Parasites in dogs include internal parasites such as roundworms and hookworms, and external parasites such as fleas, ticks, and mites. Regardless of the type, they leave your dog feeling uncomfortable and can lead to serious health issues if left untreated. Preventatives can help your dog avoid parasites, but if they haven’t been taking one and are exhibiting symptoms, you are bound to have questions about what steps to take next. We’ve taken the most frequently asked questions about dog parasites and answered them here so you can take action to avoid or treat them.

If you have questions about identifying or preventing parasites in your dog, and are in the San Francisco, CA area, please call us at (415) 333-0813.

What are intestinal parasites in my dog, and how do I get rid of them?

Intestinal parasites are worms that live in a dog’s intestinal tract. Roundworms and hookworms live in dogs’ stomachs and small intestines, while tapeworms live in the large intestines. There are also intestinal parasites that are not worms, such as coccidia and Giardia. These are one-cell organisms that are also considered parasites in the intestinal tract.

Are there parasites that live in the bloodstream?

Heartworms are parasites that live in the bloodstream. Heartworm disease is contracted from a mosquito bite—then these heartworms get under the dog's skin and work their way into the bloodstream until they reach the dog's heart. They can each grow up to 12 inches long and are life-threatening.

What are external parasites, and what can I do to prevent them?

The most common external parasites in dogs are fleas. Fleas are long, flat, and typically large enough to see with the naked eye as they crawl through the dog’s hair coat. Ticks are a little larger than fleas and easier to spot, especially in short-coated dogs. Ticks like to migrate to vascular spots on a dog’s body where they can suck blood, such as their ears and faces — but they can be found anywhere on a dog. Ear mites and lice are also fairly common external parasites. You can help your dog avoid all external parasites with monthly preventative measures. The American Veterinary Medical Association (AVMA) details each type of external parasite, including controlling and preventing them.

How soon should I bring my dog to the veterinarian if I suspect they have parasites?

If you suspect your dog has any form of parasites, you should bring them to see your veterinarian as soon as possible. Parasites are zoonotically transmitted to humans, and although everyone loves seeing dogs and kids playing together, you certainly don't want children exposed to roundworms or hookworms. Bring your dog in to see their veterinarian right away if they’re showing any signs of parasites, whether internal or external.

How will my veterinarian diagnose parasites in my dog?

We diagnose some forms of parasites visually by looking at the hair coat and skin, while other forms require specific tests. 

To diagnose external parasites in a dog, your veterinarian will:

  • Visually examine your dog’s hair coat and skin
  • Run a flea comb through their hair to see if it catches any fleas or flea “dirt”
  • Search for ticks
  • Look at skin changes that might indicate external parasites
  • To diagnose internal parasites in a dog, your veterinarian will:
  • Conduct a heartworm blood test
  • Do a fecal check

To help prevent internal parasites, be sure to wipe your dog’s feet after going for a walk and wipe their back end after they have defecated, so they don't catch anything by grooming themselves.

Is ringworm a parasite?

Ringworm is a fungus that causes an external skin issue. It's technically a saprophytic fungus, which means it comes from the soil. Ringworm is common just about anywhere, but it's not a parasite. It causes a distinctive circular rash, often with itching and patchy hair loss.

Why is early detection and diagnosis of parasites so important?

Intestinal parasites such as roundworms, hookworms, and whipworms live in your dog’s gastrointestinal system, stealing critical nutrition from them. They generally receive nutrition from your dog’s food and supplements first, with your dog receiving only the leftover nutrition. This often causes weight loss and bloody stools in dogs. Heartworms can cause significant illness in dogs, with symptoms including coughing, heart failure, liver failure, and swelling in the belly. Early detection means we can treat your dog before they get extremely sick.

While less serious in nature, external parasites such as fleas can cause flea allergy dermatitis and spread from one animal to another. They can also jump off of a dog and onto other pets and people. Ticks are a problem since they transmit a lot of diseases such as Lyme disease, Ehrlichia, anaplasmosis, Babesia, and Rocky Mountain spotted fever. 

For these reasons, we must treat both internal and external parasites right away. However, the healthier option for your dog is to take preventative measures instead of treating parasites. You should take your dog to see their veterinarian to be checked for parasites, and if negative, begin a monthly preventative so parasites never become an issue. With today’s preventive medicines, your dog can live a healthier, happier, and longer life. All parasites are easier to prevent than they are to treat.

If you have further questions about dog parasites, and you live in or near San Francisco, CA, we’d love to see your dog to ensure they’re free of internal and external parasites, so please call us at (415) 333-0813.