Parasitic worms can always be identified by looking at them.

With few exceptions, most adult worms look alike to the naked eye. Roundworm looks like long spaghetti noodles. However, in the larval stage the roundworm can be much shorter and resemble other worms. The exception is the tapeworm, the eggs of which infrequently appear in fecal analyses, which sheds clearly visible flat segments that resemble white rice and adhere to your pet’s rear end.

The identification of parasites is necessary to determine the medication for effective treatment. It is also important in order to advise you when and if the treatment should be repeated according to the particular life cycle of each type of worm. This is also helpful in giving hints to avoid reinfestation. In preparation for microscopic examination, your pet’s stool is liquefied and filtered. A sample is then scanned under the microscope for the presence of eggs that are typical of each and every parasite. All canine whip worm eggs look alike, but appear very different compared to coccidia, for example, another type of intestinal parasite.

Dogs should have a stool sample collected in the early spring and again in the fall to screen for parasites that may otherwise go undetected. An animal can be heavily parasitized and still present a batch of stool that contains no eggs. This is due to the cycle in which the female worms lay their eggs. In many instances where intestinal parasites are strongly suspected but have not been found in a stool sample, veterinarians will recommend worming (treating for worms) the animal anyway, just in case. If your cat roams outdoors and rarely uses a litter box, a fecal sample may be difficult to obtain. Even house cats benefit from fecal analyses since, as mentioned previously, it is still possible to bring eggs home on your own shoes or for your cat to swallow an insect harboring an egg from a parasitic worm.