Casualties
At the end of the war and with Paraguay suffering severe shortages of weapons and supplies, López reacted with draconian attempts to keep order, ordering troops to kill any combatant, including officers, who talked of surrender. As a result, paranoia prevailed in the army, and soldiers fought to the bitter end. Paraguay suffered massive casualties, losing perhaps the majority of its population.
The specific numbers of casualties are hotly disputed. It has been estimated that 300,000 Paraguayans, mostly civilians, died. It has also been written that up to 90% of the male population may have been killed, though this figure is without support. According to one numerical estimate, the prewar population was approximately 525,000 Paraguayans (a survey of 14 estimates varied between 300,000 and 1,337,000; see F. Chartrain : "L'Eglise et les partis dans la vie politique du Paraguay depuis l'Indépendance", Paris I University "Doctorat d'Etat", 1972, pages 134–135. His own calculation based on a 1879 census and in the military forces, gives between 700,000 and 800,000 inhabitants). A 1871 census gave 221,079 inhabitants, of which 106,254 were female, 86,079 were children with no indication of sex or upper age limit and 28,746 were male. These figures, considering the local situation, cannot be more than a very rough estimate; many men and boys fled during the war to the countryside and forests. As such, accurate casualty numbers may never be determined.
A 1999 study by Dr. Thomas Whigham from the University of Georgia published in the Latin American Research Review under the title "The Paraguayan Rosetta Stone: New Evidence on the Demographics of the Paraguayan War, 1864–1870" and later expanded in the 2002 essay titled "Refining the Numbers: A Response to Reber and Kleinpenning" give somewhat more accurate figures. Based on a census that was carried out after the war ended, in 1870 and 1871, Dr. Whigham came up with a much lower figure of 150,000–160,000 Paraguayan people left, of which only 28,000 were adult males. This leaves a woman/man ratio of 4 to 1, while in the most devastated areas of the nation the ratio was as high as 20 to 1.
Regarding the population before the war, Dr. Whigham used a census carried out in 1846 in order to calculate, based on a population growth rate of 1.7% to 2.5% annually (which was the standard rate at that time and again the aforementioned omissions), that the immediate pre-war population in 1864 was approximately 420,000–450,000 Paraguayans. This figure produces a loss of 60% to 70% of the population.
Of the approximately 123,000 Brazilians who fought in the Paraguayan War, the best estimates are that around 50,000 men died. Uruguayan forces counted barely 5,600 men (some of whom were foreigners), of whom about 3,100 died. Argentina lost around 18,000 of its 30,000 combatants.
The high rates of mortality, however, were not entirely the result of armed conflict. Bad food and very poor hygiene caused most of the deaths, many of which were due to cholera. Among the Brazilians, two-thirds of the war dead died either in a hospital or on the march. At the beginning of the conflict, most of the Brazilian soldiers came from the north and northeast regions of the country; as such, the change from a hot climate to a colder one, along with restricted food rations, may also have been a contributing factor. Drinking water from the rivers was also sometimes fatal to entire battalions of Brazilians and made Cholera the most likely chief cause of death during the war.
Read more about this topic: Paraguayan War