Many parasites survive on nutrients from pets, and can cause significant health issues for your four-legged friend. Our team at Heritage Veterinary Clinic wants to help by providing information about parasitic pet diseases, and steps you can take to safeguard your pet.

Vector-borne pet parasitic diseases

Fleas, ticks, and mosquitoes are the major vectors that spread disease to pets in the United States, and they are more than a nuisance—they can cause serious health problems for your pet. 

• Fleas — The cat flea Ctenocephalides felis is the most problematic flea species that infests cats and dogs. The flea transmits several infectious diseases, including Bartonella henselae (i.e., the bacteria that causes cat-scratch disease in humans), Rickettsia typhi, and Rickettsia felis. In addition, fleas are the intermediate host for transmitting tapeworms to dogs and cats. 
• Ticks — The most common ticks in New York state include the black-legged tick, American dog tick, and the lone star tick. These parasites transmit infectious agents, such as Lyme disease, ehrlichiosis, anaplasmosis, and babesiosis, that can cause debilitating disease in pets.
• Mosquitoes — Mosquitoes transmit heartworms, which can significantly damage your pet’s heart and lungs. A bite from a single infected mosquito can lead to disease, and infected dogs who are not treated promptly can develop heart failure, while infected cats can develop severe respiratory disease.

All pets, including indoor-only pets, are susceptible to these dangerous vectors. The best way to protect your pet is by providing year-round parasite prevention medication.

Mite-derived pet parasitic diseases

Mites can parasitize pets, causing significant irritation and potential secondary infections. Particular offenders include:

• Sarcoptic mange mites — Sarcoptes scabiei are parasitic mites that burrow beneath the skin to feed on material in and on the pet’s skin, causing the pet to itch intensely, and to chew and scratch incessantly. Hair loss is common, typically on the legs and belly, and the skin may thicken if the condition is not treated. Secondary skin infections can also occur. Sarcoptic mange is highly contagious, and humans are also susceptible.
• Demodectic mange mites — Demodex canis are parasitic mites that live in the pet’s hair follicles. They are commonly found on normal pets, and cause no harm if the pet’s immune system functions properly. If the pet’s immune system is immature or weakened, the mite numbers increase, causing hair loss that typically starts on the face, especially around the eyes.
• Ear mites — Otodectes cynotis are parasitic mites that are usually found in the ear canal, but can also live on the skin surface. Ear mites are highly contagious, and a pet who directly contacts an infected pet will also become infected. The mites cause excessive ear irritation and discharge, and secondary ear infections can occur. 

Protect your pet from sarcoptic mange and ear mites by not allowing contact with infected pets. Demodectic mange is not preventable, but young pets typically outgrow the condition when their immune system matures between 12 to 18 months of age.

Protozoal pet parasitic diseases

Single-celled protozoan organisms can cause diseases in pets, including:

• Giardia — Pets can be infected by Giardia duodenalis by ingesting cysts from contaminated water, food, or objects, or through self-grooming. The parasites damage the intestinal walls, causing malabsorption, inappropriate digestion, and diarrhea. Humans are also susceptible to Giardia.
• Coccidia — Pets can be infected by Cystoisospora species by ingesting oocysts from a contaminated environment, or eating the meat of an infected small animal. Healthy pets may remain asymptomatic, but signs can include diarrhea, weight loss, and dehydration. 
• Cryptosporidium — Pets can be infected by Cryptosporidium species by ingesting oocysts in their environment. Infection can cause diarrhea, which can be severe in immunocompromised pets. 
• Toxoplasmosis — Toxoplasmosis can affect most animals, but cats are the only natural hosts that allow the parasite to complete its life cycle. Cats become infected by eating Toxoplasmosis gondii cysts in an infected small animal’s muscle or organ tissue. They can then shed the infective oocysts in the environment, exposing other pets. Healthy pets typically don’t become ill, but signs can include diarrhea, respiratory problems, and eye disorders. Pregnant women and immunocompromised people are also at risk for toxoplasmosis.

Maintaining good hygiene and preventing your pet from eating birds and small mammals can help prevent protozoan parasitic diseases. 

Intestinal parasitic diseases

Parasites such as hookworms, tapeworms, roundworms, and whipworms can parasitize your pet’s intestinal tract and leach nutrients.

• Hookworms — Named for their hook-like mouthpiece, Ancylostoma caninum attach to your pet’s intestinal wall to ingest blood. Transmission occurs through oral ingestion, direct skin contact, in utero, or through the mother’s milk. Signs include weakness, pale gums, diarrhea, weight loss, and poor growth.
• Tapeworms — Tapeworms are long flat worms that attach to your pet’s intestinal tract. Affected pets shed tapeworm segments, which look like rice grains under their tail and in their feces. Tapeworms typically don’t cause illness.
• Roundworms — Roundworms can be transmitted through oral ingestion, in utero, through the mother’s milk, and by eating larvae in small animals. Young pets are especially susceptible, and signs include diarrhea, vomiting, weight loss, and a pot-bellied appearance.
• Whipworms — Whipworms infect pets who contact infective eggs in their environment, causing severe bloody diarrhea and death, if not treated appropriately.

Intestinal parasites can be prevented by regularly removing your pet’s feces and providing year-round parasite preventives.

Parasitic diseases are a concerning issue, but these measures can significantly decrease your pet’s risk. If you are concerned your pet may have a parasitic disease, contact our team at Heritage Veterinary Clinic, so we can determine the parasite type and the best treatment approach.