Safety Evaluation of Parastar® Plus in Dogs and Assessment of Transferable Residue of Fipronil and Cyphenothrin from Dogs to Humans

Abstract

Dogs are easily infested with fleas, ticks, and other ectoparasites serving as vectors for transmitting bacterial, viral, and parasitic diseases. Therefore, the use of ectoparasiticides is inevitable and important. The present investigation was undertaken with two specific objectives: one, to evaluate the safety of fipronil and cyphenothrin in dogs after topical application of Parastar® Plus, and two, to determine the transferable residue of these insecticides from dogs to humans. Six healthy, adult dogs (medium length hair, weighing between 20.5 and 27.3 kg) received topical application of Parastar® Plus (2.68 mL; fipronil, 9.8%, and cyphenothrin, 5.2%) on the back between the shoulder blades. At predetermined intervals, dogs were given a full physical exam, and residues of fipronil and cyphenothrin were determined in dog blood and cotton glove extracts using GC/MS. Fipronil and cyphenothrin peaks eluted at 7.453 and 9.913 min, correspondingly, and the compounds were confirmed based on characteristic ions. At no time was fipronil or cyphenothrin residue detected in blood samples. In glove extracts, residues of fipronil and cyphenothrin were maximally present at 24-h posttreatment (43.84 ± 5.69 and 59.26 ± 8.97 ppm, respectively). By 48 h, the residue levels sharply declined (16.89 ± 2.82 and 17.98 ± 2.07 ppm, respectively). The insecticides’ residues were detected in insignificant amounts after 1 week (5.69 ± 2.16 and 10.00 ± 1.51 ppm, respectively), and only in trace amounts after 2 weeks. At no time did any dog show side effects, except itching at the site of Parastar® Plus application. The findings suggest that Parastar® Plus was safe for dogs, and transferable residues of fipronil and cyphenothrin were minimal, posing very little or no health concern to pet owners or veterinary personnel. Of course, veterinary personnel, who handle many dogs daily, may require proper protection to avoid cumulative exposure.

Assessment of fipronil toxicity on wistar rats: A hepatotoxic perspective

“…In another study, authors have suggested the propensity of FPN and its metabolites in promoting adipogenesis [ 44 ]. Since FPN is found to be a lipophilic agent, its ability to accumulate in lipids cannot be overlooked [ [45] , [46] ] since its effect in similar approach on certain organisms like earthworms are also quite evident [ 47 ] which has been evidenced by increase in body weight gain of the exposed animal. The rats under high dose group showed maximum damage with findings like necrosis, degeneration of bile duct and hepatocytes, impaired sinusoids and damaged portal vein were clearly visible.…”

Parastar insecticide induced changes in reproductive parameters and testicular oxidative stress biomarkers in Wistar male rats

“…Parastar is an insecticide formulation composed of two active ingredients. Two different formulations have been reported: a mixture of fipronil and cyphenothrin, which is largely used in the United States for insect control (Case et al, 2016), and a formulation composed of a pyrethroid lambda-cyhalothrin and a neonicotinoid imidacloprid. The latter formulation is largely used in the agricultural area of Santa in the North West region of Cameroon for crop protection against insects (Nantia et al, 2017; Sonchieu et al, 2017).…”

Safety of Permethrin and Pyriproxyfen in Dogs Treated With VetGuard Plus®

“…After 15 minutes, the solvent was drawn off from the top with a disposable pipette and dispensed through a sodium sulfate filled filter into a 100 mL beaker. The solvent was allowed to evaporate overnight, and was reconstituted the next morning in methylene chloride: petroleum ether (1:1) before undergoing GC/MS analysis [7,8,13].…”

“…After the gloves were submerged for 30 minutes, the solvent was poured through a sodium sulfate filled filter into a 100 mL beaker and allowed to evaporate overnight. The next morning, the residue was reconstituted in methylene chloride: petroleum ether (1:1) before undergoing GC/MS analysis [7,8,13].…”

“…VetGuard Plus® should only be used in dogs that weigh at least 5 pounds (2.25 kg) and are 12 weeks of age or older. Once topically applied, the active ingredients are absorbed and distributed primarily throughout the sebaceous glands of the skin, which continuously release the active ingredient residues into the skin and hair coat [6][7][8].…”