Objective—To validate a novel high-sensitivity
radioimmunoassay (RIA) procedure developed to
accurately measure the relatively low serum total thyroxine
(T4) concentrations of birds and reptiles and to
establish initial reference ranges for T4 concentration
in selected species of psittacine birds and snakes.
Animals—56 healthy nonmolting adult psittacine
birds representing 6 species and 42 captive snakes
representing 4 species.
Procedure—A solid-phase RIA designed to measure
free T4 concentrations in dialysates of human serum
samples was used without dialysis to evaluate total T4
concentration in treated samples obtained from birds
and reptiles. Serum T4 binding components were
removed to allow assay of undialyzed samples. Assay
validation was assessed by determining recovery of
expected amounts of T4 in treated samples that were
serially diluted or to which T4 was added. Intra- and
interassay coefficient of variation (CV) was determined.
Results—Mean recovery of T4 added at 4 concentrations
ranged from 84.9 to 115.0% and 95.8 to 119.4%
in snakes and birds, respectively. Intra- and interassay
CV was 3.8 and 11.3%, respectively. Serum total T4
concentrations for 5 species of birds ranged from
2.02 to 7.68 nmol/L but ranged from 3.17 to 142
nmol/L for blue-fronted Amazon parrots; concentrations
ranged from 0.21 to 6.06 nmol/L for the 4
species of snakes.
Conclusions and Clinical Relevance—This new RIA
method provides a commercially available, accurate,
and sensitive method for measurement of the relatively
low serum T4 concentrations of birds and
snakes. Initial ranges for the species evaluated were
established. (Am J Vet Res 2001;62:1750–1767)
Animals—71 dogs with subcutaneous or intramuscular HSA.
Procedures—Medical records of affected dogs were reviewed. The following factors were evaluated for an association with outcome: dog age and sex, clinical signs, anemia, thrombocytopenia, neutrophilia, tumor stage at diagnosis, achievement of complete excision, intramuscular involvement, presence of gross disease, tumor recurrence, and treatment.
Results—Of the 71 cases identified, 16 (29%) had intramuscular tumor involvement. For all dogs, median time to tumor progression and overall survival time (OST) were 116 and 172 days, respectively; 25% survived to 1 year. Univariate analysis identified presence of clinical signs or metastasis at diagnosis, dog age, tumor size, use of any surgery, and presence of gross disease as predictors of time to tumor progression and OST. There was no significant difference in survival time between dogs with respect to type of HSA. Multivariate analysis confirmed that adequate local tumor control, tumor diameter ≤ 4 cm, presence of metastasis at diagnosis, and presence of gross disease were significantly associated with OST.
Conclusions and Clinical Relevance—Subcutaneous and intramuscular HSA remains a heterogeneous group of tumors that generally carries a poor prognosis. Adequate local control of smaller tumors with no associated clinical signs or metastasis may provide the best chance of long-term survival.
Objective—To characterize demographics and clinical signs and evaluate outcomes of treatments in cats with transitional cell carcinoma (TCC) of the urinary bladder.
Design—Retrospective case series.
Animals—20 cats with TCC.
Procedures—Medical records of 20 cats with a bladder mass identified as a TCC that were examined at 2 veterinary institutions between 1990 and 2004 were evaluated. Signalment, treatments, and outcome were assessed.
Results—Breeds included domestic short hair (n = 14), long hair (2), and medium hair (2) cats, Siamese (1), and Abyssinian (1). All cats had been neutered at an early age (< 1 year old; 13 neutered males and 7 spayed females). The median age at diagnosis of TCC was 15.2 years. The trigone region was affected in 9 cats. Treatments included piroxicam administration, chemotherapy, or surgery as single interventions or in combination; 6 cats were not treated. At the time of diagnosis, 3 cats had pulmonary metastasis and 1 cat had metastasis to local lymph nodes. Median survival time for all 20 cats was 261 days. Nearly all deaths were attributable to progressive disease in the urinary tract. Five cats were lost to follow-up.
Conclusions and Clinical Relevance—In cats, TCC of the urinary bladder appears to be a rare and aggressive disease that is more prevalent in male cats and frequently develops at sites distant from the trigone (unlike TCC in dogs). Nevertheless, initial clinical signs of TCC in cats in this study were similar to those reported for affected dogs.
Objective—To describe morbidity, function, outcome, and owner satisfaction associated with limb amputation in domestic rabbits.
Design—Retrospective case series.
Animals—34 client-owned domestic rabbits.
Procedures—Medical records of domestic rabbits undergoing limb amputation for any cause between 2000 and 2009 were reviewed. The Kaplan-Meier method was used to estimate survival rate and median survival time, and variables were analyzed for relationship to risk of morbidity resulting in euthanasia and to outcome (survival vs nonsurvival [death or euthanasia]). Owners were interviewed to determine satisfaction with outcome of the procedure.
Results—28 rabbits underwent pelvic limb amputation, and 6 underwent thoracic limb amputation. At the last follow-up, 18 rabbits were dead, 9 were alive, and 7 were lost to follow-up. Median overall survival time was 720 days (range, 4 to 3,250 days). Acute and delayed or chronic complications were observed in 22 of 34 and 19 of 32 rabbits, respectively, most commonly difficulty ambulating, hygiene issues, and pododermatitis (cutaneous ulcers at the hock). Six rabbits were euthanized because of complications at a median of 104 days (range, 4 to 399 days) after surgery. Risk of morbidity resulting in euthanasia increased with heavier body weight and concurrent disease affecting ambulation at the time of amputation. Weight, age, and pododermatitis at the time of amputation were significantly negatively associated with survival time. Thirty-one (91%) owners were satisfied with the outcome.
Conclusions and Clinical Relevance—Although limb amputation was tolerated by most rabbits and most owners were satisfied, complications resulted in death in 6 of 34 (18%) rabbits, and 19 of 32 (59%) developed chronic complications. Amputation in heavy rabbits or those with concurrent pododermatitis, musculoskeletal disease, or neurologic disease should be considered carefully. Because of the small sample size and retrospective nature of this study, results should be interpreted as exploratory and hypothesis generating.
Case Description—A 1-year-old sexually intact female Netherland dwarf rabbit was examined because of a 3-week history of signs of lethargy, decreased appetite, left unilateral exophthalmia, a previous draining sinus from a left maxillary facial abscess, and bilateral nasal discharge.
Clinical Findings—The rabbit weighed 1.0 kg (2.2 lb) and had a body condition score of 1.5/5. Physical examination revealed generalized muscle atrophy, bilateral mucopurulent nasal discharge, and severe left-sided exophthalmia. Diagnostic investigation revealed anemia, neutrophilia, severe dental disease, a superficial corneal ulcer of the left eye, and a retrobulbar abscess.
Treatment and Outcome—Stomatoscopy-aided dental trimming, tooth removal, and abscess debridement were performed. Antimicrobials were flushed into the tooth abscess cavity, and antimicrobial treatment was initiated on the basis of cytologic findings and results of bacterial culture and susceptibility testing.Two months after the initial surgery, minimal exophthalmia was evident and no further physical, radiographic, or ultrasonographic changes were evident.
Clinical Relevance—Stomatoscopy is a valuable technique that can facilitate diagnosis, treatment, and serial reevaluation of rabbits with dental disease.