form of
cancer.
I have gathered some material on these conditions for you. I'm posting
just brief excerpts here; for a deeper understanding, you may want to
read these articles in their entirety.
"Cerebral infarction associated with septic thromboemboli has been
reported in dogs. In one report on 10 dogs, most were older than 5
years of age and there was an acute onset of severe neurological signs
(cerebral syndrome with lateralizing signs) in 8 of the dogs. CSF
[cerebrospinal fulid] analysis revealed marked pleocytosis (including
neutrophils) and elevated protein levels in 8 of 9 dogs tested. Seven
dogs died or were euthanized, while 3 were treated successfully with
antibiotics. Pathological changes included focal infarction, sometimes
with abscess formation, vascular changes, thrombosis, and hemorrhage.
In four dogs, a primary infection focus was found outside of the CNS
[central nervous system]. Staphylococcus aureus and b-Streptococcus
were isolated in two cases.
Infarction has occasionally been observed secondary to embolic
metastatic tumors cells in dogs, including mammary adenocarcinoma and
other malignant neoplasms. Multiple CNS ischemic infarction may occur
in animals with intravascular lymphoma (malignant
angioendotheliomatosis) associated with vessel thrombosis."
International Veterinary Information Service: Neurovascular Disorders
http://www.ivis.org/special_books/Braund/braund25/chapter_frm.asp?LA=1
"Hemangiosarcoma is a malignant cancer of the cells that form blood
vessels. Because these tumors start in blood vessels, they are
frequently filled with blood. Consequently, when a blood-filled tumor
ruptures, it can cause problems with internal or external bleeding.
Hemangiosarcoma is considered to be a very aggressive tumor and can
spread rapidly to other organs.
Hemangiosarcoma is more common in dogs than in cats. It usually occurs
in middle-aged to older dogs 9 to 11 years of age, and German
shepherds appear to be predisposed to developing this cancer.
The most common primary location of this cancer in dogs is the spleen.
Other primary locations include the heart, liver, skin, and bone;
however, it can start in any location where blood vessels are present.
These tumors usually spread to the lungs, liver, spleen and heart...
The treatment and prognosis depends upon the location of the tumor.
When the tumor occurs in an internal organ such as the spleen or
heart, the chances of long-term survival are poor. Treatment is more
successful when this cancer occurs in the skin. Exposure to the sun
may play a role in the development of this type of skin cancer. Dogs
with poorly-pigmented skin and sparse hair coats, such as the whippet,
saluki, bloodhound and English pointer, are more likely to develop
this form of hemangiosarcoma. There is no known cause of
hemangiosarcoma in other locations. In humans, exposure to certain
chemicals such as vinyl chloride has been implicated as a cause.
Treatment for hemangiosarcoma may include the following:
Stabilization
Intravenous fluids
Blood transfusion
Pericardial tap
Surgery
Chemotherapy
Radiation therapy"
PetPlace: Hemangiosarcoma
http://petplace.netscape.com/articles/artShow.asp?artID=728
"Cancers are named for the cell type that they originate from;
therefore, hemangiosarcoma is a malignant cancer that comes from
hemangio meaning blood vessels or blood and sarcoma meaning malignant
cancer of the supporting structures of the body. This type of cancer
tries to build blood vessels in a haphazard fashion which essentially
makes blood blisters and disrupts normal organ function. These blood
blisters also rupture easily causing bleeding from the cancer sites.
This is a very common form of cancer in dogs and most often affects
older, large breed dogs. More male dogs than female dogs are affected
and the two most represented breeds are the golden retriever and the
german shepherd. This type of cancer could be called the silent killer
since it usually doesn't show itself until it is advanced...
The most common organs affected with hemangiosarcoma are the heart and
the spleen, both very vascular organs. If the spleen is affected, the
spleen enlarges with these lumpy blood blisters which bleed easily.
Usually by the time this is diagnosed, the cancer has spread to the
liver and other sites in the abdomen and possibly to the chest.
Sometimes early in the growth of the cancer, the enlarged spleen can
be felt and diagnosed before much bleeding has occurred. When the
heart is affected, bleeding occurs into the pericardium (the sac
around the heart). This creates so much pressure on the heart that it
can't work properly. If the blood is not drained off quickly, the
heart stops.
As you can understand, this is a very difficult cancer to diagnose at
a time when surgical removal of the cancer will really help the
patient long term. Fifty percent of these patients have already had
the cancer spread to the rest of the bodies at the time they are
diagnosed."
Vet Corner: Hemangiosarcoma
http://www.adoptagolden.com/k9stuff/vetcorner/hemangio.htm
"A form of cancer that originates in the endothelium, which is the
lining of blood vessels and spleen. These tumors are highly malignant
and can be found almost anywhere in the body. The spleen, pericardium
and heart are prone to be affected.
These tumors are most common in medium-sized or large breeds of middle
aged or older dogs but can occur in any breed, including cross-breeds.
German shepherds are reported to be more susceptible to this form of
cancer than most dog breeds. The Golden Retriever also seems to have a
higher than normal incidence.
Quite often there is little warning of the presence of these tumors
before severe clinical signs are seen. An estimate of the average time
from discovery of the tumor until death occurs in affected dogs is six
to eight weeks."
Canada's Guide to Dogs: Hemangiosarcoma
http://www.canadasguidetodogs.com/health/cancer.htm
My Google search strategy:
Google Web Search: hemangiosarcoma dog OR dogs
://www.google.com/search?hl=en&q=hemangiosarcoma+dog+OR+dogs
Google Web Search: dog OR dogs secondary infarction necrosis
://www.google.com/search?hl=en&q=dog+OR+dogs+secondary+infarction+necrosis
Please keep in mind that Google Answers is not a source of
authoritative medical advice; the material I've presented here should
not be viewed as a diagnosis, but is for informational purposes. There
is no substitute for the services of a qualified veterinary
professional.
If anything is unclear or incomplete, or if a link does not function,
please request clarification; I'll be glad to offer further assistance
before you rate my answer.
Best wishes,
pinkfreud |
