Rhinotracheitis (feline herpes virus 1) in Cats


also see Sneezing

Persistent Rhinotracheitis (feline herpes virus 1)-continued

Question: Dr Richards--second reply to same e mail--is this rhinotracheitis in any way contagious to my other cats?? I have a household of 11 cats, all but one 14 yr or older. Mitra is somewhat of a loner, tho. When she sneezes, is it likely to be contagious or is she just sneezing in reponse to mechanical irritation?? ( I realize this question probably cant be answered without seeing the cat......) -----

Answer: C- Most cats are infected with rhinotracheitis (feline herpes virus 1). Estimates vary from 70% to 95% of cats being chronically infected but it is likely that it is closer to 90% than to 70%. Cats are usually infected when they are young but because the virus is a herpesvirus it can live in the body long term and surface at times of stress or immune compromise. So the odds are that the other cats have already been infected or have some natural resistance to the infection and won't become infected. There is always a small chance that you would happen to have one of the small number of cats who aren't already infected and that the disease could spread to that cat but with the odds being what they are, this is a fairly minor concern. I don't know with certainty why a small number of cats are hit so hard by the effects of the virus. The best theory is that they have coinfections with other viruses and/or bacteria and/or mycoplasmal organisms that make them sicker and unable to cope with the combination of infections, producing severe damage in the nasal turbinates and respiratory system, which in turn lowers their local immune defenses for life. I hope that this is helpful.

Mike Richards, DVM 6/18/2004

Persistent Rhinotracheitis (feline herpes virus 1)continued

Question: Dr Richards--Mitra is on the zithromax and has improved tremendously. My vet wasnt familiar with it but after I showed him your e mail and because you are a dr he agreed to prescribe it. Ssince she had a depo shot at the same time I dont know which is working best but my plan is to try to continue with the zithromax until beyond the time at which she would need another depo shot and see if she is still OK. I give it to her twice a week and I do hear some slight sounds of congestion when she sleeps with me and her head is near my ear, but before, it was so bad I could hear her noisy breathing in the next room. She has vomited slightly about once a week or less but maintains her weight. What if any are the side effects I should look for?? My guess is she will be on this indefinitely. Searching on google I noticed that in humans it sometimes causes liver problems?? What are the side effect in cats?? also, in the June vetinfo digest you mentioned a 3/15/04 article re hyperthyroidism and pop top cat food cans. Boy does that sound bizarre. Would you be willing to share the name and address of the authors?? I want to write them for a reprint. The nearest vet school to me is UC Davis which is about 100 miles away. BTW, I have not had any problems with the vetinfo journal, am receiving it timely and only once. I'm in california if that makes any difference. Thanks again for your excellent advice and I'm sure Mitra would thank you if I could make her understand --catwoman.

Answer: Catwoman

The longest we have had to use azithromycin, so far, is about 60 days. I think that it has been used longer without much problem with adverse effects in some cats but I can't be sure that long term use might not have some ill effect. I tried to look this up in the pharmacology text I keep at home but it didn't have any advice about long term effects and only listed vomiting as a problem with short term use. I'll try to remember to check on this tomorrow at work in another text. We have treated one cat for 20 days, twice, separated by several months, with no adverse effect and the second time the rhinitis did not return. Unfortunately, we have also had some cats who did not completely clear up with treatment but we never tried going longer than 20 to 30 days with those cats as far as I can remember. I don't have an exact address for the authors of the March 15th the Journal of the AVMA but the author's names were Charlotte Edinboro (Exponent Inc. Health Practice in Menlo Park, CA), Larry Glickman (Purdue University), J. Catherine Scott-Moncrieff (no address information) and H. Leon Thacker (no address information).

Mike Richards, DVM 6/15/2004

Persistent Rhinotracheitis (feline herpes virus 1)

Question: Hi Drs. Richards-I have 15 yr old cat with dx of rhinotracheitis. It's a very long story, but on 3 29 I gave her a pill using a "pill gun" (which allows me to keep my fingers in one piece as she is extremely difficult to pill.....) . I have used this device hundreds of times but this time I guess I used too much force and she made this squeaking noise and immediately started to breathe noisily. I thought I had forced the pill down her windpipe(tho she did not breathe with her mouth open) it was an emergency. Chest XR, blood work, oral exam, laryngeal biopsy all negative exc the biopsy showed some inflammation( r/o from chronic pilling). The noisy breathing continued and on 4 29 she was given a shot of depo medrol w improvement for about a week, then gradually the noisy breathing started again. Sounds just like a baby with a cold which cant blow its nose. On 5/12 she had a cat scan, rhinoscopy, more blood work, biopsy of the nasal tissue.

There are no polyps or foreign bodies, studies show severe inflammation of both sinuses, rt greater than left. The biopsy was negative for neoplasm. By about 4 29 she had started to have clear discharge from the nose, rt greater than left, which steadily became more "pussy" looking and then bloody. After the cat scan, etc, the bloody discharge greatly increased, and the noisy breathing continues. Every time I clean off her nose (about 20 times a day), she then sneezes 7-8 times, spraying bloody stuff all over. This latest blood test, I dont know the results of. It would seem to me that this much inflammation would mean a rise in white cell count and perhaps globulin. The surgeon and radiologist didnt tell me anything but gave all the info to my regular vet whom we will see 5 /26 for another depo shot, since my vet dr l. says he cant give it to her more than once per month. In meantime she is on clavamox and periactin. The periactin was compounded into a tuna oil but nothing can disguise the bitterness of this antihistamine, and to get 1 ml into her, i usually use up 3 ml out of the bottle. Surgeon doesnt think the traumatic pilling caused this, but I cannot get over the fact that she was totally normal until the pill gun accident. Seems that the more we do to her, the worse she gets. She is eating some and has not lost too much weight, but is much less active than before. I have talked to every cat owner I run into to see if anyone else has had this happen to their cat. I dont know any other diagnoses ( or I havent been told any) other than rhinotracheitis. She is a totally indoor cat who was in good health before 3 /29. The pill I gave her was cosequin which is very helpful to her in terms of ameliorating some leg stiffness. I only vaccinate my cats with 3 in 1 about every 5 years (knowing that there is considerable controversy over how often to vaccinate) and she would have been due in May this year but due to all her problems I have deferred vaccinating her. I do have a total of 11 cats in my house but no one else is ill. It's almost like an allergic reaction to something. I do not use aerosols and no one smokes anywhere near the house or property. One friend said her cat devel. rhinotracheitis because was not vaccinated. She used Zithromax and it relieved the symptoms but cat has to take it daily. I also want to ask dr l. if we can try some other antihistamine. I tasted the tuna preparation myself and it's pretty nasty. No wonder Mitra hates it. It does seem to afford some relief. When she is sleeping the brething is not so noisy. She doesnt breathe with her mouth open except for a couple of breaths after her sneezing fits. Have you any ideas on what I can do for her??? I want to try the zithromax because that's the only thing I have heard of that works. I have asthma and allergies myself and I'm miserable w/o my inhaler and zyrtec, but I have a severe tendency to anthropomorphize..... I'm so sorry this message is so long and rambling. I'm so worried about Mitra, I dont know how to make her better and I still feel I caused this to happen. ---catwoman

Answer: C- We went to a continuing education seminar at which Dr. Leslie (I think) King was the speaker a year or so ago. She discussed an emerging disease being studied at the University of Pennsylvania which was a form of chronic laryngeal inflammation in older cats. She said that it would often respond to the use of long term corticosteroids, with antibiotics used in the beginning of therapy and sometimes longer term. This seems like it might be a possibility for some of the signs you are seeing but probably not all of them. It seems to worsen when other stuff is going on -- we have seen this once after a cat was treated for hyperthyroidism with radioactive iodine and once after we did surgery on a cat and intubated it for the anesthetic. In our experience the most common cause of bloody exudate from the nostrils is cancer. I think this would have to be the main rule out even with the negative biopsy sample since it can be hard to locate nasal cancers. Still, with the extensive work up that has been done it also seems reasonable to hope that cancer isn't present and that this is a chronic bacterial infection due to an underlying cause like rhinotracheitis. This definitely occurs in some older cats who had enough turbinate damage when they were young that they can't fight off infections when they age and their other immune responses begin to weaken. We do have by far the best results from azithromycin (Zithromax Rx) for nasal infections. It is a little irritating that the pediatric solution is only good for ten days after being mixed up, though -- it makes for a lot of waste unless your vet mixes smaller quantities or you have a compounding pharmacy willing to do that for you. I guess you could use fractions of the tablets but even for big cats this is difficult due to the relatively low dose requirements for most cats.

We have had really good luck in a couple of cats using piroxicam (Feldene Rx) when nasal inflammation was present. This can be irritating to the cat's stomach (can cause ulcers) but that hasn't been a problem so far for us. This is a non-steroidal anti-inflammatory medication. We have also used neo-synephrine nasal drops as a decongestant in cats with some luck. One drop of the solution is put in one nostril two or three times a day for three days, then in the other nostril for two or three days --- it is necessary to treat only one nostril at a time and to switch back and forth to avoid "rebound" reactions that worsen inflammation. Chlorpheniramine (Chlortrimeton Rx) is another antihistamine that works well in cats if you think that the antihistamine is having a good effect. The dosage is usually 2mg/cat every 12 hours. We have had several cats who had nosebleeds that resolved when we diagnosed and treated high blood pressure. These cats only had nosebleeds, though -- no pus. Still, it might not be a bad idea to make sure that hypertension isn't playing a role in this problem if blood pressure hasn't been checked. It seems likely it has been given the quality of the work up done so far, though.

I like to use oral prednisolone (Pediapred Rx is a liquid form if that is easier than pills) instead of Depomedrol (Rx) injections when I think it is necessary to use the injections more than once a month. This allows continuous dosing with more control over the dose. However, I have to admit that I don't think that it works as well in all cats. Some cats just seem to do a lot better with the injections than with oral medications.

Good luck with this. Mike Richards, DVM 6/15/2004

Antibiotic treatment for rhinotracheitis

Q: Dear Mr. Richards,

I have perhaps an old story to tell you or, perhaps, not that uninteresting one. In the course of events after the unfortunate development with the cat of mine the cat was treated with antibiotics (synulox resp. amoxicylin & clavuline acid) 80mg twice a day, and prednisolon tablets 5mg once a day for three weeks, then softly reduced to 3/4, after a week 1/2, after a week 1/4, after a week 1/4 tbl.once in two days. It happened that after the described treatment the 11 years old rhinotracheitis was gone, speaking in terms of acute signs (nose, eyes etc). Namely, up to now I have been told , that there is no medicine against the (viral) rhinotracheitis except paliative therapy.

I can not say, if this is really something new, it was new to me. I will be glad, if you could use the information somehow resp. if I am actually telling you a good news.

I wish you a nice day and thanks a lot again

With friendly greetings Lado

A: Lado, Thank-you for the update. The amoxicillin/clavulanic acid (Clavamox Rx here in the U.S.) combination is a good antibiotic for upper respiratory infections. I am surprised it would work so well in a case as chronic as yours, but we will post this note on our site to encourage people to keep trying! This is a safe antibiotic to use long-term or repeatedly, if necessary. Hopefully it will continue to work well. It really won't work against the viral component of the infection if rhinotracheitis continues to be a problem but a lot of the time, the secondary infections are causing most of the signs.

Mike Richards, DVM

Last edited 07/08/05


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...