Worms can infest any animal including humans, and may or may not be host-specific. Generally, in pets, worm identification is done through an understanding of clinical symptoms and laboratory procedures such as stool examination. Not all worms are visible by the naked eye.
Diarrhea, anorexia, anemia, cough, weight loss, dull coat and pot belly are common symptoms which can help to identify worms in dogs. In the laboratory, stool examination and radiography are some techniques used for this purpose. Identification of dog worms is essential in most cases, in terms of specific treatment and epidemiology (involves population), but not compulsory as many broad spectrum anti-helmintics are available to treat a range of worms. These target the worms and allow them to be expelled from the body."
Worm Identification in Dogs Through Clinical Symptoms
Clinical symptoms, although they cannot confirm a worm infestation, can provide a strong suspicion that a dog worm problem exists. Generally, a pet with diarrhea, progressive weight loss, anorexia and dullness in coat can be suspected for worm infestation but can only be confirmed on the basis of a detailed clinical examination of the dog's behavior and through laboratory examination.
Roundworms in dogs are usually suspected when a dog shows signs of immediate diarrhea, vomiting, anorexia and dullness of coat. They are visible with the naked eye and appear long. Dog roundworms can grow up to seven inches in size and can infest other animals and humans as well. They are more common in unhygienic environments.
Tapeworms in dogs can cause vomiting, itching around the anus, abdominal pain and diarrhea in some cases, and can be an indication of a tapeworm infestation. These usually require an intermediate host (flea, mouse etc.) to complete their life cycle. Segments of tapeworms appear as white, rice-like particles found in feces and around anus of infested pet.
Similarly, dog hookworms can cause anemia (drop in red blood cells, lethargy) as a major symptom along with bloody diarrhea, skin irritation, weight loss, pale gums and progressive weakness. These cannot be seen with a naked eye, thus hookworms in dogs need to be confirmed through a laboratory fecal examination.
Dog whipworms can cause diarrhea, bleeding in the large intestine, dehydration and weight loss. They are long thread-like organisms and are usually confirmed through laboratory procedures which are used for the detection of eggs.
Dog heartworms are another parasite which causes cough, lethargy, intolerance and severe cardiac complications. Worm identification is usually based upon the clinical symptoms and via the use of advanced laboratory techniques involving hematology and radiography.
Source: American Heartworm Society
Worm Identification Through Laboratory Procedures
Worms are most commonly identified by examination of the stool. This is because the most common types of worms which infest pets use the intestine as their final site of action. Thus, stool or fecal examination in the laboratory can confirm any type of worm, whether it can be seen or not with the naked eye.
Stool flotation technique, microscopic examination of fecal content slides and some advanced comparative techniques are commonly used procedures in the laboratory for canine worm identification. In some cases, such as in heartworm infestation and less frequently occurring esophageal worm infestation, serological tests, radiography and sometimes endoscopy may be required for confirmation and dog worm identification.
How Does Worm Identification Influence Treatment?
Most veterinary researchers recommend that specific treatment should only be carried out only after confirmation of type, through techniques such as a review of symptoms, laboratory or morphological examination (review of the worm appearance) of the worms.
Specific drugs used for treating canine worms are called anti–helmintics, which either kills or halts reproduction of the worms. These are therapeutic agents, thus should be used only with a prescription and with a veterinarian calculating the exact dose rate needed.
In most of cases, where confirmation is not possible, broad spectrum anti-helmintics are usually administered. Febendazole, Albendazole etc., combined with cobalt salt are some examples of such drugs, which can be prescribed on the basis of symptoms and a partial confirmation.
Homeopathic and herbal remedies can help with worm control such as Parasite Dr. Capsules. They are used as a supportive therapy only, which means they are used in addition to conventional treatments prescribed by a veterinarian. Some remedies such as the one mentioned help in clearing the digestive tract, while others can help to restore damage caused by worms.
Heartworms are usually treated with two different approaches in pets. These involve use of specific drugs, while similar drugs are strictly prohibited in some smaller breeds of dogs and in cats. Herbal tonics such as Heart & Circulation Tonic can help in maintaining strength of cardiac muscles and blood vessels in case of a heartworm infestation.
J. Brahmas., et al. Veterinary Parasitology, (Delhi Publishers, India 2004)