Pituitary tumors in Dogs

Thank you for your response. I am curious about your appraisal of my vet's
recommendation that I treat with Lysodren. It sounds like I have no choice
but to take a medical approach to this. My vet has prescribed Lysodren
along with a sustaining amount of Prednisone (sp?) followed by another ACTH
in 10 days. He says the success varies greatly with different dogs, good
results could be apparent in 3 weeks, other times in 3 months, made evident
by repeated ACTH tests. Once the optimal levels are achieved then they know
what levels to prescribe and stick with. He cautioned me that some dogs need
readjustment in the medications which is apparent by the return of symptoms
or a routine ACTH test.
My vet described the continued decline and other failures that are possible
from not treating the dog and this strategy does not sound like an option.
And this treatment could allow her to age normally, free of the current
dibilitating symptoms.
He also mentioned adjunct supplements - antioxidents to protect the organs
from the Lysodren. Do you have any recommendations of specific diet,
vitamins and food supplements?
Thank you again.
Laura

One of the older issues of the VetInfo Digest in the subscriber area is
devoted entirely to Cushing's disease. It has some information in it that
is not available on the general web site.

The dietary recommendations in "Small Animal Clinical Nutrition, 4th ed.",
Hand, et. al., are to use a low fat, moderate fiber diet with good quality
protein. Vitamin supplementation is not thought to be needed if a food
meeting the AAFCO requirements for adult dogs is being fed. Several of the
therapeutic diets on the market meet these requirements, including Hill's
w/d, Purina's DCO and OM diets (tm) and Walthams Low Fat (tm) diet. There
are probably others, as well.

Question: Dear Dr. Richards,
My 8 and a half year old Brittany Spaniel named Lucy has been diagnosed with
a pituitary based tumor causing Cushing's Syndrome. Her symptoms are
insatiable hunger and thirst, bloated belly but no weight gain and much
decreased activity level and fatigue. (She is normally an
extremely active dog.) I do not yet have the full report from her
ultrasound, but so far they ruled out an enlarged adrenal gland, therefore pointing to the
pituitary gland. She had an ACTH test earlier as well leading up to this
diagnosis.
My vet has recommended Lysodren to address the symptoms, but which will not
address the tumor. I am wondering about surgical options since we have a
vet neuro surgeon here in Seattle (who is out of town until the19th.) Do
you have any experience with surgery for this kind of tumor? If so, what
success rate has there been and what effects does the surgery have on the
dog?
I am wondering if we try medical treatment first we will still have the
surgical option later if the medical treatment isn't very satisfactory.
Would treatment with Lysodren now rule out a surgical strategy later?
Is there any urgency to medical treatment? Her symptoms just recently (the
last month) got bad enough for me to realize she needed to be seen by the
vet, but now that we have a diagnosis I realize that this has been building
for about a year.
Thank you. Lucy is a dear part of our family and we are very sad about this
illness.
Sincerely,
Laura

I am not aware of anyone doing transsphenoidal hypophysectomy (pituitary
removal) surgery on dogs in the United States. Reports on this surgery have
almost all come from Utrecht University in the Netherlands. It is hard to
be sure whether or not a surgery is being done in the U.S. and where it is
being done, since these situations change quickly, so you probably should
talk to the surgeon in your area. He may be aware of someone who does this,
if he does not.

I am not sure why surgery is not utilized more often in dogs since it is
commonly done in people. It may be an economic decision but there have been
reports of attempts to do this surgery in the US and they have not had
outcomes as successful as those of Utrecht, so poor experiences with the
surgery here in the US also has something to do with it.

I can't think of any reason why using Lysodren (Rx) now would interfere
with surgery later but I haven't seen any journal references that discuss this.

The good thing about Cushing's disease is that there are treatment options
now, making it more likely that you can find success in treating this
condition.

This is Ruth again. Our present vet here in Louisville briefly
mentioned that surgery can be done for pituitary tumors, and stated that
this surgery is costly.
What are your views as to this type of surgery??????? I have read that
this type of surgery has been, and is being done, I believe, somewhere
in the Netherlands? I also read that the success rate has not been that
good; that the animals tend to fair the surgery itself, but has
succumbed post surgery for various reasons. Have you heard anything
about this???
Surgery is supposed to be costly, but what dollar signs are we talking
about approximately????
What is your opinion of this surgery?????

This is the information that I put in the August 99 VetInfo Digest (it is
available in the subscriber area):

With the advent of accurate diagnostic imaging using CT or MRI
scans, it has become possible to locate and remove pituitary gland tumors
surgically at some institutions. The Utrecht University in the Netherlands
is one place where this surgery has been performed a number of times. While
the risk of surgery is pretty high, with 10% of dogs undergoing surgery
dying from immediate complications and almost 10% of dogs having incomplete
surgical excision of the affected portions of the pituitary gland, the two
year survival rate of patients undergoing this procedure is still
reported to be close to 80% by Meij, et al, in the May/June 1998 issue of
Veterinary Surgery. I am not sure how available this procedure is in the
United States but it is likely that it will become more common
due to the increased availability of high quality imaging and advanced
surgical facilities.

Limited reports from surgeons in this country seem to indicate a higher death
rate from surgical complications than has been experienced by the surgeons at Utrecht.

I rechecked the databases online to see if there were new developments and
couldn't find any. I do not know of any surgeons doing this surgery
routinely in the United States but that doesn't mean that someone isn't. I
had a hard time searching for vets who were doing kidney transplants in
cats when a client wanted to find one, but our client was able to find a
name after searching the web persistently. I don't know whether or not it
would be possible to arrange for surgery at Utrecht but if you would
seriously consider this I will try to find out for you.

In Pituitary dwarfism / hyposomatotrophism a deficiency in pituitary stimulation of growth hormone production leads to dwarfism. This occurs most commonly in German shepherds but has been reported in several other breeds. It is an inherited disease in German shepherds (autosomal recessive trait). This disorder must be distinguished from other conditions leading to stunted growth, including malnutrition, congenital hypothyroidism and other congenital defects leading to poor growth. Dogs with this condition do not grow like their littermates. Their hair retains its "puppy" appearance, feeling soft to the touch. Hairloss along the sides that is symmetrical often occurs. Abnormalities in bone growth lead to a deformed appearance to the legs. As other puppies in the litter appear to mature, affected dogs continue to have a puppy-like appearance and bark. Dogs with this condition may be deficient in other hormones in which the pituitary gland controls part of the process of stimulating the hormone's production. It is a good idea to check for hypothyroidism and hypoadrenocorticism in dogs with hyposomatotrophism. Human growth hormone will work to treat affected dogs but it is expensive and may be hard for the average veterinary practitioner to obtain.

Dr Mark Neff a researcher / vet is trying to start a study on dwarfism in dogs but hasn't received enough participants. If you have a dwarf dog or puppy and would like to increase the knowledge base about this disorder you can enter the study. Our reader Sarah says that Dr Neff asked her some some questions about her pup and then she said she could send him a sample a cotton swab from the pups cheek to do some testing and see how to help Bailey. The more samples he has the more he can test and see how to develop better treatment options for dwarfism, perhaps even a cure. Sarah wanted to share the study information with everyone that had dwarf puppies and dogs. Anyone with a dwarf dog can submit a cheek cotton swab to Dr. Mark Neff at UC Davis e-mail:

Dr. Mark Neff is a geneticist at the Veterinary Genetics Laboratory of the UC Davis School of Veterinary Medicine. He received his Ph.D in genetics from the University of Virginia and his postdoctoral training in the laboratory of Dr. Jasper Rine at UC Berkeley, where he helped assemble a genetic linkage map of the dog genome.

He has worked with Canine Companions for Independence, in an effort to develop a 'temporal fate map' -- 'genetic markers' in puppies that could indicate which ones are more likely to make the grade as service dogs.

He has been looking at developmental 'windows', times during which the dog's physical and psychological growth can be influenced. His work has direct application to the breeding process, evaluation of puppies, and the factors which can influence the development of those puppies. In addition he will address specific problems in the breed, such as lens luxation and deafness, and any issues raised by the participants.