Volume 4, Issue 3
Streptococcal Toxic Shock Syndrome (STSS)
*There is a PowerPoint presentation in the VetsOnly Section that contains more pictures and information for veterinarians.
While the vast majority of the
episodes of Familial Shar-Pei Fever (FSF) seen in Shar-Pei run a
fairly benign course there are occasional exceptions which can have
live-threatening consequences. Over the last few years
Streptococcal Toxic Shock Syndrome (STSS) has been seen more
frequently as a complication of FSF in the Chinese Shar-Pei.
STSS involves infection with a group G streptococcus called
canis. In the
Shar-Pei cases I've seen this streptococcal infection is a rapidly
progressing, highly invasive process which results in a necrotizing
faciitis and/or STSS leading to a shock-like syndrome and multi-organ
failure. If not recognized early STSS can lead to death in 24
hours or less. A similar syndrome has been seen in human
medicine, the so-called "flesh-eating bacteria".
consider this a
form of streptococcal infection. Dogs with NF tend to develop
extensive soft tissue sloughing along fascial planes. Fascia
is dense connective tissue which covers the muscles. Usually
this syndrome presents as large areas of skin and the underlying
fatty tissue dying and peeling away, hence it has been called "flesh
eating bacteria". Many of these dogs will survive with
debridement or clearing away of the dead tissue, but healing is
prolonged and skin grafts are often necessary. Long-term
management is intense with frequent bandage changes, cleaning of the
wounds, antibiotic therapy and the need for multiple anesthetic
procedures to repair and reconstruct the damaged areas. The
areas I've seen involved are often the hock joints, the flanks and
the abdominal skin.
Streptococcal Toxic Shock Syndrome
STSS seems to be a generalized or systemic form of streptococcal
infection. Streptococcus canis
in a potent exotoxin producer and it is thought that in
cases of STSS the toxin may be responsible for the rapid progression
of sepsis, shock and multi-organ failure (MODS). On necropsy
these dogs show severe edema of the gastrointestinal tract,
congestion of multiple organs, severe pulmonary (lung) congestion
and evidence of thromboembolism (blood clots) all pointing to shock
due to sepsis or toxemia. These dogs typically die within
24-48 hours in spite of aggressive fluid therapy, antibiotic
treatment and intensive supportive care.
Clinical signs in
the localized form of STSS, necrotizing fasciitis, consist of areas
of skin bruising, dead skin and/or areas of sloughing where the skin
is falling away. Usually there is a pus discharge from these
areas. The dogs are very painful, running a high temperature,
depressed and, in general, sick dogs. Often there is a history
of an FSF episode, dog fight wounds, or other traumatic event.
In the generalized or systemic form of STSS symptoms have a much
more rapid onset and are more shock-like such as severe weakness,
rapid heart rate, pale mucous membranes, extreme pain, collapse,
coma and acute death. Many of these dogs develop DIC
(disseminated intravascular coagulation) which rapidly leads to
multiple organ dysfunction syndrome (MODS) and death despite heroic
efforts at treatment.
The cause of this condition is
unknown. It is known that
can be part of the normal bacterial flora of the dog and
that NF and STSS have occurred in other breed. Predisposing
factors in the Shar-Pei may be related to:
Diagnosis is based on the
history of previous trauma or FSF episode, bacterial culture and
sensitivity of discharges or tissue samples, and clinical
signs. One important point is that the organism is often
resistant to enrofloxicin (Baytril®) and the
aminoglycosides such as Amikacin® and
Gentocin®. Consider the use of multiple
antibiotic therapy with agents such as Clavamox®,
cephalexin, clindamycin, lincomycin, erythromycin, penicillin and
the potentiated sulfas. Of course, the best approach is based
on sensitivity information from a culture, but that takes some time
- The increased
amounts of mucin in the subcutaneous tissues.
- The prevalence
of FSF in the breed.
- The prevalence of dog fights and bite
wounds in the breed.
- An increase in skin laxity resulting in
- Immune system insufficiencies.
- Perhaps an
increased virulence of some strain of Streptococcus canis.
Treatment of the necrotizing fasciitis
involves appropriate antibiotic selection and administration, and
basic wound care of the affected areas. I have seen dogs have
recurrence of necrotizing fasciitis with repeat FSF episodes.
Usually they seem to slough out the same area every time.
Treatment of the STSS involves intensive care with intravenous fluid
therapy, shock treatment with IV antibiotics, pain management,
steroids (?), and intensive monitoring for the development of DIC,
etc. At this time the prognosis for systemic STSS must be
considered very poor.
Increased owner awareness of NF and
STSS, rapid initiation of appropriate antibiotic therapy and
intensive supportive care are the keys to survival in this
condition. An excellent article on STSS appeared in the
October 15, 1996 issue of the Journal of the American Veterinary
Medical Association, Volume 209, Number 8, pages 1421-1426 by C.
Miller, J. Prescott, K. Mathews et al. entitled "Streptococcal Toxic
Shock Syndrome in Dogs".
Pneumonia In Shar-Pei
As you come in the door that afternoon you know something is wrong. Your 3 month-old Shar-Pei pup is not a the door to greet you.
You search the house and find him in the family room huddled in the corner, ears down, tail limp, droopy eyes, breathing heavily and
coughing softly. He feels warm to the touch. His temperature is 103 degrees and you know you've got trouble.
The scenario above is pretty typical for pneumonia in the Chinese Shar-Pei. It often occurs in pups 8 - 16 weeks old and seems to come out of
nowhere. The only specific signs which may suggest pneumonia are heavy breathing usually with an abdominal component and sometimes a productive
cough. By the time these signs are present, you have a very sick puppy and generally have a very little time to do much about it. Diagnosis must be
quick, accurate and specific. A minimal database must includea CBC and a chest radiograph. We are primarily interested in the white
blood cell count (WBC).What we want to see in the sick pup is a high WBC with some young white blood cells called "bands". This would
signal an appropriate response and that the pup is fighting the infectioin. A bad sign would be a normal or low WBC with gigh numbers of bands.
This indicates the infection is winning and this pup may die. Radiographic signs of pneumonia are pretty classic and usually apparent on
chest X-rays. Positioninig may be less than ideal as the pups will resist being put on their side and we don't want to fight them too
much - depending on the degree of lung involvement stress may overwhelm them. It is also helpful to try to stretch out the wrinkles
over the chest when the radiograph is taken. Those folds can often obscure the lung changes seen in pneumonia. Pneumonia appears as
fluid in the lungs seen in the vertral (lowest) lung fields and located in the cranial (forward) lung lobes. Fluid may accumulate in
one lung lobe, cover multiple lobes and also occur in both sides of the chest. The fluid will often obscure the heart shadow on a chest
radiograph. The definitive iagnosis is based on a tracheal wash. In this procedure, a catheter is introduced into the trachea and
sterile water is flushed into the trachea and then aspirated back out hopefully with the offending bacteria in it. This sample can then
be cultured and an anitbiotic sensitivity done. This procedure is usually done under sedation or light anesthesia and has some risk
involved in it, especially in a sick pup, but the information gathered is critical to instituting the appropriate antibiotic therapy.
What causes pneumonia in Shar-Pei pups? By the time we have a sick pup the lungs have been infected by
bacteria. These are usually Gram (-) bacteria such as E. Coli, Klebsiella and Bordetella. Gram (+) cocci such as
Streptococcus may also be isolated. It is also known that viruses such as canine distemper, adenovirus and
parainfluensa can also cause pneumonia. Shar-Pei also have an IgA deficiency which occurs in the vast majority
of dogs. IgA is a protective immunoglobulin found in body secretions such as tears, mucous, saliva, etc. It is
responsible for local immunity in the respiratory, gastrointestinal, and urogenital systems as well as the skin. IgA
deficiency may predispose an animal to bacterial pneumonia. Ciliary dyskinesis is a condition that has been
reported in the Shar-Pei in which teh cilia of the respiratory tract are abnormal or not present. Cilia are hair-like
projections on the lining of the trachea and larger bronchi which are involved in clearance of debris-laden mucous
out of the bronchi. This mechanism is vital in preventing accumulation of bacteria in the bronchi and subsequent
development of bacterial pneumonia. It appears that this is a heritable condition. Lastly, Shar-Pei are prone to
megaesophagus. This is an abnormality involving the esophagus or "food tube" which can result in accumulation
of food and secretions in the esophagus. Regurgitation is a common finding in pupuies with this condition and this
can lead to aspiration pneumonia. Megaesophagus can often be picked up on chest radiographs underlining the
importance of doing chest X-rays in any pneumonia workup. Due to the wide range or underlying causes of
bacterial pneumonia it is very important to autopsy any Shar-Pei who dies of pneumonia.
Treatment of pneumonia involves the use of antibiotic therapy based on the culture and sensitivity results obtained
via the tracheal wash. Pending getting these results back from the laboratory which may take 2-3 days it is
necessary to use "Four Quadrant Therapy". This is antibacterial therapy effective against all becterial groups -
Gram (+) aerobes and anaerobes and Gram (-) aerobes and anaerobes. My initial choice is an aminoglycoside and
a penicillin. Use of injectable medications is indicated initially. Another choice is the use of a quinolone and a
penicillin. This has the advantage of being given orally. Once the culture and sensitivity results are back specific
antibiotic therapy is based on those results. I like to use a different antibiotic every 2 weeks for at least 4-6 weeks.
The therapy should be continued for 2 weeks after the chest radiographs appear normal. There is a very real
danger of not reating pneumonia long enough and having it recur with the possibility that the antibiotic therapy
used either selected for a resistant strain of bacteria or a new bacteria is causing the problem. A "smoldering-type"
pneumonia develops and can cause respiratory problems for a long time. This is more apt to occur when a tracheal
wash - culture/sensitivity is not done. Injectable antibiotics may be used in a nebulizer which allows the abtibiotic
to be breathed into the deeper airways and reach the lungs. Additional therapy is supportive. Fluid ( IV or
subcutaneous ) are very important to maintain hydration in the sick pup and to keep secretions thin. This allows the
normal respiratory defense mechanisms such as coughing and ciliary functions to clear the bacteria from the lungs.
Use of a humidifier is useful in this regard. Adequate nutrition is vital to maintain evergy levels in the pup and
prevent secondary disease. Coupage (thumping the chest) is useful to stimulate coughing, mobilizing fluid in the
chest and stimulate deep breaths to prevent collapsed lungs (atelectasis). Mild, frequent periods of exercise help to
mobilize secretions and maintain the pup's interest and mental well-being.
Prevention centers around decreasing the pup's exposure to infectious agents. Check your vaccines and be sure
they are in-date and stored properly. Be aware of the adverse effects of stress on puppies. Puppy matches,
traveling, etc. may need be in the best interest of the young Shar-Pei pup. Isolate puppies frm visiting adult dogs.
Clean puppy areas with disinfectant frequently. Isolate any sick puppyies and care for them last always going from
healthy puppies to the sick ones. The use of Bordetella vaccine may be useful although this bacterial agent
probably represents a small number of the pneumonia cases.
Maintaining a high index of suspicion for pneumonia in the 8 - 16 week-old puppy is the best way to discover the
problem early and get treatment fast. Also remember that pneumonia isn't the only condition which can result in a
fever in pups - every fever is not pneumonia especially if not confirmed by the complete blood count and chest