Charleston: Parasite Grand Central Station

WRITTEN BY: KRISTIN HAUEISEN, Contributing Writer

Dogs are naturally susceptible to both internal and external parasites in our area of the country and protection requires year-round vigilance. Our mild winter weather simply does not reach the cold temperatures required to cease parasite life cycles, so this means our pets are at risk year-round and not just in warm months. The Companion Animal Parasite Council conducted a 2018 study of internal GI parasite transmission in the southeast US that revealed 27% of samples collected contained a GI parasite (whipworms, hookworms, and roundworms). * Parasites in dogs can present in many forms but one thing sure to be common among them all is sooner or later they will almost always impact a dog’s health. Whether you have experienced parasites up close and personal or not, education is an important part of prevention and treatment.

Internal Parasites

Giardia are single cell-organisms infectious to animals everywhere, including humans. They infect our dogs most commonly through contaminated water sources and in the lowcountry, we are no stranger to standing water. Microscopic giardia are consumed usually from a water source, digested and then travel through the digestive tract causing problems for the host dog. The primary symptom of giardia is diarrhea, and it is suspected this is because the organism is disrupting normal intestinal absorption of vitamins and other nutrients. The most reliable treatment of the parasite is a broad spectrum dewormer and supportive care.

Roundworms are most common in puppies and we can almost always assume that newborn puppies are infected with them. Have you seen a puppy with that cute little pot belly? Well, they probably have roundworms. Roundworms are one of the only intestinal worms that can be visibly seen in the feces as they are long and white, almost spaghetti-like. The lifecycle of the roundworm is complicated and has several infectious stages so several deworming treatments are necessary, especially as puppies. Symptoms of infection in young dogs include vomiting and diarrhea. Even more alarming, worms can be vomited up by the infected dog. Heavy parasite loads can be more serious as they can obstruct the intestines as they migrate through the body systems. You might not always know if your dog is infected so fecal testing as puppies and annual testing as adults is important to ensure this parasite is not around. CAPC reported surveys showing more than 30% of dogs younger than 6 months of age are shedding roundworms in their feces.*

Hookworm infection occurs when the dog ingests larvae from a contaminated environment, such as the soil as a dog park. Diarrhea and anemia are primary symptoms due to the worms feeding on blood in the intestinal tract. While a dog may be dewormed and cleared of the adult worms, the intestinal tract can be repopulated by dormant larvae that have lingered in body tissue and periodically become reactivated. Once a dog is infected with hookworms, it is often challenging to get rid of them due to this larval dormancy stage. This is also where monthly parasite prevention is key to help prevent further infection. The data on parasite prevalence from CAPC (capcvet.org) reveals that the most common parasite in Lowcountry dogs in 2020 was hookworms. In Charleston County, 1 out of every 24 dogs tested were positive for hookworms.* Whipworms are named for their whip-like shape and when passed through feces are extremely resistant to desiccation in the environment. For this reason, whipworms are difficult to avoid and can persist in the environment for several years. While we might not notice the dog is infected with whipworms when there are only a few present, a larger number can cause severe inflammation. Signs of more serious infection are a result of more whipworms imbedding into the large intestine tissue, causing bloody, gooey diarrhea. Usually, this blood loss is not an issue but can easily get out of control and dangerous if not treated. The most common broad-spectrum deworming does not work for treating whipworm infections so testing to identify the parasite can allow for selecting appropriate medication. Since it is virtually impossible to remove whipworms from the environment, there is always a concern for the dog to be reinfected. Providing continuous protection is important and selecting the preventive that covers whipworm should be used to ensure the pet is protected from future infection.

Flea Lifecycle. Source: theveterinarynurse.com

External Parasites

Fleas are the most common parasite in dogs and can cause infections. These tiny insects have a voracious appetite for blood and feed on mammals, including dogs. Flea bites are miserable for dogs and can cause itchiness resulting in self-inflicted wounds or secondary infections. Hungry fleas also bite humans leaving itchy, irritated bumps on the skin.

Once established on a host, female fleas start laying eggs within 24 hours and can produce 50 eggs per day. Their lifecycle can take up to 6 months but once hatched the adult flea will begin looking for a host and meal. If left unprotected, a dog’s brief encounter with a flea can quickly progress into a lengthy process to manage. Fleas in the pet’s environment are difficult to exterminate as they crawl into carpets, upholstered furniture, and even the interior of cars.

While you may be able to see the dark brown-black colored fleas darting around on the pet’s skin, the most preferred areas are the base of the tail and ears. If live ones are not visible, you can part the hair and look for tiny black specks the size of grains of sand. These specks are flea feces, or “flea dirt” and are composed of digested blood. Symptoms of fleas on dogs include excessive scratching, licking, or biting of the skin which can result in hair loss or hot spots. Severe flea complications include anemia as one flea can consume 15 times their own body weight in blood. Some dogs also have a heightened sensitivity to the saliva of fleas and develop flea allergic dermatitis which causes even Ticks are another problematic external parasite as tick-borne illnesses are a growing threat to dogs. Ticks attach firmly to their host and feed on their blood, sometimes for days. Although their presence is often not even noticed by their host, ticks are visible to the naked eye especially when they have already begun feeding. They are efficient carriers of disease and people generally associate them with Lyme disease, which affects both dogs and humans although the illnesses are completely different. Lyme disease is an infectious disease caused by the bacteria Borrelia which is most often found in its vector, the deer tick. Infection occurs when the dog is bitten by an infected tick and is fed on for at least 24-48 hours. Symptoms of Lyme disease are difficult to discern from other illnesses and therefore a challenge for veterinarians to diagnose. Signs of illness are usually not even noticed for weeks to months after being infected at which time they are reported to be experiencing generalized pain and lethargy. Painful lameness can occur and sometimes wax and wane in recovery. Severe infection can result in potential long-term damage to the kidneys. Because ticks transmit a wide variety of diseases, year-round protection is encouraged. Tick populations have shifted and while areas like Charleston have not had a notable tick presence in the past, tick populations are moving in and can pose a risk to unprotected pets.

We should be encouraged as pet owners to take a preventive approach to parasite protection. Consult your veterinarian to discuss the best parasite preventative for your pet. If you have concerns about your pet having parasites, your veterinarian can test a stool sample to determine if your pet is affected. It is also important that all animals in your household are protected against internal and external parasites (including indoor cats) since one pet can be contagious to the others. If you have further questions or concerns about parasites, remember your veterinarian is always there to see that you get the answers you need. For more data on parasite prevalence, prevention, and control, visit the Companion Animal Parasite Council site at capcvet.org. CAPC is an independent, non-profit organization dedicated to increasing awareness of the threat parasites present to pets and family members. ■

*Data sourced from capcvet.org, Companion Animal Parasite Council