Soft Feces Research Articles

Chemoprophylaxis of coccidiosis in lambs with a single oral dose of toltrazuril

The prophylactic efficacy of a single oral dose of toltrazuril against coccidiosis (mixed Eimeria infections) in naturally infected lambs was evaluated in two experiments. Toltrazuril at 20 mg kg −1, given on Day 7 or Day 10 after turnout on pasture, proved to be highly efficacious in preventing clinical coccidiosis under Norwegian conditions. Toltrazuril reduced the oocyst output to very low levels, prevented the development of diarrhoea and improved weight gain during the first 4–5 weeks after treatment. Treatment on Day 7 was superior to treatment on Day 10 with respect to improving weight gain and preventing the development of soft faeces. Lambs treated with toltrazuril on Day 7 seemed to be as immune as untreated lambs to natural reinfections with coccidia later in the grazing season. In one of the experiments, natural infections with the nematode Nematodirus battus produced a coccidiosis-like disease in some lambs simultaneously with the outbreak of coccidiosis.

Effect of type of fiber on the rate of passage and on the contribution of soft feces to nutrient intake of finishing rabbits.

One hundred thirty New Zealand White x California rabbits were used to study the influence of the source of dietary fiber on several digestive criteria. Five diets were formulated to provide 10% crude fiber (CF) on a DM basis. Sixty percent of this dietary fiber was supplied by alfalfa hay, citrus pulp, beet pulp, grape marc, or rice hulls in the diets. Weights of cecal contents, cecal ammonia concentration, and molar proportion of acetic acid in diets including pulps were higher and cecal levels of DM, CP, and molar proportion of butyric acid were lower than those of the alfalfa diet. Cecal ammonia, VFA, and CF concentrations of the grape marc diet were the lowest of all the diets studied; cecal CF level and molar proportion of acetic acid were significantly higher and CP level and molar proportion of butyric acid were lower in rice hull than in alfalfa diets. Diet had no influence on daily soft feces excretion (10 g DM/d), but N contribution of soft feces to N intake was higher in the diet with citrus pulp (18.7%) than in the other diets (12%). Mean retention time (R) was measured using fuchsin-stained feed and was found to be higher (21.3 h) in the rice hull diet and lower (9.3 h) in the grape marc diet than in the other diets. When coprophagy was prevented, R decreased by 0 to 7 h. In conclusion, the use of byproducts to substitute for traditional sources of fiber in rabbit diets influenced the retention time of the digesta in some segments of the gut and thus altered several digestive criteria.(ABSTRACT TRUNCATED AT 250 WORDS)

The Relationship between Digital Rectal Examination and Abdominal Radiographs in Elderly Patients

The relationship between digital rectal examination and the findings of faecal loading on abdominal radiograph was studied in elderly patients admitted to hospital. No significant association was found but there was a relationship between faecal loading of the recto-sigmoid, colonic and caecal areas of the radiograph. Soft faeces in the rectum were commoner in older patients and were associated with faecal loading in the caecal area. The digital rectal examination is useful for identifying anal and rectal lesions and faecal impaction but abdominal radiograph is required to assess faecal loading of the large bowel.

Exfoliating Colitis Associated with Enterotoxigenic Bacteroides Fragilis in a Piglet

Bacteroides fragilis is a gram-negative, non-sporeforming, obligately anaerobic bacterium found in high numbers in the intestinal tract of humans and animals. Some isolates of B. fragilis elaborate enterotoxin, which causes fluid accumulation in ligated intestinal loops of calves and lambs. Enterotoxigenic isolates of B. fragilis have been associated with diarrhea1 diseases in calves, lambs, pigs, foals, and humans. Characteristic large intestinal lesions are seen in rabbits and gnotobiotic piglets (Duimstra JR, Collins JE, Myers LL, Benfield DA: 1986, Abstr Conf Res Workers Anim Dis #285, p. 50) experimentally inoculated with human or porcine isolates of enterotoxigenic B. fragilis. Intestinal lesions associated with enterotoxigenic B. fragilis in animals with naturally occurring diarrhea1 disease have not been documented. In this report we describe colonic lesions associated with enterotoxigenic B. fragilis in a piglet with spontaneous diarrhea. An 80-sow swine herd in southeastern Minnesota experienced an epizootic of diarrhea in 2to 17-day-old Yorkshire-Landrace cross piglets. Piglets were kept on plasticcoated wire in raised crates. The breeding herd contained approximately one-third gilts and two-thirds second parity sows. Approximately 90% of the piglets in 13 of 15 litters were diarrheic during a 2-week period; mortality was negligible. A few litters of piglets failed to gain weight and were stunted, but most piglets continued to consume milk and gain weight. A live, robust, well-hydrated, 8-day-old piglet presented for necropsy excreted thick yellow feces at frequent intervals. Necropsy revealed clear edema fluid in the mesentery of the spiral colon, and soft yellow feces adhered to the colonic mucosa. Mesenteric lymphatics contained chyle, and the small intestine did not have lesions. Portions of small and large intestine were immersed in neutral-buffered 10% formalin, embedded in paraffin, sectioned at 4 μm thickness, and stained with hematoxylin and eosin (HE), Gram, and Warthin-Starry stains. Microscopically, the colon mucosa between crypt openings had severe exfoliation of surface mucosal enterocytes (Fig. 1). Clusters of enterocytes often remained attached to the mucosa by a

Summary of Toxicity Studies on Bensultap

A wide variety of toxicological study on bensultap have been conducted to assess its safety.Bensultap is a relatively low toxic substance, and the toxicological signs of treated animals included ptosis, depression, hyperactivity, tremor, urine stains, soft feces, rough coat, lacrimation, salivation and convulsion in acute toxicity studies.Bensultap technical might be a weak irritant but no-corrosive substance to the rabbit eye, and it caused no skin irritation. Bensultap technical might be a mild allergen, but its formulated product was not to be a sensitizing agent in guinea pig.In chronic toxicity and oncogenicity studies, main toxicological findings related to the treatment of bensultap were including depression of body weight, decreased hematocrit and hemoglobin values, increased kidney weight and centrilobular hepatocellular swelling in the high dose groups. No treatment-related neoplastic lesions were observed in rats and mice.The reproductive performance was not influenced with bensultap in rats, and no teratogenic potential was observed in rat and rabbit studies. Bensultap did not indicate a mutagenic potential in any assay.Bensultap and its formulation were registered on April 14, 1986 in Japan.The withhold standards for pesticide registration are listed below.Rice 0.2ppmWheat and others 0.2ppmVegetables 3.0ppmTea 20.0ppm

A six-month chronic dietary toxicity study of pyriproxyfen in rats

Groups of 21 male and 21 female Sprague-Dawley (SD) rats were fed diets containing pyriproxyfen at concentrations of 0, 80, 400, 2,000 and 10,000 ppm for 6 months. No death was found in any group. Alopecia in the neck and/or back, and soft feces were noticed in both sexes fed 10,000 ppm. A marked decrease in body weight gain was observed in both sexes fed 10,000 ppm throughout the treatment period, accompanying a decrease in food-consumption and an increase in water-intake during the initial stage of treatment. In terms of urinalysis, proteinuria, increases in K excretion, and, in number, yellowness or browish-yellowness in appearance, were observed in both sexes fed 10,000 ppm. In females fed 10,000 ppm, increases in bilirubin, Na excretion and specific gravity, and a decrease in ketone bodies, were observed. In hematology, decreases in erythrocyte count, hemoglobin concentration and hematocrit value, were observed in both sexes fed 10,000 ppm and in males fed 2,000 ppm. Also, an increase in MCH (in males), decreases in MCHC and platelet count (in females) were observed in 10,000 ppm group. Blood biochemistry revealed increases in total protein, albumin, alpha 2-globulin fraction, blood urea nitrogen, calcium (in both sexes fed 10,000 ppm), A/G ratio (in males fed 2,000 and 10,000 ppm), total cholesterol, phospholipid (in males fed 2,000 and 10,000 ppm, and in females fed 10,000 ppm), sodium (in females fed 2,000 and 10,000 ppm), gamma-glutamyl transpeptidase activity (in males fed 10,000 ppm) and alpha 1-globulin fraction (in females fed 10,000 ppm), and decreases in glucose, GOT (in both sexes fed 10,000 ppm), beta-globulin fraction (in males fed 2,000 and 10,000 ppm, and in females fed 10,000 ppm), GPT (in females fed 2,000 and 10,000 ppm), triglyceride, potassium (in males fed 10,000 ppm), and cholinesterase activity (in female fed 10,000 ppm). In organ weight, increases in liver (in males fed 2,000 ppm and 10,000 ppm, and in females fed 10,000 ppm), kidney (in both sexes fed 10,000 ppm) and thyroid (in females fed 10,000 ppm) and a decrease in pituitary (in females fed 2,000 and 10,000 ppm) were observed. Gross pathology revealed a higher incidence of blackish-brown coloration of the liver, and a lower incidence of accentuated lobular pattern of the liver (in males fed 10,000 ppm). An enlargement of the liver was seen in a few of both sexes fed 10,000 ppm. Histopathological examination showed that the sole effect attributable to treatment of this compound was on slight hypertrophy in the liver of both sexes fed 10,000 ppm, with a higher incidence.(ABSTRACT TRUNCATED AT 400 WORDS)

Effects of sennosides A + B and bisacodyl on rat large intestine.

Oral and intracecal administration of bisacodyl or sennosides A + B (10-100 mg/kg each) to rats induced a similar quantity of soft feces within 24 h and a similar acceleration of large intestinal transit time, but in each case bisacodyl had a prolonged action. Net fluid absorption in the perfused rat colon was reduced to a comparable extent by local bisacodyl in 1/10 of the molar concentration of rhein, an active metabolite of sennosides; recovery was delayed after bisacodyl. These results show that the time course of the laxative action of both drugs is different, probably attributable to their different pharmacokinetics. Both drugs influence colon motility as well as colonic secretion, but fluid secretion may contribute more to the laxative effect of bisacodyl than to that of sennosides.

Determinations of actinides in biological and environmental samples

This paper summarises the radiochemical procedures utilised in our laboratory to determine U, Th and Pu in different sample matrices, including soft tissues, bones, urine, faeces, soil, water, air-filters, lichen, and building materials such as granite, phosphate and concrete. Sample preparation, depending upon the matrix of the sample, includes either dry ashing and/or wet ashing with a mixture of HNO 3 and H 2SO 4 or HNO 3 alone with occasional additions of a few drops of HNO 3 and H 2O 2. Uranium, Th and Pu are either co-precipitated with Fe carrier as hydroxides or with Ca as oxalates. Solvent extractions are performed from 2M HNO 3, 4M HNO 3 or 10M HCl depending upon the actinide or combination of actinides to be determined. The techniques have been very successful for most samples, with radiochemical recoveries exceeding 70%. However, radiochemical recoveries of Th from soil samples have been very poor (10–30%). Attempts are being made to improve these recoveries.

Effect of diet on composition of cecal contents and on excretion and composition of soft and hard feces of rabbits.

A total of 260 New Zealand White growing rabbits were used to study the effect of diet on chemical composition of cecal contents and on production and composition of soft and hard feces. Eight diets varying in their acid detergent fiber (9.8% to 32.7%) and starch (13% to 30%) levels were evaluated. The diet affected (P less than .01) all the variables studied, except dry matter (DM) and molar proportions of volatile fatty acids on cecal contents. An increase of dietary crude fiber increased crude fiber level in cecal contents (from 11.58% to 26.53%). However, a relatively lower proportion of fibrous material was found in the cecal contents when rabbits were fed the more fibrous diets. This suggests that dietary fiber has a direct influence on the efficiency of particle separation in the digestive tract. Crude protein and volatile fatty acid concentrations of cecal contents decreased (from 30.14% to 19.65% and from 47.8 to 36.7 mmol/liter, respectively) when dietary crude fiber increased. This could be related to availability of energy to cecal microorganisms. Ammonia concentration of cecal contents was not affected by dietary crude fiber. Daily production of soft feces varied from 14.98 to 29.59 g DM/d, and the contribution of soft feces to total DM and to crude protein intake ranged from 10.6% to 15.0% and from 12.8% to 20.5%, respectively; these values were the smallest and the largest for the least and the most fibrous diets, respectively. From this study we conclude that dietary fiber has a major effect on the digestive processes in the rabbit and that dietary starch level has no influence on any of the variables studied.

Johne's Disease (Mycobacterium paratuberculosis) in a Jimela Topi (Damaliscus lunatus jimela)

A 10-yr-old male Jimela topi (Damaliscus lunatus jimela) born in captivity was eval uated by Veterinary Services, San Diego Zoo. The animal had a history of weight loss in the presence of a good appetite, abdominal distension, and intermittent soft feces. Clinical evaluation revealed a marginal anemia, hypoproteinemia, hypoalbuminemia, a lymphocyte-neutrophil reversal, and mesenteric lymphadenopathy. Radiographs, per rectal colonie biopsy, comparative intradermal tuberculin skin tests, and attempts to isolate Salmonella sp. and Campylobacter sp. were all negative. Fecal smears revealed abundant acid-fast bacilli. A diagnosis of Johne's disease was made and the animal was euthanized. Necropsy revealed an emaciated animal with a mildly thickened and hyperemic small intestine, cecum, and large intestine; lymphadenopathy of the colonie, intestinal, and mesenteric lymph nodes; and a mottled, soft friable liver. Histopathologic evaluation revealed chronic diffuse granulomatous inflammatory infiltrates in the small and large intestine, intra-abdominal lymph nodes, and hepatic peripheral lobular regions. There were abundant macrophages in all these tissues which contained large numbers of densely packed intracytoplasmic acid-fast bacilli. Mycobacterium paratuberculosis was isolated from the fecal cultures. Because of the potential transmission of Johne's disease to two adult female and three juvenile topi cohabiting with the infected animal, all herd mates were euthanized. Serologie, comparative skin tests, histopathologic evaluation, and fecal examination failed to indicate the presence of mycobacterial organisms or disease in any of these animals.

Effect of sennosides and related compounds on intestinal transit in the rat.

The effect of pure sennosides A + B on large intestinal transit (LIT) was investigated in the rat. LIT was defined as the time from intracecal administration of a color marker through a chronically implanted catheter until first appearance of colored feces. Sennosides (50 mg/kg, administered orally 2-24 h before the marker) reduced LIT from greater than 6 h in controls to a minimum of 30-20 min after a 4- or 6-hour pretreatment. Longer pretreatment times increased LIT again reaching normal values after 24 h. Intracecal administration of sennosides and their natural metabolites (sennidins A + B, rhein-9-anthrone, rhein) simultaneously with the marker accelerated LIT to approximately 50-70 min. The laxative effect was less pronounced after rhein compared with the other compounds. Indometacin, loperamide, and calcium-channel antagonists (verapamil, nifedipine) partially antagonized the effect of intracecal sennosides on LIT and delayed, but did not suppress, appearance of soft feces.

Campylobacter in the dog: a clinical and experimental study.

Faecal samples from 54 dogs with diarrhoea and 54 control dogs were cultured for Campylobacter, Salmonella and Yersinia species and controlled for enteric viruses. The campylobacter were identified as either C jejuni/coli or C upsaliensis. In the diarrhoeic group 16 dogs (29.6 per cent) were positive for campylobacter, 10 C upsaliensis and six C jejuni/coli. Concomitant infection with parvovirus was evident in six of the dogs with diarrhoea and campylobacter-positive faecal cultures. In the control group 13 dogs (24.1 per cent) were positive for campylobacter; three of the isolates were C upsaliensis and six C jejuni/coli. Four isolates could not be identified. The most prominent clinical findings in naturally occurring cases were an acute onset of vomiting (12 of 16), diarrhoea (16 of 16) which was often haemorrhagic (nine of 16) and a raised rectal temperature. Dogs were infected experimentally with both C jejuni (three dogs) and C upsaliensis (three dogs). The challenge strains could be identified in faecal samples from all the dogs, but clinical signs of diarrhoea were seen in only one dog infected with C jejuni. Soft faeces was passed by one dog infected with C upsaliensis. It is concluded that C jejuni/coli or C upsaliensis are either primary pathogens or, after predisposing factors such as virus infections, act as secondary pathogens. It also seems probable that Campylobacter species are present in the intestinal flora of the normal dog.

Origin and utilization of volatile fatty acids and lactate in the rabbit: influence of the faecal excretion pattern.

Interrelations between bacterial metabolites (volatile fatty acids, lactate) in the gut contents and the blood in relation to the faecal excretory cycle (soft or hard faeces) were studied in anaesthetized rabbits. It appeared that the level of organic acids in the alimentary tract varied cyclicly with the faecal excretion pattern. The lactate entering the portal circulation originates from the stomach, while the volatile fatty acids (VFA) originate from the hind-gut. Net absorption from the digestive tract and hepatic utilization of fermentation acids were greater when the rabbits produced hard faeces (hard-phase) compared with soft faeces (soft-phase). Propionate and butyrate reaching the liver were almost quantitatively removed; acetate and lactate were available for extra-hepatic tissue metabolism. Whatever the excretion pattern the levels of VFA in the arterial circulation remained remarkably constant; blood lactate, however, was lower during the soft-phase. Absorption of bacterial metabolites, like their metabolism in the liver, showed a circadian rhythm parallel to the changes in the activity of the adrenal glands, i.e. the activity was enhanced during the hard-phase.

Chronic oral toxicity study of proglumetacin maleate in beagle dogs

A chronic oral toxicity test of proglumetacin maleate (PGM), an anti-inflammatory agent, was studied at dose-levels of 0, 0.6, 2.5 and 10.0 mg/kg/day using male and female beagle dogs. They were treated for 12 months, followed by 1 month recovery period. Excretion soft and mucous feces was observed in females of 2.5 mg/kg/day group. In addition, excretion of diarrheal and blood-tinged feces was also found in females of 10.0 mg/kg/day group. One female animal given 10.0 mg/kg/day of PGM was found dead on day 178 of administration. For about a month before death, diarrheal and blood-tinged feces, decreases in body weight and food consumption, and anemia had been noticed. At the autopsy, brown-cloudy ascitic fluid, adhesion of visceral organs, hyperemia or hemorrhage in the mucosa and serosa of the digestive tract, and an ulcer in the duodenum were found. No significant influences of PGM were noted on the changes of body weights, food and water consumptions, excluding the dead animal. A fecal occult blood test showed an increase in no. of animals with blood-positive reaction in 2.5 and 10.0 mg/kg/day groups of both sexes, especially marked in females of 10.0 mg/kg/day group. In urinary tests, no significant changes were found in any of the PGM-treated groups of both sexes; the dead one, however, showed decreases in urine volume and electrolyte excretion on month 6 of administration. No significant hematological changes associated with the administration of PGM were found in any of the animals excluding the dead one, in which anemia and inflammation-related findings were found on month 6 of administration. Serum-biochemical tests showed no significant changes in any of the PGM-treated groups of both sexes. No significant influences of PGM were found on ICG and PSP clearances, ocular fundus and ECG. At the autopsy performed at the end of administration, no significant changes were found in any of the PGM-treated groups of both sexes. Histopathologically, a duodenal ulcer and peritonitis-related findings were observed in the female dead animal of 10.0 mg/kg/day group. No influences of PGM were found in any of the tests performed at the end of the recovery phase. From these results, the non-effective dose of PGM was estimated to be 0.6 mg/kg/day, and the toxic doses of PGM to be more than 10.0 mg/kg/day for males and 10.0 mg/kg/day for females, respectively, in beagle dogs treated orally with PGM for 12 months.

Colonic formation of soft feces in rabbits: a role for endogenous prostaglandins.

Rabbits produce hard and soft feces in a circadian rhythm. The motor activity of the haustrated proximal colon is inhibited during the formation of soft feces, whereas the spiking activity of the distal colon is stimulated. A potential role for endogenous prostaglandins (PG) in the control of the soft-feces elaboration by the rabbit colon was investigated in conscious animals by using PGE2 and PGF2 alpha and by inhibiting them with indomethacin. The infusion of both PGE2 and PGF2 alpha induced typical electromechanical events consisting of inhibition of the proximal and stimulation of the distal colon and was followed by soft-pellet defecation. Rabbits accustomed to be fed twice daily produced soft feces at fixed intervals of 252 +/- 32 min after the evening meal, with a soft-to-hard feces ratio of 1.45. After indomethacin treatment, this ratio was significantly (P less than 0.01) reduced to 0.92. These results are consistent with the concept that endogenous prostaglandins play a major role in the motor function involved in soft-feces formation by the rabbit.

Urease activity in gastrointestinal tract of rabbit and electrophoretic behaviour of urease

Urease activity in the stomach (fundus and antrum), caecal content and soft faeces of rabbit was studied. Significant differences between fundus and antral content (P less than 0.01) and between caecum and soft faeces (P less than 0.05) were observed. The urease zymograms from caecal content and soft faeces of rabbit presented two different bands. The fundus content and the caecal ureolytic Clostridium innocuum bacterium exhibited only one band. Band B of caecal content was not evident at pH 4, whereas band A, also present in the stomach, was observed both at pH 4 and at pH 6. The optimal pH of urease activity of stomach and caecal content was in the range of 4-5 and 5-6, respectively. A comparison of intestinal urease zymograms with those of the single ureolytic bacterial species was suggested in order to clarify their role in urea metabolism.

Observations by light microscopy and transmission electronmicroscopy on intestinal spirochaetosis in baboons (Papio spp.)

Spirochaetes were recognised in the large bowel of 57 of 59 baboons as a basophilic fringe at the microvillous brush border of the epithelial cells. Both caecum and colon were usually affected, but seven animals had spirochaetes in the caecum alone. Examination of three animals by transmission electronmicroscopy revealed only one type of spirochaete; ring forms and cross-walls were present. Inflammatory changes were not seen in association with the infection, and the distribution of spirochaetes in 10 animals with soft or diarrhoeic faeces resembled that in normal animals.

Coprophagy and Selective Retention of Fluid Digesta: Their Role in the Nutrition of the Common Ringtail Possum, Pseudocheirus Peregrinus.

In ringtail possums, Pseudocheirus peregrinus, fed a sole diet of Eucalyptus andrewsii foliage the mean retention time of the fluid marker 51Cr-EDTA in the gut (63 � 2 h) was longer (P< 0.002) than that of the particulate marker 103Ru-phenanthroline (35 � 2 h), indicating selective retention of fluid digesta in the caecum. In addition, the ringtail was observed to be coprophagic. The form of coprophagy was determined to be caecotrophy; hard faeces produced during the dark (foraging) phase were not eaten, but soft faeces produced during the light (resting) phase were taken directly from the cloaca. Soft faeces, collected when coprophagy was prevented by a plastic collar, were high in water and nitrogen content, and low in fibre relative to hard faeces. Coprophagy contributed 254 kJ.kg-0.75.d-� to total energy intake (equivalent to 58% of digestible energy intake), and 570 mg nitrogen per kg-0.75per day, twice the main- tenance nitrogen requirement. It was concluded that coprophagy was an important factor in explaining the ringtail possum's low requirement for nitrogen and its ability to subsist on a sole diet of Eucalyptus foliage.

Electrolyte transport across rabbit late proximal colon in vitro

1. 1. The second part of rabbit proximal colon was investigated in vitro under short circuit conditions. 2. 2. Unidirectional sodium and chloride fluxes were measured during the soft faeces period and during the hard faeces period. 3. 3. Rabbit late proximal colon has a potential difference (ψ mS) of 4mV, a tissue conductance (G T) of 10–11 mS/cm 2 and a short circuit current ( I sc ) of 1.5 μeq/cm 2 · hr. 4. 4. Under control conditions sodium (2.65 μeq/cm 2 · hr) and chloride (0.67 μeq/cm 2 · hr) are absorbed. 5. 5. Ouabain abolished ψ ms, I sc and the net sodium flux totally, whereas 0.1 mM amiloride only slightly decreased the net sodium flux. 6. 6. No differences in electrical properties and Na,Cl-fluxes were found between the faeces periods. 7. 7. Removal of sodium abolished ψ ms and I sc totally, and a high potassium solution depolarized the preparation ( ψ ms = 0). 8. 8. A linear current-voltage relation characterizes the tissue as an ohmic resistor between −40 and +50mV, and reveals a slope conductance of 14mS/cm 2 under KCl conditions. 9. 9. We conclude that the transport functions under in vitro conditions differ markedly from the in vivo situation, and that the diurnal differences of electrolyte transport in vivo occur mainly by the involvement of ionic gradients.

Anaerobic ureolytic bacteria from caecal content and soft faeces of rabbit.

Forty strains of ureolytic bacteria were isolated from the caecal content and soft faeces of seven rabbits by the anaerobic roll tube method and were characterized. The isolates were identified with Clostridium coccoides, Cl. innocuum, Peptostreptococcus productus, P. micros, Peptococcus magnus, Fusobacterium russii and Fusobacterium sp. Urease activity of representative strains of the various species was also determined. The study indicated that strongly-ureolytic anaerobic bacteria are present in the caecum of the rabbit.