World Vets - Volunteer Veterinary Projects. Merck Veterinary Manual. Rumen Physiology and Rumination. The rumen is a fermentation vat par excellance, providing an anaerobic environment, constant temperature and pH, and good mixing.
Well-masticated substrates are delivered through the esophagus on a regular schedule, and fermentation products are either absorbed in the rumen itself or flow out for further digestion and absorption downstream. Ruminants evolved to consume and subsist on roughage - grasses and shrubs built predominantly of cellulose. Despite the fact that some ruminants, feedlot steers for example, are feed large quantities of grain, this section will focus on a ruminant's "natural diet". Dynamics of Cranial Digestion. Rectal Palpation Diagrams. Animal Husbandry. Hemangiosarcoma. Hemangiosarcomas are a form of cancer which originates in the endothelium, which is the lining of blood vessels and spleen.
As might be expected of a tumor arising in the blood system they are highly malignant and can be found almost anywhere in the body since blood vessels are necessary in almost all body tissues. There is a strong predilection for the spleen, pericardium and heart. These tumors are most common in middle aged or older dogs which are medium sized or larger but can occur in any breed. German shepherds are reported to be more susceptible to this tumor than most dog breeds.