April Topic - Parasites and Your Pets

image of black dog looking seriously at the camera: Parasites and Your Pets

Parasites and Your Pets

Spring is in the air which means green grasses, blooming flowers, seasonal ponds, and warmer temperatures.  Unfortunately, with all this warmth, dense grass, and increased water sources comes a dramatic increase in the number of pests and parasites.  As the weather becomes warmer, fleas, ticks, and mosquitos become more and more common, and become increasingly greater threats to our pets.

Parasites are creatures that live in or on another organism, obtaining nutrients from that organism but offering nothing in return.  In the case of fleas, ticks, and heartworms, these parasites do more than just feed off our pets - they make them uncomfortable and can even cause disease that can threaten the lives of pets and people.


Fleas are the most common external parasite of dogs and cats.  They live in the haircoat, biting the pet and feeding off the pet’s blood. Fleas live much of their lives on their host; they feed and breed on the pet, and even lay their eggs in the pet’s hair.  These eggs fall off as the pet moves around, allowing them to be deposited all over the pet’s living area, into the carpet, rugs, furniture, or soil.
Once flea eggs hatch, they become tiny larvae which then pupate within a cocoon, where they develop into adults.  The un-emerged adult flea can delay hatching from the cocoon for up to 350 days until conditions, such as temperature, humidity, or a suitable host, are just right for them to fully hatch.  This can explain why a home can be flea-free for many months and then suddenly have a flea infestation.
In pets, the most common symptoms of fleas is itching.  This can be mild to severe, depending on the pet.  It is not uncommon for pets to even be allergic to fleas, with a bite from just a single flea causing a significant allergic reaction.  Severe flea infestations on a pet can result in anemia (low red blood cell count) from so many fleas feeding on the pet.  In addition, fleas are known to be involved in the transmission of tapeworms or even diseases such as murine typhus.

Once a home has a population of fleas, it can take weeks or even months to get under control, even with effective treatment.  Since the un-emerged adults can go “dormant,” it can appear that the home is flea-free when, in fact, there are many cocoons just lying in wait.  A few days of warm weather in winter can provide the perfect condition for the adults to hatch, leading to a flea population explosion.  For this reason, experts recommend that pets be on flea-control year-round, regardless of weather conditions.


Ticks are another common parasite seen, especially in dogs.  They are more common in some states than others, but have recently been becoming increasingly common in Southern California.  
Ticks are not insects they are actually arachnids, like spiders. Ticks eat the blood of their host, attaching themselves firmly to the dog’s skin, and eating voraciously while they are attached.  They are attracted to warmth, movement, and the carbon dioxide exhaled by animals, and will wait in long grasses or brush until a suitable host passes by. Many have a “preferred” host species but can be opportunistic when the preferred animal is not around.
While ticks feed, they can transmit many dangerous diseases including Lyme Disease, Ehrlichia, Anaplasmosis, Babesia, and Rocky Mountain Spotted Fever.  Additionally, a neurotoxin passed in tick saliva can cause a condition called Tick Paralysis.  As the name suggests, this is a neurologic syndrome characterized by acute ataxia which can progress to paralysis.
Some years back, ticks were not considered a common pest in Southern California.  However, in recent years they have become far more prevalent, and experts believe that 2023 may be one of the worst on record for tick infestations in San Diego County.


Heartworms Disease is a very serious infection common across the United States.  This disease is responsible for many canine deaths and countless sick pets every year.  Heartworm can affect dogs, cats, and ferrets, as well as wild mammals such as coyotes, foxes, sea lions, and rarely humans.
Heartworms are transmitted from pet to pet by mosquitos.  When the mosquito bites an infected dog, it can pick up immature heartworms known as microfilaria in the blood.  These microfilaria are then passed to a different animal when the mosquito feeds again.
Dogs are the “natural host” for heartworms, meaning that the parasites live most of their lives and then reproduce inside of the dog.  As these heartworms mature into adults, they take up residence in the heart, lungs, and associated vessels causing severe symptoms similar to heart and/or lung disease.  While most infected dogs can successfully be treated, the treatment is both long and can be uncomfortable.  In advanced cases with significant clinical signs, it can even be dangerous.   
In cats, heartworm disease is very different as the worms do not survive into adulthood.  The immature worms lead to a pulmonary condition in cats know as Heartworm Associated Respiratory Disease (HARD).  Symptoms of feline heartworm infection include coughing and asthma symptoms, vomiting, lack of appetite, or weight loss.  
For cats, there is no approved heartworm treatment.  Because felines are not “ideal” hosts for heartworms, some infections may resolve on their own.  Cats should be treated for symptoms associated with infection and maintained on heartworm prevention to prevent reinfection.
For more detailed information on Heartworm Disease, please visit our website Learning Center:

Prevention of Parasites

Parasites can cause problems ranging from mildly irritating to life-threatening.  More significantly, experts say that problems with parasites in San Diego County are only getting worse, with both ticks AND heartworm on the rise. Diseases caused by parasites can be scary and difficult to treat; additionally, once a parasite infestation has taken hold it can be very hard to get under control.  The key to keeping your pet (and yourself!) safe is prevention, and luckily prevention is easy!
In both dogs and cats there are a multitude of safe options that effectively prevent or treat fleas, ticks, and heartworm.  These products have been proven safe, easy to administer, and effective.  Many of these products help prevent more than one parasite, including some that protect against fleas, ticks, heartworm, and even internal parasites such as roundworms and hookworms.
The key to protecting your pet is to have them on prevention before there is a problem. Don’t wait until your pet has ticks, fleas have infested your home, or until they are actively being exposed to mosquitos.  In fact, in Southern California it is now recommended that pets be on protection year-round, regardless of weather.

If you are interested in more information on prevention products for your cats or dogs, please give us a call at (760) 736-3636.


Find us on the map

Office Hours

Our Regular Schedule


8:00 am

6:00 pm


8:00 am

6:00 pm


8:00 am

6:00 pm


8:00 am

6:00 pm


8:00 am

6:00 pm


8.00 am

2:00 pm