Composition of some urinary calculi of ruminants in Western Australia.

Forty ruminant urinary calculi, selected as being essentially inorganic and mainly obtained from sheep grazing in the drier wheatbelt areas of Western Australia, were examined by optical and X-ray diffraction techniques. Four mineral types-silica (SiO2-nH2O), weddellite (CaC2O4-2H2O), calcite (CaCO3) and aragonite (CaCO3)--were found. These minerals were present respectively in 30, 17, 13 and 1 of the 40 calculi examined and were the sole component in 12, 0, 7, and 0 calculi. One calculus was found to be composed of organic material which was subsequently shown to consist mainly of 4'-O methyl equol (4'-methoxy-7-isoflavanol, C16H16O3) with a small amount of equol and a trace of formononetin. This is the first report of a calculus of this composition. Determinative data useful for identification of 4'o-methyl equol, equol and a related substance are presented in an appendix.     

Renal calculi in wild Eurasian otters (Lutra lutra) in England

Macroscopic renal calculi were seen in 50 of 492 (10.2 per cent) wild Eurasian otters found dead in England from 1988 to 2007. Forty-eight adults and two subadults were affected. Calculi were present in 15.7 per cent (31 of 197) of adult males and 12.7 per cent (17 of 134) of adult females. There was an increase in prevalence in the study population over time; no calculi were found in 73 otters examined between 1988 and 1996, but in most subsequent years they were observed with increased frequency. Calculi occurred in both kidneys but were more common in the right kidney. They varied greatly in shape and size; larger calculi were mostly seen in the calyces while the smallest ones were commonly found in the renal medulla. Calculi from 45 cases were examined by x-ray diffraction analysis; in 43 (96 per cent), they were composed solely of ammonium acid urate. Affected otters had heavier adrenal glands relative to their body size than unaffected otters (P<0.001). There was no significant association between body condition index and the presence of calculi (P>0.05). Many otters had fresh bite wounds consistent with intraspecific aggression. The proportion bitten increased over time and this coincided with the increased prevalence of renal calculi.     

Urolithiasis in a wild red deer (Cervus elaphus) population

Renal calculi were found in eight of 325 red deer kidney pairs examined, all eight were females and only one was infected in both kidneys. A further three deer badly infected with urolithiasis were found by chance, two were males. Examples of the calculi found are illustrated to show their range of sizes and shapes. One calculus analysed for chemical composition comprised predominantly calcium carbonate.     

Dried solidified blood calculi in the urinary tract of cats

We have noted an increased number of calculi submitted to the Gerald V. Ling Urinary Stone Analysis Laboratory, University of California, Davis, that do not contain crystalline material but appear to be composed of dried solidified blood (DSB). Canine and feline laboratory records from 1986-2003 were reviewed for samples composed of >99% DSB. No calculi from dogs were found, but specimens from 49 cats were composed of >99% DSB, of which almost half (n = 22) had been submitted after 2001. The DSB calculi had been removed surgically or by postmortem examination from all areas of the upper and lower urinary tract. All samples were well formed and could be divided in half with Rongeur forceps. Detailed case information was available for 12 cats. Urinalyses were available for 9 of the 12 cats, and the mean specific gravity was 1.017 (range, 1.009-1.032). Red blood cells were reported in the sediment of all cats, with most containing >100 RBC/hpf. Ureteral obstructions but no radio-opaque calculi were visible by radiography, including radiographic contrast studies. Reports of ultrasound examinations were available for 10 cats, and discrete calculi were not recorded. In addition to polarized light microscopy, infrared spectroscopy and electron probe microanalysis were performed on a subset (n = 6, DSB calculi; n = 3, control calculi) of samples. Significantly more carbon, nitrogen, and sulfur (P = .012, P = .02, and P = .012, respectively) were present in the elemental analysis of the DSB calculi than in the control calculi, suggesting that the DSB calculi are primarily formed from organic material. At this time, we are uncertain why these DSB calculi become solidified, and we recommend that samples be submitted both in formalin and preservative free to further investigate their etiology.     

The structure of canine urinary calculi

Thin sections of canine calculi were examined using microradiographic techniques and although nuclei were detected in a few stones, their presence did not appear to be necessary for the formation of canine calculi. Concentrically arranged laminar bands were seen in the majority of magnesium ammonium phosphate calculi, but radial striation was seen only in one stone which was composed of ammonium urate. Fissures were observed in the centres of several calculi composed of magnesium ammonium phosphate.     

Glucosuria associated with renal calculi in Asian small-clawed otters

Urine from one female and 2 male Asian small-clawed otters (Aonyx cinerea) with bilateral renal calculi, one female with unilateral calculi, and one nonaffected male were evaluated for abnormal urinary crystalloid excretion. One otter with bilateral renal calculi had cystic calculi composed of calcium oxalate monohydrate and dihydrate. The 2 affected males were littermates, as were the 2 affected females, but the 2 litters were from different parents. At the time of the study, the otters did not have clinical signs of disease. Hematologic and serum biochemical, electrolyte, and enzyme values were normal. The urinary excretion of calcium, oxalate, uric acid, phosphate, citrate, and amino acids in otters with renal calculi was similar to that of the nonaffected otter. The 4 otters with renal calculi had glucosuria but the nonaffected otter did not have glucosuria. The glucosuria, in the absence of hyperglycemia, suggested a renal tubular transport defect for glucose. Other renal abnormalities were not found.     

Instrumental neutron-activation analysis of canine urinary calculi for some selected elements

Thirty canine urinary calculi, most of which had been qualitatively classified as struvite calculi, were analyzed by instrumental neutron activation analysis at the University of Missouri Research Reactor. Measurements of sodium, magnesium, aluminum, silicon, phosphorus, chloride, potassium, and calcium were possible, using a dual irradiation procedure. Magnesium was used to calculate the percentage of struvite mineral, Mg(NH4) (PO4) X 6H2O, in the calculi by making use of the stoichiometric relationship of the element magnesium to the mineral. For those calculi containing greater than 80% struvite, the mean elemental concentrations were found to be 0.12% Na, 9.35% Mg, 0.0033% Al, 12.1% P, 0.02% Cl, 0.85% K, and 2.05% Ca. A new method for determination of silicon in urinary calculi also was discussed. Two calculi were found to contain 45.0% and 37.3% silicon, and 1 mixed calculus was composed of 1.4% silicon.     

Canine urolithiasis: epidemiology and analysis of urinary calculi

The incidence of canine urolithiasis was found to lie between 0–5 to 1 per cent of the canine population. Epidemiological and analytical data were collected for 1731 urinary stones, and causal relationships investigated. Calculi were found in 72 breeds. While they were relatively common among dachshunds, dalmatians, cocker spaniels, Pekingese, bassets, poodles, schnauzers and small terrier breeds, urinary stones were relatively rare among German shepherd dogs, boxers, collies, chow chows, old English sheepdogs, spitz and rottweiler breeds. Struvite, which was found in 55-6 per cent of all calculi, proved to be the most common constituent, followed by cystine (22-5 per cent) and ammonium urate (6-6 per cent). Xanthine calculi were rare (six cases), while silicium dioxide calculi were present in only one case. The likelihood of calculi in male animals was twice that of bitches, although the latter were found to be more prone to infection of the urinary tract. Adiposity was present in 29 per cent of all dogs with calculi. The average age of the animals was seven years. In 98-7 per cent of all cases the calculi were found in the lower urinary tract, and surgical removal of the stones was required in 87-5 per cent of cases. The main types of calculi appear among specific breeds, which indicates that a careful breeding programme may help to reduce the frequency of urinary calculi.     

Cystine-containing urinary calculi in dogs: 102 cases (1981-1989).

One hundred and seven cystine-containing urinary calculi from 1 female and 101 male dogs were analyzed. Cystine-containing calculi accounted for 2% (107 of 5,375) of all canine urinary calculi submitted to the urinary stone analysis laboratory from July 1981 through December 1989. Male dogs that formed cystine calculi were compared with 3 other canine populations to determine whether certain breeds were apparently at increased or decreased risk for cystine calculus formation. In one or more of 3 population comparisons, significantly increased risk of cystine calculus formation was found in Mastiffs, Australian Cattle Dogs, English Bulldogs, Chihuahuas, Bullmastiffs, Newfoundlands, Dachshunds, Basenjis, Australian Shepherd Dogs, Scottish Deerhounds, Staffordshire Terriers, Miniature Pinschers, pitbull terriers, Welsh Corgis, Silky Terriers, and Bichon Frises. Significantly low risk of cystine calculus formation was found in German Shepherd Dogs, Poodles, Schnauzers, and mixed-breed dogs.     

Pathological findings in the bulbourethral glands of bulls

The bulbourethral glands of 323 Bos indicus or B. indicus crossbred bulls more than 1 1/2 years old were examined in an abattoir study. Bulbourethral adenitis was diagnosed grossly and confirmed by histological examination in 4 (1.2%). Unilateral chronic interstitial inflammation was seen in 2 cases; one of these was associated with a degenerative-type seminal vesiculitis. In the others adenitis was bilateral; in one case it was associated with a concretion and foreign (plant) material in the principal duct of the left bulbourethral gland; in the other bilateral case, numerous calculi were present and microscopically, a chronic active and diffuse inflammation was observed. Chemical analysis of the calculi showed calcium oxalate and tricalcium phosphate to be the most important components. Corynebacterium spp was isolated from the lesion with multiple calculi but attempts to isolate Chlamydia spp, Mycoplasma spp and Brucella abortus from the 4 adenitis cases were unsuccessful. Congenital abnormalities such as glandular fusion (2.2%) or unilateral aplasia (0.6%) were also observed. Cysts were the most common finding (19.2%), and duct dilation was frequent (7.1%). The significance of these findings in relation to fertility is considered.     

RENAL CALCULI IN APPARENTLY NORMAL SHEEP

SUMMARY The incidence of renal calculi in sheep was determined and the effects of season, sex and difference between left and right kidneys were considered. Examinations for calculi were made by x-ray photography and stereomicroscopy. The seasonal study extended from June 1972 to June 1973. The lowest incidence of calculi, occurred from November to February (25 to 35%) and the highest, in June 1972 (61%) and May 1973 (63%); in other months it generally ranged from 40 to 50%. These differences were highly significant (P < 0.001). The incidence of calculi greater than 2 mm diameter was 0% and 3% in January and February and, except for 18% in June 1972 values were about 8%. Subepithelial deposits ranged from 2% (April) to 25% (June 1972) about a mean of 11%. Calculi were found most frequently in the middle third of the kidney and near the fornices. Of kidneys with microcalculi (<0.05 mm diameter) visual assessment showed 64% contained silica, 29% oxalate, 15% carbonate and 5% material of undetermined nature. Differences in the incidence of calculi between ewes and wethers and between left and right kidneys were not significant and the distribution of calculi within these kidneys was similar to that in the seasonal study. These results are discussed in relation to urinary tract obstruction in grazing sheep and to possible factors affecting the retention in and movement of calculi from the kidney.     

Inheritance of urinary calculi in the Dalmatian

Dalmatians are unique among dogs in that they excrete uric acid in their urine as the end product of purine metabolism rather than allantoin as do other breeds of dogs. Urinary calculi form from urate (salts of uric acid) and can cause urethral obstruction in male Dalmatians. Although all Dalmatians have the primary defect, only a subset develops clinical disease. We postulated that calculi formation might have a genetic component that segregates within the breed, causing some animals to form calculi and others to never form calculi despite excreting uric acid in their urine. We used a survey to ascertain the urinary calculi status based on clinical signs of adult Dalmatians aged 6 years or older, and we used pedigrees from these same animals to estimate the heritability of the clinical manifestation of urate calculi within the breed to be .87 (.75-.96). The prevalence of the disease was 34% (24.99-43.70%) among male Dalmatians in our survey. The high heritability of the disease makes it possible for breeders to effectively select against the disease.     

Renal Calculi in Dogs and Cats: Prevalence, Mineral Type, Breed, Age, and Gender Interrelationships (1981–1993)

Three hundred seventeen specimens of urinary calculi of renal origin from 214 female dogs and 103 male dogs, and 71 specimens of urinary calculi of renal origin from 38 female cats and 33 male cats were submitted for mineral analysis between July 1, 1981, and December 31, 1993. Among dogs, 45 breeds were affected with renal calculi. Thirty-three breeds and a crossbred group were represented among females, but 8 breeds and the crossbred group accounted for 81% of the total. Among male dogs, 30 breeds and a crossbred group were represented, but 7 breeds and the crossbred group accounted for 69% of the total. Among cats, 10 breeds and a crossbred group were represented. Dogs and cats with renal calculi were older than those of 2 comparison population groups. More than one-half of the renal calculi in both dogs and cats were from the 1st known episode of urolithiasis. The risk of formation of renal calculi was found to be higher for cats than for dogs, when compared to other stone-forming cats and dogs (approximately 4.95 per 100 stone-forming cats and 2.88 per 100 stone-forming dogs). Among dogs, breeds at highest risk of developing renal calculi were Miniature Schnauzers, Shih Tzus, Lhasa Apsos, Yorkshire Terriers, and female Pugs. Also at high risk were male Dalmatians and male Basset Hounds. Among small dogs, females generally were at higher risk of developing renal calculi than were males. Regardless of size, terrier breed males generally were at higher risk of developing renal calculi. Breeds of dogs at low risk for development of renal calculi included crossbreds, German Shepherd Dogs, Labrador Retrievers, Golden Retrievers, and female Dachshunds. When only 1 kidney was involved, the risk of left renal calculus was greatest for both dogs and cats, but bilateral renal involvement was relatively common in both species (19% and 9%, respectively). Among dogs, specimens composed of 1 mineral substance (eg, struvite) occurred more often in males (58.3%) than in females (37.9%). Female dogs formed renal calculi containing struvite or oxalate more often than did males; males formed calculi containing urate more often than did females. Calculi containing oxalate, apatite, or some combination of these minerals predominated among cats; only 1 specimen from 38 female cats and only 4 specimens from 33 male cats contained neither oxalate nor apatite. Crossbred cats were significantly less likely to have renal calculi than were other breeds. A single renal calculus specimen was identified in several uncommon breeds including Tonkinese and Birman cats, and Affenpinscher, Clumber Spaniel, English Shepherd, and Field Spaniel dogs. No significant differences were observed between male and female dogs or between male and female cats with regard to mineral type of the specimen and the presence of urinary tract infection.     

Structure and composition of canine urinary calculi

The chemical constituents of 171 specimens of canine urinary calculi have been analysed by infrared spectroscopy. The analysis revealed that 46 per cent of the total contained struvite as the major component; 26 per cent contained cystine; 16 per cent were found to be composed of whewellite and, or, weddellite; 8 per cent of urates; 3 per cent of calcium phosphate (apatite and, or, brushite) and 1 per cent of silica. A series of selected samples was also studied by scanning electron microscopy and energy dispersive X-ray analysis (EDAX). This examination revealed structures similar to human stones. Potassium and complex urates containing two or more cations were commonly found in many areas of ammonium urate and sodium urate calculi. Moreover, EDAX analysis detected a calcium enriched urate in several zones of urate calculi.     

Parotid Duct Sialolithiasis in Horses

Parotid duct sialolithiasis was diagnosed in four adult mixed-breed mares. Successful surgical removal of the calculi was performed using a percutaneous approach. The salivary calculi were found to contain barley grains in the center, surrounded with mineral layers composed mainly of calcium carbonate and calcium oxalate.     

Extraction of urethral calculi by transabdominal cystoscopy and urethroscopy in nine dogs

Objectives : To describe a minimally invasive technique for treating urethral obstructions in male dogs and to review the postoperative results. Methods : All dogs (n=9) had urethral obstruction due to calculi. Obstructions were verified by radiographic and ultrasonographic examinations. Dogs with impaired kidney function were not included in the study. A 5‐mm diameter trocar and cannula were placed in the ventral midline, 2 cm cranial to the umbilicus, allowing placement of a 10‐mm diameter cannula under visual guidance, adjacent to the apex of the bladder. The bladder was then partially exteriorised and sutured to the skin. A 5‐mm diameter cystoscopy sheath was introduced into the bladder lumen and advanced into the urethra. Continuous retrograde flushing was used to dislodge the calculi from the site of obstruction and collect them upstream. Results : The nine dogs were followed up for a minimum of 6 months. No major postoperative complications were identified. One dog exhibited transient macroscopic haematuria (for 3 weeks postoperatively). All urethral calculi were removed in the nine dogs. No recurrence was found during the follow‐up period. Clinical Significance : A minimally invasive approach is used to treat urethral obstructions resulting from calculi in the male dogs.     

Evaluation of trends in urolith composition in cats: 5,230 cases (1985-2004)

OBJECTIVE: To determine trends in urolith composition in cats. DESIGN: Retrospective case series. SAMPLE POPULATION: 5,230 uroliths. PROCEDURES: The laboratory database for the Gerald V. Ling Urinary Stone Analysis Laboratory was searched for all urolith submissions from cats from 1985 through 2004. Submission forms were reviewed, and each cat's age, sex, breed, and stone location were recorded. RESULTS: Minerals identified included struvite, calcium oxalate, urates, dried solidified blood, apatite, brushite, cystine, silica, potassium magnesium pyrophosphate, xanthine, and newberyite. During the past 20 years, the ratio of calcium oxalate stones to struvite stones increased significantly. When only the last 3 years of the study period were included, the percentage of struvite stones (44%) was higher than the percentage of calcium oxa-late stones (40%). The most common location for both types of uroliths was the bladder. The number of calcium oxalate-containing calculi in the upper portion of the urinary tract increased significantly during the study period. The number of apatite uroliths declined significantly and that of dried solidified blood stones increased significantly, compared with all other stone types. No significant difference in the number of urate stones was detected. CONCLUSIONS AND CLINICAL RELEVANCE: The increasing proportion of calcium oxalate uroliths was in accordance with findings from other studies and could be a result of alterations in cats' diets. However, the decreased percentage of calcium oxalate calculi and increased percentage of struvite calculi observed in the last 3 years may portend a change in the frequency of this type of urolith.     

The distribution of canine urinary calculi and their recurrence following treatment

The composition of urinary calculi was determined in 110 cases of canine urolithiasis and it was found that phosphate was the main constituent in 44% of cases, oxalate in 32%, cytsine in 22% and urate in 2%. Magnesium ammonium phosphate calculi were frequently found in female dogs while in male animals calculi composed of calcium salts or cystine were common. The mean age of dogs with calculi composed of magnesium ammonium phosphate was 6 years while for calcium calculi the mean age was 8-6 years and for cystine calculi 4–9 years. Recurrence of urolithiasis was studied in sixty dogs and further calculi were found in thirty-two animals when examined radiographically although only nineteen of these showed clinical signs. Recurrent calculi developed in 75% of cases where the calculi were composed of calcium or cystine but in only 30% of cases with magnesium ammonium phosphate. The recurrent stones usually had a similar composition to the initial calculi. Résumé. On a précisé la composition de calculs urinaires dans 110 cas d'urolithiase canine et or trouvé que le phosphate était le principal constituant dans 44% des cas, l'oxalate dans 32%, cystine dans 22% et l'urate dans 2%. On a fréquemment trouvé des calculs de phosphates d'amrr nium magnésium chez les chiens femelles tandis que chez les animaux mâles les calculs composés sel de calcium ou de cystine étaient communs. La moyenne des âges des chiens avec des calculs coi posés de phosphate d'ammonium magnésium était de 6 ans, alors que pour les calculs de calcium moyenne des âges était de 8,6 ans et pour les calculs de cystine de 4,9 ans. On a étudié une recurren d'urolithiase chez soixante chiens et on a trouvé d'autres calculs chez trente-deux chiens quand i les a examinés à la radiographie bien que dix-neuf seulement aient montré des signes cliniqui Des calculs récurrents se sont développés dans 75% des cas oà les calculs se composaient de cystine i de calcium mais dans seulement 30% des cas avec du phosphate d'ammonium magnésium. L pierres recurrentes avaient généralement une composition semblable à celle des calculs initiaux. Zusammenfassung. Die Komposition von Harnsteinen wurde in 110 Fällen von Hunde-Har steinen bestimmt und man fand, dass Phosphat der Hauptbestandteil in 44% aller Fälle war, Oxal in 32%, Cystin in 22% und Urat in 2%. Magnesiumammoniumphosphatsteine wurden häufig weiblichen Hunden gefunden, während in männlichen Tieren Steine die aus Kalziumsalzen od Cystine zusammengesetzt waren, gewöhnlicher waren. Das Durchschnittsalter von Hunden ir Harnsteinen die aus Magnesiumammoniumphosphat bestanden belief sich um 6 Jahre während fi Kalziumharnsteine das Durchschnittsalter 8,6 Jahre war und für Gystinharnsteine 4,9 Jahre. Ma studierte das Wiederauftreten von Harnsteinen in sechzig Hunden und weitere Harnsteine fande sich in zweiunddreissig Tieren, als sie radiographisch untersucht wurden, obwohl nur neunzehn vo diesen klinische Symptôme zeigten. Emeute Harnsteine entwickelten sich in 75% aller Fälle in dene die Harnsteine aus Cystine oder Kalzium zusammengesetzt waren aber in nur 30% von Fällen m Magnesiumammoniumphosphat. Die erneut auftretenden Steine waren gewöhnlich von ähnlichi Komposition wie die anfänglichen Harnsteine.     

Survey of tortoises with urolithiasis in Japan

Urolithiasis is a disease often seen in tortoises at veterinary hospitals, however there have been no comprehensive research reports of tortoises with urolithiasis in Japan. In this study, we analyzed tortoises diagnosed with urolithiasis at three domestic veterinary hospitals. Based on medical records, we assessed the diagnostic method, species, sex, body weight, dietary history, husbandry, clinical signs, clinical examination, treatment for urolithiasis, and clinical outcome. The total number of cases in the 3 facilities was 101. As for species of tortoises, the most common was the African spurred tortoise (Centrochelys sulcata) with 42 cases (41.6%), followed by the Indian star tortoise (Geochelone elegans) with 30 cases (29.7%). Six other species were confirmed to have calculi. Almost all cases (99 cases, 98%) had a single calculus, and only 2 had multiple calculi. The prevalence of urolithiasis for the total number of tortoises having visited to one institution during the same period was 5.1%. Of the 86 cases that underwent calculi removal, 64 (74.4%) were successfully removed via the vent, and the efficacy of this method was confirmed. Nineteen cases (22%) were approached via plastronotomy, among which only 2 died postoperatively. In this study, we could not clarify the relationship between calculi formation and diets or other husbandry factors.     

Mineralised deposits in the uterine glands of mares with chronic endometrial degeneration

Chronic degenerative disease of the mare's endometrium is characterised by changes in the uterine glands, including cystic dilation, hyperplasia and periglandular fibrosis. Endometrial biopsies were taken from 23 mares with different grades of endometrial degeneration. Solid structures were identified within the lumina of the uterine glands and shown to be calcified by histochemical staining. Most of them were not homogenous but composed of a mixture of mineral and organic substances. Further examinations of these mineralised structures by immunohistochemical methods revealed the presence of the non-collagenous matrix proteins osteopontin, osteonectin and bone sialoprotein, which are known to be involved in calcification processes such as urolithiosis. Osteopontin and bone sialoprotein were identified within the calculi, frequently arranged in concentric layers. Osteonectin was the only matrix protein that was also present in the glandular epithelium. Osteocalcin was not found in either the calculi or the glandular epithelial cells.