It is unlikely the cat has caught chlamydia from the guinea pigs as different types of chlamydia infect different species. With the exception of the one that infects birds and causes psittacosis (see below), most Chlamydia species do not survive well in the environment and need direct/close contact with infected animals and their body fluids to be spread. Treatment with Doxycycline is appropriate (see below) and your friend needs to observe basic hygiene measures as would be the case with any piggie with a conjunctival infection (just ion case it may not be chlamydia - again see below)
Below is some general information - information sources includes the Merck manual and my cerebral cortex!
http://www.merckvetmanual.com/mvm/e...is/overview_of_chlamydial_conjunctivitis.html
CHLAMYDIA ISOLATES AND SPREAD
a) Chlamydia caviae infects guinea pigs. It is normally passed from mums to pups during birth. and therefore most often seen in young guinea pigs as conjunctivitis. However there may be no symptoms at all (sub-clinical infection) or there may be other symptoms in older pigs (particuarly where breeding occurs) such as infection of the ovaries/bladder of sows or urinary symtptoms in the male. Upper/lower respiratory infections can also occur but are more often associated with conjunctivitis in youngsters..
In heavily infected breeding colonies it may cause abortion or stillbirths in pregnant sows.
There has been one recorded case of
C caviae being found in the ocular secretaions of a human with oncjunctivitis - who at the time was working with 200+ diseased guinea pigs. The bug was also detected in the ocular secretions of the person's rabbit (mild conjunctivitis) and cat (no symtpoms)
b) Chlamyida felis infects cats and is caught from close contact with other infected cats. It always causes conjunctivitis, so If a cat has respiratory symptoms but no conjunctivitis then it is unlikely to be
C felis.
There has been one recorded case of
C felis being found in an immunocompromised human who was living with an infected cat.
These organisms/infections are NOT to be confused with
c) Chlamydia psittaci - this is the one that infects birds and is transmissible to huimans (Psittacosis). It can survive outside the body in dust and is spread via the air.
DIAGNOSIS
Not all guinea pigs with conjuncitivitis have Chlamydia. There are other organisms that can cause similar symptoms such as mycoplasma, Pseudomonas, Haemophilus. Trauma followed by infection with a bugs regularly living on guinea pigs (eg streptococcus or staphyloccous) also need to be ruled out.
So unless a swab has been taken and tests performed on it using histology/microscopy for the specific purpose of identifying chlamydia, then your vet is only "guessing" (albeit it might be a well-informed guess if the piggie is young and has come from a breeding colony)
However, this routine diagnostic test using histology/microscopy can only confirm the presence of the organism "Chlamydia" - it can;t tell you what species/isolate it is. Unfortunately in the past this has resulted in guinea pig owners whose pigs tested positive for Chlamydia having to have their whole herd/colony euthanased by the vet because they were mistakenly thought to have
C, psittaci and be at risk of spreading the disease to their hooman slaves.
In order to identify which isolate (ie confirm C caviae or C felis ), samples have to be subject to a special PCRtest to analyse the DNA and determine which isolate is present. If any owner is being pressurised by their vet to euthanase their guinea pigs because they have "Chlamydia" and are at risk of transmitting the disease to humans, they should ask for a PCR test to be done first.
TREATMENT
Different types of bacteria respond best to different types of antibiotics. The standard guinea pig antibiotics such as baytril and septrin which are effective against a lot of bacteria are not effective for Chlamydia, Most bacteria (including Chlamydia) are still sensitive to doxycycline. Chlamydia is not sensitive to azithromycin or gentamycin. Mycoplasma however is best treated with azithromycin.
Just to add to the confusion, we are seeing some guinea pig bugs developing resistance to certain antibiotics. Routinely we now find baytril and septrin-resistant Streptococcus and Staphylococcus cultured from URI's, abcesses etc, and some eye and ear infections in my own pigs have been found to be caused by a
Pseudomonas organism that is resistant to every antibiotic except gentamycin. Azithromycin for stubborn infections is being more widely used in place of baytril and septrin....yet I am also aware of a recently cultured azithromycin-resistant streptococcus from a dental abcess. .
It is therefore no longer appropriate to just "reach for the baytril" when considering how to treat a guinea pig.So which do you choose?
There is always a balancing act for vets and owners to consider - diagnostic tests are expensive. It could be that the first antibiotic tried will kill the bug and cure the guinea pig. More often these days however we are seeing on the forum that the first choice of abx does not work and a second has to be tried.
So in your friend's case:
If chlamydia has been properly diagnosed then treatment with doxycycline for at least 10 days is the treatment of choice.
If chlamydia is suspected (but hasn;t been confirmed by tests) then it is reasonable to use doxycycline as this would eliminate other bugs that might be causing the infection. However if after 10 days of treatment there is no improvement (or things start getting worse earlier than this) , then swabs/cultures/histology should be performed and an alternative appropriate drug selected based upon the results.
HYGIENE/PRECAUTIONS
It goes without saying that proper hygiene and disinfection procedures should be used to avoid spread between piggies and the outside possibility of spread to the human eye. Use gloves when treating the piggies and change/wash hands inbetween cages or before touching your face. An appropriate disinfectant that has been shown to have activity against chlamydia is Virkon ( tablets can be bought on the internet)
HTH - happy to answer any further questions and would be grateful if you would PM me the location of the infected piggies as it may help us point another owner in the right direction in the future.
x