Dogs and goats as sentinels for environmental lead burden in Caribbean basin islands: Jamaica West Indies

Ingested/inhaled environmental lead (Pb) continues to pose a health risk to humans (children in particular) and animals. Automobile emissions from leaded gasoline combustion (less of a problem today with the phasing out of leaded gasoline), lead contaminated foods, soil and water, lead-based paints, ceramics, batteries (more frequently encountered today), and possible electronic waste, remain major sources of environmental lead. In a study carried out in Jamaica, West Indies, blood samples from dogs (n=63 at 5 locations) and goats (n=46 at 4 locations) were collected in lead-free (EDTA) tubes and analyzed by graphite furnace atomic absorption spectrometry (GFAAS) for lead. The analytical method detection limit was 0.24 μg/dl. Overall (blood lead) PbB concentrations were 2.83 ñ 2.96 μg/dl (dogs), and 1.02 ñ 0:10 μg/dl (goats). There were significant differences among locations, and. in a location of high automobile and plant foliage/grass forage density, PbB levels were 7.03 ñ 2.96 μg/dl (n=8) and 1.91 ñ 0.83 μg/d1 (n=10) in dogs and goats respectively. Although sample sizes are small the results suggest the use of dogs and goats as sentinels for evaluating environmental lead in developing countries.

Abdominal fat necrosis in a pygmy goat associated with fescue toxicosis.

Abdominal fat necrosis was diagnosed in an 11-year-old female pygmy goat with a 10-day history of lethargy, anorexia, and progressive abdominal distension. Gross necropsy findings revealed multiple firm, dark yellow, nodular masses of fat throughout the abdominal cavity, which compressed several abdominal organs including the rumen, small intestine, spiral colon, and gall bladder. Histologically, multiple to coalescing adipocyte necrosis, saponification, and infiltration with variable numbers of macrophages, lymphocytes, and plasma cells was observed. Fat necrosis in this case was attributed to tall fescue toxicity based on the presence of high levels of endophyte (Neotyphodium coenophialum)-infected fescue identified in the goat's pasture. This is the first known report of abdominal fat necrosis in a goat and demonstrates the fat necrosis syndrome of fescue toxicosis in ruminants.

Spectrophotometric analysis of solubilized rat hair proteins following intraperitoneal injection of 2,5-hexanedione.

The neurotoxic industrial solvents n-hexane and methyl n-butyl ketone are toxic by virtue of their common metabolite, 2,5-hexanedione (2,5-HD). Our previous work showed that pyrrole-like substances in solubilized rat hair proteins from rats injected (ip) daily with 2,5-HD demonstrated maximal absorbance in the 530-nm spectral region following reaction with Ehrlich's reagent (p-dimethylaminobenzaldehyde). Modification of the current analytical methods of achieving high specificity and lower detection limits with small sample quantities could have important implications for monitoring human populations. Adult male Sprague-Dawley rats were housed in individual metabolic cages with food and water provided ad libitum. Individual rats were injected (ip) daily with either 50 mg/kg 2,5-HD or physiologic-buffered saline (PBS). Plucked hair samples (dorsal, right flank, and left flank) were obtained from each rat before and at 7-day intervals after exposure to 2,5-HD or PBS for 28 days. Hair proteins solubilization and extraction procedures were adapted from earlier studies. We read 1 mL of dialyzed hair protein solution (2,5-HD or PBS control) against a reference cuvette containing water. Analyses utilized a Shimadzu UV 160 V recording spectrophotometer at an absorbency spectral range of 450 to 600 nm. In all spectral tracings, absorbance maxima (at 530 nm) characteristic of pyrrole-like substances were detected only in samples from 2,5-HD-treated rats. Absorbance at 530 nm was detected starting at Day 7 after exposure. The authors acknowledge Dr. Richard Whorton and Dr. Barbara Buckley for advice and for the use of their spectrophotometric equipment and Dr. Lowell A. Goldsmith for his help in our choice of the subject studied. This work was supported by the Walter P. Inman Memorial Fund in an award from Duke University to Dr. Leon Lack.