Objective—To evaluate time to first recurrence (TFR)
and overall survival in cats with presumed vaccine-associated
sarcomas (VAS) treated with excision.
Animals—61 cats with presumed VAS.
Procedure—Medical records of cats that received
excision as the only initial treatment for presumed
VAS were reviewed to evaluate prognosis. Overall
survival curves and TFR were determined.
Results—Median TFR was 94 days. Median TFR for
tumors treated with excision performed at a referral
institution (274 days) was significantly longer than that
for tumors excised by a referring veterinarian (66 days).
Radical first excision yielded significantly longer median
TFR (325 days) than did marginal first excision (79
days). Cats with tumors located on the limbs had
longer median TFR (325 days) than cats with tumors
located in other sites (66 days). Median overall survival
time was 576 days. Significant differences in survival
times between groups were not detected. Few cats
(13.8%) receiving only surgical treatment had longterm
(> 2 years) survival.
Conclusions and Clinical Relevance—Radical first
excision of presumed VAS is essential for extended
TFR. Current recommendations for vaccination of the
distal portions of the extremities are appropriate,
because this practice permits radical excision of
tumors (amputation) that develop at vaccination sites;
however, surgery alone is seldom curative. ( J Am Vet
Med Assoc 2000;216:58–61)
Objective—To determine sensitivity and specificity of
physical examination, fine-needle aspiration, and needle
core biopsy of the regional lymph nodes for evidence
of metastasis in dogs and cats with solid
Animals—37 dogs and 7 cats.
Procedure—Regional lymph nodes were evaluated
by means of physical examination (palpation), fineneedle
aspiration, and needle core biopsy. Results
were compared with results of histologic examination
of the entire lymph node, the current standard.
Results—Tumors included 18 sarcomas, 16 carcinomas,
7 mast cell tumors, and 3 other tumors.
Carcinomas were more likely to have metastasized to
the regional lymph node (7/16 animals) than were sarcomas
(2/18). Sensitivity and specificity of physical
examination were 60 and 72%, respectively.
Sensitivity and specificity of cytologic examination of
fine-needle aspirates were 100 and 96%, respectively.
Sensitivity and specificity of histologic examination
of needle core biopsy specimens were 64 and 96%,
Conclusions and Clinical Relevance—Results suggested
that fine-needle aspiration may be a sensitive
and specific method of evaluating the regional lymph
nodes in dogs and cats with solid tumors, because
results correlated well with results of histologic examination
of the entire lymph node. Physical examination
alone was not a reliable method and should not be
used to decide whether to aspirate or biopsy the
regional lymph nodes. (J Am Vet Med Assoc
Objective—To determine the biological behavior of
liposarcomas in dogs and identify clinical signs, the
effect of treatment on survival time, and potential
Animals—56 dogs with histologically confirmed liposarcoma.
Procedure—Information was obtained on signalment,
tumor size, location of the tumor, stage of disease,
remission duration, overall survival time, cause
of death, type of surgery (incisional biopsy, marginal
excision, or wide excision), and any additional treatments
Results—Surgery consisted of incisional biopsy in 6
dogs, marginal excision in 34, and wide excision in 16.
Twenty-five dogs had histologic evidence of tumor
cells at the surgical margins and 28 did not (status of
the margins was unknown in 3 dogs). Twelve of 43
dogs had local recurrence. Median survival time was
694 days, and the only factor significantly associated
with survival time was type of surgery performed.
Median survival times were 1,188, 649, and 183 days,
respectively, for dogs that underwent wide excision,
marginal excision, and incisional biopsy. Factors that
were not found to be significantly associated with
survival time included tumor size, status of the margins,
tumor location, and histologic subtype.
Conclusions and Clinical Relevance—Results suggest
that in dogs, liposarcomas are locally invasive
neoplasms that rarely metastasize and occur primarily
in appendicular or axial locations and that wide excision
is preferred to marginal excision when feasible.
(J Am Vet Med Assoc 2004;224:887–891)
Objective—To test the ability of a single injection of a
sustained-release formulation of moxidectin (moxidectin
SR) to protect dogs against heartworm infection
for 180 days after inoculation with infective thirdstage
larvae (L3) of Dirofilaria immitis.
Animals—32 adult mixed-breed dogs.
Procedure—Dogs were allocated to 4 groups on the
basis of weight and sex. Dogs were injected SC with
saline (0.9% NaCl) solution or moxidectin SR at the
rate of 0.06, 0.17, or 0.5 mg/kg of body weight (day 0).
Each dog was inoculated SC with 50 D immitis L3 180
days later. On days 330 and 331, dogs were euthanatized.
The heart, lungs, and thoracic cavity were examined,
and number and sex of heartworms were determined.
Results—A mean of 35.9 heartworms was recovered
from untreated control dogs. Fourteen worms were
recovered from 1 of 8 dogs given moxidectin SR at the
lowest dosage, and none of the dogs in the 2 highest
moxidectin treatment groups were infected. Small
barely palpable granulomas were detected at injection
sites of moxidectin-treated dogs. Frequency and size of
granulomas were positively correlated with dose of
Conclusions and Clinical Relevance—A single dose
of moxidectin SR at a dosage as low as 0.17 mg/kg
can safely and reliably confer complete protection
against infection after challenge-exposure with
D immitis L3, and protection lasts for at least 180
days. This mode of prophylactic treatment against
infection with heartworms effectively eliminates failure
of prophylaxis that results from erratic administration
of medications designed for monthly administration.
(Am J Vet Res 2001;62:1721–1726)
Objective—To determine whether particular vaccine
brands, other injectable medications, customary vaccination
practices, or various host factors were associated
with the formation of vaccine-associated sarcomas
Animals—Cats in the United States and Canada with
soft tissue sarcomas or basal cell tumors.
Procedure—Veterinarians submitting biopsy specimens
from cats with a confirmed diagnosis of soft tissue
sarcoma or basal cell tumor were contacted for
patient medical history. Time window statistical analyses
were used in conjunction with various assumptions
about case definitions.
Results—No single vaccine brand or manufacturer
within antigen class was found to be associated with
sarcoma formation. Factors related to vaccine administration
were also not associated with sarcoma
development, with the possible exception of vaccine
temperature prior to injection. Two injectable medications
(long-acting penicillin and methyl prednisolone
acetate) were administered to case cats more frequently
than to control cats.
Conclusions and Clinical Relevance—Findings do
not support the hypotheses that specific brands or
types of vaccine within antigen class, vaccine
practices such as reuse of syringes, concomitant
viral infection, history of trauma, or residence
either increase or decrease the risk of vaccineassociated
sarcoma formation in cats. There was
evidence to suggest that certain long-acting
injectable medications may also be associated
with sarcoma formation. (J Am Vet Med Assoc 2003;223:1283–1292)