RESUMEN
OBJECTIVES: The aim of this pilot study was to assess cardiac troponin I (cTnI) levels in pericardial effusion (PE) and plasma from dogs with PE. BACKGROUND: A reliable marker for detecting the etiology of PE in dogs remains undetermined. cTnI is becoming the gold standard marker for detecting myocardial damage in humans. ANIMALS, MATERIALS AND METHODS: Twenty-five dogs with PE (21 and 4 secondary to neoplasia and non-neoplasia causes, respectively) and 37 control dogs were studied. RESULTS: The median cTnI plasma level from 37 normal dogs versus 15 (out of 25) with PE was 0.03ng/mL and 0.19ng/mL, respectively (p<0.0001). The level of cTnI in PE versus plasma showed a significant correlation (p<0.01) with a Spearman r coefficient of 0.7603. No significant difference could be found upon comparison of dogs with only right atrial tumors (n=14) versus other types of neoplasia (n=7), nor between the group with right atrial tumors (n=14) versus all other cases including neoplasia as well as non-neoplasia (n=11). The median cTnI level in PE from dogs with neoplasia and non-neoplasia was not significantly different. CONCLUSIONS: cTnI did rise significantly in both PE and plasma in dogs with PE, but cTnI levels did not help differentiate between etiologies according to this study. One of the study groups is too small to allow final conclusions, and thus further investigation is warranted.
RESUMEN
The objective of this study was to ascertain the ability of a single subcutaneous injection of a sustained-release (SR) formulation of moxidectin to protect dogs against challenge inoculation with infective Dirofilaria immitis larvae 364 days after administration. Twenty four purpose-bred adult mixed-breed dogs were grouped into three blocks of eight based on weight and sex. Saline solution (0.9% NaCl) or a moxidectin SR formulation at volumes designed to deliver 0.17 or 0.27 mg moxidectin/kg b.w. was injected subcutaneously on day 0. Throughout the post-treatment period, injection sites of all dogs were periodically examined visually and by palpation. Palpable swellings were characterized as to size, consistency and the presence of associated pain or erythema. On day 364, each dog was inoculated subcutaneously with 50 D. immitis L3. On days 510 and 511, dogs were euthanatized, and their hearts, lungs and thoracic cavities were inspected for the presence of adult heartworms. number, sex and viability of recovered heartworms were determined. The mean number of heartworms recovered from dogs that had received the saline control injection was 35.7. No heartworms were recovered from any dog treated with either 0.17 or 0.27 mg moxidectin/kg b.w. For variable periods of time following treatment, small (1-4 mm diameter), firm, subcutaneous swellings could be palpated at the injection sites of dogs treated with 0.17 or 0.27 mg moxidectin/kg b.w. These swellings contracted progressively and eventually disappeared except for the case of one animal treated with 0.27 mg/kg, in which the swelling persisted for the entire study period. At no time during the study was pain or erythema noted at the injection site of any dog, and no dog exhibited any adverse systemic reaction related to treatment. We conclude that under conditions pertaining in this study, a single subcutaneous injection of a moxidectin SR formulation at dosing rates of either 0.17 or 0.27 mg/kg b.w. can safely protect adult dogs against experimental challenge inoculation with infective heartworm larvae for a period of 12 months.