Heartworm has been diagnosed in dogs in all parts of the world and is actually very common. This may be due to the fact that heartworm has a virtual 100% prevalence rate in unprotected dogs living in highly endemic areas. Heartworm, also known as Dirofilaria immitis, is transmitted by mosquitoes. The mosquito injects a microscopic larvae which grows into an adult worm six to eighteen inches long inside the heart of the affected dog.
The worms can cause mild symptoms, such as coughing, but with time, more severe symptoms such as congestive heart failure, weight loss, fluid build up in the abdomen, fainting spells, anemia, collapse, and death usually occur.
Luckily we have several excellent medications which can prevent heartworm if given as directed. There are oral medications which need to be given monthly, and which also help protect against some intestinal parasites. There is one topical medication which is also applied monthly. An injectable medication, ProHeart, which is administered every six months, is back on the market after being withdrawn for several years.
Even if a dog has been given preventatives, it is still important to have annual checkups for heartworms by doing a blood test. Many people are not totally compliant about giving the preventive medication on time, and no medication works perfectly. If a dog has heartworms and it is given a dose of preventative, there can be a reaction that is detrimental to the dog, even deadly.
Heartworms were once thought to be rare in cats. Now we know the incidence is anywhere from 10% to 50% of the canine rate. Heartworm disease in cats is different than in dogs. Cats usually test negative on the routine blood test done in the hospital, the worms are smaller and usually do not produce microfilaria which are like baby heartworms that circulate in the bloodstream. Veterinarians have to do different tests, sometimes more than one, to diagnose heartworms in cats.
The symptoms in cats are different also. Cats usually have asthma signs or cough, even vomit. Cats can die acutely. The treatment for adult heartworms in dogs is expensive and potentially harmful to the dog. This is why it is much better to just prevent them in the first place. There is not a treatment for adult heartworms in cats. Many veterinarians are now recommending monthly heartworms preventative for cats in addition to dogs, since heartworm can be such a serious problem.
There are many types of mites that infect dogs, cats, and other animals. Mites are microscopic arthropod parasites that, for the most part, infect the skin or mucous membranes. Mites can even be present on birds and reptiles. The most common mites that infect dogs and cats are ear mites, Demodex, scabies, and Cheyletiella.
Ear mites are very common on cats and are occasionally seen on dogs. They live primarily in the ear canals and can cause severe irritation. They are easily transmitted between pets, so if they are found in one pet, all pets in contact should be treated. A different species of ear mite can infect rabbits.
Demodex is a mite that all dogs are exposed to, but only a small percentage of dogs develop skin problems. In young puppies, it usually causes small areas of hair loss especially on the head and front legs. Adult dogs tend to show more generalized symptoms, and usually have more red, itchy skin lesions. Adult dogs that develop Demodex usually have another disease such as hypothyroidism, Cushings, or cancer that suppresses the immune system and allows the Demodex to increase in numbers and cause lesions. It is now recognized that cats have their own species of Demodex, but the disease is much more rare in cats.
Scabies is a skin disease in dogs or people caused by the mite Sarcoptes. Most dogs with this disease are intensely itchy. Scabies is highly contagious, but not all dogs in contact are as itchy. People also have their own species of Sarcoptes; most of their cases are due to the human scabies mite, but it is possible for people to develop lesions from the dog scabies mite.
Cheyletiella species of mites can be seen in rabbits and dogs. It is especially seen in puppies as large flakes of scale and is sometimes called “walking dandruff.” There is no one treatment that will kill all the types of mites discussed here. Your veterinarian can advise you on the various treatments for each problem.
Hookworms are small, thread-like parasites of the small intestine where they attach and suck large amounts of blood. These parasites are found in almost all parts of the world, being common in dogs, and occasionally seen in cats.
Symptoms are usually diarrhea and weight loss. The parasites can actually suck so much blood that they cause pale gums from anemia, and black and tarry stools. Young puppies can be so severely affected that they die. Infection can be by ingestion of breast milk from an infected mother, by ingestion of infected eggs, or by skin penetration of infected larvae.
Since the adult parasites are so small, they are rarely seen in the stool. Diagnosis of these parasites is by the veterinarian or laboratory finding the microscopic eggs in the stool.
There are a variety of medications that can kill hookworms. The important point to know is that there is no one medicine that will kill all the types of intestinal parasites that exist. Some of the monthly “heartworm preventatives” will also work to treat hookworms.
People exposed to hookworms can develop a rash called cutaneous larval migrans. Infected larvae, usually from contaminated yards, can penetrate human skin and cause red tracts.
There are many types of parasites that are found in the GI tract of cats and dogs. Worms such as roundworms, whipworms, and hookworms are very common in almost all parts of the world. These parasites shed their infective eggs in the pet’s stool and contaminate the environment; some eggs can live on yards or fields for years. The eggs are ingested by the pet and the life cycle is completed when the worm grow into an adult in the intestine of a new host.
Tapeworms are another very common intestinal parasite of dogs and cats. This parasite is different though, in that it requires transmission through an intermediate host, most commonly a flea. Other intermediate hosts can be mice, rats, or rabbits. The dog or cat eats the intermediate host containing the tapeworm egg, and the tapeworm completes its life cycle to develop into an adult in the intestine of the dog or cat. The intermediate host is required, if a pet eats an adult tapeworm or tapeworm segment, it will not cause tapeworms to grow in its intestine.
Other parasites can live in the intestine that are not worms such as one-celled organisms called protozoa, which are also prevalent parasites among pets. Giardia and coccidia are protozoa that can be transmitted directly from animals to your pet, or your pet can be exposed from contaminated water. Diagnosis of these parasites requires your veterinarian or their laboratory finding either the microscopic parasite or its egg in the stool.
The only parasites that can be seen in the stool with the naked eye are roundworms and tapeworms. Roundworms are ivory colored, round (not flat) in shape, and about 4 to 6 inches long. Tapeworms are ivory colored and flat in shape. The adult tapeworm is several feet long, but usually you see only tapeworm segments that look like either sesame seeds or rice. Your pet could have either of these worms without the adult parasites ever being shed into the stool. If your pet’s stool looks normal, don’t think your pet can’t be infected. There is no one drug that can kill all types of intestinal parasites that exist. Your veterinarian needs to know what kind of parasite(s) infection is involved, so a correct drug can be prescribed. Also, some of the monthly heartworm preventatives will also treat roundworms, hookworms, and whipworms.
If you suspect that your pet may be affected, don’t hesitate to contact your veterinarian today for direction on what to do! Your veterinarian will also be able to answer all your questions and help you prevent your pets from getting parasites in the first place.
There are many types of roundworms, but some of the most common are intestinal parasites of dogs, cats, and raccoons. Puppies are frequently born with roundworms, and kittens can be infected via the mother’s milk or feces. Adult roundworms are ivory colored, four to six inches long, and round (not flat ) in shape. These parasites can cause diarrhea, vomiting, weight loss, and even coughing in these young patients. In the usual case, the owner will not see the adult roundworms passed in the stool. This is why it is important for the veterinarian to do a laboratory test to check for any parasites that might be present. We check for parasite eggs with a microscope. You should bring a fresh stool sample (one that was produced that day) to your puppy or kitten’s appointment.
It is important to know that animal roundworms can be transmitted to people, and in some cases can cause serious disease. In a recent study from the Center for Disease Control (CDC), it was reported that almost 14 % of all Americans are infected with Toxocara, the most common roundworm of pets. Although most people infected have no symptoms, the parasite is capable of causing blindness (especially in children) and other systemic illness. The infective agent is the microscopic egg in the animal’s stool. It is known that these eggs are very resistant to environmental conditions. They have been shown to live in yards, playgrounds, and fields for up to 10 years.
The most dangerous roundworm is Baylisascaris, a parasite of raccoons that has an affinity for brain tissue. Children infected with this parasite have suffered severe, permanent mental retardation. The majority of raccoons carry this parasite. If wildlife is present on your property, you should patrol the grounds and any raccoon stools should be treated as hazardous waste. Wear disposable gloves to double bag and dispose of the feces. The only thing that will kill the remaining eggs in the soil is fire.
The CDC recommends regular deworming of all puppies and kittens to try to reduce the exposure to people. A medication will be dispensed when your puppy or kitten is first seen. Another important measure is monthly parasite preventative, or what we sometimes call “heartworm preventative.” Many of these drugs are also effective for roundworms, and are an important part of a wellness program.
The CDC prevention measures include:
- Keep dogs and cats under a veterinarian’s care for early and regular deworming
- Clean up after the pet and dispose of stool
- Keep animals’ play area clean
- Wash hands after playing with dogs or cats
- Keep children from playing in areas where animals have soiled
- Cover sandboxes to keep animals out
- Don’t let children eat dirt
Ticks are the small wingless external parasites, living by hematophagy on the blood of mammals, birds, and occasionally reptiles and amphibians. Ticks are blood-sucking parasites that are often found in freshly mown grass, where they will rest themselves at the tip of a blade so as to attach themselves to a passing animal. It is a common misconception that the tick can jump from the plant onto the host. Physical contact is the only method of transportation for ticks. They will generally drop off the animal when full, but this may take several days. Ticks have a harpoon-like structure in their mouth area, known as a hypostome, that allows them to anchor themselves firmly in place while sucking blood. This mechanism is normally so strong that removal of a lodged tick requires two actions: One to remove the tick, and one to remove the remaining head section of the tick.
Ticks are important vectors of a number of diseases. Ticks are second only to mosquitoes as vectors of human disease, both infectious and toxic. Hard ticks can transmit human diseases such as relapsing fever, Lyme disease, Rocky Mountain spotted fever, tularemia, equine encephalitis, Colorado tick fever, and several forms of ehrlichiosis. Additionally, they are responsible for transmitting livestock and pet diseases, including babesiosis, anaplasmosis and cytauxzoonosis.