The investigation of outbreaks of toxicologic disease

Diagnostic Challenges and Guidelines Pertaining to Suspected Ruminant Intoxications

This article addresses diagnostic challenges involving toxicology cases that are multifactorial in nature, often involving sublethal exposures to multiple toxicants and/or other etiologies that are not toxic. Gold standard diagnostic approaches were developed under the assumption that cases were undoubtedly intoxications, and they still are applicable to those cases. A more integrated diagnostic approach, focusing on the initial problem list, is consistent with how veterinarians diagnose most cases. Livestock ownership attitudes continue to evolve. Ongoing threats to the financial well-being of animal agriculture ultimately will have an impact on the ability of producers to maintain health and performance of livestock.

Diagnosis and approach to poisoning in the horse

Poisoning in the horse can present a highly complex case. The practitioner, owner, toxicologist, and pathologist play important roles, and all contribute information that may be important to the case. Once all the information is available, all the evidence is collected (historical, clinical, pathologic, and analytic), and proper sampling of specimens has occurred, a complete summary of the findings can be provided to the client. Based on identification of a potential toxic source and, ultimately, the diagnosis, specific treatment of affected animals and prevention of additional cases can be initiated. Consultation with a veterinary toxicologist aids in the follow-up of a poisoning case and can help to provide a thorough background to assist in preventing reoccurrence.

Diagnostic toxicology for the food animal practitioner

In most competent veterinary diagnostic laboratories, analytic findings are interpreted by a veterinary toxicologist to determine the significance of the finding in light of historical, clinical, and pathologic findings. A veterinary toxicologist also provides consultation about possible toxic rule-outs for a case, treatment of affected animals, and prevention of additional cases. Once all of the information is available, a complete summary of the findings can be provided to the client. When the procedures outlined herein are followed, including a systematic approach to collecting all the evidence (historical, clinical, pathologic, and analytic), using proper sampling techniques, and maintaining good communication among the clinician, client, and laboratory, the usefulness of the toxicology investigation is maximized.

Evaluation of postoperative peritoneal lavage in standing horses for prevention of experimentally induced abdominal adhesions

OBJECTIVE

To evaluate the postoperative use of peritoneal lavage for prevention of experimentally induced intraabdominal adhesions in horses.

STUDY DESIGN

Areas of serosal abrasion were created on the jejunum of 12 horses. Postoperatively, six horses had peritoneal lavage, and six horses did not (controls). The number of adhesions was determined at necropsy 2 weeks after surgery.

ANIMALS OR SAMPLE POPULATION

12 horses.

METHODS

Five sites of jejunal serosal abrasion were created in each horse. A 32 French thoracic catheter was placed into the right ventral aspect of the abdomen before closure of the abdominal incision. Treated horses had abdominal lavage with 10 L of lactated Ringer's solution on four occasions, then catheters were removed from all horses 34 hours after celiotomy. Horses were necropsied at 2 weeks to quantify the number of intraabdominal adhesions.

RESULTS

All control horses and one treated horse developed intraabdominal adhesions. The number of adhesions was significantly less (P < .0293) in treated horses. No adverse inflammatory reactions appeared to be associated with repeated peritoneal lavage using lactated Ringer's solution or use of an abdominal drain.

CONCLUSIONS

Peritoneal lavage reduced the frequency of intraabdominal adhesions.

CLINICAL RELEVANCE

When postoperative adhesions are likely to develop, postoperative peritoneal lavage may decrease the frequency of adhesion formation.

Diagnostic and forensic toxicology

In most competent veterinary diagnostic laboratories, analytical findings are interpreted by the veterinary toxicologist to determine the significance of the finding in view of historic, clinical, and pathologic findings. A veterinary toxicologist also will provide consultation about possible toxic rule-outs for a case, treatment of affected animals, and prevention of additional cases. Once all of the information is available, a complete summary of the findings can be provided to the client. When the procedures outlined are followed, including a systematic approach to collecting all the evidence (historic, clinical, pathologic, and analytic), proper sampling techniques, and good communication between the clinician and the client and laboratory, the usefulness of the toxicology investigation will be maximized.

Field investigations of small animal toxicoses

An in-depth investigation of a small animal poisoning case resembles a thorough version of the traditional farm call that is provided by large animal clinicians. Goals of such investigations are to diagnose cases, identify responsible toxicants and their sources, and to make recommendations regarding treatment and prevention of further occurrences. The detailed history, interviews, site visit, record keeping, and analysis of findings are discussed.