Page 896 - Small Animal Clinical Nutrition 5th Edition

928 Small Animal Clinical Nutrition

Table 46-3. Mineral composition of feline uroliths submitted for Table 46-5. Mineral composition of feline urethral plugs
quantitative analysis to three centers.
VetBooks.ir Predominant Uroliths submitted submitted for quantitative analysis to two centers.
Predominant
Urethral plugs submitted
mineral type
during collection period (%)
Struvite 43.5 43 44 mineral type during collection period (%)
Struvite
81
83.8
Calcium oxalate 45.4 53 50 Calcium oxalate 0.94 6.6
Purine 5.0* 10** 3 Calcium phosphate 0.55 2.4
Compound 3.4 – – Urate 0.13* 1.1
Mixed 1.0 13*** – Cystine 0 0.16
Matrix 0.9 – – Silica 0 0.5
Calcium phosphate, Mixed 2.46 3.6
apatite and brushite 0.3 6 0.1 Matrix (no crystals) 11.11 4.5
Cystine 0.1 0.1 – Summary information for data sources
Silica 0.04 0.4 – Center location Minnesota Canadian
Dry solidified blood Included 1 – Urolith Center** Urolith Centre***
with matrix Plugs (n) 6,704 618
Summary information for data sources Collection period 1981-2008 1998-2003
Urolith center Minnesota Gerald V. Ling Canadian *Includes eight ammonium acid urate plugs and one xanthine
Urolith Urinary Stone Urolith plug.
Center † Laboratory †† Centre ††† **Adapted from Osborne CA, Lulich JP. Unpublished data.
Collection period 1981-2008 1985-2004 1998-2003 Minnesota Urolith Center. University of Minnesota, St Paul,
Uroliths (n) 102,191 5,230 4,866 2009.
*Includes uroliths that contained 70 to 100% urate, uric acid or ***Adapted from Houston DM, Moore AE, Favrin MG, et al.
xanthine. Feline urethral plugs and bladder uroliths: A review of 5,484
**Includes uroliths that contained any amount of urate. submissions 1998-2003. Canadian Veterinary Journal 2003;
***Includes mixed and compound uroliths. 44(12): 974-977.
† Adapted from Osborne CA, Lulich JP. Unpublished data.
Minnesota Urolith Center. University of Minnesota, St Paul,
2009.
†† Adapted from Cannon AB, Westropp JL, Ruby AL, et al.
Evaluation of trends in urolith composition in cats: 5,230 cases lation affected the relative frequency of different urolith types
(1985-2004). Journal of the American Veterinary Medical (e.g., has this contributed to increased diagnosis of calcium
Association 2007; 237: 570-576. oxalate uroliths)? 3) Does the occurrence of calcium oxalate
††† Adapted from Houston DM, Moore AE, Favrin MG, et al.
Feline urethral plugs and bladder uroliths: A review of 5,484 uroliths appear greater because fewer struvite uroliths are sub-
submissions 1998-2003. Canadian Veterinary Journal 2003; mitted for analysis due to the availability of struvite dissolution
44(12): 974-977. protocols? 4) What role has nutritional management played in
managing or causing uroliths? 5) Are there common factors
that explain increased occurrence of calcium oxalate uroliths in
cats, dogs and people? 6) During the time that calcium oxalate
Table 46-4. Mineral composition of 11,416 feline uroliths ana-
lyzed quantitatively at the Minnesota Urolith Center in 2008.* uroliths were more common in cats from North America, why
were struvite uroliths more common elsewhere (e.g., Australia,
Mineral type Percent Japan)? and 7) Why have most urethral plugs been composed
Struvite 49
Calcium oxalate 39 of struvite for more than 25 years whereas other mineral types
Urate/uric acid 4.9 of uroliths have changed?
Compound/matrix/mixed 4.29/0.7/1.0
Calcium phosphate 0.2
Cystine 0.04 PATIENT ASSESSMENT
Xanthine <0.01
*Adapted from Osborne CA, Lulich JP. Unpublished data. Each cat presenting with lower urinary tract signs should be
Minnesota Urolith Center. University of Minnesota, St Paul, 2009.
thoroughly evaluated to identify the underlying cause(s). To
guide initial assessment and need for emergency treatment
(e.g., urethral obstruction), it is helpful to categorize patients
ly report urolith data annually. In addition, some urolith types into one of four clinical presentations, realizing that some cats
are more likely to be submitted for evaluation than others. For may have features of several presentations (Table 46-6) (Lulich,
example,struvite uroliths can be dissolved with nutritional man- 2007). A thorough history, physical examination and diagnos-
agement; however, calcium oxalate uroliths are more likely to be tic evaluation including urinalysis and some form of diagnostic
removed and submitted for quantitative analysis. This could imaging (i.e., abdominal radiography and/or ultrasound) are
result in an underestimation of the occurrence of struvite indicated for every patient. Individualized treatment recom-
uroliths and overestimation for calcium oxalate uroliths. mendations can be made based on these findings.
Regarding trends in occurrence of feline uroliths, several rel-
evant questions remain unanswered: 1) What is the incidence History
(i.e., rate of occurrence among all cats, not only those present- The nutritional history should include information about spe-
ed for veterinary evaluation) of uroliths and has it changed over cific brand(s) of food fed, form (dry, moist, semi-moist or a
the past decades? 2) How has the apparent aging feline popu- combination), method of feeding (meal fed, free choice) and