Viruses are much smaller than fungi or bacteria, and they must invade a living cell to reproduce, or replicate. The virus attaches to a cell, enters it, and releases its DNA or RNA inside the cell. The DNA or RNA of the virus is its genetic information, which tak
A parasite is an organism that lives on or in another organism (usually referred to as the host), causing harm to the host. Parasites enter the body most often through the mouth or skin. Parasites that enter through the mouth are swallowed and can either remain
Rickettsiae are an unusual type of bacteria that cause several diseases, including Rocky Mountain spotted fever. Rickettsiae differ from most other bacteria in that they can only live and multiply inside the cells of another organism (host) and cannot survive on
Antibiotic drugs are commonly used in veterinary medicine to treat infectious diseases that are caused by bacteria and certain other microorganisms. There are many different classes of antibiotics available for use in animals, including penicillins, cephalosporin
An important aspect of medical treatment is the effect the treatment will have on the fetus or newborn when given to a pregnant or lactating animal. Many drugs are capable of crossing the placenta and affecting the fetus. Certain antibiotic drugs are toxic to a f
A wide range of dosage formulations and delivery systems has been developed to provide for the care and welfare of animals. Using the correct dosage is very important in terms of effectiveness and safety. Drug treatment and delivery strategies can be complicated
If your pet has been diagnosed with a condition or disease that can be managed or cured, your veterinarian will discuss treatment options. He or she will recommend drugs that are necessary, safe, and effective for both the individual animal and the specific disor
The zoonoses table in the Public Health section of the professional version of the MSD Veterinary Manual lists the most important zoonoses that have been documented. Many of these are quite rare and only occ
There are several things that can be done to minimize your risk for acquiring a zoonotic disease from animals. First, make sure your pet receives all of the recommended vaccinations for its species. This will keep your pet from becoming infected with certain dangerous diseases and spreading them to other pets or humans. Second, if yo