Does Your Pet Have an Internal or External Parasite?
Both types of parasites can cause problems for your pet. Internal parasites live inside your pet's body, while external parasites make themselves at home in your pet's skin and hair.
Common internal parasites include:
Heartworms
Roundworms
Hookworms
Whipworms
Tapeworms
Giardia and Coccidia
Many internal parasites affect the digestive system and cause vomiting, diarrhea, coughing, fatigue, weight loss, and other symptoms. Heartworm, the most serious type of internal parasitic infestation, may severely damage your pet's heart and lungs. Some parasites, like hookworms and roundworms, can spread to people.
Itchy skin, hair loss, sores on the skin, and skin infections might be signs your pet has external parasites. External parasites include:
Fleas
Ticks
Mites
Ticks can carry serious illnesses, like Lyme disease and Rocky Mountain spotted fever. Although fleas may seem like a minor problem, a severe infestation can trigger anemia from blood loss.
Diagnosing and Treating Fleas
Before offering treatment, your veterinarian must first determine which type of parasite your pet has. Some types of parasites, like fleas, can be easily identified. If it's not clear what's causing your pet's symptoms, your veterinarian may:
Look for Evidence of Eggs, Worms, and Parasites by Examining a Stool Sample Under a Microscope
Test Your Pet's Blood (Testing can be helpful for tick-borne diseases, heartworm, and other parasitic infections).
Take Samples of Your Pet's Skin to Identify External Parasites
Treatment depends on the type of parasite. Medication, including drugs that kill worms and eggs, may be prescribed if your pet has internal parasites. Some pets may need intravenous fluids if they've become dehydrated due to frequent vomiting or diarrhea. A bland diet can be helpful while your pet recovers from an internal parasite.
Heartworm, the most serious type of worm infestation, affects dogs, cats, and ferrets, according to the American Heartworm Society. The worms are spread by mosquitoes. Prescription medication can kill adult and immature heartworms in dogs, but surgery may be needed if your pet has many worms. If your dog has a bacterial infection caused by heartworm, antibiotics will be prescribed. You will need to restrict your pet's activities until it finishes heartworm treatment.
Unfortunately, the same medication that kills heartworms in dogs isn't safe for cats and ferrets. Instead, your veterinarian may prescribe antibiotics, anti-inflammatory drugs, or heart medication.
Topical and oral medications kill fleas, although you may also need to treat your home to prevent a new infestation. If you haven't already removed ticks from your pet's skin, your veterinarian will remove them and test them for disease. Your veterinarian can also test a tick you removed yourself. Antibiotics and pain medication can be helpfuI if your pet has developed Lyme disease following a tick bite.
Oral or topical anti-parasitic medication kill mites and their eggs. If mites have invaded your pet's ears, your veterinarian may prescribe anti-parasitic ear drops.
Preventing Parasites
You can reduce your pet's risk for parasitic infestations by:
Using Oral or Topical Flea and Tick Medication Year-Round
Treating Your Yard with Pet-Safe Flea Spray and Mosquito Repellant
Using Oral, Topical, or Injectable Medications to Protect Your Pet from Heartworm (Some tick and flea products include heartworm prevention).
Picking up Poop and Cleaning Litterboxes Promptly to Prevent the Spread of Worms and Other Parasites
Checking Your Pet's Fur and Skin Weekly for Signs of External Parasites
Worried that your pet may have external or internal parasites? Contact our office to schedule a visit with the veterinarian.
Sources:
American Veterinary Medical Association: Internal Parasites in Cats and Dogs
https://www.avma.org/resources-tools/pet-owners/petcare/intestinal-parasites-cats-and-dogs
Cornell Feline Health Center: Gastrointestinal Parasites of Cats, 6/2018
American Kennel Club: External Dog Parasites: Fleas, Ticks, Lice, Mites, 3/4/2022
https://www.akc.org/expert-advice/health/external-dog-parasites/
Merck Veterinary Manual: Fleas in Dogs and Cats, 8/2024