Changes

==Toxicity==

==Toxicity==

===Dog:===

===Dog:===

Excess dietary calcium has caused bone abnormalities in growing dogs but this seems to be confined to puppies of large breeds. Hazewinkel et al.<ref>Hazewinkel, HAW, Goedegebuure, S, Poulos, P, Wolvekamp, W (1985). “Influeneces of chronic calcium excess on the skeletal development of growing Great Danes”. J. Am. Anim. Hosp. Assn. 21:377-391.</ref> found that Great Dane puppies fed a diet containing 3.3% calcium DM developed <span style="color:red">osteochondrosis (link to glossary)</span> and stunted growth. In contrast, when Nap et al.<ref>Nap, R, Hazewinkel, HAW, van den Brom, WE (1993). “45Ca kinetics in growing miniature poodles challenged by four different dietary levels of calcium”. J. Nutr. 123:1826-1833.</ref> fed a similar diet to miniature poodle puppies no significant skeletal problems were observed. These effects of excess calcium intake appear therefore to be confined mainly to puppies of large breeds. Nevertheless, Dobenecker et al.<ref>Dobenecker, B, Kasbeitzer, N, Flispach, S, Köstlin, R, Matis, U, Kienzle, E (2006). “Calcium excess causes subclinical changes of bone growth in beagles but not foxhound crossbred dogs, as measured by X-rays”. J. Anim. Physiol. Anim. Nutr. 90:394-401.</ref> investigated the effects of calcium excess on beagles and foxhound crossbred puppies between 6 and 27 weeks of age. X-ray measurements of bone lengths and widths showed a growth-reducing influence only in beagles, i.e. the smaller breed, although there were no effects on general health or clinical parameters of skeletal health in either group. There are apparently no reports of adverse effects of calcium excess in adult dogs. A more general effect of very high calcium intakes is '''interference with the absorption of other minerals and trace elements''', such that deficiencies can occur at dietary levels that would otherwise be regarded as adequate. Such an effect has been observed in cats (see below).  

Excess dietary calcium has caused bone abnormalities in growing dogs but this seems to be confined to puppies of large breeds. Hazewinkel et al.<ref>Hazewinkel, HAW, Goedegebuure, S, Poulos, P, Wolvekamp, W (1985). “Influeneces of chronic calcium excess on the skeletal development of growing Great Danes”. J. Am. Anim. Hosp. Assn. 21:377-391.</ref> found that Great Dane puppies fed a diet containing 3.3% calcium DM developed [[osteochondrosis]] and stunted growth. In contrast, when Nap et al.<ref>Nap, R, Hazewinkel, HAW, van den Brom, WE (1993). “45Ca kinetics in growing miniature poodles challenged by four different dietary levels of calcium”. J. Nutr. 123:1826-1833.</ref> fed a similar diet to miniature poodle puppies no significant skeletal problems were observed. These effects of excess calcium intake appear therefore to be confined mainly to puppies of large breeds. Nevertheless, Dobenecker et al.<ref>Dobenecker, B, Kasbeitzer, N, Flispach, S, Köstlin, R, Matis, U, Kienzle, E (2006). “Calcium excess causes subclinical changes of bone growth in beagles but not foxhound crossbred dogs, as measured by X-rays”. J. Anim. Physiol. Anim. Nutr. 90:394-401.</ref> investigated the effects of calcium excess on beagles and foxhound crossbred puppies between 6 and 27 weeks of age. X-ray measurements of bone lengths and widths showed a growth-reducing influence only in beagles, i.e. the smaller breed, although there were no effects on general health or clinical parameters of skeletal health in either group. There are apparently no reports of adverse effects of calcium excess in adult dogs. A more general effect of very high calcium intakes is '''interference with the absorption of other minerals and trace elements''', such that deficiencies can occur at dietary levels that would otherwise be regarded as adequate. Such an effect has been observed in cats (see below).

 

===Cat:===

===Cat:===

There is some evidence of adverse effects of high dietary calcium in cats. Howard et al.<ref>Howard, KA, Rogers, QR, Morris, JG (1998). “Magnesium requirement in kittens is increased by high dietary calcium”. J. Nutr. 128 (suppl):2601S-2602S. </ref> found that kittens fed a dietary calcium level of 2.3% DM had depressed food intake, decreased growth and a higher requirement for magnesium. Nevertheless, these effects are not linked to severe skeletal abnormalities as seen in the giant dog breeds.   

There is some evidence of adverse effects of high dietary calcium in cats. Howard et al.<ref>Howard, KA, Rogers, QR, Morris, JG (1998). “Magnesium requirement in kittens is increased by high dietary calcium”. J. Nutr. 128 (suppl):2601S-2602S. </ref> found that kittens fed a dietary calcium level of 2.3% DM had depressed food intake, decreased growth and a higher requirement for magnesium. Nevertheless, these effects are not linked to severe skeletal abnormalities as seen in the giant dog breeds.