Diagnosis. The condition is rarely diagnosed, because, as one of the kidneys continues to act, no acute disturbance follows. Only in cases where the cystic kidney projects into the flank are suspicions aroused. Examination per rectum will then permit of the diagnosis being made.
Prognosis. Hydro-nephrosis being, as a rule, unilateral, the prognosis is not very grave as regards immediate danger. As the condition is hopeless, however, the lesions being irreparable, the animal should be prepared for slaughter.
Treatment. Practically there is no treatment. Puncture of the cystic cavity or even the removal of the hydro-nephrotic kidney certainly suggests itself, but, as such operations are usually opposed to the interests of the owner, they are rarely or never practised.
INFECTIOUS PYELO-NEPHRITIS.
Fig. 229.—Section of a kidney affected with hydro-nephrosis. The gland substance is almost entirely atrophied, and each lobule shows marked dilatation.
The term “infectious pyelo-nephritis” describes an inflammation which may involve any portion of the mucous membrane of the urinary tract, and which is produced by a special bacillus. As a rule, this inflammation commences in the mucous membrane of the calices and pelvis (pyelitis). It afterwards extends into the depths of the uriniferous canaliculi (nephritis), but in grave and old-standing cases the mucous membrane of the ureters and the bladder may also be affected. The disease had long been known in France (Rossignol, 1848). It was afterwards described in Germany (Siedamgrotsky, 1875; Pflug, 1876), in Switzerland (Hess, 1888), and also in France (Lucet, 1892; Masselin and Porcher, 1895).
Causation. Female animals are more frequently affected than males, because the lesions are produced by an ascending infection, originating very frequently in genital infection after delivery. Nevertheless, calculus formation is also an important factor in producing the disease.
Many different agents are capable of producing pyelo-nephritis. Hofflich in 1891 described a bacillus about 2 to 8 micromillimètres in length, which stained readily with aniline colours and with Gram solution. Lucet in 1892 found a short bacillus which did not stain with Gram, and later another thin bacillus which did. Kitt has described cocci, but no other organisms. Masselin and Porcher discovered a cocco-bacillus which stained with Gram and reproduced the disease in an animal lent by Moussu, after a single intra-vesical injection of the culture. Cadéac has met with staphylococci, and Moussu has discovered various bacilli, some resembling the colon bacillus, and pyogenic streptococci.
There is no doubt that many different organisms may produce pyelo-nephritis by ascending infection. The most common seem to be forms of paracoli, such as the Bacillus ureæ. Moussu nevertheless believes that Hofflich’s bacillus, which was rediscovered by Porcher, is that which produces typical pyelo-nephritis. It grows in the bladder without producing cystitis, and is succeeded by an ascending infection of the ureters without causing primary ureteritis, the local inflammation occurring chiefly, it would seem, in the pelvis and the kidney. All the other organisms which Moussu has tested have caused lesions of cystitis and of ureteritis, together with those of pyelo-nephritis.