Intermediate Syndrome of Chlorpyriphos Toxicity (Polaris®) in a Caracal (Caracal caracal)

Abstract

A 5-yr-old spayed female caracal (Caracal caracal) was presented with complaints of acute onset of mental dullness, ataxia, and ventroflexion of 24-hr duration. The animal's garden territory was sprayed a day earlier with an organophosphate (OP) insecticide (chlorpyriphos-methyl). The caracal was treated for OP toxicosis and mildly improved. It was discharged a day later at the owner's request, although clinical signs did not resolve. During the following week, the caracal was confined to prevent further toxin exposure but did not improve and was presented 8 days later with similar clinical signs. Serum butyril-cholinesterase activity was markedly low. The relatively long interval from OP exposure, along with the duration of clinical signs, suggested an intermediate syndrome of OP toxicity. The caracal was treated symptomatically and progressively improved. It was discharged after 8 days of hospitalization and made full recovery 30 days later. This is the first report of OP toxicity in a caracal, suspected to progress to an intermediate syndrome of OP poisoning.

Clinical manifestations, laboratory findings, treatment and outcome of acute organophosphate or carbamate intoxication in 39 cats

“…1,7,9,15 There are only few limited published case series of OP or carbamate intoxication in cats. 8,14,15,25,26 This study of such intoxications in 39 cats is, to the best of our knowledge, the largest one yet.…”

“…Small animal intoxications occur via contact with environmental residues, direct in‐habitat contact, on‐animal usage and malicious poisoning 1,7,9,15 . There are only few limited published case series of OP or carbamate intoxication in cats 8,14,15,25,26 . This study of such intoxications in 39 cats is, to the best of our knowledge, the largest one yet.…”

“…Carbamate and OP intoxication may lead to several neurological syndromes, including acute cholinergic crisis (type‐1 syndrome), 1,4–6 intermediate syndrome (type‐2 syndrome) 11–14 and OP‐induced delayed polyneuropathy, myopathy and central nervous system (CNS) impairment 15–17 . Acute cholinergic crisis is the most common syndrome in animals, occurring mainly from oral, dermal or inhalation exposure 1 .…”

“…Commonly used OPs, from most to least toxic, include disulphoton, terbufos, phorate, parathion, chlorpyrifos, fenthion, diazinon, malathion and tetrachlorvinphos. 10 Carbamate and OP intoxication may lead to several neurological syndromes, including acute cholinergic crisis (type-1 syndrome), 1,[4][5][6] intermediate syndrome (type-2 syndrome) [11][12][13][14] and OP-induced delayed polyneuropathy, myopathy and central nervous system (CNS) impairment. [15][16][17] Acute cholinergic crisis is the most common syndrome in animals, occurring mainly from oral, dermal or inhalation exposure.…”

“…It typically occurs 24-96 hours after intoxication, and may last for several days to weeks. 1,[11][12][13][14] OP-induced delayed polyneuropathy is characterised by distal degeneration of long and large-diameter motor and sensory peripheral and spinal cord nerve axons. 1,[15][16][17] The diagnosis of OP and carbamate intoxication is based on a history of exposure to a toxic compound, characteristic clinical signs, response to spe-cific appropriate therapy, identifying the toxic compound in GI content, when available, and demonstrating decreased red blood cell (RBC) AChE or serum butyrylcholine esterase (BuChE) activity.…”