Introduction
Parasites are organisms that live on or inside another organism, known as the host, and benefit by getting food, shelter, or other needs for survival. There are many different types of parasites that can infect cats, ranging from tiny single-celled organisms to larger organisms like fleas, ticks, worms, mites, and more. Some of the most common parasites that cats encounter include fleas, ticks, roundworms, hookworms, tapeworms, giardia, coccidia, ear mites, ringworm, and heartworms.
These parasitic organisms can enter a cat’s body in a number of ways. Fleas and ticks will latch onto a cat’s skin and feed on their blood. Worms, protozoa, and other internal parasites can be ingested when a cat hunts and eats infected rodents or other prey. They can also be transmitted from the mother cat to kittens before birth or through nursing. In addition, parasites can be picked up from contact with infected feces, soil, or other contaminated environments. Overall, parasites are highly prevalent in the feline population.
While some parasites may not cause significant illness, others can lead to serious health problems in cats if left untreated. It’s important for cat owners to understand the most common feline parasites, how infection occurs, and what symptoms to look for. With preventative care and prompt treatment, parasitic infections can be well-managed.
Fleas
Fleas are tiny, wingless, blood-sucking parasites that can infest both outdoor and indoor cats. The most common flea found on cats is the cat flea, Ctenocephalides felis. The flea life cycle has four stages – egg, larva, pupa, and adult. Adult fleas live and feed on animal blood, while eggs, larvae and pupae live in surrounding environments. After feeding, adult female fleas lay eggs, which fall off the animal into carpets, bedding or soil. Fleas hatch into larvae within days, feeding on organic debris before developing into pupae and finally emerging as adult fleas which then jump onto cats to restart the cycle.
Fleas can hitch rides on other pets and spread to indoor cats. Outdoor cats can pick up fleas while hunting or exploring outside. Even indoor-only cats are still vulnerable if fleas are brought inside on other pets, human clothing or shoes. Fleas can cause significant irritation, itching, hair loss and skin problems in cats. Fleas are also vectors of diseases like bartonellosis, hemoplasmosis and plague.
To prevent flea infestations, routinely treat outdoor pets and clean inside the home. If fleas are found on your cat, speak to your veterinarian about flea control products and environmental treatments. Maintaining flea prevention is important even for indoor cats, as just one flea can lead to an infestation. Be vigilant checking for fleas and addressing any signs of infestation quickly.
Ticks
Ticks are small arachnids (vcahospitals.com). Although they are commonly thought of as insects, ticks are actually more closely related to spiders and mites. Ticks go through four life stages – egg, larva, nymph, and adult. After hatching from the egg, ticks must eat blood at every stage to survive. Ticks can’t fly or jump, but they climb or drop onto cats from blades of grass or foliage. Once on a cat, they crawl around looking for places with thinner skin to attach and feed.
Ticks spread diseases like Lyme disease, Cytauxzoonosis, Anaplasmosis, Ehrlichiosis, and Babesiosis to cats (bluecross.org.uk). Ticks can be difficult to spot in cats’ fur which is why prevention is key. There are many tick preventatives available including collars, spot-ons, oral products. Checking your cat’s coat daily and removing any ticks promptly can also help prevent disease transmission. Ticks must be attached for 24-48 hours before transmitting disease.
Intestinal Worms
Intestinal worms, or helminths, are one of the most common parasites in cats. There are different types of intestinal worms including roundworms, hookworms, tapeworms, and whipworms. These worms live in a cat’s intestines and shed eggs that are passed in the feces. Once the eggs are deposited in the environment, they can survive and infect other animals (source).
Roundworms are one of the most prevalent intestinal worms in cats. The eggs hatch in the intestines, and the larvae migrate through the liver and lungs before being coughed up and swallowed. This allows the roundworms to mature and produce more eggs in the intestines. Roundworms can cause respiratory illness, a pot-bellied appearance, and vomiting (source).
Hookworms attach themselves to the intestinal wall and feed on blood. This can cause anemia, weight loss, and dark and tarry feces. Hookworm eggs are passed in the feces and larvae can also penetrate the skin and cause infection. Tapeworms are contracted when a cat ingests a flea or rodent infected with tapeworm larvae. The larvae then mature into adult tapeworms that shed segments containing eggs. Whipworms are less common but can cause inflammation of the large intestine.
A key aspect in the life cycle of intestinal worms is their transmission through feces. Their eggs can survive in the environment and be inadvertently ingested by cats during grooming. This fecal-oral route of transmission allows intestinal worms to spread and reinfect cats. Proper sanitation of litter boxes along with deworming treatments can help break this life cycle.
Heartworms
Heartworms are spread through the bite of an infected mosquito carrying microscopic heartworm larvae (https://www.heartwormsociety.org/heartworms-in-cats). When a mosquito bites an infected animal, it ingests these larvae. The larvae then mature inside the mosquito for several weeks before they can infect another animal. Once mature, the larvae migrate to the mosquito’s mouth where they can enter a cat or dog during the next bite (https://vcahospitals.com/know-your-pet/heartworm-disease-in-cats).
Inside the cat, the larvae migrate to the heart and blood vessels, maturing into adult worms over several months. The adult heartworms produce offspring called microfilariae, which circulate in the bloodstream (https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/heartworm-cats). When another mosquito bites an infected cat, it ingests these microfilariae, continuing the life cycle.
Prevention involves avoiding mosquito exposure and using monthly heartworm preventatives prescribed by a veterinarian. There are no approved treatments to kill adult heartworms in cats, so prevention is critical.
Protozoa
Protozoa are single-celled organisms that can infect cats and cause illness. Some of the most common protozoan parasites in cats include Giardia, Coccidia, and Toxoplasma species (Source 1).
Giardia is a common intestinal parasite that causes diarrhea in cats. It spreads through ingestion of contaminated water or food and contact with infected feces. Coccidia species also infect the intestinal tract, causing diarrhea that may contain mucus or blood. Both kittens and adult cats can get coccidia. Toxoplasma gondii is another intestinal protozoan parasite that cats may ingest from hunting rodents or birds. While generally asymptomatic in cats, toxoplasmosis can be dangerous if transmitted to pregnant women, potentially causing birth defects.
Preventing protozoal infections involves keeping the litter box clean, washing hands after handling cat feces, keeping cats indoors, and avoiding raw meat diets which may contain parasites. Vets can test fecal samples and provide medications to treat infected cats, reducing the risk of spreading protozoa to other pets and people (Source 2).
Ear Mites
Ear mites, known scientifically as Otodectes cynotis, are microscopic parasites that live on the skin surface in a cat’s ear canal. These mites are highly contagious and spread through direct contact between cats (VCA). Infestation most often happens from mother to kitten, since close contact occurs during nursing. Ear mites can also spread through contact with bedding or grooming. The mites cause intense itching inside the ear, which leads to ear scratching, head shaking, and crusty scabs in the ears. You may see your cat tilting or shaking their head, pawing at their ears, or scratching their ears frequently. The intense itchiness leads cats to damage their ear canals and outer ears (Cornell Feline Health Center).
To treat ear mites, your veterinarian will thoroughly clean your cat’s ears to remove debris. Medicated ear drops or injections will be prescribed to kill the mites. All bedding should be washed and the environment thoroughly cleaned. All other cats in contact with the infested cat should also be treated. With prompt treatment, most ear mite infestations can be cured within 1-2 weeks. Untreated ear mites can lead to secondary bacterial or yeast infections which may cause deafness if left untreated (VCA). To prevent ear mites, limit your cat’s contact with stray/outdoor cats and keep their environment clean.
Ringworm
Ringworm is a fungal infection that is highly contagious among cats. It is caused by dermatophyte fungi that live on skin, hair, and nails. Ringworm gets its name from the ring-shaped sores that can form on the skin, but not all cases exhibit this classic lesion. The fungi spread through direct contact with an infected cat or indirectly by contact with contaminated objects like bedding. Microscopic spores from an infected cat can survive for long periods in the environment. Any surface or object can become contaminated with ringworm spores when touched by an infected cat.
To prevent ringworm, it is important to isolate infected cats until they receive treatment. All objects the cat came into contact with should be thoroughly cleaned and disinfected. Ringworm can be difficult to eliminate from a multi-cat household because reinfection readily occurs. New cats should be screened for ringworm before introducing them to a household. There are environmental sprays that can help kill ringworm spores. Keeping surfaces clean and reducing exposure to stray/infected cats can help prevent infection (Purina).
Prevention
There are several steps cat owners can take to prevent parasites from infecting their cats (Dryden, 2005). This includes both external and internal parasites.
For external parasites like fleas and ticks, regular use of parasiticides is recommended. Topical or oral treatments like Revolution, Frontline, or Nexgard can kill adult fleas and ticks and prevent reinfestation (https://www.petbucket.com/blog/65715/preventing-parasites-in-cats-tips-for-a-healthy-feline.html). These should be administered year-round or at least during flea and tick season. Treating the home environment may also be necessary.
For internal parasites, regular deworming is important. Kittens should be dewormed every 2 weeks until 12 weeks of age, then monthly until 6 months old. Adults should be dewormed 1-4 times per year depending on risk factors. Broad spectrum dewormers that treat roundworms, hookworms, and tapeworms are ideal (https://portal.cityvet.com/cityvet-blog-article-parasite-prevention.php).
Vaccinating against certain parasitic diseases like feline leukemia can help prevent infection. Keeping the environment clean by promptly disposing pet waste, washing bedding frequently, and using flea control measures also helps block sources of parasite transmission.
Conclusion
In conclusion, there are many different types of parasites that can infect cats, including fleas, ticks, worms, heartworms, protozoa, ear mites, and ringworm. These parasites can enter a cat’s body through contact with an infected animal or environment, bites from parasites like fleas and ticks, or ingestion of parasite eggs or larvae. While some parasites like fleas and ticks live on the outside of a cat’s body, others like worms and protozoa take up residence in the digestive tract, heart, bloodstream or other organs. Parasitic infections can cause irritation, discomfort, illness, and even death if left untreated. The best way to protect cats from parasitic infections is through preventative care including routine veterinary checkups, monthly flea/tick/heartworm prevention medication, keeping cats indoors, and proper sanitation. With vigilance and proactive measures, cat owners can help keep their feline friends parasite-free and healthy.