On frogs, toxins and true friendship: an atypical case report

Abstract The authors report a series of events including the scientific interest for poisonous dendrobates of French Guiana, the human confrontation with the immensity of the evergreen rainforest, the fragility of the best-prepared individuals to a rough life, and the unique and very special manifestation of a solid friendship between two experts and enthusiasts of outdoor life. In the evergreen forest of South America, as in many other scientific field expeditions, everything may suddenly go wrong, and nothing can prepare researchers to accidents that may occur in a succession of uncontrollable errors once the first mistake is done. This is what happened during an expedition in search for dendrobates by an experienced forest guide and naturalist. The authors decided to report the story, considering that it deserved to be brought to the attention of those interested in venomous animals and toxins, in order to illustrate the potential danger of dealing with these organisms.

Toad poisoning in three dogs: case reports

Toad poisoning is frequent in dogs, but has been infrequently addressed in published case reports and review articles. Dogs can be poisoned when they bite a toad or otherwise ingest the venom. The venom effects manifest soon after the accident, since the toxin is rapidly absorbed by the mucous membrane of the digestive system. Hospital records of three dogs, diagnosed with toad poisoning, were retrospectively reviewed from January 2005 to July 2007. Poisoned dogs may present only local irritation or systemic signs in the gastrointestinal, cardiac and neurological systems. All three cases presented herein had clinical signs of gastrointestinal alterations including vomiting, sialorrhea and diarrhea. Two dogs developed abnormal cardiac rhythm and two exhibited neurological signs. A poisoned animal requires emergency care and symptomatic therapy with intense monitoring of its clinical parameters. Although there have been reports on the low mortality of dogs poisoned by toads, one animal died even after appropriate therapy. The severity of clinical signs and the risk of death must be considered by the veterinarian.

Intoxicação por veneno de sapo em um canino / Toad venom intoxication in a dog

O sapo do gênero Bufo possui nas suas glândulas paratóides uma secreção mucóide contendo toxinas como bufaginas e Bufotoxinas, que são esteróides cardiogênicos. Os cães podem atacar os sapos, entrando em contato com o veneno por meio das mucosas. Um canino, da raça Bulldog Francês, foi encaminhado ao Setor de Patologia Veterinária da Universidade Federal do Rio Grande do Sul (UFRGS) para a necropsia com histórico de provável intoxicação por veneno de sapo. Na necropsia o canino apresentava pulmões aumentados de volume, avermelhados e com edema, e rins de coloração vermelho-escura. As alterações microscópicas indicaram congestão, hemorragia e edema pulmonar. Nos rins, no baço e nos linfonodos foi observada congestão. As análises toxicológicas para os venenos de rotina foram negativas. Porém, a investigação do veneno de sapo a partir de cromatografia por camada delgada e gasosa demonstrou resultado positivo, revelando ser esta a causa da morte do canino.

The toads of the genus Bufo produce, in their parotoid glands, a mucoid secretion containing toxins such as bufagins and Bufotoxins, which are cardiogenic steroids. The mucous membranes of dogs can absorb this venom when they attack the toads. A French bulldog with a history of probable toad venom intoxication was referred to Veterinary Pathology Section of Federal University of Rio Grande do Sul (UFRGS) for necropsy. The necropsy revealed enlarged, reddish, edematous lungs, and kidneys displaying a dark red color. The microscopic alterations indicated the presence of congestion, hemorrhage, and pulmonary edema. Congestion was observed in the kidneys, spleen and lymph nodes. The routine toxicological analyses for venom detection were negative. Nevertheless, the toad venom test result was positive as assessed by thin layer and gas chromatography, indicating that toad venom intoxication was the cause of death.

Ranas venenosas de Colombia / Poisonous frogs of Colombia

Colombia es uno de los países del mundo más rico en biodiversidad. Ocupa el primer lugar en Amphibia, tanto en número de especies como en toxicidad. La familia Dendrobatidae está representada por los géneros Phyllobates, Dendrobates, Epipedobates y Minyobates, todas ellas venenosas. La mayoría de las especies están distribuidas en el occidente colombiano y a lo largo del Pacífico.Palabras claves: Dendrobatidae, batrachotoxinas, histrionicotoxina, pumiliotoxina, epibatidina, lehmizidina.

The venomous "Sapito minero" (dendrobates leucomelas steindachner 1864) (Dendrobatidae): its medical importance and the phenotypic variations in specimens from two regions of The Amazonas State, Venezuela

El sapito minero (Dendrobates leucomelas) ha sido descrito en el Amazonas venezolano. Una variación fenotípica, la cual ilustramos en color, fue encontrada en la serranía del Cuao, municipalidad de Atures del estado Amazonas y presenta marcadas diferencias en coloración con los especímenes del norte del mismo estado. En estudios muy preliminares de la toxina de estos animales venezolanos hemos empezado a demostrar sus actividades tóxicas sobre ratones inoculados, caracterizados por dificultades locomotoras, parálisis parcial del tren posterior, salivación, convulsiones y muerte en menos de 20 min.