Objective—To evaluate whether use of recombinant human (rh) thyroid-stimulating hormone (TSH) induces equivalent stimulation, compared with bovine TSH (bTSH), and to evaluate activity of rhTSH in dogs of various large breeds.
Animals—18 healthy research Beagles and 20 healthy client-owned dogs of various breeds with body weight > 20 kg.
Procedures—The 18 Beagles were randomly assigned to 3 groups, and each dog received either 75 μg of rhTSH, IM or IV, or 1 unit of bTSH, IM, respectively, in a crossover design. The 20 client-owned dogs received 75 μg of rhTSH, IV. Blood samples were taken before and 6 hours after TSH administration for determination of total serum thyroxine (T4) concentration. Additional blood samples were taken after 2 and 4 hours in Beagles that received rhTSH, IM.
Results—There was a significant increase in T4 concentration in all dogs, but there were no differences between values obtained after administration of bTSH versus rhTSH or IV versus IM administration of rhTSH. Although there was a significant difference in age and body weight between Beagles and non-Beagles, there was no difference in post-TSH simulation T4 concentration between the 2 groups.
Conclusions and Clinical Relevance—Results indicated an equivalent biological activity of rhTSH, compared with bTSH. Use of 75 μg of rhTSH, IV, did not induce a different magnitude of stimulation in large-breed dogs, compared with Beagles. Euthyroidism was confirmed if post-TSH simulation T4 concentration was ≥ 2.5 μg/dL and at least 1.5 times basal T4 concentration.
Objective—To evaluate the use of recombinant human (rh) thyroid-stimulating hormone (TSH) in dogs with suspected hypothyroidism.
Animals—64 dogs with clinical signs of hypothyroidism.
Procedures—Dogs received rhTSH (75 μg/dog, IV) at a dose independent of their body weight. Blood samples were taken before and 6 hours after rhTSH administration for determination of total serum thyroxine (T4) concentration. Dogs were placed into 1 of 3 groups as follows: those with normal (ie, poststimulation values indicative of euthyroidism), unchanged (ie, poststimulation values indicative of hypothyroidism; no thyroid gland stimulation), or intermediate (ie, poststimulation values between unchanged and normal values) post-TSH T4 concentrations. Serum canine TSH (cTSH) concentration was determined in prestimulation serum (ie, before TSH administration).
Results—14, 35, and 15 dogs had unchanged, normal, and intermediate post-TSH T4 concentrations, respectively. Basal T4 and post-TSH T4 concentrations were significantly different among groups. On the basis of basal serum T4 and cTSH concentrations alone, 1 euthyroid (normal post-TSH T4, low basal T4, and high cTSH concentrations) and 1 hypothyroid dog (unchanged post-TSH T4 concentration and low to with-in reference range T4 and cTSH concentrations) would have been misinterpreted as hypothyroid and euthyroid, respectively. Nine of the 15 dogs with intermediate post-TSHT4 concentrations had received medication known to affect thyroid function prior to the test, and 2 of them had severe nonthyroidal disease.
Conclusions and Clinical Relevance—The TSH-stimulation test with rhTSH is a valuable diagnostic tool to assess thyroid function in selected dogs in which a diagnosis of hypothyroidism cannot be based on basal T4 and cTSH concentrations alone.
OBJECTIVE To determine survival estimates and outcome predictors for shelter cats with feline panleukopenia virus (FPV) infection.
DESIGN Retrospective cohort study.
ANIMALS 177 shelter cats with FPV infection.
PROCEDURES Medical records of cats treated for FPV infection from 2011 through 2013 were reviewed to collect information pertaining to signalment; history; results of physical examination, CBC, serum biochemical analysis, and blood gas analysis; and treatments (antimicrobials, antiparasitics, antivirals, antiemetics, analgesics, crystalloid or colloid solutions, and blood products). Survival time and outcome predictors were determined by means of Kaplan-Meier estimation, logistic regression, and mixed-model ANOVA.
RESULTS Median survival time after hospital admission was 3 days; 20.3% (36/177) of cats survived to discharge from the hospital. Risk of nonsurvival was greater in cats with (vs without) signs of lethargy, rectal temperature < 37.9°C (I00.2°F), or low body weight at hospital admission. Lower (vs higher) leukocyte count on days 3,4, and 7 of hospitalization, but not at admission, was associated with nonsurvival. Amoxicillin–clavulanic acid, antiparasitics, and maropitant but not interferon-ω were associated with survival, whereas glucose infusion was associated with nonsurvival.
CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that FPV infection carried a poor prognosis for shelter cats. Several variables measured at admission or during hospitalization were associated with outcome. Remarkably and contrary to the existing literature, leukopenia at admission had no association with outcome, possibly owing to early prevention of complications.