Chronic lead poisoning in horses.
Abstract: Lead acetate was fed to 4 groups of 2 horses each to study chronic lead intoxication. A 5th group of 3 horses was maintained as controls. The leas was fed in capsules, with the minimum dosage of 6.25 mg/kg/day of lead as lead acetate (group I). The dose was increased from group I through group IV in an approximate geometric series, with each group being given about 125% of the dose given the previous group. These doses were given for 105 days, a period designated as phase 1. Since clinical signs were not observed after 105 days, the doses were increased and fed for an additional 190 days (days 106 to 295). This period was designated phase 2. The smallest daily dose in phase 2 was set at about 125% of the largest daily dose in phase 1. The doses in each group was increased by about 125% of that of the previous group, as was done in phase 1. Seven horses died or were euthanatized after 18 to 190 days of phase 2 (123 to 295 days after the 1st dose). One horse in group I did not develop any clinical signs of intoxication. Dose-related responses were unnoticed with doses larger than 15.3 mg/kg/day. All horses given lead had increased blood lead and serum iron concentrations. During phase 2, the hematocrit (erythrocyte volume) and hemoglobin contents were depressed. The lead concentration in kidney, liver, spleen, pancreas, brain, bone, and heart was increased in the treated horses. The dose level required to produce lead intoxication was greater than that reported for cattle and that estimated in epizootiologic studies of horses.
Publication Date: 1978-06-01 PubMed ID: 666092
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research study was conducted to explore chronic lead poisoning in horses. Involving multiple control groups, it involved feeding varying dosages of lead acetate to the horses and recording the effects over an extended period. The study revealed that the dosage levels required for lead intoxication in horses were found to be higher than those reported for cattle and horses in previous studies.
Experiment Setup
- The experiment was set up with four groups of two horses each and a fifth group of three horses as a control group. The point of diversity among these groups was the amount of lead fed. It was administered in capsules as lead acetate.
- The minimum dosage started at 6.25 mg/kg/day (group I) with a consistent increase by 125% in successive groups, forming a geometric series of dosage levels from group I through group IV.
Testing Phases
- The experiment had two phases. Phase 1 lasted 105 days with the initially planned dosage levels. The observation indicated a lack of visible clinical signs at the end of this phase.
- For Phase 2, the dosage levels were increased and maintained for an additional 190 days. The smallest daily dose in this phase was 125% of the largest daily dosage from Phase 1.
- Similar to Phase 1, in Phase 2, each group’s doses were also increased about 125% from the dose of the previous group.
Results
- During Phase 2, seven horses either died or were euthanized. The timescales ranged between 18 to 190 days into the phase, or 123 to 295 days after the initial dosage.
- One horse from group I did not show any noticeable symptoms of chronic lead poisoning.
- The researchers found no dose-related responses with dosages larger than 15.3 mg/kg/day.
- All horses survived the first phase showing increased blood lead and serum iron concentrations. However, during phase 2, both the erythrocyte volume (hematocrit) and hemoglobin contents were lower than expected.
- Lead concentration significantly increased in the horses’ organs including the kidney, liver, spleen, pancreas, brain, bone, and heart.
- The amount of lead that led to intoxication was greater than what earlier studies had estimated for horses and reported for cattle.
Cite This Article
APA
Dollahite JW, Younger RL, Crookshank HR, Jones LP, Petersen HD.
(1978).
Chronic lead poisoning in horses.
Am J Vet Res, 39(6), 961-964.
Publication
Researcher Affiliations
MeSH Terms
- Animals
- Chronic Disease
- Female
- Hemoglobins / analysis
- Horse Diseases / blood
- Horse Diseases / chemically induced
- Horse Diseases / pathology
- Horses
- Iron / blood
- Lead / blood
- Lead Poisoning / blood
- Lead Poisoning / pathology
- Lead Poisoning / veterinary
- Male
Citations
This article has been cited 1 times.- North MA, Lane EP, Marnewick K, Caldwell P, Carlisle G, Hoffman LC. Suspected lead poisoning in two captive cheetahs (Acinonyx jubatus jubatus) in South Africa, in 2008 and 2013. J S Afr Vet Assoc 2015 Aug 13;86(1):E1-5.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
