As the warmer weather of spring brings the outdoors back to life with flowers and animals, the parasites that feed on those animals also make their presence known. Unfortunately, these parasites are numerous and would love to make your pet their new home. Spring and summer means that flea and tick season has arrived, and mosquitoes are also out and about and ready to pass on heartworm disease to dogs and cats. Other parasites, less well known but still important to protect your pets from, include roundworms, hookworms and whipworms.

Fortunately, the veterinary community now has a wide variety of products available to help protect your animal companions. Here’s a quick look at some of the parasites and what they mean for the health of your pet.

External Parasites

Ticks, a type of arachnid, are small external parasites that feed on the blood of a host, usually deer, small mammals or birds, and just as easily dogs, cats or humans. They are often found in wooded or forested areas, in tall grass, brush or woodpiles and are common along hiking or deer trails or even in your backyard. They move onto a host as it passes by and then attach to the skin by using the mouthparts to embed their head so they can feed on the host’s blood. Through this connection to the bloodstream they can pass diseases such as Lyme, Erlichia and Rocky Mountain Spotted Fever.

While many modern flea control products can also kill ticks, they are difficult to manage because the majority of reproducing ticks are on their natural wildlife hosts so re-infestation easily occurs when pets spend time outside.

To remove a tick, do not use gasoline, alcohol, Vasoline or a hot match as they do not work and may case harm to your pet. Instead, use small tweezers or special tick removal tools (sold by your veterinarian, pet stores and outdoor supply shops) to grab the tick’s head and gently pull.

Fleas are insects, with the predominant species being the cat flea, and are parasitic, feeding on the blood of a host. They are spread from animals outside—other pets, feral cats, raccoons, opossums, etc.—which constantly re-infest yards, patios and porches. Once the flea gets on your pet and feeds on its blood, it begins laying eggs. The eggs fall off and contaminate rugs, carpets, and animal and human bedding, all of which must be cleaned and treated to eliminate the infestation. One flea can lay 50 eggs per day!

Symptoms of a flea infection are itchiness, scratching/chewing, hair loss and scabbing of the skin, and a visual inspection might turn up flea “dirt,” black or brown specks that are actually flea feces. Fleas can also transmit tapeworms and Bartonella (Cat Scratch Fever in humans) as well as cause flea allergy dermatitis (an allergic reaction to flea saliva), and anemia if the infestation is severe. Though small, they can be seen moving on the pet if the hair is parted, especially over the rump. Many flea control products have been developed; let a veterinarian advise an integrated flea control program using an insect growth regulator and adulticide treatment.

Perhaps the most common summer parasites are mosquitoes, those annoying blood-sucking insects. They are especially important to dogs and cats because they transmit the heartworm larvae. Skin inflammation around the eyes, bridge of nose or ear flaps may occur with excessive exposure to mosquitoes.

Internal Parasites

Heartworm is a long thread-like worm which causes cardiac and circulatory problems in dogs. Symptoms include coughing, lethargy and weakness, and severe infestation can be fatal. In cats, the larvae migrate through the lung and create extreme inflammation which may cause an asthma-like respiratory condition. Unfortunately, some cats show no or few signs other than sudden death. Prevention with this parasite is absolutely key, and fortunately is also easy. Many monthly products are available, for both dogs and cats.

Roundworms are an intestinal parasite commonly diagnosed in dogs and cats. It is spread through feces-contaminated soil, by eating the tissue of host animals or from mother to offspring. Signs of intestinal parasites include an increase in flatulence, soft stools, blood in stool, diarrhea, weight loss in heavy worm burden cases, and vomiting. The adult roundworm looks like thin spaghetti and may be seen in an infested animal’s feces or vomitus. Multiple treatments may be needed to eliminate this parasite but most heartworm preventatives also control re-infestation. While very rare, this parasite is dangerous in humans as the immature roundworm can migrate to the eye and cause ocular larval migrans which can lead to blindness or loss of the eye. Washing hands after working in the soil outside or after cleaning up after your pets is extremely important. Whipworm is a type of roundworm, named for the whip-like shape of the worm.

Hookworm is a microscopic intestinal parasite, which is also spread outside through contaminated soil or by eating other host animals. It affects both dogs and cats and can cause diarrhea and anemia in heavy infestations. In humans, contact with contaminated soil can allow larvae to invade and their migration can cause an inflammatory response called cutaneous larval migrans. As with roundworms, wash your hands and feet, as well as those of your pet, after contact with soil. Multiple doses of medication may be needed to treat them and heartworm preventatives help with control.

Parasites tend to be unpleasant things, and it may sometimes seem like they are everywhere, just waiting for the opportunity to latch on to our pets. The warmer months of spring, summer and early autumn are the worst for parasites because this is when their hosts are the most available. The good news is that parasites and their ill effects can be combated and treated and in many cases are preventable.

Pay attention if your pet starts to exhibit unusual behavior, and keep a good relationship with your veterinarian. Regular screenings can find diseases and parasitic infestation so they can be treated. But as always, it’s better to prevent than to cure, and your veterinarian can suggest and prescribe preventative medications which can save both you and your animal friend a lot of pain and discomfort.