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Coprophagia is a condition described as the compulsive consumption of faeces. It is an uncommon manifestation associated with several underlying mental health conditions. We present the case of a 32-year old male, diagnosed to have schizophrenia and on treatment with clozapine, who developed coprophagia in response to command auditory hallucinations. His condition responded to a combination of pharmacological and psychological therapy.

Objectives To assess the impact of four rabbit diets (hay only, extruded diet with hay, muesli with hay and muesli only) on faecal pellet size, faecal output and caecotrophy. Materials and Methods Thirty-two Dutch rabbits were studied over 17 months. Faecal pellet size and weight were measured in weeks 3, 9, 21 and 43 and faecal output in weeks 10, 22 and 45. Number of uneaten caecotrophs was recorded weekly. Results Faecal pellets were consistently smaller and lighter in rabbits fed muesli only, and the size of pellets produced by those fed muesli with hay decreased over the course of the study. Faecal output was greatest in rabbits with the highest hay intake. Uneaten caecotrophs were found in greatest frequency in rabbits fed muesli. Clinical Significance Muesli diets have a negative effect on faecal output and caecotroph ingestion and may therefore predispose to digestive disorders. Higher hay intake is associated with greater faecal output and fewer uneaten caecotrophs and may assist in preventing the gastrointestinal stasis.

Guinea pigs are assumed to practice caecotrophy to a higher degree than rats. Studies from leporids suggest that through the practice of caecotrophy, hindgut fermenting species could build up microbial fatty acids (FA) in body tissues. We hypothesized that microbial FA would be detectable in the body tissue of guinea pigs and rats, and this to a higher degree in guinea pigs. Twenty-four rats and guinea pigs were fed with four different pelleted diets (lucerne-, meat-, meat-bone-, insect-based) in groups of six animals for 8 weeks. Perirenal adipose tissue differed in FA composition between the species in spite of the common diets. FA typically associated with microbial activity (saturated FA (SFA; typically 18:0), monounsaturated FA (MUFA; typically trans-fatty acids TFA), and odd- and branched-chain FA (Iso-FA)), were all detected. Guinea pigs had higher SFA levels than rats except on the lucerne diet. Concentrations of 18:0 were higher for guinea pigs on the meat and bone diet. Iso-FA concentrations in guinea pigs exceeded those of rats on all diets. FA profiles with a microbial fingerprint appear-although in low proportions-in the body tissue of both species, and this seemingly to a higher extent in guinea pigs. With respect to whether consumption of rodent meat rich in microbial FA has particular effects on human health as shown for ruminant products, microbial FA concentrations are probably too low to cause any distinct effects.

Aim and objectives The aim of this study was to evaluate the control of intestinal helminth infections in dogs with different anthelmintics administered at three different intervals in field conditions and highlight its limiting factors. Objectives of the study: 1. To evaluate the efficacy of febantel/pyrantel–embonate/praziquantel (Drontal® Plus, Bayer), emodepside/praziquantel (Profender®, Bayer) or milbemycin oxime/praziquantel (Milbemax®, Elanco) administered at 1-, 3- and 6-month intervals for control of intestinal helminth infections in dogs; 2. To examine the factors limiting the evaluation of control programs in field conditions; 3. To evaluate the prevalence of E. intermedius (pig strain, G7), E. multilocularis and Taenia spp. in a population of village dogs after 6 years following long lasting regular praziquantel treatment during E. intermedius control program.Scientific novelty and practical significance In this study the efficasy of three broad spectrum anthelmintics administered at three different regimes against intestinal helminth infections was evaluated in a controled field study with naturally infected village dogs. It was recorded, that exrection of T. canis eggs one month after the treatment of dogs with emodepside/praziquantel (Profender®, Bayer) and milbemycin oxime/praziquantel (Milbemax®, Elanco

Canine atopic dermatitis (cAD) is a common allergic skin condition in dogs that causes chronic pruritus. The overall quality of life in dogs with cAD is known to be reduced, and human patients with pruritic conditions report significant psychological burdens from pruritus-induced stress, and atopic dermatitis is associated with significant psychopathological morbidities. We tested the hypothesis that dogs with cAD would display more problem behaviours that could be indicative of stress than would healthy controls. Behavioural data were gathered directly from owners using a validated dog behaviour questionnaire for 343 dogs with a diagnosis of cAD and 552 healthy controls, and scores were also provided for their dog&rsquo, s pruritus severity. Regression modelling, controlling for potential confounding variables (age, sex, breed, neuter status or other health problem(s)) showed for the first time that pruritus severity in dogs with cAD was associated with increased frequency of behaviours often considered problematic, such as mounting, chewing, hyperactivity, coprophagia, begging for and stealing food, attention-seeking, excitability, excessive grooming, and reduced trainability. Whilst causality cannot be ascertained from this study, the behaviours that were associated with pruritus severity are redirected, self/environment-directed displacement behaviours, which are often considered indicative of stress. Further investigation is warranted, and stress reduction could be helpful when treating dogs with cAD.

This paper shows how Austrian psychiatrists of the 1870s developed the first pathological accounts of institutional coprophagia, examining how they related the behaviour to mental illness and dementia. These ideas about coprophagia contrasted dramatically to the long European pharmacological tradition of using excrement for the treatment of a wide range of health conditions. Recent medical scholarship on institutional coprophagia is also reviewed here, with a novel hypothesis proposed about why some patients in long-term care resort to the behaviour in institutions where there is little opportunity for healthy human–microbe interactions.

Naked mole-rats form eusocial colonies consisting of a single breeding female (the queen), several breeding males, and sexually immature adults (subordinates). Subordinates are cooperative and provide alloparental care by huddling and retrieving pups to the nest. However, the physiological mechanism(s) underlying alloparental behavior of nonbreeders remains undetermined. Here, we examined the response of subordinates to pup voice and the fecal estradiol concentrations of subordinates during the three reproductive periods of the queen, including gestation, postpartum, and nonlactating. Subordinate response to pup voice was observed only during the queen’s postpartum and was preceded by an incremental rise in subordinates’ fecal estradiol concentrations during the queen’s gestation period, which coincided with physiological changes in the queen. We hypothesized that the increased estradiol in the queen’s feces was disseminated to subordinates through coprophagy, which stimulated subordinates’ responses to pup vocalizations. To test this hypothesis, we fed subordinates either fecal pellets from pregnant queens or pellets from nonpregnant queens amended with estradiol for 9 days and examined their response to recorded pup voice. In both treatments, the subordinates exhibited a constant level of response to pup voice during the feeding period but became more responsive 4 days after the feeding period. Thus, we believe that we have identified a previously unknown system of communication in naked mole-rats, in which a hormone released by one individual controls the behavior of another individual and influences the level of responsiveness among subordinate adults to pup vocal signals, thereby contributing to the alloparental pup care by subordinates.

We have studied the distribution of plant fibers of different sizes in the digestive tracts of two hare species: the brown hare (Lepus euopaeus) and the mountain hare (L. timidus). In all studied hares (18 specimens), the highest amount of fine-sized fibers (less than 0.25 mm length) was observed in the cecum (50-70% of the total fiber mass). It was found out that the fine-sized content in the digestive tract, and especially in the cecum, is provided not only by the separation mechanism of the colon, but also by coprophagy. It was shown that repeated passage of food through the digestive tract compensates small volume of the cecum and increases the period of digestion of the same portions of food.

The efficacy of anthelmintic treatment at 1, 3, and 6 month intervals was evaluated in a prospective controlled field study with naturally exposed Lithuanian village dogs by monthly coproscopy during 1 year. A placebo-treated control group (C) (n = 202) and groups treated with two broad-spectrum anthelmintics, febantel/pyrantel-embonate/praziquantel (Drontal® Plus, Bayer) (D1, D3, D6; n = 113–117) and emodepside/praziquantel (Profender®, Bayer) (P1, P3, P6; n = 114–119), were included. At the beginning of the study, eggs of Toxocara canis (4.02%) and T. cati (0.44%) identified morphometrically and/or molecularly and eggs of taeniid- (0.78%) and Capillaria-like eggs (5.03%) were present in the feces without significant differences in prevalence between groups. Significant decreases in excretion of T. canis eggs was found 1 month after the treatment with Drontal® Plus in February (D1) and with Profender® in October (P1), November (P1), December (P3), February (P1), and March (P1, P3), as compared to controls in the same months. The incidence of egg excretion per dog at least once a year was significantly lower in group P1 for T. canis (4.24%; p

Coprophagia is a common canine habit, although it is aversive for human beings. Despite absence of clinical risk to animals and their owners, this behavior may lead the owners to get rid of their dogs. The lack of information and effective corrective methods make it difficult for veterinary clinicians to contribute to eradication of this problem. The objective of this study was to evaluate nutritional, behavioral, and hereditary aspects involved in the manifestation of coprophagia in dogs, the effectiveness of the most common corrective methods, and the perception of owners about the subject through a questionnaire designed for coprophagic and non–coprophagic dogs’ owners. Owners of 70 adult animals were interviewed, of which 42.8% (n = 30/70) were coprophagic and 57.1% (n = 40/70) were non-coprophagic. There was no difference between sex, habits, lifestyle, habitat, number of meals, nutritional background, commercial diet, and reproductive status. However, development of coprophagia appears to be influenced by the presence of a coprophagic cohabitant.

Unraveling the relationship between the unusual feeding behaviors and the nutritional intake of endangered species may provide crucial information for understanding species response to habitat unpredictable changes. Primates occasionally re-ingest fruit seeds alongside ingestion of feces, a behavior called coprophagy. The nutritional benefit is one of the several non-mutual exclusive hypotheses proposed to explain this behavior. We investigated the ecological correlates of coprophagy in wild western gorillas. We tested whether coprophagy occurred during periods of lower fruit availability and whether it led to higher nutrient intake in comparison to the other food. Data integrated phenological, fecal and nutritional analyses of gorilla food with behavioral observations collected at two sites in Central Africa (Mbeli Bai: ad libitum observations on 15 groups/solitary males, October 2002-November 2005; Bai Hokou: 5-min scan on a habituated group, December 2004-December 2005). Coprophagy occurred at the end of the high-fruiting season in association of two Dialium species. Coprophagy correlated positively with the occurrence of Dialium spp. fruit in gorilla feces and in the feeding scans, and showed a positive trend with Dialium availability but not with total fruit availability. Nutritional comparison of Dialium seeds with other important gorilla food showed higher fat and mineral content, particularly of Mg, but also of phenols and tannins in Dialium seeds. We discuss how the effect of gut processing and gut heat via coprophagy may act as cooking-like effect: increasing the ability to maximize nutrient intake by concurrently softening fibers and decreasing the toxic effect of antifeedants, like in human traditional cooking. Our results support both the multiple nutritional benefit hypothesis and the toxicity reduction hypothesis. Since Dialium is precious timber, the importance of this tree for the critically endangered western gorillas should be taken with high consideration when planning controlled logging of degraded forests or in face of habitat changes.

In the present study called “An Ethological Study of Young Horses” we focused on the behaviour of foals from their birth to separation from their mother. We observed and analysed their behaviour and daily activities, and from the achieved results we drew conclusions for practical horse breeding. We studied the following forms of behaviour of the foals: feeding behaviour (sucking, drinking, eating roughage and concentrates, gleaning, coprophagia), defecation and micturition, comfortable behaviour and mutual comfort behaviour, manifestations of relaxation (resting posture, lying down), movement manifestations, playful behaviour, stereotype behaviour, other manifestations (acoustic, olfactory etc).As a result we recommended several changes in the technology, e.g. larger stables, salt-lick out of reach of the foals, more frequent exchange of bedding, shelter for horses grazing in the open.

A behavioural animal model of faecal continence and/or incontinence would be of value in experimental studies of the mechanisms by which sacral neuromodulation can effect continence mechanisms in humans. The aim of this behavioural study was to establish whether the rat, an obligate coprophagic species, exhibits patterns of faecal continence. Standard rat cages were modified to consist of a food and drink area, a nesting area and an empty latrine area. Three floor pressure pads were connected to hour meters to record the time spent in each area over the course of 4 days. The door to the latrine was open for 2 days and closed for another 2 days to create a physical barrier that could only be surmounted by climbing over a partition. In the first 2 days, most faecal pellets (74 ± 20 %; p

Coprophagia and entomophagia are two phenomena not commonly reported in the medical literature and their occurrence is usually associated with mental disorders. We present the case of a 59-year-old man with a history of alcohol abuse who was evaluated due to cognitive deterioration and disturbed eating habits including feces and living insects. Organic causes were ruled out and an important cognitive impairment became evident on neuropsychological formal test. The behavior remitted after antipsychotic pharmacologic therapy and alcohol detoxification, leaving the diagnostic impression of alcohol related dementia. This report shows a rare association of these two conditions in a patient with dementia., info:eu-repo/semantics/publishedVersion

Consult-liaison psychiatrists often encounter difficult clinical scenarios. We present a pediatric case of presumptive coprophagia. After a negative medical work-up, the pediatrics team asked psychiatry to assist them in managing this relatively rare disorder in the hospital setting. Little is known about the etiology and treatment of coprophagia in the pediatric population. Using the case as a catalyst, we discuss what is known about this disorder as well as treatment strategies in the hospital setting.

To assess the impact of four rabbit diets (hay only, extruded diet with hay, muesli with hay and muesli only) on faecal pellet size, faecal output and caecotrophy.Thirty-two Dutch rabbits were studied over 17 months. Faecal pellet size and weight were measured in weeks 3, 9, 21 and 43 and faecal output in weeks 10, 22 and 45. Number of uneaten caecotrophs was recorded weekly.Faecal pellets were consistently smaller and lighter in rabbits fed muesli only, and the size of pellets produced by those fed muesli with hay decreased over the course of the study. Faecal output was greatest in rabbits with the highest hay intake. Uneaten caecotrophs were found in greatest frequency in rabbits fed muesli.Muesli diets have a negative effect on faecal output and caecotroph ingestion and may therefore predispose to digestive disorders. Higher hay intake is associated with greater faecal output and fewer uneaten caecotrophs and may assist in preventing the gastrointestinal stasis.

Plastic debris is a widespread contaminant, prevalent in aquatic ecosystems across the globe. Zooplankton readily ingest microscopic plastic (microplastic,1 mm), which are later egested within their faecal pellets. These pellets are a source of food for marine organisms, and contribute to the oceanic vertical flux of particulate organic matter as part of the biological pump. The effects of microplastics on faecal pellet properties are currently unknown. Here we test the hypotheses that (1) faecal pellets are a vector for transport of microplastics, (2) polystyrene microplastics can alter the properties and sinking rates of zooplankton egests and, (3) faecal pellets can facilitate the transfer of plastics to coprophagous biota. Following exposure to 20.6 μm polystyrene microplastics (1000 microplastics mL(-1)) and natural prey (∼1650 algae mL(-1)) the copepod Calanus helgolandicus egested faecal pellets with significantly (P0.001) reduced densities, a 2.25-fold reduction in sinking rates, and a higher propensity for fragmentation. We further show that microplastics, encapsulated within egests of the copepod Centropages typicus, could be transferred to C. helgolandicus via coprophagy. Our results support the proposal that sinking faecal matter represents a mechanism by which floating plastics can be vertically transported away from surface waters.

We report on the unusual behavior of coprophagia (eating one’s own feces) in neurologic disorders. The Mayo Clinic Health Sciences-computerized clinical database was queried for all patients evaluated at our institution between 1995 and 2015 in which coprophagia was documented in the medical records. Twenty-six patients were identified of which 17 had coprophagia. Of the 17 patients, five were excluded due to age at onset less than 10 years, leaving 12 adult patients for this study. The median age at onset of coprophagia in the 12 patients was 55 years (range 20–88 years), and half were female. Additional behaviors were common including scatolia (fecal smearing), hypersexuality, aggression, and pica (eating objects of any kind). Coprophagia was associated with neurodegenerative dementia in six patients, developmental delay in two, and one each with seizures, steroid psychosis, frontal lobe tumor, and schizoaffective disorder. Brain imaging in the six patients with dementia showed moderate-to-severe medial temporal lobe atrophy, as well as mild frontal lobe atrophy. Autopsy examination was performed in one patient and revealed frontotemporal lobar degeneration pathology. Many different behavioral and pharmacologic therapies were implemented, yet only haloperidol was associated with discontinuation of the behavior. Coprophagia is associated with different neurologic disorders, particularly neurodegenerative dementias. The behavior may be related to medial temporal lobe atrophy, similar to the Kluver–Bucy syndrome. Haloperidol appears to be effective in treating the behavior, at least in some patients.

Incidental observations of coprophagia (consumption of faeces) were made of an Australasian Darter Anhinga novaehollandiae . This is the first known documented instance of this behaviour in this species and order of birds. The behaviour is reviewed in the context of the current understanding of the reasons for coprophagy in bird species.

A sensitive and reliable biomarker has yet to be identified for marginal copper deficiency in humans. The need for such a biomarker is critical, because increased cases of human copper deficiency evolve following bariatric surgery and other secondary factors besides diet. Four experiments were devised to induce marginal copper deficiency through copperdeficient (CuD) diets (5 wk for mice and 4 wk for rats). In Expt. 1 and 2, male postweanling mice were raised in either solidbottom plastic cages (Expt. 1) or stainless steel hanging cages (Expt. 2) and compared. Postweanling rats (Expt. 3) and adult mice (Expt. 4) were also studied using stainless steel cages. Copper-adequate controls were fed a semipurified diet containing 9 mg Cu/kg. CuD rats exhibited the most severe changes in biomarkers due to copper limitation, including major reductions in plasma ceruloplasmin (Cp) and erythrocyte superoxide dismutase (Sod1) and augmentation in copper chaperone for Sod1 (CCS). The CuD mice in Expt. 2 were more deficient than the CuD mice in Expt. 1, likely due to coprophagia differences. In fact, the CuD mice in Expt. 1 had unaltered Sod1 or Cp levels. Importantly though, these marginally deficient mice and CuD adult mice that had no changes in Cp activity or liver copper level had robust augmentation of CCS. Erythrocyte CCS was the only consistent biomarker to change in copper deficiency for all dietary groups, suggesting that CCS may be an excellent biomarker for human confirmation of marginal copper deficiency. J. Nutr. doi: 10.3945/jn.111.150755.

A dog presenting for chronic purulent nasal discharge was diagnosed with an Eucoleus boehmi infection based upon rhinoscopic appearance of the nasal worms in situ, identification of the adult parasites in rhinoscopic nasal biopsies, and ova in the feces. The dog was successfully treated with a 2 wk course of fenbendazole and measures preventing reinfection through coprophagia. Patients with chronic nasal discharge should have a fecal examination performed to rule out infection with E. boehmi.

A colonic separation mechanism (CSM) is the prerequisite for the digestive strategy of coprophagy. Two different CSM are known in small herbivores, the 'wash-back' CSM of lagomorphs and the 'mucous-trap' CSM of rodents. Differences between these groups in their digestive pattern when fed exclusively hay were investigated in six rabbits (Oryctolagus cuniculus) and six guinea pigs (Cavia porcellus). Intake, digestibility (by total faecal collection), solute and particle mean retention times (MRT, using Co-EDTA and Cr-mordanted fibres) were measured. Rabbits selected less fibrous parts of the hay than guinea pigs, leaving orts with higher content of neutral detergent fibre [NDF; 721 ± 21 vs. 642 ± 31 g/kg dry matter (DM) in guinea pigs]. They also expressed a lower NDF digestibility (0.44 ± 0.10 vs. 0.55 ± 0.05 of total), a similar particle MRT (15 ± 3 vs. 18 ± 6 h), a longer solute MRT (51 ± 9 vs. 16 ± 4 h), and a lower calculated dry matter gut fill (19.6 ± 4.7 vs. 29.7 ± 4.1 g DM/kg body mass) than guinea pigs (p < 0.05 for each variable). These results support the assumption that the 'wash-back' CSM, exhibited in the rabbits, is more efficient in extracting bacterial matter from the colonic digesta plug than the 'mucous-trap' CSM found in the guinea pigs. Related to metabolic body mass, rabbits therefore need a less capacious colon for their CSM where a more efficient bacteria wash-out is reflected in the lower fibre digestibility. A lighter digestive tract could contribute to a peculiarity of lagomorphs: their ability to run faster than other similar-sized mammals.

Summary Using the 14C-PEG dilution method, cecal volumes were measured in 2 domestic rabbits at 2 different times of day. Each experimental period lasted 8–12 hours. The cecal volumes were 22.6 ± 4.3 ml./kg. during daytime and 17.0 ± 4.3 ml./kg. during the night. The larger cecal volume coincided with the time following the coecotrophy period, the smaller one with the time before and during the next one. The day-time figure corresponds closely to a volume of cecal contents of 24 ± 7 ml./kg. measured post mortem in 7 other animals. The relationship between cecal volume and coecotrophy is discussed. Zusammenfassung Tagesrhythmische Unterschiede des Blinddarmvolumens bei Kaninchen. In vivo-Messungen mit 14C-PEG Mit der 14C-PEG Verdunnungsmethode wurden die Blinddarmvolumina von zwei Hauskaninchen zu verschiedenen Tageszeiten gemessen. Jede Versuchsperiode dauerte 8–12 Stunden. Die Blinddarmvolumina waren 22,6 ± 4,3 ml/kg wahrend des Tages und 17,0 ± 4,3 ml/kg wahrend der Nacht. Die groseren Blinddarmvolumina wurden jeweils in der Zeit nach der Coecotrophie gefunden, die kleineren in der Zeit vor und wahrend der Coecotrophie. Die wahrend des Tages gemessenen Werte entsprechen einem bei 7 anderen Tieren post mortem gemessenen mittleren Volumen des Blinddarm-inhalts von 24 ± 7 ml/kg. Beziehungen zwischen Blinddarmvolumen und Coecotrophiephasen werden diskutiert. Resume Variations nycthemerales du volume caecal chez le lapin mesurees in vivo avec de 14C-PEG On a mesure avec la methode de dilution 14C-PEG les volumes du caecum a differents moments de la journee chez deux lapins domestiques. Chaque periode de recherche a dure de 8 a 12 heures. Les volumes du caecum furent 22,6 ± 4,3 ml/kg durant le jour et 17,0 ± 4,3 ml/kg durant la nuit. Les plus gros volumes furent toutefois trouves apres la coecotrophie et les plus petits avant ou pendant la coecotrophie. Les valeurs mesurees pendant le jour correspondent au volume moyen du contenu du caecum de 24 ± 7 ml/kg mesure chez 7 autres animaux post mortem. On discute les rapports entre les volumes du caecum et les coecotrophies. Resumen Variaciones diurnas del volumen cecal en el conejo, medidas in vivo con 14C-PEG Usando la tecnica de dilucion de 14C-PEG, se midieron los volumenes cecales en 2 conejos domesticos en 2 ocasiones diarias. Cada periodo experimental duraba de 8–12 horas. Los volumenes ciegos median 22,6 ± 4,3 ml/kg durante el dia y 17,0 ± 4,3 ml/kg durante la noche. Los volumenes cecales mayores se hallaron cada vez en el tiempo tras la cecotrofia, los menores en el tiempo anterior a la cecotrofia y durante la misma. Los valores medidos durante el dia equivalen al volumen medio del contenido cecal de 24 ± 7 ml/kg, medido post mortem en 7 otros animales. Se discuten las relaciones que existen entre el volumen cecal y las fases de cecotrofia.

The present work is aimed to establish, in Ctenomys talarum, the physiological and behavioral adjustments undergone by individuals when they are allowed to dig burrows in soils with different hardness and fed with diets of different quality. For each soil-diet combination, we estimated: resting metabolic rate (RMR), body temperature (T(b)), body mass, digestibility, food consumption rate, transit time, reingestion rate, feces production and time devoted to feeding, resting, locomotor activity and coprophagy. Soil type and diet quality affected RMR, but response to soil hardness was verified later. Animals fed with high quality (HQ) diet showed similar body temperature irrespective of soil condition, while animals fed with low quality (LQ) diet showed lower T(b) under soft soil (SS). Individuals fed with LQ diet showed lower RMR and both, lower digestibility and high transit time of food than those fed with HQ diet. Moreover, increments in feeding and defecation rates were observed in the former group. Number of reingested feces did not differ between animals fed with diets of different quality. However, when incidence of reingestion was considered, animals fed with HQ diet showed higher values of feces ingestion. Either feeding, resting and activity patterns were arrhythmic. However, for animals fed with LQ diet a tendency to rhythmic coprophagy was observed and it could be considered as a way to optimize feeding. This study shows that RMR is limited by digestive efficiency which is influenced by diet quality, but also thermal stress may limit the conversion of assimilated energy into work and heat.

Helminth infections and nutrition can independently alter the composition and abundance of the gastrointestinal microbiota, however, their combined effect is poorly understood. Here, we used the T. retortaeformis-rabbit system to examine how the helminth infection and host restriction from coprophagy/ready-to-absorb nutrients affected the duodenal microbiota, and how these changes related to the acquired immune response at the site of infection. A factorial experiment was performed where the bacterial community, its functionality and the immune response were examined in four treatments (Infect, Infect+Collar, Control+Collar and Control). Helminths reduced the diversity and abundance of the microbiota while the combination of parasites and coprophagic restriction led to a more diversified and abundant microbiota than infected cases, without significantly affecting the intensity of infection. Animals restricted from coprophagy and free from parasites exhibited the richest and most abundant bacterial community. By forcing the individuals to absorb nutrients from less digested food, the coprophagic restriction appears to have facilitated the diversity and proliferation of bacteria in the duodenum. Changes in the microbiota were more clearly associated with changes in the immune response for the infected than the nutrient restricted animals. The functional and metabolic characteristics of the duodenal microbiota were not significantly different between treatments. Overall, infection and diet affect the gut microbiota but their interactions and outcome can be complex. These findings can have important implications for the development of control measures to helminth infections where poor nutrition/malnutrition can also be a concern.

The chinchilla (Chinchilla laniger) is a herbivorous hystricomorph South American rodent for which no mean digesta retention times have been reported so far. Six animals (mean body mass ± standard deviation: 513 ± 99 g) on a diet of grass hay and lucerne-based pellets were given a pulse dose of a solute (cobalt-EDTA) and a particle (chromium-mordanted fibre,2 mm) marker with subsequent frequent faecal collection. Dry matter intake was 45.2 ± 8.0 g/kg(0.75) /day. Mean retention times were 22.2 ± 5.3 h for solutes and 25.4 ± 5.2 h for particles, with the difference being not significant within individuals. This indicates the presence of a 'mucus-trap' colonic separation mechanism, which is in accord with morphological descriptions of the typical colonic furrow in chinchillas. Corresponding to a strategy of colonic digesta separation and caecotroph formation, secondary marker excretion peaks indicated coprophagic events that were spaced approximately 12 h apart. Given that these retention times appear longer than measures reported for rabbits (Oryctolagus cuniculus) or guinea pigs (Cavia procellus), it would be interesting to compare the digestive efficiency of chinchillas on high levels of dietary fibre to other species.