Number 3 - November 15, .2010

Farmina Vet Research Journal

Nutritional management of
struvite urolithiasis in dogs.

www.FarminaChannel.com

Study carried out in agreement with Departiment of Animal
Science and Food controll of the University of
Naples “Federico II”.

Study carried out in agreement with Departiment of Animal
Science and Food controll of the University of
Naples “Federico II”.

Urolithiasis

Farmina Vet Research

2

3
Farmina Vet Research Group (FVR), with its scientifically demonstrated dietary nutrients (Vet Life Formula), aims to
support the Veterinarian with the management of some pathologies commonly occurring in pets.
It also intends to provide valid solutions to dietary problems and scientific consultancy through the cooperation of theAnimal Science and Food Control Departiment of the Faculty of Veterinary Medicine of University of Napoli Federico II.
Farmina Vet Research is capable of maintaining a scientific dialogue with the Veterinary world, delving into clinicaland dietary issues.
Farmina Vet Research is part of the scientific division of the Farmina firm supported by the competence and the hard

The formation of stones along the urinary tract

The first paper documents that testified to the finding

the most frequent afflictions of the urinary tract inwhich were sacrificed, date back to Herodotus and(urolithiasis) is universally acknowledged as one ofmen and animals. The oldest finding of human stones
was discovered in an Egyptian tomb dating back to5000 B, whereas the first findings of animal urinarystones are even older: the skeleton of a marine reptile,of concretions in the kidneys and bladder of animals,
Aristotle (Anke and Anning, 1973). There are no

definite data concerning the nature of these stones.
Nevertheless, it was supposed that they could beconstituted by calcium carbonate and/or struvite.

Table 1 – Composition of the concretions in different animal species (modified by Anke and Anning, 1973).

work of several professionals focusing on delivering effective consultancy services.
Farmina Vet Research integrates its production by studying technological innovations and by improving new products
through manufacturing processes aimed at keeping up with future challenges. The high quality of its products
contributes to the wellbeing and health of our pets.

SpeciesComposition

Sturgeon, Carp

GuanineFrog

Struvite, calcium phosphate

Turtles, Lizards, Snakes

Urate

Monogastric herbivores

Calcium carbonate

Dogs

Struvite, apatite, calcium oxalate, urate, cystine, xanthine, silicate

Flamingos, Cranes, Pigeons
Sheep, Cows
Pigs

Cats

Uric acid, urate
Struvite, silica

Calcium phosphate, calcium carbonate

Struvite, apatite, calcium oxalate, urate, cystine

The various animal species have a greater tendency

which lived approximately 80 million years ago,containing a calcium carbonate (calcite) and calcium
phosphate (apatite) stone, and that of a bear that

lived in the Pleistocene and found in a pit; the stone
was made from calcium carbonate in this case too

towards specific types of stones, as stated in Table
1, e.g. monogastric herbivores (horses, donkeys

and rabbits) mostly have carbonate calcium urate(Neumann et al. 1994).

(Hesse et al., 1998).

Scientific Magazine by Farmina Vet Research

Publication n. 3 - november 2010

Publication n. 3 - november 2010

Scientific Magazine by Farmina Vet ResearchStudy carried out in agreement with Departiment of Animal
Science and Food controll of the University of
Naples “Federico II”.

The urinary stones in vertebrates, particularly

the stones requires analysis with a polarizing light

sedimentation of the calcium phosphate, therefore

significant correlation was found between the purine

certain magnitude. In domestic carnivores urolithiasis

analysis method (Osborne et al., 1990).

of the urine, stimulating the thirst to prevent thepurine on one hand and the urinary excretion of thesedomestic ones, represent an economic problem of a4

Study carried out in agreement with Departiment of Animal
Science and Food controll of the University of
Naples “Federico II”.

is a recurrent and rather common problem (Bartges,

or diffraction microscope or any other quantitative

1998).

The surgical removal of the stones is the mostfrequent treatment used, whereas in some cases

Calcium carbonate stonesof recurrences. The long-term efficiency of an

herbivorous mammals. In rabbits it is known thatstones to be dissolved and is useful in the prevention

These stones are the most frequently found in

urolithiasis treatment depends on the identification

an excessive administration of calcium does not

etiopathogenesis of every type of urolithiasis inorder to handle the specific factors that arise, whichmeans that the minerals present in the stone must

be analysed correctly. In some cases the number andshape of the stone leave no doubts on the composition
without requiring specific analysis (Osborne et al.
1989). Nevertheless, it is extremely important toestablish the composition of the concretions as thepathogenesis and, consequently, the therapy andprevention of recurrences are extremely different
according to the type of urate. The microscopic
evaluation of the urinary sediment is only anindicator of suspicion of the composition of any typeof stone as its formation, development and dissolution
are associated with a complicated set of variables.
The definitive identification of the composition of

reduce the intestinal absorption of this element, but
it may act towards increasing the urinary excretion(Kamphues 1991). Moreover, many edible plants

contain significant quantities of oxalate, which may
give rise to inclusions of calcium oxalate.

Nevertheless, more so than the level of calcium, theparameter that seems to have a greater effect on

the urinary excretion of calcium appears to be thecalcium/phosphate ratio. Calcium oxalate stones are

not particularly frequent in dogs (Hesse et al., 1998),
even though this element is a minor amorphous

component in many stones. Even if the pH is reduced
to levels less than 8.0, the crystallization of thecalcium phosphate in case of excessive concentrationof calcium is always possible; only the reductionof the pH to levels less than 6.4 may prevent the

Scientific Magazine by Farmina Vet Research 

Publication n. 3 - november 2010

bases ingestion and the plasma concentration ofelements in 24 hours on the other hand. The high rate

formation of stones.

of urinary excretion of uric acid may not be enoughto explain the formation of stones. This is associatedUrate stones

Pathogenesis

dietetic and/or pharmacological treatment allow theof the type of stone and knowledge of the specific

it is indispensable to guarantee a sufficient dilution

As well as lizards, snakes and birds, Dalmatian dogs

are particularly predisposed to the formation of urate
and ammonium urate concretions especially. Other

dog breeds (Pekingese, Fox Terrier, Chow Chow and

Pinscher) also produce concretions of urate, albeit inthese cases the etiopathogenesis is different.

Different hepatic enzymes, like xanthine-oxidase anduricase, break down the endogenous and nutritional
purines in to xanthine, uric acid and allantoin. The
latter is excreted through the kidneys. Case et al.

(1993). The human species does not present uricase,so the purinic derivative that is excreted through theurinary tract is uric acid. In Dalmatians the plasma
concentration of uric acid is triple what is found inother dog breeds and the excretion of uric acid is ten

with a greater secretion in terms of the ammonium
ion tubes.

Limiting the levels of the purines administeredbecomes an indispensable condition for prevention.

The addition of potassium citrate enables the urinary
pH to be reduced to at least 7.0. Nevertheless,it may also be considered that these urinary pH
levels encourage the formation of phosphatecrystals. Consequently also in this instance themost reasonable thing is to stimulate diuresis.

Using allopurinol to suppress the xanthine oxidase,
the production of uric acid may be reduced. An

appropriate preventive compromise lies in correcting
the diet and administering pharmacologicaltreatment.

times higher. Nevertheless, there’s no difference as

Cystine uroliths

the high plasma concentration of uric acid, which

Cystinuria is a congenital metabolic disordermainly be ascribed to the lack of uric acid conveyed

renal tubes of cystine and other animo acids. In

regards the activity of hepatic uricase, meaning that
may only be limited through renal excretion, should
to the liver (Giesecke et al. 1985). In Dalmatians, aPublication n. 3 - november 2010

distinguished by an abnormal reabsorption in thehumans, other amino acids are also found in thisScientific Magazine by Farmina Vet Research

5Study carried out in agreement with Departiment of Animal
Science and Food controll of the University of
Naples “Federico II”.

uroliths, such as lysine, arginine and ornithine. In
dogs, very different frameworks of amino acidic

excretion have been discovered; in addition to the6

Study carried out in agreement with Departiment of Animal
Science and Food controll of the University of
Naples “Federico II”.

numerous other factors such as bacterial infections of

the low urinary tracts, alkaline urinary pH, unsuitable

aforesaid amino acids, concretions of citrulline(1.3 mmol/l) the formation of crystals is practicallyguaranteed.

Struvite stones
Struvite (MgNH4PO4 6H2O) is regarded as thecommon form of stones in dogs, cats and humans(Hesse et al., 1998; Deng & Ouyang, 2006; Pintilie etal. 2010), even if in recent years some studies havehighlighted a decline in the incidence (Osborne et al.,
1999; Picavet et al., 2007). These concretions havealso been found in sheep and cows.

The over-saturation of urine by the ammonium

magnesium phosphate ions is one of the fundamental
requisite for the formation of struvite uroliths,

although their formation may be influenced byof uroliths is extremely different, what enables therecognition in the urinary sediment. Experimental

compared with other forms of urolithiasis.
diets and genetic predisposition.

The formation of struvite stones was often associatedwith bacterial infections of the urinary tract(Buffington et al., 1998). In particular the involved
bacteria are capable of breaking down the urea

into ammonia and carbon dioxide, such as somestrains of Proteus, Staphylococcus and Klebsiella. A

slight increase in the concentration of ammonium
and bicarbonate ions is seen in a marked urine

To dissolve struvite concretions caused by bacterial
infection it is necessary to treat the infection, dilutethe urine, reduce the protein levels of magnesium andphosphates in the diet, increase sodium chloride forthirst and induce polyuria and, lastly, acidify the urine
with ammonium chloride or methionine to levels lessthan 6.2.

Calcium oxalate stones

calcium and phosphate. If there is excessive bacterial

they are much less frequent in animals (from 3.6%

the entire renal pelvis. The bacterial inflammation
may lead to the formation of a mucoid matrix that

gradually incorporates the precipitated crystals so
as to form voluminous aggregates. In this case thestones contain the bacteria that during treatment

Scientific Magazine by Farmina Vet Research 

Publication n. 3 - november 2010

considerable increase of the incidence of such stones
has been seen in recent years in cats and dogs.

Isolated cases have been documented in hamsters,
rabbits, deer and sheep.

Two different types of calcium oxalate concretions

Publication n. 3 - november 2010

in the main with high concentrations of calcium

and magnesium, whereas dihydrate calcium oxalatestones come from the stabilization of oxalate andurate (Hesse et al., 1976; Berg et al., 1976). They are

the most frequent stones in small-sized breed. 90% ofstones were found in male subjects, mostly above thediet carnivores may cause an excessive ingestion offound in humans (75% of the total of cases), whereas
to 17.5% of such Hesse et al., 1998), although aconcretions are somewhat unstable, tending to form

The use of large quantities of plant foods in the

Calcium oxalate stones are those most frequently

flora, struvite crystals may rapidly form so as to blockstudies have shown that monohydrate calcium oxalate

age of 6 years (Hesse et al., 1998).

alkalinization. A pH urinary higher than 7.0 andthe high concentration of ammonium, magnesium,

2H2O), which represent 56.8 and 43.2% of the total of
et al. (1998). The morphology of these two types

predisposed to the formation of these stones

citrulline in the remaining 72%. Even if the only

monohydrate calcium oxalate (CaC2O4 H2O) and thecalcium oxalate urolith respectively, stated by Hesse

and Bernese Mountain seem to be particularly

the cases, whereas they found lysine, arginine andwhereas when the concentration exceeds 340 mg/lother consisting of dihydrate calcium oxalate (CaC2O4

Pekingese, German Shepherd, Shih Tzu, Bobtailof cystine, amounting to approximately 28% ofconcentrations greater than 200 mg/l (0.65 mml/l),

completely (Sanders et al., 1986; Kienzle et al., 1993).

it is fundamental that the concretions are removed

involve struvite . Some breeds like Cocker Spaniel,

recorded an incidence of stones exclusively consisting

is cysteine, which may crystallise when present inhave been acknowledged: one characterized by

On average, 58% of cases of urolithiasis in dogs

and threonine have been found. Hesse et al. (1998)

amino acid that is only partially soluble in urine

may suddenly become active again. This explains why

oxalates with consequent hyperoxaluria. In humans,
the patients affected by calcium oxalate stones

show a greater intestinal absorption of oxalate thenhealthy subject. This may be due to gut inflammatory
phenomena, low calcium and magnesium intakes

hyperlipidic diets or enterectomy. In dogs, the urinary
excretion of oxalates is 3 to 4 times higher than in
humans, whether in healthy subjects or in thoseaffected by urolithiasis, thus why crystals may form

Scientific Magazine by Farmina Vet Research

7

Study carried out in agreement with Departiment of Animal
Science and Food controll of the University of
Naples “Federico II”.

Study carried out in agreement with Departiment of Animal
Science and Food controll of the University of
Naples “Federico II”.

very easily if the predisposed subject.

8higher than in healthy one, with low concentrations of
citrate and high concentrations of magnesium.

•changes and the type of nutrition. There is, however,an evident need to regularly monitor the urine in thepredisposed subjects.

Urolithiasis may be defined as a multifactorialstone’s primary nucleus;

dilution; the specific weight of the urine should be

and 46% of calcium oxalate.

the crystalization theory, on the other hand, isbased on the assumption that the first step insaturation of the urine with the formation of an

growing incidence of calcium oxalate stones in catsa larger number of predisposed species, or lifestyleuroliths consisted of struvite and 33% of calcium

the urolith formation is represented by the over-At present it is not possible to evaluate whether theand dogs is due to changes in the population, such as

saturation, therefore the prevention of any typepolysaccharides, which could represent the

The subjects that form stones show calcium

concentrations in the urine, which are significantlyof an organic substance, mostly protein and•inorganic matrix;

3. the crystalization suppression theory,

according to which there is a partial or total lackof the factors suppressing the crystalization at thebasis of the formation of the stones (Osborne etal., 1986).

disorder in which predisposing and conditioning

As is often the case, all of the theories mentioned

formation of concretions.

organic matrix consisting of protein, glycoprotein andfactors are recognised that may influence theDiverse predisposing factors have been recognisedin the formation of stones, such as disturbances of

the urodynamics due to pathological and anatomicalchanges, metabolic disorders, genetic factors, andenvironmental and nutritional factors.

Over the years various theories have been formulated
concerning the origin of the formation of uroliths:•

the so-called matrix theory, which is based on
the assumption that the stone is formed fromthe formation of a primary precipitate consisting

contain some truth. In fact in different stones an

glycosaminoglycans can be made out with litogenic
and inhibitory effects. Likewise, the importanceof substances capable of inhibiting or increase theprecipitation of crystals cannot be negated. These

substances are capable of influencing the intestinal
absorption and the renal excretion of the elementsthat may go towards forming the stone.

Pathogenetic factors that contribute towards

the formation of different types of stones can besummarized as follows. The formation of crystals

in the urine may only occur in conditions of over-

Scientific Magazine by Farmina Vet Research 

Publication n. 3 - november 2010

oxalate; whereas in 2003 40% consisted of struviteof uroliths requires an adequate level of urinary

below 1.010 (Borghi et al., 1996; Hesse et al 1997a,b).
The urinary pH is equally fundamental; e.g. calcium

carbonate stones only develop in subjects affected byhypercalciuria, if the urinary pH is between 7.5 and9.5.

Epidemiology of the urolithiasis in dogs
The results of some epidemiological studies publishedin the last decade are extremely interesting (Hesse etal., 1998; Osborne et al., 1999; Picavet et al., 2007). In
particular Picavet et al. (2007) whilst analyzing over

4,000 uroliths taken from dogs (65%) and cats (35%)
between 1994 and 2004 saw a significant increaseof the cases; whereas in 1994 the authors analyzed
110 stones, of which 85% came from dogs, in 2003

they recorded 1,067 stones with 59% from dogs. The

The authors also saw that there was a significant
effect due to species, size, breed and gender. The

average age of the subjects affected by urolithiasis
was 7.3 years and 7.2 years in dogs and cats

respectively. The authors concluded that the results
obtained from samples coming from the Benelux

countries were similar to those obtained by Osborne

et al. (1999a) with stones taken in North America andthat over the last decade in Benelux, as in the USA,the relative incidence of calcium carbonate stones

has increased compared with struvite uroliths in bothcats and dogs. The number of stones subjected toqualitative analysis also increased significantly in thesame period, in confirmation of the greater awarenessof veterinarians for a correct investigation about thetype of stones removed from pets.

authors also found substantial changes in relation to
the types of concretions in the period examined, inparticular whereas in 1994 77% of cats were affectedby stones consisting of struvite and 12% had stones

made of calcium oxalate, in 2003 32% of the uroliths

from felines consisted of struvite and 61% of calcium
oxalate. The same trend, albeit with less evident

differences, was observed in dogs. In 1994 51% of

Publication n. 3 - november 2010

Scientific Magazine by Farmina Vet Research

9Study carried out in agreement with Departiment of Animal
Science and Food controll of the University of
Naples “Federico II”.

Study carried out in agreement with Departiment of Animal
Science and Food controll of the University of
Naples “Federico II”.

Experimental partUse of two diets for the managementof struvite urolithiasis in dogs

the subject throughout the period using abdominal
ultrasound or radiography and urine analysis.

The symptoms usually subside quickly, whereas fors

10

In dogs, the majority of struvite stones are

acidifying substances. The use of therapies for thisthe Staphylococcus and Proteus strains, capableproductive.

associated with bacterial infections sustained byof producing urease by increasing the levels ofammonium, phosphates and carbonates in the urine
and, consequently, raising the pH.

Many struvite concretions also contain small

quantities of other minerals like calcium phosphate

and ammonium urate. Finding sterile struvite stones

in dogs is rather rare. In these cases the causes of theuraths formation are due to a genetic predisposition,
incorrect nutrition or metabolic disorders (Osborne
et al, 1995).

Struvite stones caused by bacterial infection requirea treatment based on the association of appropriate
antimicrobial agents and diet capable of dissolving
the stones. In the case of sterile stones, a dietary
therapy is enough, associated (if needed) withthe administration of urine acidifying substances(Osborne et al, 1999b; Rinkardt & Houston, 2004).

Nevertheless, the majority of commercial diets for thetreatment of struvite urolithiasis is integrated withpurpose is therefore useless, if not actually counter-the complete dissolution approximately 3 months

may be needed. This period may be brief (5-6 weeks)in cases of sterile stones (Osborne et al, 1999b)

The aim of the work was to compare the effects on thevital bacterial capable of causing recurrences cannot

feeds formulated for the treatment of struvite

linger in the concretions (Seaman & Bartges, 2001).
The diets formulated to dissolve the struvite calculi
must contain limited levels of protein (15-20% in adiet of 4000 kcal/kg) so as to limit the quantity of

urea available for any urease reducer bacteria. Diets

with low concentrations of fibre are also preferred tolimit the intestinal reabsorption of water and, at thesame time, to maintain a high level of digestibility.

In terms of the mineral component, these diets must
contain reduced concentrations of phosphorus andmagnesium and are integrated with sodium chloride
to stimulate thirst (Lulich et al., 2000).

The nutritional treatment must last for at least amonth after stones dissolution in order to guarantee

the complete excretion of all fragments, including thenot-detectable. It is advisable to regularly monitor

Scientific Magazine by Farmina Vet Research 

Publication n. 3 - november 2010and microbiological analysis, whereas blood was only
taken at the beginning and end of the experiment.

The two diets were analised for chemical composition
according to AOAC (2006), as well as determining

the mineral profile (de Ruig W.G., 1986) by atomic
absorption spectrography.

Once defined, the antibiotic treatment must continue

until the stones cannot be seen by x-ray to ensure thatdays) in order to determine the physical, chemical

urinary pH of two different completely dry compound

The acid/bases equilibrium was therefore calculatedusing the equation put forward by Langendorf, H.

(1963): mEq/kg ss = 49.9Ca+82.3Mg+43.5Na+25.6K64.6P-62.4S-28.2Cl.

urolithiasis.

The results relating to the parameters of the urine

analysis were subjected to variance analysis by PROC.

Material and methods

GLM of the statistical program SAS (2000).

Twelve dogs were recruited for the study (averageage 4.3 ± 1.2; live weight 20.2 ± 10 kg) of different

breeds affected by struvite urolithiasis, confirmed by
microscopic analysis of the urinary sediment.

The subjects were divided into two groups, whichwere fed with diet A and B, respectively for threemonths. The owners of the dogs were asked not toprovide other foods and to stimulate the voluntarywater intake and increase the number of outdoor
walks to stimulate greater passing of urine.

Throughout the experiment, urine samples weretaken from the dogs six times at regular intervals (15Publication n. 3 - november 2010

Scientific Magazine by Farmina Vet Research

11Study carried out in agreement with Departiment of Animal
Science and Food controll of the University of
Naples “Federico II”.

Study carried out in agreement with Departiment of Animal
Science and Food controll of the University of
Naples “Federico II”.

Results

Table 4 -Mineral contents of the diets
Age

A

12
In Table2 the ingredients of the two diets are stated. In

The main mineral contents of the two diets are shown inchloride to stimulate thirst (Stevenson et al, 2003b).

registered higher values of calcium, sodium, phosphorus

both products you can make out the addition of sodium
Table 2 – Ingredients of the diets

Table 4, as well as the relative acid/bases balances. Diet A

Ca

7,88

B

6,20

Mg

1,12

1,40

Na

K
g/kg ss

3,67

7,50

3,35

7,93

excretion of nitrogen catabolics.

with diets formulated to dissolve struvite stones thathydrolized form is used in both cases to limit the urinary
In Table 3 the average values of the chemical compositionof the two feeds used are stated. Both diets have protein
and fibre contents in the ranges shown by Lulich et al.

(2000). Although diet A had more protein, lipid and raw
cellulose contents than diet 2, the energy density valuesof the both diets were virtually the same.

Table 3 – Chemical composition of the diets
Diet

Raw proteins

Ether extract

acid/bases equilibrium, which is plausible when dealing
requires a reduction of the urinary pH, nevertheless due

to higher concentrations of phosphorus and sulphur anda lower magnesium content, diet A showed a ratio of over
10 mEq/kg ss lower than diet B.

Ash%Metabolizableenergy- 192

by (Stevenson e Rutgers, 2006) as suitable for stones

stated by other authors (Osborne et al, 2009; Rinkardt
and Houston, 2004).

The average urinary pH values registered at the end of

the experiment by both groups (5.6 ± 0.5 and 5.9 ± 0.4,
fro group A and B, respectively) are indicative of the*: P < 0,05

consequently deemed advisable to also combine with thenutritional treatment a pharmacological treatment withfluoroquinolone in tablets for one week.

As from the second urine analysis, all the dogs showed aneed to block the administration of both diets beyond

the three months, so as to avoid creating an environmentthat supports the formation of other types of stones(urate and/or cystine) (Stevenson e Rutgers, 2006) orrepercussions on other systems.

sample showed bacterial contamination. As shown in the
Figure, after two months of treatment, all the subjects

MJ/kg

A

21,7

19,6

2,7

4,3

16,6

B

19,5

19,0

1,5

4,4

16,5

Scientific Magazine by Farmina Vet Research - 203

progressive reduction of the pH level in the urine and noUpon the first sampling the urinary pH was rather
Raw cellulose

7,51

mEq/kg ss

dissolution. The results obtained were in line with those

Rice, dried chicken meat, animal fats, potatoes, oats, whole powdered eggs, linseeds, hydrolysed animal
protein, fish oil, potassium chloride, calcium sulphate, vegetable oil, sodium chloride.

and sulphur than diet B. Both diets registered a negative

5,43

7,50

acid/bases

samples also had bacterial contamination. It was

A and B, respectively); approximately 70% of the
Average pH values registered during the experimentMoreover, it is evident that high-organic protein or in

8,63

5,76

Cl

showed pH values in the range of 5.9 and 6.1 stated

Ground corn, dried chicken and turkey protein, animal fats, hydrolysates, ground soya beans, vegetableoil, whole powdered eggs, linseeds, calcium sulphate, potassium chloride, salt, taurine, trace elements andvitamins, EU-approved antioxidants.

B

9,61

S

high in both groups (8.0 ± 0.5 and 8.0 ± 0.8 for groups

Diet
A

P

Publication n. 3 - november 2010

Data subject published to the Waltham International Nutrition Science Symposium Pet Nutrition – Art orScience? Cambridge, UK September 16-18, 2010 Calabrò S., Tudisco R., Bianchi S., Grossi M, De Bonis A.,
Cutrignelli M.I. Management of strivite uroliti in dogs.

Publication n. 3 - november 2010

Scientific Magazine by Farmina Vet Research

13

Study carried out in agreement with Departiment of Animal
Science and Food controll of the University of
Naples “Federico II”.

Study carried out in agreement with Departiment of Animal
Science and Food controll of the University of
Naples “Federico II”.

Bibliography

Ettinger SJ, Feldman EC (eds). Textbook of Veterinary
Internal Medicine - Diseases of the Dog and Cat. 5thedition. WB Saunders Co, Philadelphia: 1747-1781

14

Anke, M.; Henning A. (1973): Harnsteine bei Tiercn.
In: Henzsh. E.; Schneider HJ. (cds), Der Harnstein,
Gustav Fischer, Jena, Germany, 53-65.

AOAC, 2006: Official Methods of Analysis. Associationof Official Analytical Chemists, Arlington, VA, USA
Bartges, J. W., 1998: Emerging from the stone age:feline urolithiasis–past, present, future. In: J. Wills
and B. Stanley (eds.), Waltham Focus, Focus on the
Urinary Tract, Waltham Centre for Pet Nutrition,
Leicestershire, UK, pp. 5–8.

Borghi L, Meschi T., Amato F., Briganti A., Novarini
A, Giannini A. (1996) Urinary volume, water andrecurrences in idiopathic calcium ncphrolithiasis: a5-year randomized prospective study. J. Urol. 155,
839-843.

Buffington D., Chew D. (1998) Effects of diet on nonobstructive lower urinary tract diseases in cats. J.
Anim. Physiol. a. Anim. Nutr. 80, 120-127.
Case CL.; Ling GU.; Rubya L.; Johnson DL.; Frantic
E.; Stevens F. (1993) Urolithiasis in Dalmatians. 275
cases (1981-90). J.A.V.M. A 203,96-100.

de Ruig W.G. (1986) Atomic Absorption Spectrometricdetermination of calcium, copper, iron, magnesium,
manganese, potassium, sodium and zinc in animal
feeding stuffs: interlaboratory collaborative studies
Deng F. and Ouyang J.-M. (2006) Comparative
investigations of ultrafine crystals in urine of healthy
human and lithogenic patients Mater. Sci. Eng.C, vol.
26: 688–691
Giesecke D.; Kraft W.; Tiemeyer W. (1985): Warum
Dalmatiner Harnsaure ausschcidcn. Tierarztl. Praxis
13, 331-341.

Hesse A., Berg W., Schneider HJ., Hienzsch E. (1976)
A contribution to the formation of calcium oxalate
urinary calculi. 11. In vitro experiments concerning
the theory of the formation of whewellitc andweddellite urinary calculi. Urol. Res. 4, 157-160.

Hesse A., Graf C., Bongartz D., Albrect F. (1997a)
Current composition and breed distribution ofcanine urinary stones. Bed. Munch. Tierartzl. Wschr.
110,436-439.

Hesse A., Sanders G. (1988) Atlas of Infrared Spectra
for the Analysis of Urinary Concrements. Georg
Thieme, Stuttgart, New York.

Hesse A., Steffes HJ., Graf C. (1998) Pathogenic factorsof rinary stone formation in animals. J. Anim. Physiol.
a. Anim. Nutr. 80: 108-1 19
Hesse A., Tiseluis HG, Jahnen A. (1997b) Urinarystones, Diagnosis, Treatment, and Prevention of
Recurrence. Karger, Basel, pp. 131-147.

Kamphues JS., 1991: Calcium metabolism of rabbits as
an etiological factor for urolithiasis. J. Nutr. 121: 595596.
Kienzle E., Meyer-Lindenberg A., Schuknecht A., Noi
TE (1993) Investigations on dietary treatment of
struvite urolithiasis: 3. Effect of an acidifying diet on
acid-base- and mineral-balance of cats after acuteurethral obstruction. Deutsch. Tierarztl. Wschr. 100:
473-476.
Langendorf H. (1963) SÃure-Basen-Gleichgewicht
undchronische acidogene und alkalogeneErnÃ¤hrung./. Ã‘utÃS.ci., Suppl. 2.

Lulich JP, Osborne CA, Bartges JW, Lekcharoensuk
C. (2000) Canine lower urinary tract disorders. In:

Scientific Magazine by Farmina Vet Research 

Publication n. 3 - november 2010

Osborn CA, Poffenbarger EM, Clinton CW., Klauser
JS, Lulich J., Polzin D., Johanston SD (1986) Canine
calcium oxalate urolithiasis. Proc. ACVIM Annu. Mcd.
Forum 1: 423-427.

Osborne CA, Lulich JP, Bartges JW Unger LK, Bartges
JW, Felice LJ, Thumchai R, Koehler LA, Bird KA.
(1995) Canine and feline urolithiasis: Relationshipof etiopathogenesis to treatment and prevention.
In: Osborne CA, Finco DR (eds). Canine and feline
nephrology and urology. Lea & Febiger, Philadelphia:
798-888.
Osborne CA, Lulich JP, Polzin DJ, Allen TA, Kruger JM,
Bartges JW, Koehler LA, Ulrich LK, Bird KA, Swanson
LL. (1999b) Medical dissolution and prevention ofcanine struvite urolithiasis. Vet Clin North Am Small
Anim Pract 29: 17-38.

Osborne CA, Sanna JJ, Unger LK, Clinton CW and
Davenport MP (1989) Analyzing the mineralcomposition of uroliths from dogs, cats, horses, cattle,
sheep, goats and pigs, VetMed 84: 750–764
Osborne CA. Lulich JP., Swanson LL., Albasan H. Druginduced urolithiasis. Veterinary Clinics of North
America: Small Animal Practice, 39,I: 55-63
Osborne, C. A.; Davis, L. S.; Sanna, J.; Unger, L. K.;
O’Brien, T. D.; Clinton, C. W.; Davenport, M. P. (1990)
Identification and interpretation of crystallury indomestic animals: A light and scanning electron
microscopic study. Veterinary Medicine 85: 18–37.

Pintilie (Popescu) GS, Varga I., Ionescu I. and Preda(2010) Urinary calculi as consequence of renal
infection and relationship between their incidence
and different dietary factors. Proceedings of the
Nutrition Society 69: (OCE3), E269

Rinkardt NE, Houston DM (2004) Dissolution of
infection-induced struvite bladder stones using a noncalculolytic diet and antibiotic therapy. Can Vet J; 45:
838-840.
Rinkardt NE, Houston DM (2004) Dissolution of
infection-induced struvite bladder stones using a noncalculolytic diet and antibiotic therapy. Can Vet J; 45:
838-840.
SAS, 2000: User’s Guide Statistics. Version 8.2. SAS
Institute, Inc. Cary, NC, USA.

Seaman R, Bartges JW (2001) Struvite urolithiasis.
Comp Cont Edu; 23: 407-426.

Stevenson A., Rutgers C. (2006) Nutritional
managment of canine urolithiasis In Encyclopedia of
Canine Clinical Nutrition ED. Aniwa SAS: 285-315

Stevenson AE, Hynds WK, Markwell PJ (2003)
Effect of dietary moisture and sodium content onurine composition and calcium oxalate relative
supersaturation in healthy Miniature Schnauzers andLabrador Retrievers. Res Vet Sci 74: 145-151.

Osborne, C. A.; Lulich, J. P.; Polzin, D. J.; Sanderson, S.
L.; Koehler, L. A.; Ulrich, L. K.; Bird, K. A.; Swanson, L.
L.; Pederson, L. A.; Sudo, S. Z. (1999a) Analysis of 77
000 canine uroliths. Perspectives from the Minnesota
Urolith Center. Veterinary Clinics of North America.
Small Animal Practice 29, 17–35.

Picavet P., Detilleux J., Verschuren S., Sparkes A., LulichJ., Osborne C., Istasse L. and Diez M. (2007) Analysisof 4495 canine and feline uroliths in the Benelux. A
retrospective study: 1994–2004. Journal of Animal
Physiology and Animal Nutrition 91 247–251

Publication n. 3 - november 2010

designed by UPcomAgency
art: G. De Sarno

Scientific Magazine by Farmina Vet Research

15

designed by UPcomADV > info@upcomagency.com

Farmina Pet Foods Ltd
Ingatestone - England

I Tel. +39 0818236723
			 +39 0818236000
www.farminachannel.com
www.farmina.com
info@farmina.com