By: Jessica Larson, DVM, DACVIM—Coral Springs Animal Hospital Internist
Signalment:
Meet
“Riley” – a 4 year old
female spayed Border
Collie
anemia persisted. She again was considered clinically
normal for another 3 months and then presented with
similar signs of acute lethargy, although this time the
fever returned and she had moderate joint effusion on
physical exam. She was again hospitalized for 2 days
Chief Complaint: Recur-
with multiple diagnostics performed to try to identify a
rent, although not cy-
focus of infection causing persistent neutropenia; all
clic
predictable,
were negative. She recovered quickly with supportive
bouts of fever, lethargy/
care including antibiotic therapy and has not been hos-
malaise
variable
pitalized again! She remained clinically normal at home
anemia
following this episode although her serial CBC results
or
and
neutropenia,
and thrombocytopenia
History: Riley originally presented to CSAH 2 ½ years
ago, at the age of 6 months, for an acute onset of lethargy and fever (106ºF). At that time anemia (Hct 25%)
was noted with mildly low platelets (122,000 K/uL) and a
normal neutrophil count (7,190 K/uL). She was discharged after 2 days of hospitalization with supportive
care. She recovered uneventfully and was considered
clinically normal until almost 2 years later. She again
presented with non specific signs of acute lethargy,
have continued to reveal moderate leucopenia with
neutropenia, mild thrombocytopenia and very mild
anemia. Given her unusual signs and recurrent nature
of disease she was treated briefly (for just over 1 month)
for a suspected immune-mediated neutropenia with
steroid therapy. She tolerated the steroid therapy well
but it was tapered at home (without routine follow ups)
and ultimately her CBC results remained similar (e.g. she
never had a CBC performed while receiving steroid
therapy).
weakness, and inappetance. Emergency examination
While Riley continued to do well at home, we remained
with lab findings revealed hypoglycemia with normo-
frustrated that a definitive cause for leukopenia with
thermia – early septic shock was suspected and she
lethargy/malaise/fever was not identified. A veterinary
was urgently hospitalized for supportive care. In retro-
medical literature search and American College of Vet-
spect her family felt that she had slowed down and was
erinary Internal Medicine list-serv query performed by
exhibiting unusual exercise intolerance (which says a lot
Dr. Larson revealed two uncommon considerations: 1.
for a Border Collie!). Other findings at that time re-
Trapped Neutrophil Syndrome (TNS) (in Border Collies, it
vealed severe neutropenia (1,230 K/uL), moderate
is a genetic malformation causing dysfunctional neutro-
thrombocytopenia (94,000 K/uL) and normal hemato-
phils with severe neutropenia usually leading to death
crit (37%) although the red blood cell indices (MCV,
from sepsis, similar to Cohen’s disease in humans), and
MCH) were low, suggesting abnormal red blood cell
2. Border Collie Imerslund-Gräsbeck syndrome (I-GS) (a
volume. During this hospitalization event (3 days in dura-
disease similar to humans in whom there is a familial
tion), Riley improved greatly with supportive care in-
form of vitamin B12 deficiency caused by malfunction of
cluding antibiotic therapy and nutrition. She was tenta-
the receptor located in the terminal ileum). She didn’t
tively diagnosed with pancreatitis causing septicemia
exactly fit either description as most dogs in the litera-
from which she recovered with return to normal leuko-
ture died from sepsis at very young ages, and most had
cyte counts, although mild thrombocytopenia and
phenotypic abnormalities (small stature, very elongated