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    Can Fleas and Ticks Make My Pet Sick?
    M Duffy Jones, DVM posted:
    Fleas and ticks make pet owners recoil in disgust. No one likes to consider these creepy-crawlies being on their pets, let alone possibly being on themselves. In southern states, we deal with fleas and ticks every day. They are everywhere in the environment. And unless you have proper flea and tick control, your pet will get fleas and/ or ticks sooner or later.

    Besides fleas and ticks just being a nuisance, they can be harmful to your pet. Fleas can cause intense itching and scratching, which can lead to secondary skin infections. Severe infestation can also lead to a disease called flea anemia. This occurs when there are so many fleas taking blood meals from your pet that the animal actually becomes anemic, meaning the amount of red blood cells in his body are decreased. The anemia causes the pet to become very lethargic, and in the worst case, can lead to death. The good news is most pets will recover if your vet can kill the fleas and offer supportive care, such as fluids or blood transfusions if needed.

    Ticks, on the other hand, can cause a whole host of illnesses, such as Lyme disease, Rocky Mountain spotted fever, ehrlichiosis, and anaplasmosis to name a few. These diseases are a diagnostic challenge. They can have very subtle warning signs and can occur weeks to months after the tick has bitten the pet. Because of the difficulty in diagnosing these diseases, many vets screen for these diseases on an annual basis. I also run titers for these diseases if I have a suspicion that a pet may have contracted one.

    Ticks are incredibly difficult to kill. But the good news is that a tick usually has to be attached to your pet for hours to transmit these dreaded diseases. Therefore, it is wise to check your pet for ticks after a walk through dense woods or a joyful roll in the brush.

    Since fleas and ticks can be a medical hazard, I stress good flea and tick control all year round to help prevent exposure to these diseases. Talk to your veterinarian. He or she can recommend how to best protect your pet based on medical history and outdoor exposure.
    srstephanie responded:
    Hi Dr Jones and all,

    Just wanted to add a little to your wonderful post. Though your post subject says "pets", you mentioned only dog related diseases. So, I just wanted to mention a few reasons that flea and tick control is important for cats, too.

    Cats can have the same flea problems as dogs in terms of itching, scratching and in severe infections, flea anemia. Many cats also have an allergy to fleas so that even a single flea bite can cause severe dermatitis (skin infection). And, Fleas are a source of tape worms, so cats that have had fleas should also be wormed.

    Also important in terms of fleas and cats is the transmission of two diseases (among others) ... Bartonella henselae (aka Cat Scratch Disease) ... and Mycoplasma hemofelis (formerly called Hemobartonella felis and sometimes called Feline Infectious Anemia).

    My understanding is that Bartonella (Cat Scratch Disease) is transmitted, not by the flea bite, but by cats ingesting infected flea feces (flea dirt), which is common with cats when they groom themselves. It is felt that most cats do not become sick from Bartonella (though some specialists now feel that it may be a disease factor in some cats) ... the concern is that it can be transmitted to humans, particularly those with compromised immune systems.

    I seldom see many talk about tick disease in cats, but there is one very serious and often lethal disease that is transmitted to cats by ticks called Cytauxzoonosis. It's primary reservoir is the Bobcat which transmits it to ticks that can then infect domestic cats. It seems to be found mostly in the SE US with the American Dog tick as the tick most likely to transmit it. I think the experts used to feel that Cytauxzoonosis was nearly always fatal, but now believe that there are some strains that are less virulent and some cats survive after getting sick and some seem to not get sick even though infected. Even so, the CAPC website states that mortality is over 50%.

    I think many people in the SE use tick preventatives on their dogs but don't think about doing so with their cats. But if their cats go outside (or dogs may bring ticks inside) it might be wise to give preventatives to cats as well.

    A couple webpages of interest are:

    1. Bartonella henselae (Cat Scratch Disease) on the Veterinary Partner website:

    2. Mycoplasma haemofelis (Feline Infectious Anemia) on the Veterinary Partner website:

    3. Feline Cytauxzoonosis on the Veterinary Partner website:

    4. Feline Cytauxzoonosis on the CAPC website (Companion Animal Parasite Council):

    Well, I just wanted to add a little to the good info you gave on dogs. I'm not a vet or anything, and hope most of my info is correct. My "hobby" is listening to recordings of talks from vet CE conferences (NAVC, CVC, AAHA, etc) and I enjoy learning, though am painfully aware of how little I know.

    By the way, I saw on your bio that you live in the Atlanta area. Do you know a vet there, now retired ... Dr Karen Thomas? While I live in Montreal, I have been corresponding with Dr Thomas for a couple years and she has become a friend and teacher.

    Stephanie in Montreal
    jeanniey replied to srstephanie's response:
    Hi Stephanie,

    Thanks for posting the links for some of the diseases that cats can get. My vet tested my cat recently and told me that he has Mycoplasma from a blood test he drew during the exam. But the website on this parasite says it's hard to diagnose so I'm not so sure. Anyway, I'm currently giving my kitty doxycycline, hopefully, he'll recover fully so he red blood cell counts goes back up.

    If you have any more info on this, please post it. Thanks.

    M Duffy Jones, DVM replied to srstephanie's response:
    Great input, Stephanie.

    Yes, I did focus more on dogs than cats, and you are correct that we see many issues with cats related to fleas and ticks. I am rather lucky because I practice in an urban area where most of my cat patients live the good life in nice climate controlled high rises. However, even these pampered indoor cats can be exposed to fleas and ticks who catch a free ride in on a human visitor. They can suffer from flea allergies and are also susceptible to Bartonella and Mycoplasma.

    Bartonella is an interesting disease and there is lots of controversy about its role in causing disease in cats. Yes, it is responsible for Cat Scratch Fever in humans and we see a higher prevalence in cats in areas where the Cat Flea (Ctenocephalides felis) is more common. Yes, we are particularly concerned about this disease in patients with impaired immune systems. In people who have impaired immune systems, I make sure they understand how important good flea control is not only for their animal but for their health as well.

    Mycoplasma (the disease formerly known as Hemobartonella) might be a different story. In the lab, scientists have been able to isolate the disease in the flea after feeding off an infected cat, but they have not been able to infect a cat from these fleas, so we are still unsure if the flea is the main mode of transmission. It would make sense that the flea can spread the disease, but we have traditionally thought of bite wounds playing a role in transmission. But to be honest, we have ideas but are not exactly positive how transmission happens, so good flea control is an important way to at least prevent one possible way this disease is spread.

    Cytauxzoonosis is more difficult because of the mortality rate. The mortality rate might be even higher than 50%, since many cases go unreported because pets can die rather quickly and may not even make it to our office. It does have a geographic distribution to the Southeast and is a very serious concern for our outside unprotected cats.

    Stephanie, you provided us with some great information and web links on cat flea and tick control. Keep up your passion of listening to the recordings of the conferences. We are all constantly learning new things in this field.
    M Duffy Jones, DVM replied to jeanniey's response:

    There are times that the diagnosis can be made from the clinical signs your cat is showing and from a blood smear. If you are lucky, you can see the Mycoplasma on the outside of the red blood cells. I will typically run a PCR test to confirm the diagnosis.

    Also remember if you are giving tablets of doxycycline to make sure you give some water after the pill. Doxycycline in tablet form has been know to get stuck in their throat and can cause some problems. Many times I will have it compounded into a liquid for our feline patients.

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