Dogs have the poorest urinary excretion rates of any laboratory animal. The US EPA used silver nitrate excretion in dogs to determine for RfD for silver in humans. Dogs primarily process silver through the liver.
(This is a chapter from the book Colloidal Silver : Medical Uses, Toxicology and Manufacture)
Colloidal Silver : A Literature Review: Medical Uses, Toxicology & Manufacture - Third Edition - By John Hill
This book is the most comprehensive and objective reference on colloidal silver available. It covers what is known about colloidal silver, what it does, how it works, and what its risk of toxicity is. This third edition has incorporated a lot of new information from recent research and development activity. Argyria and silver toxicity is addressed in detail from an objective perspective. Information from both old and recent medical and scientific publications is summarized and presented in an objective framework. It covers medical applications, mechanisms of action, absorption and elimination and other related aspects. The basic process of making colloidal silver by the low voltage cathodic method is discussed. 136 references are cited.
(my comments in parenthesis)
"In one research project, dogs died from injections of a type of protein bound silver (my comment mild silver protein) in dosages ranging from 500 mg (equivalent to the silver found 1 litre of 500 ppm mild silver protein) to 1.9 grams (my comment almost 4 litres of 500 ppm) of silver depending on the dosage and frequency of administration. (46) This was equivalent in silver content to giving a 150 pound adult between 150 and 570 liters of 10 PPM colloidal silver, or between 75 and 285 liters of 20 PPM colloidal silver, or between 50 and 190 liters of 30 PPM colloidal silver. The 10 gram estimated lethal dose for humans from Goodman and Gillman (56) is equivalent in silver content to 1000 liters of 10 PPM colloidal silver.
In this study (46), the authors were attempting to cause anemia in dogs for experimental purposes rather than test the effect or safety of colloidal silver. They injected Collargol(a brand name mild silver protein), which contains approximately 87% silver (my comment 8,700 ppm) with the remainder being albuminous proteins.
In one test, they injected 500 mg of Collargol into a 23 kg dog. The dog died 12 hours later. They further noted that doses of 1.3 to 1.5 grams of Collargol are tolerated (before death occurs) if divided and given at the proper intervals over a period of 3 to 7 days. Single doses of 200 to 300 mg were well tolerated. Death usually followed a single large dose.
Upon necropsy, the following pathological changes were noted:
(1) There was moderate congestion and marked edema of the lungs.
(2) The reticuloendothelial cells of the liver and spleen contained coarse silver deposits. So did lymph nodes, bone marrow, and to a lesser degree, the kidneys.
(3) The bone marrow showed slight to marked hyperplasia with no death to the parent cells and contained many mononuclear cells filled with brown (silver) pigment.
(4) The hematocrit dropped 10 to 14 percent.
(5) There was a slimy exudate from the nose.
(6) Those overdosed over a longer time period became emaciated.
The administration of smaller doses, 20 to 50 mg over intervals resulted in mild leukocytosis and an increase in hematocrit.
The authors reference another article in which a human died two hours after receiving an intravenous injection of 50 mg Collargol. An autopsy revealed changes nearly identical to those described for the dogs.
More recently, Motohashi performed an experiment in which Collargum was injected into rabbits. After the injection, he observed that the hemophages began "ingesting the animal's own erythrocytes abnormally." He determined that the minimum dose of injected Collargum into rabbits which caused increased hemophage activity was 1 cc of a 1:10000 dillution per kilogram of weight. (123)
In another case (47), an individual ingested an estimated 124 grams of silver nitrate over a period of 9 years. She developed argyria and an assortment of neurological symptoms as well. The authors note that the silver tended to complex with sulfur in the form of Ag2S. A moderate presence of silver-sulfur granules were seen in the perineural tissue, in the peripheral nerves and along the elastic fibers, and to a lesser extent along the collagenous fibers, and in macrophages. These deposits were noted to have an affinity for basal membranes. The neurological manifestations included taste and smell disorders, vertigo, and hyeresthesia. This report is often used by critics to attribute neurological disorders to colloidal silver consumption. For comparisons to be meaningful, differences in dosage regimens must be accounted for.
It may be helpful to put this in perspective with the quantity of silver that is consumed in food and drinking water from natural sources. The EPA publishes a reference dose (RFD) for silver which is an estimate of daily exposure to the entire population that is unlikely to be associated with a significant risk of adverse effects over a lifetime. The current RFD for oral silver exposure is 5 micrograms/kg/day with a critical dose estimated at 14 micrograms/kg/day. (My comment for a 160 pound individual about 6 tablespoons of 10 ppm) The maximum contaminant level proposed by the EPA for silver in the drinking water is less than 0.1 mg/L (0.1 PPM).
Based on this RFD, a 150 pound adult should not exceed 350 micrograms/day. (which is 1 1/8). If the silver in drinking water meets EPA standards, an average person drinking 2 liters per day will consume less than 200 micrograms of silver. (about 4 teaspoons at 10 ppm).
In addition the daily diet may contain about 90 micrograms of silver. (63) 350 micrograms of silver is equivalent to 70 milliliters (14 tsp) of 5 PPM colloidal silver. This is the amount that the EPA standards permit an individual to consume from natural sources.
(My comment the EPA researched 1920's-1930's vintage research on silver which stated silver is excreted through the liver. The Altman study disputes this, kidney excretion of 10 ppm silver in 24 hours 97% up to 40 teaspoons)
Nowhere in the above was their any mention of kidney injury in dogs in the manner you described.