Yunnan paiyao and pyometra in dogs

B. Salgado, R. Paramo and H. Sumano. Successful Treatment of Canine Open Cervix–Pyometra with Yun-Nan-Pai-Yao, A Chinese Herbal Preparation. Veterinary Research Communications, 31 (2007) 405–412

Methods: "Nineteen bitches were included in this trial. All were treated with Yun-Nan-Pai-Yao and no control bitches with open cervix-pyometra were included in this trial because spontaneous remission of this disease has never been documented, and hence ethical considerations reject the possibility of including control groups. Also, only open cervix-pyometra bitches were included because bitches affected with closed cervix-pyometra are usually brought for medical attention in very critical conditions (grade III) and it is unsafe to wait for a slow clinical response."

"Patients with open cervix-pyometra were categorized as I, II or III, according to the severity of clinical signs and laboratory data (Table II). Only categories I and II were included in the intervention study" [according to severity of vaginal secretion, polyuria, anorexia, plasma creatinine and weakness].

Doses used ranged from 500mg/kg/day for dogs weight 1-4.9 kg (1 capsule bid) to 1500mg/kg/day for dogs weighing 30-60 kg (2 capsules TID).

Table IV: Oral dose of Yun-Nan-Pai-Yao in 250 mg capsules, for the treatment of open cervix-pyometra in bitches

Size of dog Weight (kg) Dose/frequency (mg/kg/day)

Small 1–4.9 1 capsule BID 500
Medium 5–12.9 1 capsule TID 750
Large 13–29.9 1capsule QID 1000
Giant 30–60 2 capsules TID 1500


"Fifteen patients (75%) showed full recovery in 3 weeks of treatment, while 20% needed 5 weeks. Therewas good correlation between severity grading
and number of leukocytes using Spearman rank-order correlation (r > 0.9; p < 0.05).
Only one patient did not respond well and was dropped from the trial; this was regarded as treatment failure and the patient later subjected to overiohysterectomy with a good outcome." [interestingly, they report that this was a doberman with 'hind limb paralysis'].

The authors appear to speculate that the effect of Yunnan Paiyao against pyometra was due to an enhanced immune response, and they did not try to relate this effect to the well known coagulant effect we use it for more often.

Two things struck me about this study. First, I wondered about the claim that spontaneous resolution has never been reported. I'm wondering if anyone has ever let a bitch with open pyo go as long as 3-5 weeks before taking them to surgery. Anyone know? (I'd check my books but they are in storage until a find a new house...wah). Second, their dose table is messed up and doesn't make any sense - it seems to suggest that they are using doses as high as 1500mg/kg/day which is pretty high for an herb extract, and that they are using progressively higher doses as the dog's weight increased, which also doesn't make sense.

I don't know what to make of this study and will have to check with my therio friends.