Who saw that coming? Trippy paper.

"Hunting and Hallucinogens: The use psychoactive and other Plants to improve the Hunting ability of dogs", Bennett & Alarcón 2015 https://www.dropbox.com/s/32ulhvew5hxsqnb/2015-bennett.pdf / http://sci-hub.bz/46d8910b378abb6c358904850bd44374/bennett2015.pdf / https://mega.co.nz/#!zl1wmAgJ!sGzDUPS5ZPXHBA9jLamReqbp7Bj6pbRwWgBFBeylrNU ; excerpts:

"*Ethnopharmacological relevance*: Cultures throughout the world give plants to their dogs in order to improve hunting success. These practices are best developed in lowland Ecuador and Peru. There is no experimental evidence for the efficacy of these practices nor critical reviews that consider possible pharmacological effects on dogs based on the chemistry of the ethnoveterinary plants.
Aim: This review has three specific aims: 1. Determine what plants the Ecuadorian Shuar and Quichua give to dogs to improve their hunting abilities, 2. Determine what plants other cultures give to dogs for the same purpose, and 3. Assess the possible pharmacological basis for the use of these plants, particularly the psychoactive ones?
Methods: We gathered Shuar (Province of Morona-Santaigo) and Quichua (Napo and Orellano Provinces) data from our previous publications and field notes. All specimens were vouchered and deposited in QCNE with duplicates sent to NY and MO. Data presented from other cultures derived from published studies on ethnoveterinary medicine. Species names were updated, when necessary, and family assignments follow APG III (Angiosperm Phylogeny Group 2009). Chemical data were found using PubMed and SciFinder.
Results:
The Shuar and Quichua of Ecuador use at least 22 species for ethnoveterinary purposes, including all but one of their principal hallucinogens. Literature surveys identified 43 species used in other cultures to improve hunting ability. No published studies have examined the pharmacological active of these plant species in dogs. We, thus, combined phytochemical data with the ethnobotanical reports of each plant and then classified each species into a likely pharmacological category: depuratives/deodorant, olfactory sensitizer, ophthalmic, or psychoactive .
Conclusions: The use of psychoactive substances to improve a dog’s hunting ability seems counterintuitive, yet its prevalence suggests that it is both adaptive and that it has an underlying pharmacological explanation. We hypothesize that hallucinogenic plants alter perception in hunting dogs by diminishing extraneous signals and by enhancing sensory perception (most likely olfaction) that is directly involved in the detection and capture of game. If this is true, plant substances also might enhance the ability of dogs to detect explosives, drugs, human remains, or other targets for which they are valued.

In lowland areas of the Neotropics, the primary role of canines is to assist in hunting wild game. Hunting efficiency using dogs compares favorably to other forms of hunting (Koster 2009). The percentage of hunting trips that included dogs varies widely across cultures from a high of 83% (Mayangna and Miskito of Nicaragua) to 3% (Piro of Peru). Hunting success with dogs depends in large part on the targeted species. Although canines can be employed for any terrestrial species, they are particularly effective against pacas (Cuniculus paca, Fig. 2), agoutis (Dasyprocta spp.), and other animals that thrive in anthropogenic environments. The absence of dogs among some lowland cultures may be due to high mortality rates of dogs, rather than a canine aversion.

Within many cultures, hunting dogs receive particularly good care (Koster 2009). A Shuar woman, for example, may nurse a pup along with her own children (Bennett et al. 2002). In training dogs, both the Shuar and Quichua maintain the animals with a minimal diet supplemented with wild plants. While many plant species are employed to target canine illnesses, the majority are used to enhance the hunting ability of dogs. In a study that focused exclusively on ethnoveterinary practices, Jernigan (2009) identified 34 plants, that the Peruvian Aguaruna give to their dogs, most often to improve their hunting prowess. Plants are employed in baths to reduce their scent or to mask odors and thus decreasing their detectability by the targeted prey. Plants also function to clean buccal and nasal cavities to enhance olfaction (e.g., Lans et al. 2001, Sanz-Biset et al. 2009) or to enhance night vision (Wilbert 1987).

Koster (2009) notes the “occasional” use of hallucinogens, but the use psychoactive plants is actually frequent and widespread in many parts of the Old and, especially, the New World tropics (e.g., Bennett et al. 2002).

The Shuar and Quichua are the largest indigenous groups in lowland Ecuador. They mostly reside at elevations from 300 to 1,200 m in terra firme forests. This territory spans two of Holdridge's (1967) life zones, tropical moist forest and premontane tropical wet forest. Study sites were located in the Provinces of Morona-Santiago and Napo (Fig. 3). Both groups are horticulturists, growing manioc (Manihot esculenta) and plantains (Musa × paradisiaca L.) as their principle starches. Hunting (Fig. 4) and fishing supplement animal sources of protein from domesticated chickens and pigs.

The Shuar and Quichua employ at least 22 species for dogs (Table 1). The studies from which these data were drawn did not focus on ethnoveterinary medicines. It is therefore likely that more exist. In most case, the plants have corresponding human uses. However, some species or varieties are especially designated for canines. Four Shuar ethnoveterinary plants carry the name yawá, which means dog in the Shuar language: yawá kunkunari (Justicia pectoralis), yawá urints (Alternanthera paronychioides), yawá piripiri (Cyperus sp.) and yawá maikua (Brugmansia versicolor). With the exception of Brunfelsia grandiflora D. Don., all the principal Shuar hallucinogens are given to dogs.
Seven of the plants were utilized for purely medical reasons, mostly to treat botfly or other infections. The remaining plants are given to hunting dogs specifically to enhance their hunting prowess. Nine were used for the general purpose of improving hunting ability. A mixture of manioc and akapmas (Fittonia albivenis) was said to improve the ability to track game. Kunápik (Tabernaemontana sananho) and yawá piripiri (Cyperus sp.) appear to initiate hunting predilections in dogs. Quichua give payanshi (Abuta grandifolia) to their hunting dogs to keep them quiet and both the Quichua and the Shuar give the potent stimulant wais (Ilex guayusa, Fig. 5) to their hunting dogs so that “they will not be lazy.”

The use of plants to improve the hunting ability is best documented in Ecuador and Peru but examples can be found in other South American countries as well as the Caribbean, Indochina, Papua New Guinea, and the Solomon Islands (Table 2). Examples from the literature revealed 71 citations of 65 species that are used in 54 combinations. Of these, the majority (43) are said to improve hunting ability (e.g., Dendrobium pulchellum). Five enhance hunting success for specific game (e.g., Xanthosoma brasiliense for wild hogs). Four are believed to make hunting dogs more alert (e.g., Petiveria alliacea) and four are said to specifically enhance olfaction. The Secoya of Ecuador apply latex from Tabernaemontana sananho fruits to a dog’s nose so that “it can smell far.” A mixture of ginger (Zingiber officinale) and tobacco (Nicotiana tabacum, Fig. 6) is thought to enhance night vision in both hunters and their dogs. Ten plants are employed in baths for hunting dogs. A mixture that includes Tabernaemontana sananho and Brugmansia sp. is given to dogs so that they “can communicate with their masters.”
The combined data from the Shuar and Quichua data (Table 1) and the literature (Table 2) omitting those species that are not related directly to hunting or those species that have not been determined to at least the genus, reveals 71 species in 34 families that are given to dogs to improve their hunting ability (Table 3). There is some chemical data for most of the species or from close relatives. By combining the phytochemical data with the ethnobotanical reports of plants use, we classified each species into a likely pharmacological category. Twenty six are depuratives/deodorants (e.g., Siparuna guianensis), and many of these also have antimicrobial or anti-inflammatory activity. Ten species are classified as olfactory sensitizers Araceae (e.g., Caladium schomburgkii ). The largest category was psychoactives, with 25 species. Nineteen of these species are hallucinogens (e.g., Banisteriopsis caapi, Fig. 7) and most of the remaining are stimulants (e.g., Ilex guayusa). Two are opthalmic (discussed previously). The remaining are either unknown or difficult to classify.

3.3.1 Depuratives/Deodorants
More than half of the depuratives/deodorants have noticeably strong odors (Table 4). Dendropanax arboreus has a distinctive odor due to the presence of polyactetylenes. The specific epithets of Mansoa alliacea and Petiveria alliacea, together with some of their common names, refer to the plants’ garlic-like odor. Siparuna and Piper spp. possess abundant volatile terpenoids compounds that contribute to their strong and distinctive aromas. Cucurbitacins found in Momordica charantia produce its characteristic and pungent smell. Sesquiterpenes and monoterpenes in Renealmia alpinia and Zingiber officinale contribute to the distinctive ginger aroma of these plants.

3.3.3 Psychoactives
The psychoactive plants given to dogs are dominated by hallucinogens (Table 6). While most of these are well-known as hallucinogenic plants and are commonly used in shamanistic rituals (e.g., Anadenanthera peregrina, Banisteriopsis caapi) the activity of others is yet to be determined (e.g., Fittonia albivenis, Dendrobium pulchellum). The stimulants Ilex guayusa (caffeine & other methylxanthine alkaloids) and Nicotiana tabacum also are given to hunting dogs. Quichua heat tabacco leaves, then administer them through the noses of their dogs to keep them active and resilient during the hunting trips.

Dogs respond to commonly-used hallucinogens in a similar manner to humans. Vaupel et al. (1978a) showed that beta-phenethylamine and d-amphetamine increased respiration, dilated pupils and produced restlessness in chronically spinalized dogs. Frith et al. 1987 recorded circling, dilated pupils, hyperactivity, rapid breathing, and salivation in dogs given methylenedioxymethamphetamine. These effects potentially could enhance a dog’s hunting ability.

Only two species were cited as nocturnal ophthalmics – agents that improve vision. Wilbert (1987) reported that a mixture of tobacco and ginger is applied to the eyes of both hunters and their dogs to improve night vision. Few studies have examined the effects of plant extracts on night vision. Tetrahydrocannabinol from Cannabis sativa L. has been shown to enhance night visions in some studies (e.g., Russo et al. 2004). The effects of tobacco are less clear. While some studies have shown that tobacco smoke decreases night vision, others have31 shown that nicotine enhances night vision, presumably due to the stimulating effects of nicotine (Anonymous 2011). There are no studies on the effects of ginger on night vision. Though the atropine containing genus Brugmansia was one of the more frequently cited psychoactive plants given to hunting dogs, the reason for its use was never explicitly said to be related to improvement of vision. Atropine is well-known as a mydriatic and homatropine has been shown to improve nocturnal myopia (Koomen et al. 1951).

Both the Shuar and Quichua give Ilex guayusa, which contains methylxanthines, to their hunting dogs. The methylxanthine alkaloid theobromine is toxic to dogs (Strachan and Bennet, 1994). Small doses of the related alkaloid caffeine generate benign arrhythmias in dogs; higher doses cause severe arrhythmias (Mehta et al. 1997). There is clearly a dose-dependent response in canines. Small doses may induce alertness in habituated animals. Quichua deliver small nasal doses to their dogs.

Nonetheless, the practice of administering psychoactive plants to canines is well-established. Could such a practice persist if it impaired hunting success? This is unlikely as hunting is a crucial complement to subsistence practices in the lowland tropics. Vollenweider (1994) hypothesized a disruptive effect of activity of psychedelic substances on sensory gating–the filtering of redundant or superfluous stimuli. Riba et al. (2002), in contrast, suggest ayahuasca has a P50 suppressing effect on sensory gating in humans. We hypothesize that hallucinogenic plants alter perception in hunting dogs by diminishing ancillary signals and enhancing others that aid in the detection and capture of game (Fig. 8). If this is true, the implications are significant. Perhaps plant substance could enhance the ability of dogs to detect explosives, drugs, human remains, or enhance the scores of other abilities for which dogs are valued."