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Blood borne Parasitic problems in dogs

Dogs > Immune and Blood System > Blood borne Parasitic problems in dogs

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New Information on Tick and Vector Borne Diseases

The ability to do DNA testing has led to the discovery of new tick borne diseases and the recognition that many of the older diseases have been classified incorrectly or have more ability to cause disease than was previously recognized. Information in this field is changing fast and it is sometimes hard just to keep up with the name changes. This is a brief overview to help you keep up with the changes if you find yourself searching for information on one of these diseases.

Feline hemobartonellosis is now called feline homotrophic mycoplasmosis (FHM). If your veterinarian is as old as I am, he or she might refer to this disease as feline infectious anemia. This is a disease which causes anemia in cats and is thought to be spread by insect vectors and bite wounds, although it is unclear how big a role each of these plays in the transmission of the disease. There are two different strains of this organism, one of which is now referred to as Mycpolasma haemofelis and the other is in the process of being renamed but will probably be Mycoplasma haemominutum. There is a third organism, Mycoplasma haemocanis, which causes similar disease in dogs, although much less commonly than in cats. These organisms all try to live in red blood cells, leading to immune destruction of the cells in an attempt to kill the parasite. Traditionally this disease has been diagnosed by recognizing the organism in blood smears but this test is pretty unreliable.

At the present time there is a new test using polymerase chain technology (PCR testing) that can more accurately detect this disease. Treatment for FHM usually consists of administration of doxycycline for 2 to 3 weeks. If necessary, it is acceptable to give prednisone or other corticosteroids to control the immune response while the antibiotic has time to work. In most cases treatment will control clinical signs but it is unclear whether it is possible to totally eliminate the organisms and recurrence of disease has been documented.

American canine hepatozoonosis is a relatively newly recognized tick borne disease caused by the organism Hepatozoon americanum, carried by a type of tick, Amblyomma maculatum, which is commonly referred to as the Gulf Coast tick. As you can imagine based on the name, this is a disease found in Southern states. This disease causes severe illness characterized by fever, pain, lameness and accumulation of mucopurulent material around the eyelids. White blood cell counts can be very high and anemia may be present. Changes in bone and other organs are sometimes seen. A related disease caused by Hepatozoon canis, recognized more widely in Europe, Asia and Africa, causes less severe symptoms in most dogs, consisting of fever and sometimes anemia. Diagnosis has been most accurate through muscle biopsies but Oklahoma State University has developed a blood test (serology) for this disease. (Vincent-Johnson NA, 2003). Treatment for this disease currently requires using a combination of antibiotics (trimethoprim-sulfa, clindamycin and pryimethamine) and long term use of decoquinate (Deccoxx Rx) to control relapses. With aggressive therapy there is a fairly good prognosis for long term control of this disease. If your dog has a real mystery disease with some or all of these symptoms, it may be worth asking your vet to check for this disease.

There is a saying at sporting events, "You can't tell the players without a scorecard". This seems to hold true for several organisms previously classified as members of the Ehrlichia family, which was formally part of the rickettsial disease family but now is considered to be part of the Anaplasmataceae family. Since these diseases occur all over the world, it is probably easiest just to list the reclassified names of several ex-members of the family to aid in searches for information on these diseases. Ehrlichia equi is now Anaplasma phagocytophilia. Ehrlichia platys is now Anaplasma platys. Ehrlichia risticii is now Neorickettsia risticii. Salmon disease, which occurs in the Northwest U.S. is now thought to be caused by Neorickettsia helminthoeca. Ehrlichia canis, Ehrlichia chaffeensis and Ehrlichia ewingii all got to keep their names. While this family of organisms has mostly been associated with disease in dogs, cats can develop diarrhea due to Neorickettsia risticii and an unclassified Ehrlichia organism has been isolated from several sick cats.

Keeping pets away from ticks is the best plan but is often impractical. Tick control in the environment outside of a kennel or small yard is pretty difficult so for most pets tick prevention will depend on using a good preventative. As we discover more tick diseases and new manifestations of older tick borne diseases it is becoming increasingly clear to me that good tick control might eliminate a number of the mystery diseases that sometimes occur in dogs and cats.

Dr Mike Richards, DVM
03/02/2004

Ehrlichiosis in Borzoi

Question: Dr. Richards,

I'm a new subscriber, and looking forward to learning more.

My 3 1/2 year old borzoi bitch was diagnosed with ehrlichia at the age of 11months. Actually my vet at the time tentatively diagnosed it as one of therickettsial diseases; ehrlichia wasn't that well recognized then, or as commonin Israel as it is now. She was treated with tetracycline, and seemed torecover. No real follow up was done - the vet didn't know and I hadn't yetlearned enough to ask for a follow up titer and blood test.

A year and a half ago she showed signs of neck pains, the vet (same vet still)thought it might be wobblers syndrome or CVI, and referred me to a veterinaryneurologist. At that point I started reading, found a reference to neck painbeing a sign of ehrlichia, and went to a different vet. Titers were highpositive for ehrlichiosis and there was thrombocytopenia, she was put on acourse of doxycycline which improved her blood chemistry. 6 months later hertiters were still high but the blood chem was fine - and since titers can stayhigh for up to a year the new vet wasn't worried. 6 months later a new vet (wemoved) did a blood chemistry, saying that titers could stay high for years andthat once a dog tested positive there was little meaning in future positives.The blood showed some very mild low platelet levels (185), though the lab saidthat the platelets had clustered and that actual levels were estimated muchhigher. Hemoconcentration was also high, although this is somewhat normal forsighthounds, as far as I know. There was also mild neutropenia. Based on thesefindings, the vet prescribed another course of doxycycline - she just finished6 weeks. The new blood chem just came back, and there was very little change.She is feeling fine, and although she is a really lazy couch potato - commonfor borzois, has plenty of energy when she feels like it

Answer: Marcia-

I do not deal personally with many cases of ehrlichiosis, so what I amgoing to relate is my understanding of ehrlichiosis based mostly onliterature references. I definitely understand your feeling that thisdisease is confusing because there are disagreements in the literaturesources, because a full understanding of ehrlichiosis has not beenachieved yet.

In reviewing abstracts of articles on ehrlichiosis that I could find on thePubMed web site and veterinary databases, there seem to be some trends thatmight help in your interpretation of what is happening.

* Doxycycline is still considered to be the most effective medication fortreatment of ehrlichiosis but it does not work in all cases. A roughestimate of the failure rate based on several conflicting studies issomewhere between 25 and 40% of dogs treated. Other medications that may besucessful include tetracycline, chloramphenical, imidocarb andfluoroquinolones such as enrofloxacin (Baytril Rx). Some studies havesuggested that imidocarb and fluoroquinolones are as effective asdoxycycline and some suggest they are not nearly as effective. I think itwould be reasonable to try another medication if clinical signs returned,though.

* When it can be reasonably shown that ehrlichia organisms are verysignficantly depressed or no longer present, using tests as Westernblot, polymerase chain reaction (PCR) testing or negative blood cultures,titers tend to drop significantly, although a measurable titer may persistfor long periods of time. I do not know how to arrange for these tests soit wouldn't surprise me if many other general practitioners don't know,either. So you may have to talk your vet into talking to an expert in thisfield. In the reference search suggestion below, Dr. Waner is from Isreal,so it may be possible for your vet to confer with him or her.

*In several studies, platelet counts returning to normal levels was apositive sign for response to therapy that correlated pretty well withother testing.

* It is not unusual for dogs to have more than one ehrlichia organism,another tick borne disease or even an organism that cross reacts onehrlichia titer testing that may be confusing when interpreting titers orresponse to therapy.

* Dogs that have had ehrlichiosis do not appear to be immune to newinfections, even when they have positive titers to the organism at the timeof a new exposure. Either that, or chronic infection is being mistaken fornew infections. I am not sure that it is possible to be certain which ishappening at this time but at the literature references favor thesusceptibility to new infections theory as far as I can tell.

If the titers did drop within a couple of months after treatment it wouldbe a good sign. If not, I would continue to be a little worried about thepossibility of a chronic infection. That would also hold true if plateletcounts continued to be low normal on future (and non-clumped) samples. Itis probably a good idea to check platelet counts for a couple of months.

You can find much of this information by searching the PubMed websitehttp://www.ncbi.nlm.nih.gov, and using "Waner T" as the search term, thenclicking on the related articles links. You might want to do this andconsider printing out some of the research. It may be that your vet canarrange for one of the other testing procedures if you find yourselfcontinuing to question the response to therapy based on clinical orlaboratory signs (low platelet counts, continued high titers).

Mike Richards, DVM
5/22/2001

Chronic ehrlichiosis - bone marrow suppression

Question: Dear Dr Richards,

I am a new subscriber to the Vet Info Digest. I've often read your excellent information on theWeb when researching for information for my pets, namely for my dog who has ehrlichiosis.

Balzac is an eight-year old mix of Black Labrador and Great Dane who was born here inMontreal, Canada. I adopted him from the SPCA when he was three months old. I brought himalong to live with me when I moved to Mexico about when he was nine months old. We liveddown there for about 4 years and then moved back to Montreal. Last summer, during a routineheartworm blood test to determine if he still had the disease, (he had tested positive the summerbefore)- (and was negative this summer after 12 months of treatment with Heartguard), we foundout that his white and red blood cell counts were below normal and subsequent testing revealedthat he had ehrlichiosis, which he probably caught in Mexico, where there are many ticks andwhere this disease is rapidly becoming endemic. In fact, the other dog that I had at the time that Ilived in Mexico had caught the disease while we were living down there, so I was familiar with it.

However, contrary to my other smaller older dog, who was abruptly assaulted by this diseaseliterally overnight, starting with diarrhea, gradual loss of appetite, trembling of the head and loss ofusage of the hind legs, all this within about 2 weeks, and who was completely cured within twomonths, Balzac seems to have well surmounted the initial acute phase without symptoms and wenton to the chronic phase without us really noticing anything. He was getting older and has a bit ofarthrosis in his hips, which we thought accounted for the gradual loss of energy, playfulness andmobility he was experiencing. But after the diagnosis, we realized that it was the ehrlichiosis thatwas making him sick.

In mid-August, he initially tested positive for ehrlichia canis at 1/20 or greater - the end-point titerwas positive up to 1/1600. Less than 2 months later his titer was at 1/10240, which shows that hisimmune system really kicked in. He was treated starting in August, upon the recommendation of afriend who is a neurological vet and with the agreement of my own vet, for eight weeks with 500mg/day of Doxycycline. I was told it was useless to repeat the end titer test for at least six to eightmonths, because the titer would not go down until then. We did however, continue to monitor hisred and white blood cell count - the red count went back to normal but the white is still down alittle. In conjunction with the Doxycycline, we started him on ADEKs multi-vitamins with zinc dailyas well as 500 mg of glucosamine and 400 mg of chondroitine which he still takes now.

He seems to have regained his health, he is now completely transformed - energetic and happy, heruns and plays again, eats and sleeps well. His white blood cell count however, remains a little lowand that bothers me. My vet does not know why - ehrlichiosis is not a very-well known disease inCanada - and we don't quite know what to do about it, if anything.

I understand that Balzac's remission may be temporary and that the ehrlichiosis may come back, inwhich case he will immediately be put back on Doxycycline. Now that I know the symptoms, Iwill notice it more easily.

I would like to know what you think of this case, if you have ever seen anything like it, what youthink of the low white blood cell count and what recommendations you may have.

Any information that may contribute to the well-being of my beloved dog will be greatlyappreciated. Thank you so much for your time and attention.Sincerely yours, France

Answer: France-

According to "The Textbook of Veterinary Internal Medicine, 5th Ed." by Ettinger and Feldman, itcan take up to a year for the bone marrow to recover after a patient with chronic ehrlichiosis istreated for the disease. The reason that bone marrow suppression persists for so long has not beendetermined. If I interpreted the information in this reference correctly, giving doxycycline on acontinuous basis to try to speed up the recovery process (or to try to ensure death of the organisms)actually slows down the recovery process in the bone marrow, so even though it is hard to waitaround and see what happens, that is actually the best approach. While doing this it probably is agood idea to be very vigilant for signs of illness, since the depressed white blood cell counts, plateletcounts or red blood cell counts (all are possible) could make it easier for other diseases to occur.

I do not see a great number of cases of ehrlichiosis but we have seen occasional patients with thiscondition. So far, I can't recall a patient with a recurrence of the illness, perhaps because we do notpractice in an area in which the odds of reinfection are high. If that is the reason, then I would thinkthat you also have a really good chance of never seeing a recurrence of the illness in Balzac, sincereinfection isn't too likely where you live, either. There are reports of dogs who do not totallyrespond to therapy for ehrlichiosis but whether this means they are chronically infected or that theirbone marrow or immune system has been permanently damaged is unclear. Our experience,although it is with a small number of patients, suggests that a recurrence of clinical signs is not verylikely once patients are treated.

Good luck with this. I would be very hopeful that you will see a complete clinical recovery, includinga return to normal white blood cell counts but it may take more time. It is good to keep track of thisrecovery. Patients in which the Ehrlichia canis or E. chafeensis organisms are eliminated usually havedramatic reductions in the titer, or no measurable titer, after six to eight months. It will be reassuringif you get a good result when you do recheck the titers.

Mike Richards, DVM
2/19/2001

Identifying vector for leishmaniasis in US outbreak

Question: Dear Dr Mike,

First let me tell you that my pup that hadErhlichiosis is doing great now with a normal rangeplatelet count like you suggested. Thanks so much forthe advice.

I am returning to the US in April and I wondered whatthe latest information is on Leishmaniasis in the US.

Here in Europe there is a collar called Scalibor (likea flea/tick collar) that is used to repel the sandflies that transmit the disease here. It is made byHoechst and the active ingredient is Deltametrina.It is tested 97% effective.

I wondered if the sand fly is the vector in the US?Or are they still trying to assess that fact? Thereare sand flies in the US though?

Also here in Italy local vets are suspicious that itis possible for dogs to get CanL (Leishmaniasis) byeating horse manure and I am wondering if that is thetransmitter in the US since many of the cases havebeen hunting fox hounds who have contact with horses.

I would appreciate an update on this disease and yourviews. Also can you tell me what states are havingproblems currently.

Thank you very much. Regards, Kim

Answer: Kim-

Mike Richards, DVM
2/14/2001

Babesiosis, anemia, and a tumor in Giant Schnauzer

Question: We have a 6 1/2 year old Giant Schnauzer. He has a mass on the underside of his left front paw at the base of a toenail. He has had a similar mass once previously. At that time it was removed and testedand found to be a fibrous mass and it was benign. His apetite seems normal, there is no evidence ofblood in stools or urine. He seems to have nearly his normal energy level. We were about to have thiscurrent mass removed as before hoping for a similar result.Pre-operative testing indicated a low red blood cell count and low platelet count. Our vet did notwant to operate until we find the source of the blood count problem since she believes it is aseparate issue and not related to the toenail mass. A number of tests have been done including afull SMA, tick titers, tests for brucellosis, xrays and an ultrasound. Test for auto-immune diseasewas negative. So far we have found nothing except on the tick titers. Rocky mountain spottedfever=negative, erlichiosis=negative, lyme disease=positive. Our veterinarian said he doesn't haveany profound symptoms of Lyme disease, but he has definitely been exposed to it. A friendsuggested that it might be "babesiosis" which she said frequently happens along with Lyme diseaseinfection. We will have to ask our veterinarian if they tested for this, it wasn't mentioned. We aregetting very anxious about getting the mass on the base of the toe nail removed. We are worriedabout losing this wonderful friend.

Is there a likelihood that babesiosis could be the problem?If so, what is the treatment or cure?What drugs or antibiotics would help?Are there any specific foods that we should be giving him?He is now taking a 21 day couse of antibiotics for the Lyme disease exposure(doxycycline). Willthat help or hurt his condition if babesiosis is the problem?Any information will be very much appreciated. We dearly love this gentle giant and we are veryworried about him.Thank you in advance for your help.

Answer: Frank-

It is possible that the anemia could be related to the mass itself, especially if it is a malignant tumorsuch as a melanoma. It is also possible that there is a second problem leading to the anemia. Animportant differentiating factor between anemia from chronic illness and anemia from babesiosis orother infectious organisms is that the presence of immature red blood cells in a blood smear. Theseare referred to as reticulocytes. If there are a high number of reticulocytes in the blood smear, thenthe body is attempting to respond to the anemia. This is typically what happens when babesisosis orehrlichiosis is present. If there are few reticulocytes, or no reticulocytes, then it is more likely that theanemia is the result of a tumor or some other chronic illness. Since you and your vet have tested fora wide variety of possible underlying illnesses, I would have to worry about the possibility that thetumor is the cause.

Your vet may have already determined whether or not the anemia is regenerative. It would beworthwhile to ask. Babesiosis is tested for by examining blood smears for the organism itself, whichlives inside of red blood cells. It is usually present in blood smears when it is causing problems.There is a serologic test, as well. A positive titer would not necessarily indicate active disease,though. The treatment for babesiosis is imidocarb diproprionate (Imizol Rx) which was approved foruse in the United States within the last couple of years. As far as I know, there are no commonlyused antibiotics which are effective agains this organism.

If the anemia is not regenerative, I think that I would want to look for metastases of a tumor in thelungs with X-rays. If I didn't find evidence for metastasis I would want to remove the tumor unlessthe red blood cell count was low enough that I really thought the patient might die during the surgery.Your vet may have different experiences than I have had, prompting the more cautious approach (orthe anemia might be regenerative, which would also signal a different cause for it).

I hope that things have already improved and you have been able to deal with the tumor. If not, itmay be worth checking to see whether the anemia is regenerative and whether Babesia organismsare visible in the blood smears and then pursuing whatever course of action seemed appropriate.

Mike Richards, DVM
1/15/2001

Ehrlichiosis in Rhodesian Ridgeback

Question: Dear Dr. Mike,

Thank you so much for this wonderful service. I am US
military serving overseas and it is often difficult to
obtain veterinary advice.

My 6 month old Rhodesian has tested positive for
Ehrlichiosis (Elisa test). We put him on Doxycycline
but I am worried that his platelet count is not
improving.

His count before treating with Doxy was 174, after two
weeks of treatment 168 and now after three weeks of
treatment it is 146.

Is it possible that the dosage is not high enough to
fight the disease? Or is this normal for this
particular tick borne disease.

Any advise would be welcome.

Thank you.

Regards, Kim

Answer: Kim-

The platelet counts that you are seeing in the test results are within thenormal range for dogs, so it is possible that this is the level of plateletproduction that your dog normally achieves. It is definitely a high enoughplatelet count to produce expected blood clotting effects, as long as theplatelets are functioning properly (usually there is no problem with thisin ehrlichiosis).

It is possible that some platelet destruction is occurring and that you areseeing rises in the platelet levels by now. It wouldn't worry me, at all,if a patient of mine continued to have platelet numbers in this range, though.

Hope this helps.

Mike Richards, DVM
11/26/2000

Ehrlichiosis and Rocky Mountain Spotted Fever

Question: Dear Dr. Mike,

First, you have a very nice site and do the animal owners a service. Havingjust discovered your site while searching for information, I am happy tosubscribe both to support your efforts as well as to give me the opportunityto ask a question of you.

I have read all the information I could find on your site concerningErlichiosis and Rocky Mountain Spotted Fever, so I am hopeful that perhaps youcan add to what you have already published.

I live back in the Tennessee woods, and although I have always used Frontlineon my dogs, I usually skip January and February, and this year (to myeverlasting shame), I was too preoccupied with my work schedule to go by myvet's office and hence ended up missing March as well. Apparently, a bigmistake. I have a very athletic 4-1/2 year old SchH III German Shepherd bitchwho competed in the DVG Nationals last year and who has earned a spot thisyear as well. Since I had her hips & elbows OFA'd before I bred her inJanuary, and since she has never had any joint pains (not even "pano"), I wasdumbfounded to see her limping a week ago after just a brief workout.(Because she had nine puppykins, this was the first time I had worked hersince early February.) Headed straight to my vet. He examined herand re-Xrayed and saw nothing. So, knowing this was a big deal to me, hestarted digging. The titers for Erlichiosis and Rocky Mountain Spotted Feverwere 1:80 and 1:128, respectively, and he stated that this particular test(??) was to be interpreted as positive for titers less than 1:40 and 1:64,respectively. He started her on Doxycycline immediately, and she's stilltaking it.

Now the questions. The more I try to learn about this disease, the moreconflicting information I find, so I hope you can offer some clarifications.Since, in her case, we believe we caught the disease early on, can you giveany odds for a complete recovery?? (My vet would only say that if the titers,when repeated in 6 weeks, were negative, that she _likely_ would be cured, butthere was a possibility that it would end her working career.) Can you offerany more definitive/quantitative assessment of the likely outcome? Is thereany additional treatment that would improve the odds?

Second, this was only her second litter, and I had planned to breed her twoor three more times over the next few years as she has produced some verynice pups. If she does not recover fully and I have to retire her fromcompetition (which would kill her as much as me -- she loves to work),would it likely stress her system too much or cause her pain to breed heragain in the future? If not, is there any possibility that the puppies wouldbe affected in any way?

I appreciate any "enlightenment" you can share.

Thanks & regards,Richard

Answer: Richard-

The current information on ehrlichiosis is that any positive titer at allshould be considered as sufficient evidence to treat for this particulardisease if there are clinical signs and known exposure to ticks. Doxycylineis the drug of choice at the current time. There is a great deal ofcontroversy over whether or not dogs are completely cleared of thisorganism so it is not surprising that you are confused. The titer to theinfection may stay high for years after an exposure and some dogs havepersistently high titers who have never shown signs of clinical illness.The assumption in these cases is that the dog probably had a good immuneresponse to the rickettsia that causes ehrlichiosis and did not needtreatment. Some dogs respond well to treatment initially and then haverelapses that really do appear to be due to recurrences of theehrlichiosis and the assumption is that they were never completelycleared. However, most dogs that show clinical signs will respond todoxycycline and will not have chronic long term joint damage, as issometimes seen with Lyme disease. So basically, your vet has given you thebest possible answer with the information available at this time. There issome hope that in the future PCR testing or some other form of identifyinglow numbers of ehrlichia organisms will allow us to differentiate the dogsthat have almost been cured from the ones that have been cured. I don'tthink you can count on the titer to this disease disappearing any time soonbut I would not overly worried about this ending her competitive career,since high titers persist in a lot of normal acting dogs. If there isclinical disease due to Ehrlichia, the earlier it is treated, the better.Early treatment resolves clinical signs more effectively than latertreatment and may reduce the potential for long term infection.

Rocky Mountain spotted fever (RMSF) is even harder to draw conclusions about based on titers. I am somewhat convinced that anytime I want a diagnosis for a patient when I am struggling to find one that I can run RMSF titers and get a positive result. The situation probably isn't that bad but we get a lot of positive titers in situations in which we are not certain that the results are accurate. On the other hand, when there are clinical symptoms, when tick exposure is certain, or likely, and when there are titers greater than 1:64, we will treat for this disease. Doxycycline is also a good choice for RMSF, so we don't have to know which tick disease is present, for sure. I have a couple of patients that I have treated for reasonably certain cases of RMSF who had residual soreness or lameness for several months, so I think it is conceivable that it does some damage to the joints, although I have not been able to document this with X-rays. Most dogs seem to do fine after a few weeks to a few months, though.

Some of the more recent work on tick borne illnesses suggests that multiple infections are very likely to be present, so it is entirely possible that your dog could have both conditions or could have been exposed to both organisms.

I do not know of any additional therapy, except perhaps the use of anti-inflammatory medications to lessen the effects on the joints, if lameness seems to be persisting.

I would also consider the possibility that this is all just a red herring. Titers to tick borne diseases are present in a lot of dogs without any clinical signs, making interpretation of these titers difficult, as you have discovered. The most common problem leading to rear leg lameness in German shepherds that do not have hip dysplasia or cruciate ligament degeneration is probably intervertebral disc disease. This may present as an intermittent weakness or lameness, in some cases. If the lameness persists, it would be worthwhile to continue to try to rule out alternative problems. Especially since ehrlichiosis is usually associated with polyarthritis (affecting more than one limb) and since other signs, such as platelet deficiency, are very common with this infection and do not appear to have been a problem.

If she continues to be lame, breeding could cause problems, as the weight gain is hard with almost any orthopedic condition. Some bitches who have had ehrlichiosis will have future problems with breeding, including difficulty conceiving, abortion or death of puppies shortly after birth. I could not find any indication of how likely these effects are, though. Presumably they would be more likely in dogs with chronic illness (intermittent weight loss

I know this didn't clarify things, much. If you have additional information that you would like to ask about please feel free to write again.

Mike Richards, DVM
5/4/2000

Ehrlichiosis

Ehrlichiosis is caused by the rickettsial organism Ehrlichia canis. Other examples of rickettsial organisms are Riskettsia rickettsi, which causes Rocky Mountain Spotted Fever and Ehrlichia risticii, which causes Potomac Fever in horses. These organisms tend to be carried by ticks and other insect vectors, in some cases. For ehrlichiosis, the most common vector is the brown dog tick. For this reason, ehrlichiosis occurs anywhere this tick occurs. At present, it has been reported in 34 states, with the northern states being spared in most instances. The southeastern and south central states are the most heavily affected. A few cases of Ehrlichia canis infection have been reported in people after tick bites.

Ehrlichia infection can cause a number of clinical signs. It can be extremely hard to diagnose due to the wide range of symptoms that can occur. Most dogs infected with this organism will have be lethargic, lose weight, show less interest in food and become anemic. Other possible clinical signs include hemorrhages under the skin or in around the gums, swollen lymph nodes, muscular or joint soreness, nasal discharges or nosebleeds, severe neck or back pain, blood in the urine and eye problems ranging from exudates to severe inflammation of the internal eye structures. Neurologic signs such as seizures and difficulty walking can occur. Respiratory or heart related signs can occur due to hemorrhaging and compensation for anemia if it becomes severe. Hemorrhaging occurs primarily due to decrease in platelet counts from the infection. While most dogs show a number of symptoms when first infected with Ehrlichia, there is also a chronic infection that can occur if the acute infection is not treated. In this case, the dog may appear to be normal or may show vague signs of illness occasionally. This is one cause of the complaint that "my dog just isn't doing right". The chronic illness can suddenly become very severe again if the dog is stressed in some manner or become less immune competent for some reason.

The best method of diagnosing this disease is through testing of serum from the dog using an immunofluorescent antibody (IFA) test. Unfortunately, a positive test only indicates exposure. Still, in the presence of clinical signs or if the titer rises after treatment or stays consistently high, infection is strongly implied by the lab results.

Ehrlichia canis is normally susceptible to treatment with tetracycline antibiotics, including doxycycline. In some situations the organism will not respond to these antibiotics or their use is contraindicated due to the young age of a dog or pregnancy. In this case, chloramphenicol can be used and there is anecdotal evidence of success using cephalosporin antibiotics. The bleeding tendencies in this disease are related to a drop in platelets (thrombocytopenia) so it can be necessary to use corticosteroids to treat this condition if the platelet counts are low. While this can be life saving, the use of corticosteroids should be discontinued as quickly as possible so that their immunosuppressive effect does not interfere with successful treatment. Extensive supportive care, including intravenous fluids, administration of blood products and hospitalization may be necessary to treat this problem in some dogs. The survival rate is good if the disease is recognized and treated aggressively.

Mike Richards, DVM

Leishmaniasis and Ehrlichia

Q: Hi Dr., our dog may have a severe case of Ehrlichia Canis, our vet says. However, most of the symptons described in the Q+A do not really show. Is nose-bleeding a symptom? She has had this a couple of times recently, and it was extremely hard to stop. She also may be possibly infected with Lichmaniosis (SP?), a disease that comes from a meditarrenean sand-fly. (she spent the first 4 months of her life in Portugal)? Are there any experiences as to the cross-reactions or interactions between Ehrlichia and Lichmaniosis? Thanks, Klaus

A: Klaus - I am sorry for the delay in replying. I practice in an area in which leishmaniasis is not a problem and I was not familiar at all with this problem. This does occur naturally in some areas of the United States (mostly Texas) and it is a problem in the Mediterranean area, as you note. A dog moving to the US from an area in which the infection occurs does have to be considered as a suspect for it when clinical signs are present.

Leishmaniasis is caused by a protozoan in the Leishmania species. Skin disease, polyarthritis (arthritis in multiple joints), mucosal disorders (lumps on tongue, gums, etc), damage to internal organs and possibly bleeding disorders. It is diagnosed by examination of tissues from affected dogs or by serology through antibody titers. I am not sure if there is a consistently effective medical treatment for this condition since there appear to be a lot of semi-effective medications listed in the veterinary literature.

The skin signs seen with this disease include loss of hair, scaling of the skin, ulceration of the skin on the limbs or ears, formation of nodules on the body and sometimes pustules.

Ehrlichiosis causes bleeding disorders and nosebleeds can occur when a dog is infected with this organism. It is usually a good idea to consider using an antibiotic, such as doxycycline, when ehrlichiosis is suspected. I am sure your vet already has done that.

Nose bleeds do sometimes occur with ehrlichiosis.

I could not find any information on dual infections but it is possible that the vet school at Texas A&M University may be able to provide more information on this since the problem occurs in their area, if there is still doubt about the diagnosis or prognosis at this point.
Mike Richards, DVM

Ehrlichiosis

Q: I have an Old English Sheepdog that was not diagnosed for 2 years with Ehrlichiosis...she is having a relapse and I am afraid I will lose her...She has been on Doxi and Batril for 2 years but never gets better...her white and red blood cell counts are grim....Any Ideas ??? Please let me know , I love her very much , she is all I have ....

A: Dream- I am sorry for the later reply. We do not practice in a area in which ehrlichiosis is common and therefore do not have much practical experience with this. When doxycycline doesn't work, imidocarb dipropionate is sometimes recommended as an alternative. I do not know if it is possible to obtain imidocarb in the United States, though. If doxycycline is controlling the Ehrlichia organisms but the anemia continues to be non-responsive corticosteroids are supposed to be beneficial in some cases, or other immunosuppressive medications may be used. Blood transfusion are sometimes necessary in acute ehrlichiosis and it doesn't seem like they would be ruled out by the chronic nature of the problem you are seeing but they do have a short term benefit and would not probably be a good long term solution to the anemia and low white blood cell counts you are seeing.

I hope that this situation has been resolved successfully by now.

Mike Richards, DVM

Ehrlichia

Q: We have just been informed by our vet that our dog (a black lab mix) has ehrlichea. We found this out because we were having her tested to try to find out the cause of seizures she was having. How successful are the antibiotics usually used to combat this disease? Where can I find out more info on the disease? Any help would be greatly appreciated. Thank you, Glen

A: Glen- Tetracyclines, especially doxycycline, seem to be very effective for ehrlichiosis. Once in a while there is a recurrence of the condition despite apparently successful treatment. I hope this was the cause of the seizuring but suspect that it was not -- you may need to continue to treat that problem separately. Your vet will work with you that, I'm sure.

I'm pretty sure we have information on ehrlichia in our Dog Information area.

Mike Richards, DVM

also see Adaquan and Your Dog

also see Ehrlichia in dogs

also see Giardia

also see Allergy Problems in Dogs