Infectious Diseases of Cats


Bartonella henselae

Question: One of my cats has been diagnosed with Bartonella (level 4). As a foster home for rescued cats, I currently have 14 cats waiting to be adopted in my home. A few questions: 1) What does level 4 mean? 2) Can this cat give it to my other cats by sharing water and food - or does it have to be through a bite or grooming? 3) What would your recommendation be for my other cats. Should I just treat them all whether they are positive or not? 4) Is Zithromax the drug of choice? (If so, what dosage do you recommend?) Any other suggestions greatly appreciated! Thank you! Audrey

Answer: Audrey- Bartonella henselae, which is the usual species of Bartonella in cat infections is currently thought to be transmitted mostly through flea bites. Strict flea control is thought to be the best way to control spread of the disease. It can also be spread by blood transfusion. With this in mind it seems likely that it can be spread through any method in which an exchange of blood occurs, so fighting among cats would seem to place them at risk, as well, although I can't recall seeing any proof for this mode of transmission.

I really don't know what Level 4 means in the test results and you are the second person to ask me this, so it has to be something that one of the labs is reporting. The titer considered positive for infection is 1:64 at the NC State Vector Borne Disease Laboratory so that doesn't seem to correlate. Your vet should be able to find out from the testing laboratory what the level 4 designation refers to. There is a lot of disagreement over how often Bartonella causes disease in cats. When disease does occur the clinical signs are thought to be fever, lymph node enlargement, gum infections, eye inflammation (uveitis) and transient depression. These signs are possibly more likely to occur in cats with feline immunodeficiency virus (FIV).

Whether Bartonella can cause serious disease by itself in cats is still open to some debate. Two classes of antibiotics seem to be most helpful, macrolides (erythromycin, azithromycin, clarithromycin) and combinations of a penicillin based antibiotic (ampicillin, amoxicillin, others) and a fluoroquinolone ( enrofloxacin (Baytril Rx), dicloxacin (Dicural Rx), others). I do not believe that the ability of any antibiotic or antibiotic combination to completely clear B. henselae from the blood stream of cats has been proven at this time, but I could be wrong.

There are several recommended dosing schedules for azithromycin but we tend to use 5 to 15mg/kg every 24 hours for 3 days and then every 48 hours. It is necessary to treat for at least 6 weeks when treating for Bartonella henselae. Since it doesn't appear likely at this time that it is possible to completely eliminate B. henselae from the blood stream of cats with antibiotics it probably doesn't make a lot of sense to try to treat all the cats and it might not even make sense to treat the cat with the positive titer, unless it seems like B. henselae is actually causing disease symptoms at the present time. There is a good summary of B. henselae infection on the NC State web site --

Mike Richards, DVM 1/27/2005

Infectious diseases and prevention

Question: Hello. I'm Alexandra Petrison from St. Francis Xavier school. I was wondering if you could help me on a project that I'm doing. It's about cats. If you wouldn't mind, I'd like to ask you some questions. How long have you been working with cats? What information can you give me about taking care of cats and keeping them from getting FeLV or any other diseases? Do you know how long it took to find a vaccine for FeLV? Thank you very much and if you could email me back i would appreciate it.

Answer: Alexandra-

I have been a veterinarian for 22 years and have worked on cats throughout my career.

Cats are susceptible to a number of viral infections, including feline leukemia virus. The virus that infects the most cats is probably feline herpes virus 1, which is also called rhinotracheitis virus. It is likely that most cats are infected with this virus. There is a vaccination for rhinotracheitis but it helps infected cats prevent signs of the disease, such as sneezing or runny eyes, rather than preventing infection with the virus.

Calicivirus is also a common viral infection of cats and also causes upper respiratory infections.

Panleukopenia, or feline distemper, is a less common virus at this time, probably because vaccination for it works very well. Panleukopenia causes a high death rate in cats infected with it, so it is good that the vaccine works.

Feline corona virus is a common intestinal virus that may cause no clinical signs or may cause diarrhea in cats who are infected with it. This is considered to be a minor viral infection in most cases, but when feline corona virus mutates, it can become deadly. If the mutant virus can invade the rest of the cat's body it is referred to as feline infectious peritonitis (FIP), which is almost always a fatal infection. There is a vaccination for this virus but there are some questions about how well it works and most veterinarians do not use the vaccine on a routine basis.

Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) are retroviruses. These are viruses that attack the immune system and weaken it. This can lead to severe infections or even cancer in cats infected with these viruses. There is no vaccine for FIV at this time. There is a vaccine for FeLV. It is not as effective as vaccines against other types of viruses are but it works well enough that most veterinarians recommend it for cats who may be exposed to an infected cat. This would include outdoor cats, cats who live indoors and outdoors and even indoor cats who are routinely exposed to a cat who goes in and out. Cats are most susceptible to feline leukemia virus when they are young and develop a natural immunity as they get older.

Feline leukemia virus was discovered in 1964 and a test to detect it that could be used in veterinarian's offices was developed in 1973. A vaccine was not approved until 1985, so it took almost twenty years for a vaccine to reach the market that would help prevent this disease.

Over the last five or six years it has become apparent that some cats vaccinated against feline leukemia virus developed cancers where the vaccines were given. The cancer is usually fatal if untreated somewhere between 50 and 70% of cats in which the cancer is treated will die from it. The rate of development of this cancer is thought to be between 1 in 2500 and 1 in 10,000 cats who are vaccinated against FeLV. Due to this problem, veterinarians are trying much harder to figure out if a cat is at risk for getting feline leukemia virus before giving the vaccine. In young cats, it is usually better to give the vaccine if there is any suspected risk. In older cats (over 2 years of age) it is probably better not to give the vaccine unless there is a definite risk of exposure to an infected cat.

I hope this helps some with your project.

Mike Richards, DVM 11/7/2001

Cat scratch Fever - Bartonella

Question: Dear Dr. Mike:

My one year old male cat has been diagnosed with bartonella (cat scratch fever). He had a cyst in his mouth that was removed and has grown back. It was diagnosed as benign. The vet has diagnosed the above disease. I can find information on this in humans but how do you treat the cat so he gets over it. My vet said she would have to research it, but I thought you might know what to do?

Answer: L-

Bartonella henselae is the cause of bartonellosis in cats, which is the organism associated with cat scratch fever in humans.

The first thing that you should do if your cat has this infection is institute a very good flea control program, because the disease is spread by flea bites. Using imidocloprid (Advantage tm), fipronil (Frontline Topspot tm) or selamectin (Revolution tm), possibly in conjunction with lufenuron (Program tm) would be best.

There have been several recommended treatment programs for cats. It is not clear at this time if it is possible to clear the infection from all cats with antibiotics but many cats recover without antibiotics over time, anyway. The recommendations that have been reported in the literature are to use enrofloxacin (Baytril Rx) for extended periods, doxycycline for extended periods, doxycycline for one to two weeks followed by amoxicillin for two weeks or with amoxicillin-clavulonic acid (Clavamox Rx). Clindamycin (Antirobe Rx) is potentially useful but I am not sure that its use has been proven. The newest recommendations, based on the treatment that works in humans is to use azithromycin (Zithromax Rx) at 5 to 15mg/kg every 12 to 24 hours for 5 days, then every 72 hours until the infection is cleared. This has not been proven to work in cats to the best of my knowledge but logically should since this antibiotic works in humans and can be used in cats.

Mike Richards, DVM 11/1/2001

Primaxin (Rx) and Bordetella

Question: Dear Dr. Mike,

I am from Lisbon, Portugal . I thought perhaps you wouldn't mind to supply me with some information concerning a drug called Primaxin, since we cannot find any reference to it. What is the principle of this drug?

This is because a friend of mine who owns several cats is having a serious case of Bordetella in the household and her Vet is having difficulties in the treatment.

I, myself have a household of many many cats and some dogs amd I am also afraid that the disease can reach me and therefore your valuable help will be highly appreciated.

Thank you very much. Manuela

Answer: Manuela-

I am sorry for the long delay in responding to your question. I was not familiar with Primaxin (Rx) and it took me a little while to find information on it.

Primaxin is a combination of two medications, imipenam and cilastatin. Neither drug is absorbed well from the digestive tract, so the medication must be given intravenously. The dosage is 2 to 5mg/kg every 6 to 8 hours. I would think that these dosing requirements would make this medication unattractive unless it is the only medication found capable of killing the bacteria after a culture and sensitivity test.

My recommendation would be to do culture and sensitivity testing, if possible. This would probably turn up a less expensive and easier to administer medication. However, if this test has been done and the results indicate that this is the antibiotic combination that will work, you may be stuck with it. If it is not possible to do culture and sensitivity testing then there is no reason not to try a different antibiotic, such as doxycycline, to see if it would be helpful.

Bordetella isn't usually a devastating illness unless it occurs in very young kittens. In older cats it is usually a transient disease, lasting one to two weeks and clearing up. If you are seeing more severe cases than this, it is likely that there is an underlying cause, usually a viral illness occurring at the same time as the bordetellosis. This can be a difficult situation to deal with, since the viral infection has to run its course due to the lack of effective therapy for the viral upper respiratory diseases in cats.

I hope that this information is helpful.

Mike Richards, DVM 5/9/2001

Feline leukemia and FIV testing

Questions: Dear Dr. Richards, I have recently fostered two kittens in my home to socialize them until they could be adopted by someone else. Both kittens tested negative for feline leukemia & aids when they were first rescued. At 5 months of age, they were both tested again (before being adopted) and both found to be positive. I have two questions: 1) Is there an age at which kittens are too young to be tested? When the anti-bodies from their parents are temporarily protecting them? 2) Needless to say, I am very concerned about my own cats having been exposed to these positive kittens for two months. Although I plan to have my cats tested right away, is there a period during which the infection might not yet show up? Also, after reading all your listings for leukemia, it looks as though my cats could test negative but still be harboring the virus in their bone marrow, is that correct? Thank you so much. You are a wonder!!


Answer: Rhoda-

Feline leukemia virus tests are pretty accurate. They test directly for the leukemia virus. It takes from two weeks to several months from the time a cat is infected to the time that there is enough of the virus in the blood stream for detection. The average time before infection is detectable is between two and eight weeks. This may explain why the kittens were negative on initial testing but are now positive for this virus.

Other explanations are false positive test results, which do occur at times and infection at your house after the original tests. This second possibility is not that likely unless one of your adult cats did test positive for the feline leukemia virus at this time. Even if a cat is harboring the virus in the bone marrow or central nervous system and is therefore negative on blood tests, it won't pass the virus on to other cats. To try to eliminate the possibility of false positive test results, it might be worth checking an IFA test (sent to a lab) as well as the in-house ELISA test. IFA tests are not as sensitive (not as likely to detect the virus), but they are more specific (meaning that they are less likely to give false positive results).

Testing for feline immunodeficiency virus (FIV) is different. At the present time there is not a test to detect the virus directly. Therefore, the tests are for antibody to the virus. Despite this, it is likely that a cat that tests positive for FIV is positive for it, since cats are persistently infected with the virus and there is not a very high rate of false positives on this test.

The fact that the FIV test is an antibody test means that young kittens may test positive if they have antibody from their mother in their bloodstream. Maternal antibody may not disappear from the bloodstream for up to sixteen weeks. On the other hand, if they do become infected, there is a lag time of five to nine weeks from the time of infection until antibodies are formed against the virus. This makes testing a kitten really tough prior to sixteen weeks of age. However, in the case of these kittens, the original negative test, followed by the positive test, makes it very likely that these kittens do have FIV.

It is possible for cats to remain infected with feline leukemia virus that is sequestered in their bone marrow or central nervous system and to test negative for feline leukemia virus. Sometimes cats infected in this manner never have problems with the virus and sometimes it resurfaces years later due to an immune system problem or some other major stress. I do not think this should be a major worry but it is a possibility.

Hope this helps.

Mike Richards, DVM 8/8/2000

Transmissible disease and new kittens from different sources

Question: Dear Dr. Richards,

I wrote you in March about my kitty that had been diagnosed with mammary and lung cancer. Unfortuantely, I lost her in April. I have one new kitten now who we estimate is three months old and I am taking him tomorrow to have him tested for Feluk and started on his vaccinations. I am also getting a Ragdoll next week. I have several question related to properly introducing them and cutting down on the possiblity of disease transmission.

When we first got Wyley, I took him to the Vet who estimated his age to be around 7 weeks. He appeared to be in good health. Well-fed, no ear mites no fleas not even any worms. The vet tried to draw blood from him but had a terrible time getting a vein. He said that he really didn't trust the test until around 3 months of age. Wyley should now be 3 months of age and I am taking him in tomorrow for the test and vaccines. I hope that the test will be accurate.


It is particularly important since I don't know Wyley's background although he appears to be in good health.

Next, the breeder that I am buying a kitten from has informed me that she has had a problem in her cattery. She had thought that she had a respiratory infection spreading around but after an autopsy of the worst affected kitten (which she says is the only one that got really sick) it was determined to be pneumonia in the case of that kitten. She said that they treated them all as a precation which sounds reasonable to me. She says that her vet informed her that the other kittens probably just had chalymedia (spelling??) I realize that this is common and nothing to be overly concerned about. Also, the kitten with pneumonia was not in the same litter.



Thanks for your help. Susan

Answer: Susan-

Feline leukemia (FeLV) testing is accurate at any age, within the limits of the test (>96% accuracy for most tests ). This test detects the virus particles directly, so if they are present in the blood stream the test will be accurate. This is not true of the feline immunodeficiency virus test, which is an antibody test. For this test to be accurate the virus must be present, it must cause the immune system to respond and to produce antibodies. Due to this there is a lag period between infection and the time the test is positive. In addition, kittens get antibodies from their mothers and these antibodies will make the test positive, even if the kitten isn't really infected. It can take four to six months for these antibodies to disappear, so this test is not accurate in kittens until they reach this age range and is only positive if they have been infected long enough to cause antibodies to form.

Bacteria usually cause the pneumonias that occur in kittens. Chlamydia psittaci is probably the most common bacterial cause of pneumonia but Bordetella bronchiseptica bacteria has been identified as the cause of some pneumonias in kittens and appears to be a problem in catteries at times. It is probably more likely to cause a kitten to die but I am not sure of this. Cats with either of these diseases can become carriers of the infections, so there would be some risk in adoption of a kitten. I do not know a statistical risk factor (like 10% become carriers) so I can't give you any firm idea of how likely it would be to adopt a carrier. It is possible to test for these bacteria but Bordetella can be isolated from normal cats and Chlamydia is hard to culture even when it is present. If there is evidence of upper respiratory disease suspect either disease. Coughing is more likely with bordetellosis. Both of these diseases are less common than feline herpes virus (rhinotracheitis) virus as a cause of upper respiratory disease, though.

It is a good idea to keep a new cat separated from the resident cats for at least a week to two weeks on arrival into a new home. Doing this helps to reduce the risk of introduction of a disease. If the new cat shows signs of illness from the stress of adjusting to a new home, increase the length to quarantine. Once it seems safe to assume that the new cat isn't ill, it is OK to begin an introduction process. In some cases the quarantine allows the cats to get used to the smells and sounds of the new cat and the introduction goes pretty easily. In other cases it helps to switch the living quarters so the new cat is in the area the other cats were previously and the visa versa. Do this for a few days and then try introducing the cats again. The product Feliway (tm) is helpful in introducing cats sometimes when there is some tension. It is a synthetic pheromone that cats use to denote a friendly encounter and can help to reduce the tension in the household when a new cat is introduced.

Hope this helps.

Mike Richards, DVM 7/2/2000

Bordetella bronchiseptica infection in cats

Question: Dear Dr. Mike,

There have been reported three cases in central Ohio (my home) of a dog virus that has been found in cats. The affected cats have no sneezing but lots of mucus coming from the nose and eyes. It does not diminish their appitite. Cases can be fatal. I believe the virus starts with a b and sounds like bartello. Heard anything about this. Thanks as usual.


Answer: Angela-

I am pretty sure that you are thinking of Bordetella bronchiseptica infection. This is a bacterial infection which is most notorious as the cause of "kennel cough" in dogs. Recent studies have implicated this bacteria in some of the outbreaks of upper respiratory disease in cats in shelters and other situations in which cats congregate. It can be fatal in young kittens. Coughing is unusual in upper respiratory disease in cats but does occur with bordetellosis, which helps in the diagnosis of this condition. The manufacturers of a new vaccine for this condition say it is very common but I am not convinced at this point.

Rhinotracheitis, or feline herpes virus, is the most common cause of upper respiratory disease in cats. The signs are variable and may include runny eyes, runny noses, sneezing, loss of appetite and even skin disease in some cats.

If you need more information on this, let me know.

Mike Richards, DVM 6/14/2000

Bordetella in cats

Question: Dear Dr Mike, Thanks for the welcome as subscriber. Indeed I have a question. My vet advises me to vaccinate my cats against Bordetella with a new vaccine that is given intranasally. When I browse the Internet, people are not aware yet of such a vaccine (some are). Do you know this vaccine, does it make sense to vaccinate cats against Bordetella? Is it practical, intranasal application? Thank you for your time. Bea

Answer: Bea-

Bordetella bronchiseptica is a common inhabitant of the upper respiratory tract of cats and dogs. It is not clear how often it is also a cause of disease in cats. There is reasonable evidence that this bacteria does occasionally cause outbreaks of upper respiratory disease, usually including coughing, in cats that are in shelters, multi-cat households and other situations in which multiple cats are in contact with each other. In these cases it is probable that one of the cats has a strain of the bacteria that is a little more pathogenic than normal and shares it with the other cats. In a single cat household or when there are a small number of housecats without much exposure to other cats it is much less likely that outbreaks of bordetella will occur.

At present, my opinion is that this vaccine is probably not necessary for cats that live alone or in small groups. It may be a good idea for catteries, shelters and other places with a lot of cats and in which the members of the cat population change frequently. We have not used this vaccine because I don't really have many patients that seem to need it and those that might tend to be in situations in which the cost is prohibitive.

Bordetella is usually not a life-threatening illness except in very young kittens.

Intra-nasal vaccinations can be difficult to administer but they do seem to work well, since they act directly at the site the bacteria lives.

Hope this helps.

Mike Richards, DVM 5/3/99

HIV AIDS -can dogs and cats get infected

Question: I am looking to find some information with regard any truth that cats and dogs are getting HIV AIDS due to used syringes in parks and streets. I have not heard this and am trying to track information to veryify this one way or another.

thank you


Answer: Angela-

It is always hard to be absolutely certain that there is no truth at all behind a rumor like this. However, there are no reports that I am aware of in the veterinary or the human literature suggesting that either dogs or cats can be infected by the human immunodeficiency virus. Therefore, it seems to be almost impossible that this could be happening.

There is some confusion regarding the difference between human immunodeficiency virus (HIV) and feline immunodeficiency virus (FIV). These are entirely different viruses and there has been no indication in the literature that these strains of virus can cross react. The FIV virus has been used as a model for studying the human infection and this research has been published. One example was the recent "Lessons from the cat: feline immunodeficiency virus as a tool to develop intervention strategies against human immunodeficiency virus type 1", by Elder et. al, AIDS Res Hum Retroviruses, June 1998. It can be hard for people to accept that such closely related viruses do not cross species lines but that appears to be the case based on studies to date.

If dogs have a retroviral infection similar to HIV it has not been identified. There is some suspicion that they do and a recent paper "Possible relationships between canine hematopoietic neoplasia, other malignancies and immune mediated diseases" by G. Theilen, in Leukemia April 1997 suggested that there may be an unidentified retrovirus infecting some dogs. However, it has not been suggested that this is human immunodeficiency virus.

Dogs and cats are both being used in studies relating to the control or cure of HIV but these studies do not involve infection of dogs or cats with the HIV virus. They relate to things like immunosuppression of T cells with cyclosporin or similar treatments that are studied in dogs or cats in the hope that the information will apply to human patients who actually are infected with HIV.

You can search for information on HIV at the PubMed site:

I hope this helps to set your mind at ease.

Mike Richards, DVM 2/16/99

FeLV transmission

Question: Dear Dr. Richards, My name is Veronica A and yesterday my cat was diagnosed with FeLV. I found this cat in the woods about 3 weeks ago, and was told the cat was about 5 months old. My cat, Oliver is scheduled for a retest in October. I also have 2 other cats in my home, abut my question is, is it safe to have Oliver living in my home upstairs, while I have my other 2 cats living downstairs and outdoors? Is there still a chance that my 2 other cats can still get infected? Should I wait for the retest before making any decisions? Please let me know what you think. I would really appreciate it.

Thank You , Veronica

Answer: Veronica-

Feline leukemia virus is transmitted by contact with bodily fluids from one cat to another. The virus does not live more than a few seconds in the environment, so it is generally considered to be safe to keep a cat with feline leukemia if it can be kept physically separated from other cats in the household. In addition, feline leukemia virus is most easily transmitted from an infected cat to a kitten and natural immunity to the virus appears to be pretty strong in adult cats. Since you have an inside/outside cat I am presuming that the other cats are also vaccinated against this disease, making it less likely that they would be infected as well. With all of these things going for your downstairs cats I really think it is probably safe to keep Charlie upstairs and separate from them without worrying too much about the other cats contracting feline leukemia virus.

It is a good idea to retest, after at least a three to six week interval, whenever a cat tests positive for feline leukemia virus. Many cats can either free themselves of the virus or suppress it sufficiently that they do not pose a threat to other cats. In either case, the test should be negative on the second test. If the cat continues to test positive on two tests this far apart if may be a good idea to test using another testing method or to assume that the cat is infected and capable of transmitting the virus, in which case it should be kept separate from other cats.

Hope this turns out well on the second test.

Mike Richards, DVM

Feline Leukemia Kitten

Question: Dr. Richards,

I received your e-mail address from a feline leukemia support site. I don' t know where to start --- my kitten, who is almost three months old was diagnosed with FeLV three days ago. My husband and I had just gotten her and were taking her in for her initial vet exam. We do not know if she got it from her mother or from another cat she was with. We are so confused and keep getting conflicting information. We do not want to put her down - she is healthy at this time. We feel so helpless though. I guess my first question is this -

a) as a kitten with it, is it possible for her to be healthy? It seems to me that a kittens immune system would already be weaker than an adults cats and therefore it be at a disadvantage with this virus.

b) have there been any cases where a kitten (whether getting it from another cat or in the womb) has been able to pass this virus out of their system?

I know that there are no simple answers - I'm just scared for our kitten and want to keep her healthy as long as possible --- (do you recommend vitamins? or foods with vitamins (i don't want to stress her out by making her take pills at this time...) I don't think we are alone in our crusade and our desire to keep her around.

These are just the beginning questions - tons more are swarming around. Thank you so much for reading and responding to this. Please let me know where I can turn for info. -- It's scary being ignorant. Many thanks - Sean and Karla

Answer: A -

Some kittens are able to clear the virus from their system. Others are able to suppress it sufficiently that they are not affected by the virus and do not transmit it to other cats. The exact percentage of cats able to do one of these two things is not known exactly but it probably is at least 30% and may be as high as 50% or more of infected kittens.

Kittens that remain positive for the virus on two or more tests done at 3 to 6 week intervals are likely to remain positive. These kittens often have several years of relatively normal life and then develop problems associated with the feline leukemia infection. In some cases there is severe illness early in the infection, though. These kittens are also potentially infective to other cats and need to be kept isolated from other cats who are not also positive for the feline leukemia virus. As long as this is possible I see no reason not to try to provide a good life for a cat infected with the feline leukemia virus.

You are correct in the assumption that kittens are at a disadvantage when infected with this virus. Feline leukemia virus infects kittens much more readily than it does adult cats. Most cats that are infected with this virus probably were infected as kittens. Even so, there are a number of kittens who can suppress the virus.

I hope that your kitten is one of the lucky ones. If not, you can still provide her with a good quality of life, potentially for several years. It means being responsible for her and not allowing her to have contact with cats or kittens who might become infected but that usually isn't too difficult to accomplish.

Mike Richards, DVM

FIP and FIV..testing kittens

Question: I found a kitten who is 4 weeks old. I had her examined by our Vet. He called me yesterday with bad news, he said, she tested positive for FIP. He suggested that I bring her back in 6 weeks to get tested again. I am very upset and I don't know what the right thing for me to do is. I could not bear to keep this cat and get even more attached and have it get deathly sick. Also I would not be able to pay for costly medical bills. Do you have any thoughts, advice suggestions you can share with me?

Answer: Dear Donna-

I can not understand why your vet would test this kitten for FIP or for FIV (just in case you have the name of the test wrong) at this age. Both of these tests are for antibodies to the disease named; FIP = Feline Infectious Peritonitis and FIV = Feline Immunodeficiency Virus.

Actually, I can think of one reason to test for FIV. This test is often combined with a test for feline leukemia in "in-office" test kits. Many vets find it easier to just stock the combined test than to keep two separate tests. So lots of kittens get tested for FIV when the vet really only means to test for feline leukemia virus (FeLV). When the kitten is negative for FeLV but positive for FIV, the test results have to be carefully explained.

Kittens receive antibodies to many diseases in the first milk, known as colostrum, from their mother. If the kitten's mother was exposed to either FIP or FIV virus and developed antibodies, she would pass them on to her kitten. There is no way to tell if the kitten itself has been exposed to the virus based on an antibody titer at this age. I think that most infectious disease specialists would probably recommend retesting after the kitten is six months of age for FIV and that most would not bother retesting for FIP.

If there is a good reason to suspect that the kittens mother had FIP it should be reassuring to know that the standard method of preventing infections from kittens in catteries where FIP is a problem is to wean them by six weeks of age and raise them separately from their mother and the other adult cats in the cattery. This works very well to prevent FIP in the kittens and should work well for the kitten you have.

If the kitten's mother had FIV she may or may not pass it on to her kittens. I think that it is more likely that she would not pass it on than that she would but am not absolutely certain of this. The only way to know if the kitten is infected for sure is to retest later. I would wait longer than your vet recommended but your vet may have information I am unaware of to suggest that retesting sooner is OK, if this it the virus he is concerned about. It would be better if the kitten didn't have FIV but many cats infected with this virus do live reasonably normal lives, including having long lifespans. They do sometimes require more veterinary care during their lives because they get sick more easily than other cats but for single cats living indoors the additional cost is usually pretty low.

Please check for sure on the name of the virus that your vet tested for. Then you can make a decision more easily. I would not be very concerned about the kitten having a positive titer to FIP. If the kitten has a positive titer to FIV then you have to think about what to do a little harder. If you were planning on keeping the kitten and it will be an only cat, I wouldn't be overly concerned about a positive FIV titer, either. But that is just my personal opinion.

Four weeks is very young for a kitten to be weaned from its mother. There is a higher risk of all kinds of pediatric problems due to early weaning but many kittens will do OK. No matter what the test was and no matter what the test results were you have already undertaken a difficult task in trying to raise an orphaned kitten. If you are up to that you are probably up to dealing with waiting a while to find out whether the test results are really meaningful.

Mike Richards, DVM

FIP testing - part2

Question: Thank you for all your information and advice. I rescued the kitten from a garbage can. So I did not intend to keep her because I have a German Shorthaired Pointer who hates cats. My friend was going to adopt her but insisted the kitten get tested for everything before adopting her because she has another cat. This is why I believe my Vet tested her. Now she is still in my care and seems healthy. None of the shelters will take her and I refuse to abandon her. I would like to confirm once again, that this Kitten testing FIP positive will not harm my dog's or any humans health. I believe this is true. Thanks for letting me know about the subscription, that is a good idea. Many thanks for everything!

Answer: Donna-

The FIP test is an antibody test that detects antibody to feline corona virus. There are two types of feline corona virus. One causes diarrhea and gastrointestinal signs in affected cats, may occur in cats without any signs of illness and is estimated to affect up to 70 to 80% of cats in multiple cat households and about 25% of cats in single cat households. The second form of feline coronavirus infection is FIP, which is thought to be fatal over 90% of the time when it infects cats. Obviously a much smaller number of cats are infected with this form of the virus since the cat population would be much smaller if that were the case. The test can not distinquish between the two types of corona virus exposure. Which is why FIP tests are hard to interpret. For the most part, testing a cat for FIP that has no clinical signs of illness is not very useful. A positive titer indicates that antibodies are present to one of the two forms of coronavirus but not much else.

There is no evidence that I am aware of that FIP infects either dogs or humans. It is extremely unlikely that your cat is infected with FIP virus at this age. The antibodies are almost certainly from the mother and the kitten is probably protected from infection by them. I think it is safe to keep the kitten.

Mike Richards, DVM

Herpes virus or chlamydiosis

Question: Hi Dr. Mike! Love your web site! We got a kitten from an ad in the paper about 2 weeks ago. She is about 8weeks old now and we have noticed in the past week or so that she has a discharge from her eye. It started in one eye and seems to have moved to the other as well. In addition, she is sneezing a great deal. As far as we know, she was not given any of the first shots and we were planning todo that in the next week or so. Otherwise she seems very healthy, active and eats a lot. I have cleaned her eyes out a few times with just water and that seems to have cleared it up fairly well, although there is still a tiny bit of "crust" when she wakes from a nap. In addition, she seems to be better when we leave the air conditioner and ceiling fans off. We don't have a great deal of money so can you possibly tell me the right questions to ask the vet we go see so that I know they are not doing anything unnecessary to charge more. (I have had this happen in the past - and found out too late) It sounds to me like she has that herpes virus(?) We love her to bits and want to make certain we do everything right. Thank you! Carrie

Answer: Carrie - Herpes virus (rhinotracheitis) and chlamydiosis (a bacterial infection) are the two most likely causes of the clinical signs you are seeing. Since it is sometimes hard to tell them apart and since secondary bacterial infections can occur with herpes virus conjunctivitis most vets just treat with an antibiotic eye ointment to be cautious. If there is a strong suspicion of chlamydiosis oral antibiotics may be prescribed as well. Most kittens require deworming and it is a good idea to vaccinate for common diseases.

Mike Richards, DVM

Panleukopenia (distemper)

Question: Dr. Mike, We have a 5 month old kitten. The last few days he has been sleeping alot and has not been eating. I took "Scooby Doo" to out vet on 1/28/97. His temp was 104 degrees. He took a CBC, the white blood cell count was low. The vet checked him for feline AIDES, and tested negative. I have not gotten the kittens vaccinations yet, as I planned to get them for him when he was neutered, in two weeks. Our vet thinks he has distemper (the kitten doesn't have diarrhea, vomiting nor is he dehydrated, yet). The vet gave him a shot of penicillian, and sent amoxicillian home for us to give him. Is there anything other than distemper that this could be? If he has distemper, what are his chances of living? At what point is he in too much pain and we tell the vet to stop treating him and put him down? If he has distemper, this will be a very hard decision for us put we don't want to prolong his life if he will eventually die. Thank you Dr. Mike for helping us with our problem.

Answer: I think that your vet may just be listing off the possible problems. A kitten that is 3 to 5 months old, with a fever of 104 degrees and a low white blood cell count definitely could have distemper, especially since he has not been vaccinated. On the other hand, there are other possible causes of fever and low white blood cell counts.

Your vet sounds like he explained the signs of distemper (panleukopenia) pretty well. Normally it causes fever, depression, vomiting and dehydration. It can cause diarrhea, nervous system damage, provoke secondary infections and cause death.

If further signs develop, more intensive therapy will be necessary, including some form of fluid therapy and possibly administration of blood products to help with protein loss and secondary blood system effects.

Panleukopenia can be successfully treated in many kittens with aggressive therapy. Don't hesitate to bring your kitten back to your vet for more intensive care if necessary.

Mike Richards, DVM

Feline Rhinotracheitis or Calici Virus

Question: We adopted a new kitten from our local SPCA. They vaccinated her for these viruses but could not guarantee she was not already exposed. We have had an epidemic in our Thurston County (Olympia, WA) area.

Well, we brought her home, and on the advice of the SPCA, kept her isolated for a week from our other cat. She showed no symptoms. She has not been outside since we got her. We have now had her since 12/13 and just two days ago, she started to sneeze, get watery eyes, and seems tired and doesn't want to leave her bed. We have isolated her again from our other cat. She is still eating well and is responsive to me when I talk to her and pet her.

We already love this little girl. We don't want to lose her. Is there anything we can do if she has this disease? Is there anything to relieve any of her symptoms?

Something else. We lost power in Olympia for 24 hours following a bad storm. Our house got very cold. It was right after this happened that our kitty started to show these symptoms. Could it be something else like a really bad cold?

Thanks in advance for any advice you can give.

Answer: It is possible that your kitten could have been exposed to one of the diseases mentioned and just now be showing signs, even on an initial exposure. This is a pretty long incubation period for either virus, though. A more likely scenario is that your kitten has already had one of these diseases previously and is now experiencing a recurrence of the virus. Rhinotracheitis is a herpes virus and it will recur at times of stress, just as the human herpes viruses tend to do. Calicivirus is pretty hard for the cat's body to totally clear and occasional reoccurrences of disease signs occur with it, as well. Another possible problem is one of the cat retroviruses, such as feline leukemia virus or feline immunodeficiency virus (FIV). It is possible to test for these viruses but the test for FIV can be inaccurate in young kittens. Until you can have her examined by your vet, it would be best to keep her warm and keep the stress to a minimum if that is possible with the power outages and weather y'all are having. Recurrences of the upper respiratory viruses are troublesome but are not usually fatal. There really isn't much that can be done except to treat symptoms but it can be reassuring to know that is the only problem. Good luck with this.

Mike Richards, DVM

Last edited 07/08/05

Infectious Diseases of Cats

also see Rhinotracheitis infections
also see Cholagiohepatitis/Hepatitis
also see Eye problems
also see Feline Infectious Peritonitis (FIP)
also see Feline Immunodeficiency Virus (FIV)
also see Feline Leukemia(FeLV)
also see Herpes Virus
also see Toxoplasmosis
also see Zoonotic Disease


Michael Richards, D.V.M. co-owns a small animal general veterinary practice in rural tidewater Virginia. Dr. Richards graduated from Iowa State University's College of Veterinary Medicine in 1979, and has been in private practice ever since. Dr. Richards has been the director of the PetCare Forum...