There are about 75 species of American marsupial (pouched mammal), all of which are called opossums. These are divided into 3 family groups: American opossums. shrew opossums, and the colocolo or monito del monte.
Rodents and Their Classification
Rodents are the world's most successful mammals and are found in just about every habitat on earth. There are 3 main groups: squirrel-like rodents, mouse-like rodents, and cavy-like rodents.
Classification of Mammals
The mammals are the most advanced of all vertebrates and are the dominant land animals all over earth. There are a number of features that distinguish mammals from other animals.
Fishes: Classification, Feeding and Reproduction
The words "reptile" and "bird" are precise in meaning, for they denote a member of a particular class of vertebrate animals. The word "fish," however, although extremely useful, is not specifically precise, for there is no class "Fishes." The animals usually referred to as fishes belong to several classes. All are aquatic and are constructed on a similar pattern, but there are a number of important differences between the classes.
The first elephants to walk the Earth lived in the Eocene times some 60 million years ago.The earliest known fossils - discovered in Egypt - are of a creature called <i>Moeritherium</i>. In general appearance this creature was nothing like a modern elephant. It was only about 2 feet high and had no trunk. However, the structure of the skull and the form of the teeth show that it was a very primitive kind of elephant.
Placental Mammals (Placentals)
The young of placental mammals, however, have a long period of development within the mother. This is permitted by means of an elaborate organ, the <i>placenta</i>. It allows extremely close contact between the blood vessels of the mother and those of the growing embryos so that adequate supplies of food (e.g. sugar molecules) are continually carried to them.
No one can fail to be impressed by the great size of some whales (they include the largest animals ever known on Earth), but more striking than size alone are the features of their anatomy and physiology which makes them so wonderfully adapted to lead their entire life in water.
The pouched mammals, or <i>marsupials</i>, differ from the highest group of mammals (<i>placentals</i>) in a striking way. The young are born at a very early stage in their development - in the opossum from only 8 to 13 days after fertilization has occurred. They then crawl to a pouch on the abdomen of the female where they spend the early part of their lives, being suckled on milk from the mammary glands.
Meet Westphalian Dachsbracke
The Westphalian Dachsbracke is a medium-sized, sturdily built, hunting dog of German origin who takes his work duties very seriously. This breed is the short-legged variety of the German Hound (Bracke). It is quite similar in essential points to the long-legged variety, but gives a compacter, more powerful impression.
Meet Spanish Hound
The Spanish hound, or Sabueso espanol, as it is called in its native Spain, is a medium-sized scenthound usually used for hunting small game. The Sabueso español is a great specialist in hunting the hare with his doubling habit and he is also most efficient in blood tracking (searching of wounded big game).
Treatment for Skin Cysts
Dermoid cysts, also called dermoid sinuses, are rare developmental abnormalities that may occur as single or multiple lesions resembling follicular cysts
Common Cancer in Dogs: Mastocytoma
The mastocytoma is sometimes called as "the great deceiver" as it can show up with a wide range of appearances and clinical signs.
Histiocytic ulcerative colitis
If you Boxer dog is less than 2 years of age, and you noticed blood in his stool, you need to talk to your veterinarian about this condition.)
Oligodendroglioma - Brain Tumor and Seizures in Dogs and Cats
Whenever a dog or cat that is greater than five or six years of age has a new onset of seizures, a brain tumor is a possible differential and ruled out by a full diagnostic workup.)
Cystinuria and Kidney Stones
Cystinuria has been recognized in more than 60 breeds of dogs and a severe form, resembling type I cystinuria, has been characterized in the Newfoundland breed.)
Some disease have similar signs and symptoms, as is the case with this condition which can be sometimes mistakenly diagnosed as dilated cardiomyopathy. Some breeds are especially susceptible to this condition.)
You dog eats well and his appetite remains normal, but he looks malnourished. Vomiting of food eaten 24 hours previous is essentially indicative of pyloric stenosis (gastric retention). )
Fibrosarcoma: Third Most Common Oral Cancer in Dogs
This fast-growing cancer has poor prognosis, but with aggressive radiation and chemotherapy may extend the life of your pet.)
Clostridial Enteritis in Hamsters
Your hamster's hair looks ruffled, he lost appetite, and has diarrhea. These may be signs of a deadly disease called clostridial enteritis.)