Cat G-Strep

"G-Strep" is the short version of "Group G Streptococcal". "G-Strep" is part of the normal microbial flora of the gastrointestinal tract, vagina, and skin of cats. "Streptococci" are normally non-pathogenic, but a few species can cause significant morbidity and mortality ranging from death in young kittens, from pyometra, pneumonia and upper respiratory infection.

Beta-haemolytic streptococci belong to the Lancefield groups A, B, C or G classification.

  • Genus: Streptococcus

    • Group A Streptococcal

      • S. Pneumoniae

      • S. Zooepidemicus

    • Group B Streptococcal

      • S. Agalactiae

    • Group C Streptococcal

      • S. Equi

    • Group G Streptococcal

      • S. Canis


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"Streptococci Infections" in adult cats have a high probability of show no symptoms! Unfortunately kittens have a weak immune system making them more subseptable to death may show symptoms prior to death. Many kittens will show no clinical symptoms of illness until hours before death. Usually not all of the kittens in the litter are affected. Kittens are typically infected with the bacteria from the queen's vagina during birth. This can result in an abscess of the umbilicus which spreads into the liver and abdominal cavity, leading to peritonitis and septicaemia. Some kittens may have an obvious umbilical abscess or swelling.

  • Unexplained spontaneous abortions or absorption.

  • Unexplained death of newborn kittens.

  • Birth abnormalities (Intestines on outside, cleft palette).

  • Affected kittens die between 1 and 10 days, rare cases of up to 6 weeks old.

  • No clinical symptoms of illness until hours before death.

  • Affected kittens show slower than average weight gain.

  • All the signs of Chlamydia but negative on testing.

  • Difficulty swallowing due to swelling.

  • Fever

  • Lethargy

  • Coughing

  • Pneumonia


G-strep requires specialized equipment to grow however other common bacteria can be detected through vaginal smear with sensitivity test. Many veterinarians are not aware of G-Strep and can mistake it as Upper Respiratory Infection, Chlamydia, Calicivirus or Panleukopenia.

  • Highly suggested to perform a feline upper respiratory PCR test and bacterial culture to rule out other possible ailments that present with the same symptoms such as Feline Mycoplasma.

  • Highly suggested to perform a vaginal culture with sensitivity test on a female if you suspect G-Strep. If the culture results in not definite answer, consider the treatment protocol listed below.

    • Cases have been documented can ecolli imbalance found through vaginal smear. This makes testing crucial to determine if breeders are treating for the wrong problem!


Please see the G Strep Updates: The Continuing Story: Part 2 and Additional Comments and Follow Up to G Strep article (2004). Read all three articles before treating your cats. Since I wrote my articles, I have received feedback and requests for information for literally several hundred breeders around the world. It seems that this problem is becoming even more widespread, in every country and in every breed.
— Written by Marva Marrow 7th Heaven Orientals

Consult with your veterinarian before any treatment.


  • Dehydration: Re-hydration is also important for restoring the body with fluid and flushing the system of the infection. Kittens will be unable to digest food if too dehydrated.

  • Weight-loss: All felines, especially kittens, in your household should be weighed immediately so you can determine weightloss.

  • Respiratory Distress: Cat(s) showing signs of respiratory distress of any level should be seen by the veterinarian immediately they may require intensive veterinary supportive care (Incubator with oxygen therapy, fluids and antibiotics).



  • After clindamycin treatment, the G Strep will most likely still be retained in the normal flora at a very low level. Therefore, the cat could always be a potential G Strep carrier with respect to breeding only. In other words, we should be concerned with the breeding aspects of the Strep G rather than whether the cats do not have any G Strep at all, since the clindamycin will most likely not get every last bit of it - even at a 3 week dose. The other thing (which you may already know) is that a culture will take about 10 days, and will most likely come back with "normal flora", because the G Strep is at such a low level that it won't "register" on the lab tests.

  • Beta-haemolytic Streptococci are usually resistant to sulfamethoxazole, tetracycline and gentamicin. Resistance to penicillins or cephalosporins is very rarely detected.

Stories From Breeders

All was well until the kittens were ten days old. That morning, I picked up the first baby, to check them as I usually did, first thing when I woke up. The baby’s little nostrils were clogged shut with mucous! I had never seen signs of URIs (upper respiratory infection) in such young babies, so, alarmed, I quickly picked up the next kitten. All the babies had clogged nostrils and it seemed to me that their breathing was labored. Despite Baytril, Clavomox and Amoxi all kittens died one by one.

A girl (one of my DMs) who had had four healthy litters of 5-6 had a litter with five kittens, four of them stillborn. Only one lived.

A young girl I had been showing, with over 160 points to her grand, on the morning of a show, she presented herself to me with a pyometra. I rushed her to the veterinarian. She was treated successfully with Baytril and prostaglandins. I bred her on the next heat. The breeding took. She aborted her kittens at eight weeks. I bred her again. It took. She AGAIN aborted her kittens at eight weeks into the pregnancy.

My other DM girl who had had two good litters was bred to my stud THREE times and the breeding did not take.

I had litters of one or two kittens where before I had had normal litters of 4-6. In two of these litters of one, the kitten was fine in the morning and suddenly dead in the evening - signs of a quick and intense pneumonia and nothing I could do.

A girl who came for breeding (all tests and healthy) produced two kittens with spinal deformities that died at a few weeks of age. The sire had had many healthy litters with never any sort of deformity or problem.

Needless to say, I couldn’t understand what was going on as all blood panels and other diagnostic tests came back totally normal, there were no signs of ill health: coats were shiny, eyes were bright, appetites were excellent, energy levels were great. I was getting really discouraged and depressed.

Then, a breakthrough.. A breeder friend in Australia forwarded me an e-mail from an Australian feline health list. The post was from Dr. Sue Rodger-Withers PhD, a microbiologist and university lecturer in that country. She and her colleagues had done research on low grade uterine infections due to Gp G-Strep (Group G Streptococcus bacteria) and the use of Antirobe (clindamycin) for treatment.

Read more:
— Marva Marrow, 7th Heaven Orientals, USA