Some friends of ours recently had a problem with one of their ferrets that was
fairly common in symptoms, but had an uncommon outcome. Thanks to the
thoroughness of Dr. Richard Henderson of the Galveston Veterinary Clinic, in
consultation with Drs. Kawasaki and Williams, Patty is a healthy ferret today
and should live a full life.
Dr. Henderson suggested that, due to the unusual outcome of this case, the
case history and pathology report should be posted to the FML. It could very
well change the decisions that a ferret owner might make, should their ferret
exhibit the same symptoms. In short, what looked like it might have been
lymphoma was, in fact, an entirely different problem that was effectively
cured by the removal of the spleen and a short course of treatment with
prednisone.
Please pardon the length of this post. But we all feel that this kind of
information is important and needs to be dissiminated as widely as possible.
The Case History and an excerpt from the Pathology Report Follow.
-------------------------------
Additional Notes to Pathology Report:
Case History, Patty (Grant)
At her annual physical examination on 30 September, 1993, Patty a gill ferret
of Marshal Farms stock and approx. 4-5 years old, presented with an enlarged
spleen, but no other apparent symptoms. The attending veterinarian, Richard
Henderson, DVM, of Galveston Veterinary Clinic, recommended monthly
examination to observe for other symptoms.
>From October 1993 to late January 1994, the splenic enlargement became more
marked. The animal was increasingly lethargic and bloodwork (CBC) showed
severe anemia and a high production of leucocytes. Tentative diagnosis was
lymphoma and 5.5 cc of whole donor blood was transfused. Chemotherapy course
was started, consisting of dosage-by-weight of vincristine, cytoxin and
prednisone. One dose of vincristine was administered intravenously, at the
time of transfusion, and one dose of cytoxin given orally two days later.
One-quarter (1/4) tablet of prednisone was given daily, by mouth.
Dr. Henderson contacted Dr. Kawasaki, in Virginia, a well-known authority on
diseases in ferrets, and specifically in ferret oncology.
After consultation with Dr. Kawasaki, Dr. Henderson decided to perform a
splenectomy, since, by this time, the spleen had grown to such size that it
presented, in itself, an immediate threat to the animal's life. Immediately
prior to surgery, the ferret weighed 1-1/2 pounds.
Splenectomy was performed in early February. At the time of surgery, the
spleen was so grossly enlarged that it was clearly visible through the
animal's skin. A 3 cm incision was made at the cranial abdominal midline and
the spleen was eased out, partially rupturing outside the body during the
process of ligation of blood vessels due to its friability. A slight
enlargement of the incision - about 1/2 cm - was necessary after that.
Immediately post-op, another transfusion of 7.5 cc was given and a second dose
of vincristine was also administered. Weight immediately following surgery
was 1 lb. The spleen had weighed 1/2 lb. - roughly the size of a normal
spleen in a 30-35 lb. dog. Biopsy materials of the spleen tissue were taken
and sent to the United States Department of Veterinary Pathology, and written
report received from US/DVP is attached.
One week post-op, a third dose of vincristine was administered intravenously,
since no information on further diagnosis was yet available from biopsy; but
Dr. Henderson opted to reserve further use of cytoxin unless it was absolutely
necessary. It was his opinion, by this time, that the pathology report might
indicate a diagnosis other than lymphoma, since exploratory done during
surgery had yielded no abnormality of the lymph glands, adrenals, pancreas or
liver.
Report on the biopsy and telephone conference with Maj. Bruce Williams, DVM
proved this hypothesis correct, with a confirmed diagnosis of extramedullary
splenetic hematopoiesis. Dr. Williams opinion at this point was that the
splenetic enlargement was due to an autoimmune anemia. Treatment protocol
indicated for this splenectomy and prednisone given pre- and post-surgery.
At 7 days post-op, hematocrit was 31. The course of prednisone begun at 7
days pre-op was continuing, with taper off doses given for 2 months. Last
dose was given at the end of the 3rd week of April, and on 12 May, Dr.
Henderson examined Patty and another CBC was run. This showed a hematocrit of
37 and normal levels of white cells. Weight on 12 May was 2 lb., a 100%
increase from her weight immediately post-op. Her energy and activity level
is normal-to-high, and she shows no symptom of illness. Her present prognosis
is excellent and she is expected to remain healthy and to have a normal
lifespan.
Bone marrow biopsy is not deemed necessary, since her hematocrit levels
indicate normal bone marrow function. She will, however, be observed at home
for any indication of recurrent anemia; i.e. white nose, lethargy, etc., in
addition to her regular annual physical exam.
Camille Grant
17 May, 1994
-------------------------------
(Excerpt from Pathology Report on Patty, received from US/AFIP -
dated 4 March 1994 - Accession number 2440936-9)
AFIP DIAGNOSIS: S-0883-445 Spleen, red pulp: Extramedullary hematopoiesis,
diffuse, moderate, ferret, mustelid.
COMMENT: The cause of the marked anemia in this ferret was not evident
in the sections we examined. The splenectomy described in the
clinical history is due to moderate extramedullary hematopoiesis. The
extramedullary hematopoiesis seen in the spleen suggests a regenerative
response to the anemia documented in the clinical history. Submission
of bone marrow would have been beneficial in this case to further
investigate the cause of the pancytopenia documented in the clinical
history.
Thank you for submitting this case to the Registry of Veterinary
Pathology.
RICHARD K. Harris, DVM
LtCol. USAF, BSC
Chairman, Department of
Veterinary Pathology
Bruce H. Williams, DVM
MAJOR, VC, USA
Department of Veterinary Pathology
AFIP F/L 61
15 May 87
-------------------------------
The moral of the story is that what looks like lymphoma may not always be
lymphoma. Some people hearing the diagnosis of lymphoma and not having the
funds to pay for the extended treatment might choose to put the animal down
rather than watch her suffer. This shows that there are some cases where this
action could, in fact, be a terrible error. The operation and treatment,
though not inexpensive, had a finite cost that many vets would likely be
willing to finance. In any case, I believe that most ferret owners, when
faced with this possibility, would find a way to come up with the money. If
the vet finds indications of lymphoma during exploratory, the ferret, at the
owner's discression might never wake up. But this way, the ferret at least
has a chance. I understand that Dr. K. told Dr. Henderson that as much as 20%
of cases that present this way, are actually ESH (extramedullary splenetic
hematopoiesis).
--
John Gaver ([log in to unmask]) | Action Rubber Stamp Company
"Cats may be cool, | Ph:713-668-3557 Fax:713-666-3276
but Carpet Sharks rule." | Custom rubber stamps by phone or fax.
** MENTION THE FERRET LIST FOR 20% DISCOUNT. FERRET RELATED STAMPS 30% OFF. **
[Posted in FML issue 0848]
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