Histopathology
Spontaneous microscopical lesions in Göttingen minipigs.
Lars Wichmann Madsen and Steen Larsen, Dept. of Pharmacology and Pathobiology, The Royal Veterinary and Agricultural University, Bülowsvej 17, DK-1870 Frederiksberg, Denmark.
Eighteen clinically healthy, microbiologically defined Göttingen minipigs, reared under strict barrier conditions, were examined in a scheme covering both sexes and three different ages i.e., 3, 6, and 12 months. A total of 57 tissues from each animal, consistent with international guidelines for toxicological research, were sampled and examined by light microscopy.
The most common microscopical lesion was focal accummulations of mononuclear inflammatory cells in various tissues. Such infiltrates were primarily seen interstitially or paravascularily and only rarely in the parenchyma of the organs. They were observed in the following tissues. Adrenal glands, cerebrum (Fig. 1), epididymis, oesophagus, kidneys, liver, lung, mandibular gland (Fig.2), meninges (cerebral, cerebellar and medullar), parotid gland, rectum, stomach, testes, tongue, and vagina. Mononuclear cell infiltrates are commonly found in other species as well and may indicate a normal immunological potential.
Lesions apart from these can be found listed in the table and selectively presented in the photomicrographs. The distribution of the lesions according to sex and age of the animals was not statistically significant.
The nature of most inflammatory lesions were suggestive of a focal traumatic or non-specific infectious aetiology. Iron deposition was probably caused by preventive iron administration, and was consistent with findings in previous studies in the Göttingen minipig, where the amount of iron deposition has been shown to correlate with the dosage of iron-dextran. The epithelial changes in the oesophageal part of the stomach was similar to lesions observed in domestic swine, where the incidence of hyperkeratosis is related to the feeding of finely ground rations and
pelleted feed.
Although this material should be regarded as a sample only, the findings indicate that spontaneous lesions in microbiologically defined Göttingen minipigs held under strict barrier conditions are generally of a mild and focal nature.
| Organ |
Lesion |
Incidence |
| Colon |
Focal lymphoid follicle necrosis |
2 |
| Eye |
Focal retinal dysplasia (Fig. 3)
Focal lymphocytic keratitis
Focal superficial keratitis |
1
4
1 |
| Kidney |
Iron deposition (Fig. 4)
Focal chronic interstitial nephritis
Subcapsular granuloma (Fig. 5) |
10
1
1 |
| Liver |
Iron deposition |
9 |
| Lung |
Vacuolated alveolar macrophages (Fig. 6) |
2 |
| Mammary gland |
Focal, mild thelitis
Exudative galactophoritis (Fig. 7) |
3
1 |
| Mandibular lnn. |
Focal eosinophilic inflammation
Iron deposition |
1
13 |
| Mesenteric lnn. |
Iron deposition |
1 |
| Ovary |
Follicular cyst |
1 |
| Prostate |
Epithelial sloughing
Focal prostatitis (Fig. 8) |
2
1 |
| Skeletal muscle |
Focal myocyte necrosis (Fig. 9) |
1 |
| Skin |
Periocular hyperkeratosis and exudation (Fig. 10) |
3 |
| Spleen |
Focal follicular necrosis |
1 |
| Stomach |
Hyper-/parakeratosis (Fig. 11)
Microabscessation
Focal necrotizing arteritis (Fig. 12)
Focal perivasculitis |
15
3
1
2 |
| Thoracic duct |
Granuloma |
1 |
| Tongue |
Focal dyskeratosis |
1 |
From:
Scand. J. Lab. Anim. Sci. 1998, 25 (3), 159-166 |
