Luzerne en bedorven vismeel leverden een verbinding met lager en hoger molecuulgewicht, die vitamine K1 en K2 werden genoemd (3, 4). K1, K2 en K3 In 1939 werd de isolatie gerapporteerd van twee zuivere stoffen met vitamine K-activiteit. Voor zijn initiële en verdere onderzoek over vitamine K kreeg Henrik Dam in 1943 de Nobelprijs voor geneeskunde. De K staat mogelijk voor "koagulering", het Deense woord voor stolling. In 1935 stelde Dam voor om de onbekende, actieve stof vitamine K te noemen (2). Varkenslevervet was vele malen actiever dan tarwekiemolie, hetgeen vitamine E uitsloot als behoedende factor. Hoge doseringen van de vetoplosbare vitamines A en D waren niet effectief. Vervolgonderzoek liet zien dat vethoudende fracties, verkregen uit onder meer varkenslever, hennepzaad, tomaten en boerenkool, beschermden tegen de bloedingen bij kuikens (2). Het experimentele voeder, dat bestond uit caseine, zetmeel, bakkersgist, zouten en kabeljauwleverolie (Noot 1), veroorzaakte ook groeivertraging. In 1934 beschreven de Kopenhaagse onderzoekers Dam en Schönheyder voedingsgeïnduceerde, interne bloedingen bij kuikens, die leken op scheurbuik, maar niet werden voorkómen door vitamine C (1). Er zijn voedernormen gesteld, maar noodzaak, omvang en vorm aangaande vitamine K-suppletie van petfood blijven discutabel. De kwantitatieve vitaminebehoefte via de voeding is onbekend, mede omdat de darmflora ook vitamine K levert. Een tekort leidt tot verminderde bloedstolling en interne bloedingen. Vitamine K voor hond en kat Vitamine K is een essentiële voedingsstof voor hond en kat. Type of coprophagy (allo-and/or autocoprophagy) and housing (individually or in The article states that all dogs practiced coprophagy and that it was said to be a general problem. Carbohydrate intake In 1973, Kronfeld published his diet-intervention study in a group of 16 racing sled dogs that performed poorly (7). Clearly, its application would be primarily autocoprophagy-directed. In itself, the principle of making feces repellant by a safe dietary constituent or supplement seems achievable. The same holds for the coprophagy deterrents on the market. In conclusion, there is no demonstrable evidence, in the form of outcomes of controlled studies, that even one of the proposed diet changes significantly diminishes canine coprophagy. Three questionnaire-based studies indicate that coprophagy-treatment products are not very successful and that preventing access to feces is the most commonly used and most effective way to stop canine coprophagy (3, 5, 6). A commonly used substance in coprophagy deterrents is an extract from the desert plant Yucca schidigera, but there is no convincing experimental evidence for its efficacy. Most products enclose substances that allegedly make stool less appealing to dogs. Presumably in response to the unsubstantiated theories on diet and canine coprophagy, several supplements contain thiamin and digestive enzymes, including alpha-amylase which breaks down starch. Various dietary supplements, in the form of chewable tablets or powders, are marketed as coprophagy deterrents for dogs eating their own feces (Note 6). As to dietary behavior, the recent web-page survey (3) shows that greedy eating is associated with coprophagy. None of the diet factors proposed to initiate or intensify canine coprophagy is backed by available research data. More specifically, high carbohydrate (starch) intake, insufficient supply of vitamin B1 (thiamine), diets with below-average digestibility and low-fiber diets have all been suggested to promote coprophagic behavior (Notes 4, 5). Unsubstantiated theories have advanced that diet affects canine coprophagy. Thus, an association between diet and coprophagy, if there is any, was undetectable beforehand due to limited variation of diet type. The paper on the large-scale study states explicitly that the vast majority of the dogs was fed on dry food (3). The web-page survey (3) and two other questionnaire-based studies (4, 5) did not ascertain an association between type of diet and coprophagy. The conspecific coprophagy was mainly directed at feces no more than two days old (3). A web-page survey completed by 1475 dog owners found that 16% of pet dogs engaged in frequent eating of their own or other dogs' feces (3, Note 3).
In addition, the habit of dogs eating feces disgusts many owners. But dogs' risk of contracting certain parasites is increased by ingesting feces of conspecifics (Note 2). Otherwise, it might be considered normal canine behavior. Coprophagic behavior is clinical when caused by digestive disease (1) or chronic stress (2, Note 1). Quite a few dogs eat feces of hoofed animals, their own feces and/or that of other adult dogs.
For several weeks after puppies are born, bitches ingest their feces, likely for hygienic purpose. Diet and canine coprophagy Coprophagy, or stool eating, is a common behavior among dogs.
0 kommentar(er)
