| Disorder |
Age of affected pigs |
Cause |
Lesion distribution |
Gross features |
Histopathology |
| Osteoporosis (Doige 1982Doige C.E. 1982. Pathological findings associated with locomotory disturbances in lactating and recently weaned sows. Can. J. Comp. Med. 46(1):1-6. <PMid:7200384>, Craig et al. 2016Craig L.E., Dittmer K.E. & Thompson K.G. 2016. Bones and joints., p.17-146. In: Maxie M.G. (Ed.), Jubb, Kennedy and Palmer’s Pathology of Domestic Animals. Vol.2. 6th ed. Elsevier, St. Louis.) |
Growing and adult pigs |
Cu/Ca deficiency, starvation, vitamin A toxicity, increased stress |
Vertebrae, ribs, long bones, flat bones of the skull |
Reduced breaking strength of ribs. Marked depletion of cancellous bone in the metaphyses and epiphyses. Reduced cortex thickness |
Bone trabeculae decreased in thickness and number, disconnected, “free-floating trabeculae”, increased porosity of the cortical bone due to enlargement of Haversian canal, low level of osteoblastic activity |
Fibrous osteodystrophy (Thompson & Robinson 1989Thompson K.G. & Robinson B.M. 1989. An osteodystrophy apparently caused by vitamin D deficiency in growing pigs. N. Z. Vet. J. 37(4):155-157. <https://dx.doi.org/10.1080/00480169.1989.35593> <PMid:16031553>
https://doi.org/10.1080/00480169.1989.35...
) |
Growing and adult pigs |
Ca and vitamin D deficiency, excess P |
Skull bones, especially mandibles and maxilla. Also, scapula and vertebral column |
Bilateral enlargement of the bones of the skull, movable teeth, jaw swelling. Soft, pumice-like bones, and decrease in bone density. Ribs may bend or snap with little effort |
Increased osteoclastic bone resorption, marked fibroplasia, and increased osteoblastic activity with formation of immature woven bone, frequently poorly mineralized |
Rickets (Pepper et al. 1978Pepper T.A., Bennet D., Brown P.J. & Taylor D.J. 1978. Rickets in growing pigs and response to treatment. Vet. Rec. 103(1):4-8. <https://dx.doi.org/10.1136/vr.103.1.4> <PMid:676016>
https://doi.org/10.1136/vr.103.1.4...
, Dittmer & Thompson 2011Dittmer K.E. & Thompson K.G. 2011. Vitamin D metabolism and rickets in domestic animals: a review. Vet. Pathol. 48(2):389-407. <https://dx.doi.org/10.1177/0300985810375240> <PMid:20634407>
https://doi.org/10.1177/0300985810375240...
, Madson et al. 2012Madson D.M., Ensley S.M., Gauger P.C., Schwartz K.J., Stevenson G.W., Cooper V.L., Janke B.H., Burrough E.R., Goff J.P. & Horst R.L. 2012. Rickets: case series and diagnostic review of hypovitaminosis D in swine. J. Vet. Diagn. Invest. 24(6):1137-1144. <https://dx.doi.org/10.1177/1040638712461487> <PMid:22991390>
https://doi.org/10.1177/1040638712461487...
, Gris et al. 2020Gris A., Peres Neto E., Silva K.S., Gomes T.M.A., Surian S.R.S., Fronza N. & Mendes R.E. 2020. Outbreak of rickets in pigs in the west of Santa Catarina. Acta Scient. Vet. 48(Supl.1):545. <https://dx.doi.org/10.22456/1679-9216.101236>
https://doi.org/10.22456/1679-9216.10123...
) |
Growing pigs |
Deficiency of Ca, P, vitamin D. Ca/P imbalance |
Sites of rapid growth, metaphyseal and epiphyseal regions of long bones, and costochondral junctions of the large middle ribs |
Weak bones that bend before breaking with a weak snap and have enlarged growth plates, giving a clinical appearance of swollen joints, increased volume of costochondral joints (rachitic rosary), kyphosis |
Decreased mineralization of the growing bone, evident persistence of hypertrophic chondrocytes at sites of endochondral ossification |
| Osteomalacia (Craig et al. 2016Craig L.E., Dittmer K.E. & Thompson K.G. 2016. Bones and joints., p.17-146. In: Maxie M.G. (Ed.), Jubb, Kennedy and Palmer’s Pathology of Domestic Animals. Vol.2. 6th ed. Elsevier, St. Louis.) |
Late finishing and adult pigs |
Deficiency of Ca, P, vitamin D. Ca/P imbalance |
Vertebrae, femur, pelvis, and ribs |
Bones with reduced resistance to pressure and tension. In severe cases the marrow cavity is expanded, the cortex is thin, spongy, and soft |
Decreased mineralization with the significant remodeling of the mature bone. Localized accumulation of osteoid at sites of mechanical stress |
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