Treatment and precautions
Treatment of leptospirosis involves antibiotic therapy and supportive care for acute renal failure. Early antibiotic therapy
inhibits multiplication of the organism and limits the hepatic and renal damage. Initial antibiotics of choice are either
penicillin G (25,000-40,000 U/kg SC, IM, or IV q 8 h) or ampicillin (22 mg/kg PO, SC, or IV q 8 h) for 14 days to eliminate
leptospiremia. A second course of antibiotics is required to eliminate the carrier state. This is accomplished by administering
doxycycline at a dosage of 5 mg/kg PO q 12 h for 2 weeks.
Because leptospirosis is a zoonotic disease, the following precautions should be taken when handling suspect cases:
- 1. Gloves, goggles and gown should be worn when handling the dog or hosing down runs.
2. The dog should be placed in a bottom cage with disposable bedding and not moved until it has received antibiotic therapy
for three days.
3. Catheters, bedding, gloves and anything else that contacts the dog should be disposed of in a biohazard container.
4. If the animal urinates outside the cage, the area must be disinfected. Iodophors are effective in killing spirochete bacteria.
5. Hands should be washed immediately after handling the dog.
6. After discharge, the cage should be thoroughly cleaned and disinfected and not used for 24 hours.
Supportive care for acute renal failure involves the following recommendations:
1. Placement of a jugular catheter allows for frequent blood sampling, IV fluid diuresis and measurement of central venous pressure.
2. Placement of a urinary catheter allows for safe collection and disposal of urine through a closed system and monitoring of
urine output in animals with oliguria (<1 ml/kg/h).
3. Fluid deficits are corrected rapidly over four to six hours using the following formula: percent dehydration x body weight
(kg) x 1000 = number of ml. In addition, maintenance needs (1 ml/lb/h) and fluid to replace contemporary losses from vomiting
and diarrhea are added to the hourly rate.
4. If possible, serum electrolytes and blood gases should be checked. Hyperkalemia can be treated with the following therapeutic
options: (a) regular insulin (0.5 units/kg IV) plus 1 gram of dextrose per unit of insulin diluted to 20 percent and given
IV; (b) sodium bicarbonate 1-2 mEq/kg slowly IV; or (c) calcium gluconate, 0.5-1 ml/kg IV over 10 to 15 minutes. Severe metabolic
acidosis can be corrected with the following formula: 0.3 x body weight (kg) x base deficit = number of mEq NaHCO3 needed
to correct the deficit. One-fourth to one-third of the dose is given slowly introvenously and the rest is added to the IV
5. After the fluid challenge, the animal's blood pressure should be normal to slightly high, and the CVP should be 5-8 cm H2O.
If the urine output is < 1-2 ml/kg/h, polyuria should be induced by administering one or all of the following: (1) manni-tol,
0.5 g/kg IV over 20 minutes; (2) furosemide 2 mg/kg IV with repeated doses if no response seen or CRI of 3-8 ug/kg/min; (3)
dopamine 0.5-3 ug/kg/min CRI.
6. After volume expansion has been achieved, the IV fluid rate is established by determining "ins and outs." Urine output is
quantified every four hours. The new hourly rate is set by dividing the urine amount by four and adding 1 ml/lb for maintenance
7. Nausea and vomiting are treated with metoclopramide (1-2 mg/kg/day CRI or 0.2-0.4 mg/kg q 8 h SQ). Gastric hyperacidity is
treated with ranitidine (1-2 mg/kg q 12 h IV) or famotidine (0.5-1 mg/kg q 24 h IV) or sucralfate (0.5-1 gm PO q 8 h).
8. Nutrition can be provided by PPN, TPN or enteral feedings. Pancreatitis can be a serious complication of acute renal failure
and should be ruled out prior to feeding. A restricted protein diet low in phosphorus is recommended.
9. Animals that do not respond to aggressive medical management may require hemodialysis or peritoneal dialysis.
10. Prognosis for recovery is fair. About 80 percent of dogs treated aggressively for leptospirosis recover within seven to 10
days. Some experience full recovery and some have residual renal insufficiency. Renal function should be monitored for the
next six to 12 months.
A new vaccine is available that protects against serovars pomona and grippotyphosa as well as icterohemorrhagiae and canicola.
Dr. Hoskins is owner of Docu-Tech Services. He is a diplomate of the American College of Veterinary Internal Medicine with
specialities in small animal pediatrics. He can be reached at (225) 955-3252, fax: (214) 242-2200 or e-mail: firstname.lastname@example.org