There are too many internal and external parasites that dogs develop to list here. They begin in the fetal life of the pup and most times, the Mom already had them when she became pregnant. After about forty days of pregnancy, the parasites will travel through the placenta to the fetus. Parasites can also be passed through the mother’s milk. Of those parasites that have infected a pup, Most are quite mobile. They can move to the intestines and lungs.
An awful internal parasite is the heartworm. Transmitted by mosquitoes, they can be fatal to your dog. Have a blood sample taken and analyzed. Even if the test is negative, the vet will probably start your pup on heartworm medicine that he will take once a month. If positive, the animal will have to hospitalized.
Roundworms can be a problem because most puppies are born with them. The larvae are transmitted from the Mom to the fetus. They are easily transmitted to humans in the dog’s stool. They can be ingested if your dog eats another animal’s stool. Wash your hands frequently after handling the puppy and remove all feces from the yard. Some people have no symptoms at all. There have been cases where the worms have migrated to the liver, brain, and eyes of humans. Your puppy should be wormed at two, four, six, and eight weeks of age.
An external parasite is the tick. These animals live on th dog’s skin. They look like small black dots. You must use tweezers to pull them off the skin. DO NOT use fingers. Ticks can bite and suck blood out through the skin as well as transmitting diseases such as Lyme Disease and Rocky Mountain Spotted Fever. You must make sure the whole tick comes off the skin as they can burrow deep.