IN VITRO EVALUATION OF CONTRAST MEDIUM CONCENTRATION AND DEPTH EFFECTS ON THE RADIOGRAPHIC APPEARANCE OF SPECIFIC CANINE UROLITH MINERAL TYPES

Nine pure mineral types of canine uroliths (bladder or urethral origin only) identified in a chronologic sample from the Minnesota Urolith Center were compared to sequential dilutions of iodinated radiographic contrast medium in vitro. The uroliths studied were those composed of 100% magnesium ammonium phosphate, calcium oxalate monohydrate, calcium oxalate dihydrate, calcium phosphate appatite, calcium hydrogen phosphate dihydrate (brushite), ammonium acid urate, sodium acid urate, cystine, and silica. The radiopacity of the uroliths was classified as radiolucent, isopaque, or radiopaque, as compared to the radiopacity of the contrast medium solutions in which they were placed, using 2.0 mm and 5.0 mm depths in petri dishes radiographed using a table-top technique. A statistically significant relationship was found between the effective atomic number of the uroliths and the effective atomic number of the contrast medium solutions to which they were compared for the endpoints of isopacity, first luceney (in increasing iodine concentration sequence), and optimal visualization of internal architecture. In general, uroliths isopaque or radiolucent in contrast medium solutions weaker than 23.5 mgI₂/ml are most likely ammonium acid urate or sodium acid urate. Uroliths isopaque or radiolucent in contrast medium solutions between 23.5 mgI₂/ml and 44.4 mgI₂/ml are probably magnesium ammonium phosphate, cystine, or silica. Uroliths that remained radiopaque in solutions stronger than 44.4 mgI₂/ml, and particularly those radiopaque in contrast medium solutions stronger than 80 mgI₂/ml, almost always contained calcium. This relative opacity assessment is proposed for use in double contrast cystography as an aid in differentiating urolith mineral types clinically to facilitate appropriate use of medical protocols to dissolve uroliths or to prevent their growth or recurrence.     

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.     

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.     

Radiographic features of suspected suture‐associated cystic calculi in dogs

This retrospective case series describes the radiographic features of suspected suture‐associated cystic calculi in six dogs with a history of at least one or multiple prior cystotomies. One of the dogs presented twice. Suspected suture‐associated cystic calculi were multifocal, short, predominantly linear mineral opacities localized in the center of the urinary bladder on abdominal radiographs. One patient (n = 1) presented with multifocal round, pin point, and linear radiopaque calculi. The calculi were all calcium oxalate in composition. On gross examination, the calculi had a hollow center. Six cystotomies used monofilament absorbable suture material (polydioxanone [n = 4] or poliglecaprone 25 [n = 1]) in prior cystotomies. Suture material in two of the cases was unknown. Suspected suture‐associated cystic calculi are a rare occurrence in veterinary medicine but should be considered in dogs that have a history of prior cystotomy, hollow core on gross analysis, and radiographic evidence of mineral opaque, predominantly linear, cystic calculi.     

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.     

Semen-Matrix Calculi in a Juvenile Chinchilla (Chinchilla lanigera)

A 10-month-old, intact male chinchilla (Chinchilla lanigera) was diagnosed with urolithiasis, unilateral hydroureter, and hydronephrosis secondary to ureteral obstruction confirmed by radiography and ultrasonography. Nephrectomy and cystotomy were performed, and the urolith was suspected to be a semen-matrix calculus (mineralized copulatory plug) based on the discovery of sperm within the renal pelvis of the nephrectomized kidney on histopathology; this was later confirmed through a postmortem examination. Three months after initial presentation the chinchilla was diagnosed with recurrent urolithiasis, hydroureter, and hydronephrosis of the remaining kidney and ureter, and euthanized due to poor prognosis. Necropsy confirmed the presence of semen-matrix calculi in the ureter and urinary bladder. Veterinary clinicians should consider semen-matrix calculi as a differential diagnosis for radiopaque calculi within the bladder or urethra of male chinchillas. Pathogenesis may be formation of a coagulum secondary to retrograde ejaculation.     

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 Herd of Beef Cattle Associated with Oxalate Ingestion

An unusually high incidence of urinary calculi in a group of feeder cattle is described. Necropsy findings in one affected animal suggested that oxalates in the feed, specifically in fescue (Festuca spp.) seed screenings, may have been the cause. Low dietary calcium and decreased water intake by the cattle appear to have been predisposing factors. Control measures are discussed.     

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.     

Comparison of effect of high intake of magnesium with high intake of phosphorus and potassium on urolithiasis in goats fed with cottonseed meal diet

The effect of high intake of Mg on urolithiasis was compared with high intake of P and K in goats being fed with a cottonseed meal and rice straw diet. Eighteen wether goats were randomly allocated into group A, B and C evenly and fed with cottonseed meal and rice straw diet for three months. From day 60 onwards, KH₂PO₄ and K₂HPO₄ were provided via drinking water to goats in group B to increase the intake of P, K, and MgO to goats in group C to increase the intake of Mg. Blood and urine samples were collected to analyze the concentration of P, K, Mg and Ca, and the activity product (AP) of potassium magnesium phosphate (MKP) in urine was also calculated. The composition of calculi and urinary sedimentary crystals were examined by chemical qualitative analysis, X-ray diffraction, X-ray energy dispersive spectrometry and Fourier transform infrared spectroscopy. The results showed that the incidence of urolithiasis in group C (6/6) was higher than that in group A (1/6) and B (1/6) (P < 0.05). The calculi were mainly composed of magnesium ammonium phosphate (MAP) and partly composed of MKP. MKP presented in crystals of different phases in this experiment. The high intake of Mg contributed to a significant increase of plasma Mg, but additional P, K did not cause a further increase of plasma P, K. Urine P, K, Mg and Ca and AP of MKP in group C decreased significantly after the onset of urolithiasis. In conclusion, high intake of Mg was more important in inducing struvite calculi compared with high intake of K and P in goats under these feeding conditions. Cottonseed meal and rice straw with additional Mg is a good dietary model for inducing struvite calculi in castrated goats.     

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.     

Allantoic fluid electrolytes and urate of embryonic Japanese quail subject to differential water loss

1. The composition of allantoic fluid from Japanese quail was measured from days 9 to 14 of incubation.

2. The effect of the inhibitor of urate synthesis, allopurinol, upon weight, electrolytes and urate of allantoic fluid was investigated in eggs subject to different rates of water loss. The composition of plasma and the solid fraction of allantoic fluid was also investigated.

3. During the second half of incubation allantoic fluid water weight decreased, as did pH, and sodium, chloride and bicarbonate concentrations. Fluid urate and potassium concentrations increased, but osmolality was unchanged.

4. Allantoic urate and electrolyte concentrations were greatest, and fluid weight lowest, in eggs subject to high water loss.

5. Allopurinol reduced the total urate of allantoic fluid, and increased osmolality and electrolyte concentrations. Allopurinol had no effect on plasma osmolality.

6. It is concluded that in eggs of high water loss allantoic fluid osmolality was reduced by sequestration of sodium by urate in the fluid solid fraction. In eggs subject to low water loss fluid osmolality was reduced by the replacement of chloride by colloidal urate.     

The Technique and Applications of Lymphography

The technique of radiographic examination by lymphography of normal lymphatic structures regional to the hind limbs is described in the rabbit, dog and rhesus monkey. Radiographic appearances of normal lymph nodes and possible applications to veterinary science are indicated.

Normal lymph node microstructure is illustrated using in vivo intralymphatic injection of a brightly colored radiopaque silicone rubber. Angiogenesis in active germinal follicles during the period of an immune response is displayed. Further applications of the casting technique are suggested.

     

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.     

Odontogenic hamartomas in cultured angelfish (Pterophyllum scalare)

BackgroundOdontogenic tumors present diverse clinical and histopathological behaviors that range from benign odontoma or hamartoma lesions to malignant tumors. In angelfish Pterophyllum scalare, findings of tumorous masses have been reported in the frontal region of the mouth, encompassing both the maxilla and mandible. Histologically, oral tumors have been characterized as angelfish lip fibroma or ameloblastoma.MethodsIn this report, we describe the occurrence of a compound odontoma/hamartoma in 60 angelfish from a population of 300, all of which were collected from a Mexican ornamental fish farm.ResultsAll fish presented a tumor-like mass on the rostral part of the mouth. Histological analyses revealed the tumor-like mass was covered by a hyperplastic stratified squamous epithelium, with fully differentiated denticles in various states of organization, immersed among normal dental tissues and showing a mild disorganized pattern. Radiograph analysis revealed radiopaque denticles in a radiolucent protuberance. Bacterial and viral isolation procedures and electron microscopy analysis revealed no presence of these microorganisms.Conclusion and clinical relevanceAlthough findings of odontogenic tumors in the mouth of angelfish are reported as sporadic, our study detected odontogenic mouth tumors in 60 angelfish, but the possible cause of alteration is not yet clarified. Further research is needed to clarify pathogenesis and to identify possible genetic abnormalities.     

Interference by urate in the determination of plasma glucose

Very low concentrations of glucose were found when studying plasma samples obtained from some chicks suffering from fatty liver and kidney syndrome. This was due, in part, to interference in the glucose assay method by raised concentrations of urate in the plasma. Four techniques for the accurate assay of plasma glucose, in the presence of high urate concentrations, were investigated; the method based on the procedure of Morley et al. (1968) proved to be most satisfactory of those tested.     

Spiroceca lupi infection in dogs in Kenya

The prevalence of Spirocerca lupi infection in 346 dogs in Kenya was 78% (85% in 294 native dogs and 38% in 52 pet dogs). S. lupi lesions were distributed as follows: aorta (269 dogs), esophagus (217), thoracic spondylosis (16), stomach (8), lung (6), mediastinum (5), diaphragm (4), and kidney and omentum (1 each). Only one dog with an esophageal granuloma lacked concomitant aortic lesions. Clinical laboratory findings in dogs with and without spirocercosis were not significantly different. Upon fecal examination for S. lupi, eggs were found in 56% (81) of 145 native dogs with esophageal granulomas having a patent opening. One native dog and two pet dogs had osteosarcoma of the esophagus. Metastases of this tumor were observed in all three dogs, two of them had hypertrophic osteoarthropathy, and two had thoracic spondylosis. Fifty-three percent of 241 native dogs had renal calculi. In areas of high S. lupi prevalence, cattle, chickens, dung beetles and dogs were in close association.     

Oxidative Stress Produced by Xanthine Oxidase Induces Apoptosis in Human Extravillous Trophoblast Cells

Oxidative stress has been recognized as an important factor in the pathophysiology of preeclampsia. It has been reported that the expression of xanthine oxidase (XO) in the cytotrophoblast and plasma hydrogen peroxide (H₂O₂) level are significantly higher in preeclamptics than in control women. The aim of this study was to clarify the biological influence of reactive oxygen species (ROS) produced by XO on extravillous trophoblast (EVT) cells. TCL1 cells, a human immortalized EVT cell line, were incubated with xanthine and XO (X/XO). We then measured the cell number, urate level of the culture media and the apoptotic cell ratio. Similar experiments were performed with additional administration of allopurinol, catalase, L-NAME or D-NAME, and with administration of H₂O₂ in substitution for X/XO. We assessed the effects of H₂O₂ on invasion ability, tube-like formation and protein expression of HIF1A and ITGAV of TCL1. Finally, the apoptotic cell ratio using primary cultured trophoblasts was measured following exposure to H₂O₂. X/XO decreased the relative cell number and increased the urate level and apoptotic cell ratio significantly. Elevation of the urate level and apoptotic cell ratio was attenuated by allopurinol and catalase, respectively. L-NAME and D-NAME had no influence on these effects. H₂O₂ also decreased the relative cell number. Pretreatment with H₂O₂ significantly inhibited the invasion ability, tube-like formation and HIF1A and ITGAV of TCL1. H₂O₂ also induced apoptosis in primary cultured trophoblasts. In conclusion, ROS produced by XO induced apoptosis and affected EVT function including invasion and differentiation.     

Complex extrahepatic portocaval shunt with unusual caval features in a cat: computed tomographic characterisation

A two-year-old, neutered male domestic shorthair cat was evaluated for a history of urate calculi, and neurologic signs. Diagnostic imaging revealed an elongated and tortuous single extrahepatic portosystemic shunt which appeared to receive normal tributaries of the caudal vena cava. Surgical correction of the shunt was carried out using cellophane banding. Eight months following surgery, clinical signs had resolved. Computed tomographic angiography allows thorough, rapid imaging of complex vascular anomalies to aid proper surgical correction. Errors in the formation of the portal vein and caudal vena cava can produce complex anomalies of the abdominal vasculature. Persistence of the embryologic left subcardinal vein is proposed to account for the lesion.