First I would recommend moving the healthy newts into separate housing, and in my view should be housed in an aquatic environment. If you have to keep them terrestrial (vets advice?) stop using newspaper and go for kitchen roll. The newspaper will no doubt have all sorts of chemicals upon it, not to mention all the other things that can harm amphibians a skin.
They are also Europe's largest newt reaching approx 8 inches (20 CM) are they living in a cramped condition, what sizes are the newts?
Natural Range and Habitat:
Spanish ribbed newts are found throughout the Iberian Peninsula and Morocco. These regions are very arid and known for periodic droughts. Ribbed newts are
almost entirely aquatic and prefer little or no current. They inhabit any standing water they can find, including ponds, lagoons, damns, and irrigation systems. If their water dries up, they will hide under rocks or in crevices, anywhere they can stay moist.
Housing:
The most suitable housing for ribbed newts is an aquarium, heavily planted, with a small floating land mass. Water level should be at 15 - 20 cm (6 - 8 in) outside of breeding season. It can be raised to higher water levels when breeding is desired. Gravel, if used, should be a size that will not be swallowed with food.
Temperatures are best kept below 21°C (72°F), as some animals become stressed at high temperatures (see information below about the effect of elevated temperature on eggs and larvae). This species encounters temperatures around freezing in the wild, so adults are able to tolerate cold.
The above was taken from
http://www.caudata.org/cc/species/Pleurodeles/P_waltl.shtml
P. waltl in Captivity Pleurodeles waltl are very hardy in captivity, breeding regularly with little effort from their keepers. They can be considered one of the "indestructible" species. However, this does not mean they are impervious to problems if house improperly. Like all amphibians,
P. waltl are susceptible to health problems and death from poor water quality, overcrowded conditions, mixed species tanks, etc.
Pleurodeles waltl are large newts, capable of reaching up to 12 inches in total length, and averaging around 8-9 inches.
P. waltl tend to nip at each other, and during feeding times can be blatantly violent. Because of their impressive size and voracious feeding habits, it is necessary to house these newts in large tanks with plenty of individual room.
P. waltl are found at considerable depths in the wild, so a tall and wide tank is appropriate for this species.
Although
P. waltl are tolerant of warmer temperatures for periods of time, the water temperature should be kept within the 68°F- 73°F range during the warmer months. During the winter months, temperatures of 55°F-63F° are acceptable.
The above was taken from
http://www.livingunderworld.org/caudata/database/salamandridae/pleurodeles/waltl/
Hope this is of some use to you.