Internal Parasites

There are many types of internal parasites that can make your rottie very sick. Some are worms that live in the intestines and feed on the nutrition your dog needs or that actually feed on his blood. Some worms, such as heartworms, live in the heart, bloodstream, and lungs. Other internal parasites are microscopic, but these can still cause extreme diarrhea. Regardless of the type of internal parasite, your vet can help you in your fight to keep your rottie parasite-free.

Never deworm your dog with over-the-counter dewormers. These only work on specific types of worms and will do no good if you treat for the wrong type of worm. Since all dewormers are poisons, it is best to have your vet diagnose the type of infestation and then recommend the appropriate dewormer.


A dog or puppy becomes infected when he accidentally ingests the worm's eggs. The most common source of contamination is fecal material. However, your rottweiler can also contract worms from eating raw meat from infected animals such as rodents, game, or farm animals. Fleas carry tapeworms that, when accidentally ingested, can infest your rottweiler. The most common worms are roundworms, hookworms, tapeworms, and whipworms.

Roundworms, and to a lesser extent, tapeworms, can infect people through the oral-fecal route. Children have contracted round-worms, but because people aren't the normal host for them, the roundworms migrate to places like eyes, causing blindness. It is very important to keep your dogs worm-free.

Although worms are common in puppies, worms will make your rottweiler sick. When you take your rottweiler to the veterinarian, ask him if you should bring a fecal sample. Your veterinarian may want to run a fecal test and check for parasites.

If your rottweiler has diarrhea, bloating, weight loss (or is not gaining weight), bloody stools, anemia, or rice-like flecks around the anus, have your veterinarian run a fecal test to look for worms. Rottweilers that scoot on their bottoms are more likely to have impacted anal sacs than worms, but you should have your veterinarian check for worms anyway.


Roundworms (Toxocara canis) are the most common worms. Your rottweiler may have been infected with roundworms even before he was born! Roundworms lie dormant in a female dog's body and start migrating to the puppies when the female becomes pregnant. Roundworms can even infect the mother's milk, and the puppies can pick them up while nursing. Other avenues for transmission include fecal matter.

Contracting roundworms is not a statement of the breeder's care. If your rottweiler's mother has ever had roundworms during her life, your puppy has probably contracted them through her. However, the breeder should deworm the puppies.

Roundworm infestation can be serious in puppies and in old and debilitated dogs. Roundworms feed off the nutrition intended for your rottie. A puppy that is infested may have a pot belly, may lose weight, and may have a poor coat. Other signs include vomiting, diarrhea, and a garlic odor to the breath. Take your puppy and a fecal sample to the vet. Roundworms can be quite serious and can kill a puppy.


Hookworms (Ancylostoma caninum) are smaller than round-worms and feed in the small intestine from your rottweiler's blood. Dogs contract hookworms either through skin penetration (they can burrow into a dog's skin) or through the mother's milk. Severe infestations can be life threatening and can cause severe anemia. Diarrhea, weight loss, and lethargy are signs of hookworm infestation.

Whipworms (Trichuris vulpis) are difficult to diagnose because they don't always produce eggs in fecal matter. These worms feed on blood in the large intestine. Like hookworms, these worms can be serious and cause severe anemia. Dogs become infested by eating something in contaminated soil.


Tapeworms (Dipylidium caninum) are long, flat worms that may infest your rottweiler's intestines. These worms may break off and be excreted in his feces. They look like grains of rice in the feces or around the dog's anus. Fleas commonly carry tapeworms. Your rottweiler may swallow a flea, thus becoming infested with tapeworms. Other modes of transmission include raw game meat. Some dogs catch and eat mice or other rodents that carry tapeworms.


Heartworm is a deadly internal parasite that lives in the heart, bloodstream, and lungs. Mosquitoes carry heartworm from an infected dog to others by injecting the larvae into the dog as it feeds on the dog's blood. Heartworm is prevalent in most of the continental United States. Dogs in warmer climates need to be on heartworm preventive year round, while dogs from northern states must be on a preventive during the spring and summer months.

Your veterinarian should test your rottie for adult heartworm before putting him on a preventive. If your rottie has a heartworm infestation, it should be treated before he is put on a preventive. Heartworm treatment used to be very dangerous, requiring the veterinarians to administer an intravenous arsenic-based solution. There is a new heartworm treatment that veterinarians administer intramuscularly. This new treatment is less risky and has fewer side effects. If your rottweiler has heartworms, be sure your veterinarian is using a newer treatment than the old arsenic-based treatment. Heartworm treatment is still risky and expensive, so it is better to prevent heartworm than treat it.

Heartworm is spreading through the United States. As a result of our mobile society, places that didn't have heartworms even ten years ago now have it. Ask your vet what the incidence of heartworms is in your area.

There are many excellent heartworm preventives. Most available are chewable and are given monthly. Do not use the old daily heartworm preventive as it is less effective when not administered properly. Some monthly heartworm preventives now also control other internal parasites.

Giardia and Coccidia

Other internal parasites include microscopic organisms that can cause diarrhea and vomiting. The most common of these organisms are giardia and coccidia.

Giardia is a common microorganism that lives in streams. Metronidazole is the common method of treatment for giardia. Your veterinarian will have to run a test on a stool sample to determine if your rottie has giardia and may prescribe medication to treat it. Sometimes giardia comes back, and you may need several treatments to thoroughly eliminate it. There is a new vaccine on the market that protects dogs from giardia.

Coccidia is a common microorganism in puppy mills and large kennels. This protozoa is generally associated with unsanitary conditions. However, as the disease is often carried by birds, reputable breeders may have coccidia in their kennels. Once it is introduced into an environment, it is very difficult to eliminate.

Symptoms of coccidia include diarrhea and vomiting. Your rottie may contract coccidia through ingesting feces or licking a contaminated surface. Pick up all feces and use an ammonia-based pine cleaner to kill the microorganisms. Bleach will not kill coccidia; only strong ammonia-based cleaners will be effective. The treatment of choice for coccidia is Albon, which is available through your vet.

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