Pattern of Dying During Cold Water Drowning in Dogs

Veterinary Forensic Pathology

“…17,30,40 Bradycardia 2,54,81 occurs immediately following submersion 8,26 or after brief tachycardia. 17,27 Blood pressure immediately increases and then progressively decreases. 27,53…”

“…17,30,40 Bradycardia 2,54,81 occurs immediately following submersion 8,26 or after brief tachycardia. 17,27 Blood pressure immediately increases and then progressively decreases. 27,53 Submerged, nonanesthetized dogs struggle violently for 1.5 minutes, 44,52 and because the glottis is closed, thoracic inspiratory movements are attempted and liquid is swallowed, but 2,64,81 gas exchange does not occur.…”

“…17,27 Blood pressure immediately increases and then progressively decreases. 27,53 Submerged, nonanesthetized dogs struggle violently for 1.5 minutes, 44,52 and because the glottis is closed, thoracic inspiratory movements are attempted and liquid is swallowed, but 2,64,81 gas exchange does not occur. If unconsciousness occurs due to hypoxemia, the larynx relaxes and water is aspirated, 47 or, if the animal remains conscious, apnea ceases and water is aspirated and swallowed due to deep inspiratory gasping.…”

“…81 Cardiac asystole or observed death occurs usually within 5 minutes, but occasionally up to 10 minutes following submersion. 8,27,44,52,56,72,85 The initial hypoxemia in fresh and salt water drowning is intensified by pulmonary edema, and is exacerbated by exponential catecholamine release, subsequent vasoconstriction, cardiac arrhythmias, 17 pulmonary hypertension, and right to left intrapulmonary shunting. 17,33,46 Electrolyte and intravascular changes during drowning depend on the salinity and/or volume of water aspirated.…”

“…18,50,59 Accidents while in water including electrical shock, entrapment, entanglement, and neurologic dysfunction such as ataxia and epilepsy are reported in animals that have drowned, or have been resuscitated following rescue from water. 1,30 Experiments in which dogs or other animals were drowned to determine physiological and biochemical responses to various volumes, temperatures and salinity of water or other liquids 2,3,8,11,17,26,27,53,55,57,72,73,82,83 provide information into the drowning process. Because most of these experiments were done between 20 and 200 years ago, the lack of consideration for the welfare of animals used in these experiments is often disturbing.…”