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How are the ratios maintained?
The organs that maintain control of the electrolytes are:

1.The lungs:
The lungs remove carbon dioxide, which is the basis of bicarbonate. They can remove greater or lesser amounts of bicarbonate depending on what is happening in the body fluids. Their primary function as regards electrolytes, is to provide for the control of acid balance in the body.

2.The Kidneys:
The kidneys control the amounts of sodium and potassium excreted by the body. Almost all the sodium can be saved, but there is an irreducible amount of potassium that is lost, even when the body is potassium depleted. The kidneys also can save nearly all the water except that which is lost in the lungs and skin, and in the feces. The kidney can deal with overloads of sodium and potassium by secreting these elements into the urine. *Normal kidneys can take care of about 1 meq potassium per kilogram of body weight per hour. This would be equal to an IV infusion rate of 7.5 to 10 meq/hour for a 15 lb. Lhasa - a rate almost impossible to acheive. The usual maximum rate would be more like 4 meq/hr assuming a very high 200cc /hour of a 20meq/liter solution. Normal infusion rates for a 15 lb. dog would be more in the neighborhood of 20 - 50 cc/hour, or 0.4 to 1 meq/hour of potassium.

Daily intake requirements for a healthy 15 lb. dog
Calories = 250 - 500
Water = 300 cc
Protein = 3.2 grams
Sodium = 6.5 meq
Potassium = 5.5 meq

Dehydration and its treatment
If you look at what may be lost in vomit and diarrhea, it is obvious that all the important salts can be lost at an astonishing rate. In Parvovirus infection, plasma and blood are also being lost. Obviously, unless these fluids and salts are replaced, the animal will die. The small bowel lining is destroyed by the parvovirus, so that nothing will be absorbed by mouth, not to mention that the vomiting and diarrhea also make the oral route impossible. Treatment is based on:

1.Replacement of water:
This is estimated on the basis of the amount being lost, plus the daily requirement. Losses may be much greater than estimated, since very large amounts of fluid can be sequestered in the bowel, and in swelling of the bowel wall. In this regard it is very useful to immediately weigh any animal which had begun to have vomiting or diarrhea, before it has dehydrated, so that you have a baseline from which to estimate losses.

2.Replacement of salt:
The initial fluid used should contain about the same salt composition as blood plasma, because that is approximately what is being lost. Later, more potassium, and magnesium may need to be added to compensate for the disproportionate losses. One reason for this is that hydrochloric acid is lost from the stomach with vomiting. In order to maintain acid-base balance in the body, for each atom of hydrogen lost from the stomach, the kidney is obliged to give up a potassium atom to the urine.

3.Maintaining an energy source:
In order to keep the vital organs functioning, the blood sugar has to be maintained. Solutions containing 5% glucose, while not meeting the caloric needs of the animal, can support the energy requirements of vital organs.

4.Prevention of secondary infection:
The small bowel has been stripped of its lining by the parvovirus. This leaves it wide open to invasion by bacterial pathogens. Antibiotics which cover gram negative bacteria are normally used. If broad spectrum antibiotics are used for more than a week, a superinfection of a bacterium, Clostridium Difficile, can occur, which can also cause a severe diarrhea. This can be prevented by using oral Metronidazole 2.5 - 5 mg/kg three times a day.

5.Nursing care:
Nothing is more important than warmth, comfort, skin care, and the presence of a trusted human caretaker. Animals can easily give up the will to live if deprived of social interaction and comfort. I would urge anyone who has a desperately ill animal to do home care, with the cooperation of your vet, unless there is a facility available which offers intensive care. No-one can give your dog what you can, even if that is only a happy death. Anyone can learn how to manage IVs at home, and how to put IV medications in the tubing.

How do you know it's working?
At home you do not have the luxury of a laboratory to measure the electrolytes. Fortunately, that is not necessary. Monitoring progress depends on three easily observable signs:

1.Urine volume:
Most young dogs with parvovirus have good kidneys. When the blood volume has been replenished with fluid, a normal amount of urine will be produced. You've gone too far if the quantity is much greater than normal. Normal urine output for a healthy, well hydrated 15 lb. dog would be 100 to 200 cc in 24 hours.

2.Pulse:
Dogs the size of a Lhasa normally have a pulse of 90 - 120 per minute. Dogs with parvovirus are anemic, so their pulses will be higher than normal, but you know fluid replacement is heading in the right direction when the pulse is approaching normal.

3.Respirations:
You can easily take the respiratory rate of one of your other dogs of the same age (at rest) to get an idea of the normal rate. If the rate is very rapid, this is an ominous signal of air hunger. The animal may need transfusion. The vet can do this, particularly if you have a healthy, related donor.

Armed with this bit of knowledge, you can be in a position to evaluate the care your Veterinary Hospital may or may not be capable of giving, and of applying a common sense rationale to caring for your dog (if your vet will co-operate) at home.

Catherine Marley, MD
Kai-La-Sha

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