Introduction
Intestinal parasites are organisms that live in the gastrointestinal tract of cats and can cause a variety of symptoms and health issues. Some of the most common intestinal parasites found in cats include roundworms, tapeworms, hookworms, whipworms, giardia, and coccidia. These parasites are transmitted through contact with infected feces or ingestion of intermediate hosts like fleas, birds, and rodents. Intestinal parasites can cause symptoms like diarrhea, vomiting, weight loss, dull coat, and a pot-bellied appearance. Kittens and cats with weakened immune systems are more susceptible to intestinal parasites. Diagnosing intestinal parasites involves fecal examination and treatment usually consists of dewormers and medications to kill the parasites. Preventative measures like routine deworming, flea control, sanitation, and limiting access to intermediate hosts can help protect cats from intestinal parasites.
Hookworm
Hookworms are intestinal parasites that attach to the intestinal wall and feed on blood. The hookworm lifecycle begins when larvae infect the cat through contaminated soil or the mother’s milk. Once inside the intestines, the larvae mature into adults that produce eggs that pass into the cat’s feces. The eggs hatch into larvae in the soil and can then reinfect cats by penetrating the skin or being ingested. Hookworms are prolific egg producers, and just one worm can produce over 10,000 eggs per day. This allows rapid reinfection in environments contaminated with feces.
Major symptoms of hookworm infection include:
- Anemia caused by blood loss
- Dark and tarry feces due to the presence of digested blood
- Diarrhea
- Dehydration
- Weight loss
- Dull coat
- Weakness and lethargy
Kittens are especially susceptible to hookworms. The worms can stunt growth and cause serious illness in young cats. Blood loss anemia is the main risk, which is life-threatening in kittens if left untreated.
Roundworm
Roundworms are a common intestinal parasite in cats. The scientific name for the most common feline roundworm is Toxocara cati. Cats can become infected with roundworms from the environment, from their mother prior to birth, and through ingesting mice or other prey.
Roundworms have a direct lifecycle, meaning no intermediate host is required. Eggs are passed in the feces of infected cats. These eggs can survive and remain infective in the environment for years. If another animal ingests the eggs, the eggs will hatch in the intestinal tract and the larvae will migrate to various tissues in the body. The larvae encyst dormant in tissues until a female gives birth. The larvae are reactivated and infest the nursing kittens. Kittens can also become infected by ingesting eggs from a contaminated environment.
Major symptoms of a roundworm infection include:
- Distended belly
- Vomiting
- Diarrhea
- Poor growth
- Dull coat
- Coughing
In severe cases, roundworms can cause intestinal blockages or damage. Kittens with heavy roundworm infections may have visible worms in their feces or vomit. Treatment involves deworming medication prescribed by a veterinarian.
Tapeworm
Tapeworms are flat, segmented intestinal parasites that attach themselves to a cat’s small intestine using hook-like mouthparts. Tapeworms have a complex lifecycle that requires a flea intermediate host. Flea larvae ingest tapeworm eggs passed in the feces of infected cats. The tapeworm then develops into a cyst inside the flea. When a cat grooms itself and swallows an infected flea, the cyst hatches inside the cat’s intestine and becomes an adult tapeworm.
The most common symptoms of a tapeworm infection include:
- Scooting or dragging rear along the ground
- Excessive licking or biting at the fur over the tail/hindquarters
- Visible tapeworm segments around the anus or in the feces that look like rice grains
- Mild diarrhea or constipation from intestinal irritation
- Increased appetite but still losing weight
Cats become infected by ingesting fleas carrying tapeworm larvae. Tapeworm segments may also be ingested while grooming or from contamination in shared litter boxes. Kittens and outdoor cats that hunt rodents are also at higher risk of infection. Preventive flea control is the best way to avoid tapeworms in cats.
Source: https://www.petmd.com/cat/conditions/infectious-parasitic/c_ct_cestodiasis
Whipworm
Whipworms, or Trichuris vulpis, are intestinal parasites that affect cats. The whipworm lifecycle begins when eggs are passed in an infected cat’s feces. The eggs can survive in the environment for years. If a cat ingests the eggs, usually by grooming or ingesting contaminated soil or food, the eggs hatch in the small intestine. The larvae mature and travel to the large intestine, where they embed themselves in the lining of the intestinal wall. The females lay eggs which are passed in the feces, continuing the cycle.
Major symptoms of a whipworm infection include:
- Bloody diarrhea, sometimes containing mucus
- Weight loss
- Dehydration
- Lethargy and general malaise
- Anemia in severe cases
Severe infections can also cause watery diarrhea, inflammation of the colon, abdominal pain, and rectal prolapse. Whipworms feed on blood and tissue in the colon, causing bleeding and damage to the intestinal lining (PetMD).
Giardia
Giardia are microscopic parasites that can infect cats and cause an illness called giardiasis. Cats can become infected with giardia by ingesting the parasite from contaminated sources. Giardia is spread through the feces of infected cats. The most common means of transmission is fecal-oral, from infected feces contaminating food or water sources (https://vcahospitals.com/know-your-pet/giardia-in-cats).
The major symptoms of giardia infection in cats include:
- Chronic, intermittent diarrhea
- Loose or watery stool
- Weight loss
- Greasy stool
- Gas and foul-smelling stool
- Abdominal discomfort
Cryptosporidium
Cryptosporidium is a microscopic parasite that infects the small intestine of cats. It is spread through contact with infected feces or environments contaminated with the parasite. Cryptosporidium is highly contagious and can be transmitted directly from cat to cat or indirectly through ingestion of contaminated food or water [1].
The major symptoms of cryptosporidium infection in cats include:
- Severe, watery diarrhea
- Abdominal cramps
- Nausea and vomiting
- Dehydration
- Fever
- Lethargy
- Weight loss
Infected cats, especially kittens, can become extremely ill from cryptosporidium. It is important to take cats showing these symptoms to the veterinarian for diagnosis and treatment [2].
Diagnosis
There are several diagnostic tests that can be used to detect intestinal parasites in cats:
Fecal exams: This is the most common way to check for intestinal parasites. A small stool sample is collected and examined under a microscope to look for parasite eggs, larvae, or protozoan cysts. This allows the veterinarian to identify the type of parasite present. Fecal flotation or sedimentation techniques may be used to concentrate and isolate parasite stages from the stool sample (VCA Animal Hospitals).
Fecal smears: A small amount of stool is smeared onto a slide, stained, and examined under a microscope. This allows direct visualization of some parasites.
Fecal cultures: Allowing a stool sample to incubate may allow detection of parasites through microscopic examination at different life stages.
ELISA tests: This detects antigens from Giardia and Cryptosporidium in feces.
PCR tests: PCR allows detection of parasite DNA in feces and confirms identification of specific parasites.
Endoscopy: Using an endoscope inserted into the stomach or intestines allows direct visualization of some worms.
Biopsy: Taking intestinal tissue samples and examining them under a microscope can reveal attached parasite stages or damage caused by parasites.
Treatment
Treating intestinal parasites in cats often requires medication prescribed by a veterinarian. Broad-spectrum dewormers, such as fenbendazole, pyrantel, or moxidectin, are commonly used to treat multiple types of worms. These medications paralyze and kill both adult worms and larvae in the cat’s intestines.
For specific parasites, vets may prescribe targeted medications. For example, praziquantel is effective against tapeworms, and metronidazole treats giardia. Some dewormers come as oral tablets or paste that can be administered at home. Others are injections that must be administered by a vet.
In addition to medication, vets may recommend supplements or probiotics to support the cat’s digestive health and immune system. Thorough cleaning of the home environment is also important to remove parasite eggs and prevent reinfection.
For severe infestations, multiple doses of dewormers may be needed over several weeks to fully eliminate the parasites. It’s critical to follow up with the vet and complete the full course of treatment as prescribed. Vets generally recommend annual fecal tests and deworming to protect cats against parasitic infections.
Prevention
There are several things cat owners can do to prevent intestinal parasites in cats:
- Give your cat monthly preventative medication like Drontal or Advantage II. These products kill intestinal parasites and prevent reinfestation.
- Clean the litter box daily to remove parasite eggs before they can develop into infective stages.
- Wash food and water bowls frequently with soap and hot water to kill any parasite eggs or cysts.
- Vacuum and mop floors regularly.
- Avoid feeding your cat raw meat or fish, which can contain parasite eggs and cysts.
- Take new kittens to the vet for deworming treatment. Kittens are especially prone to roundworms.
- Keep your cat indoors to prevent exposure to parasite eggs and infected rodents or feces.
Consult your veterinarian about the best intestinal parasite prevention plan for your cat. With proper precautions, you can help protect your furry friend from these harmful organisms.