Table 2.
Time to development of post-treatment renal azotemia, and selected pre- and post-treatment clinical data in 19 cats (group 2, cats 20–39) that developed renal azotemia following treatment of hyperthyroidism
| Time to azotemia (months) | TT4 (nmol/l) | Creat (μmol/l) | SUN (mmol/l) | Phos (mmol/l) | USG | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Pre | Post | Pre | Post | Pre | Post | Pre | Post | Pre | Post | ||
| 20 | 0.5 | 117.0 | 26.7 | 106.1 | 185.6 | 8.0 | 16.6 | 1.2 | 1.0 | 1.052 | 1.040 † |
| 21 | 5 | 74.1 | 96.9 * | 123.8 | 168.0 | 10.7 | 13.3 | 1.2 | 1.6 | 1.025 | 1.018 |
| 22 | 2 | 52 | 21 | 123.8 | 194.5 | 10.7 | 16.4 | 1.2 | 1.4 | 1.045 | 1.020 |
| 23 | 5 | 73.3 | 21.5 | 97.2 | 168.0 | 11.1 | 11.6 | 1.2 | 1.3 | 1.042 | |
| 24 | 3.5 | 64.9 | 28.3 | 122.0 | 212.2 | 9.4 | 10.5 | 1.5 | 1.1 | 1.045 | 1.025 |
| 25 | 1 | 192.0 | ND ‡ | 114.9 | 168.0 | 12.9 | 12.2 | 1.0 | 1.2 | 1.035 | |
| 26 | 3 | 74.2 | 25.8 | 150.3 | 185.6 | 10.6 | 15.0 | 1.6 | 1.2 | 1.042 | 1.031 † |
| 27 | 4 | 112.0 | 18.1 | 88.4 | 265.2 | 9.1 | 14.1 | 1.6 | 1.7 | 1.054 | 1.015 |
| 28 | 3 | 162.0 | 145 ‡ | 97.2 | 327.1 | 6.7 | 36.4 | 1.6 | 3.3 | 1.038 | 1.010 |
| 29 | 1 | 70.9 | ND * | 106.1 | 176.8 | 10.2 | 15.3 | 2.3 | 3.9 | 1.015 | |
| 30 | 2 | 107.0 | 12.8 | 61.9 | 185.6 | 10.5 | 16.5 | 1.3 | 1.6 | 1.016 | 1.014 |
| 31 | 3 | 49.0 | 25.7 | 88.4 | 221.0 | 12.1 | 31.3 | 2.0 | 3.2 | 1.018 | 1.014 |
| 32 | 6 | 181.5 | <12.87 | 79.6 | 168.0 | 8.2 | 14.9 | 1.4 | 1.0 | ND § | 1.015 |
| 33 | 6 | 146.0 | <12.87 | 61.9 | 176.8 | 9.1 | 16.0 | 2.0 | 1.6 | 1.058 | 1.020 |
| 34 | 0.75 | 77.2 | <12.87 | 88.4 | 176.8 | 11.1 | 11.7 | 1.3 | 1.2 | ND § | 1.030 |
| 35 | 2.7 | 89.3 | 33 | 132.6 | 176.8 | 13.4 | 13.1 | 1.9 | 1.9 | 1.042 | 1.015 |
| 36 | 0.75 | 72.5 | <12.87 | 123.8 | 159.1 | 12.0 | 13.9 | 1.3 | 1.1 | 1.016 | 1.015 |
| 37 | 3 | 374.0 | 18.7 | 88.4 | 176.8 | 11.4 | 17.3 | 1.5 | 1.6 | 1.023 | 1.020 |
| 38 | 1 | 68.2 | 30.89 | 106.1 | 159.1 | 7.9 | 12.2 | 1.2 | 1.030 | 1.015 | |
| 39 | 2 | 66.9 | <12.87 | 132.6 | 132.6 | 12.9 | 16.7 | 1.9 | 1.4 | ND § | 1.012 |
TT4 = serum total thyroxine concentration, Creat = serum creatinine concentration, Phos = serum phosphorus concentrations, USG = urine specific gravity, UP = urine protein concentrations, SUN = serum urea nitrogen. Reference intervals are as follows: TT4, 15–48 nmol/l; creatinine, 0.0–132.6 μmol/l; SUN, 5.0–12.1 mmol/l; phosphorus, 1.3–2.3 mmol/l; and potassium, 3.8–4.5 mmol/l.
TT4 measurements not done at the time of diagnosis of renal insufficiency; post-treatment euthyroidism was confirmed previously.
Urine specific gravity was above the upper limit of the selection criteria, but renal insufficiency was determined based on clinical signs, azotemia and a consistent further decline in renal function at all subsequent hospital visits.
These cats were euthyroid within 1 month of treatment.
Renal insufficiency was noted to progress in these cats over the ensuing months.