Page 822 - Small Animal Clinical Nutrition 5th Edition

852 Small Animal Clinical Nutrition

VetBooks.ir Table 1. Results of selected urinalysis and serum biochemistry
parameters of a two-year-old male English bulldog with recurrent
urocystoliths.
Day
Factors Reference
values 1* 35 78 114
Urine specific gravity - 1.035 1.005 1.006 1.027
Urinary pH - 6 6 7.5 6
Hematuria - 0 0 + +
Pyuria - 0 0 0 +
Crystals - Urate 0 0 Urate
Urine culture - Neg Neg Neg Neg
SUN (mg/dl) 7-28 13 4 4 8
Creatinine (mg/dl) 0.5-1.5 1.1 0.7 0.7 0.9
Albumin (mg/dl) 2.4-3.8 3.3 3.0 3.1 3.5
Key: 0 = absent, + = present, Neg = negative, SUN = serum urea
nitrogen.
*Therapy consisting of a moist urate litholytic food and allopurinol was
initiated on Day 1 and discontinued on Day 78.
Figure 2. Survey abdominal radiograph of the same dog described
in Figure 1. The dog voided small ammonium urate uroliths during
micturition. Note that radiodense uroliths are not detectable in the
Assess the Food and Feeding Method bladder.
a
The dog was fed a commercial dry grocery brand food free
choice.
Questions
1. Based on the available information, what is the most likely
mineral composition of the uroliths in this patient?
2. Outline a treatment and feeding plan for this dog.
3. How should response to therapy be monitored?

Answers and Discussion
1. The mineral composition of the uroliths in this dog is most
likely ammonium urate based on the following: 1) multiple
radiolucent uroliths, 2) urinary pH = 6.0, 3) ammonium urate
crystalluria, 4) sterile urine, 5) a slight increase in serum uric
acid concentration and 6) English bulldog breed. Quantitative
mineral analysis of a voided urolith would be important to Figure 3. Double-contrast cystogram of the same dog described in
confirm this diagnostic assessment. Figure 1 demonstrating numerous ammonium urate urocystoliths.
2. Dissolution of ammonium urate uroliths can be induced using
a combination of a commercial veterinary therapeutic urate
c
litholytic food b and allopurinol. Secondary urinary tract
infections should also be eradicated or controlled with appro-
priate antimicrobial therapy.The urate litholytic food contains
low levels of dietary purines, which are the precursors of uric
acid, and results in production of less concentrated, alkaline
urine that enhances urate crystal solubility. Allopurinol is a
xanthine oxidase inhibitor that decreases production of uric
acid, and thus the quantity of uric acid in the urine.
3. Therapeutic efficacy should be monitored by physical exami-
nation and serial evaluation of radiographs, urinalyses and
quantitative urine cultures, if necessary. Dietary therapy and
allopurinol should be continued for one month following radi-
ographic disappearance of uroliths. Compliance with the feed-
ing plan is indicated by a reduction in the serum urea nitrogen Figure 4. Double-contrast cystogram of the same dog described in
concentration and formation of less concentrated, alkaline Figure 1 obtained 35 days after initiating therapy. There is no evi-
dence of urocystoliths.
urine.