Predictors of Feline Kidney Disease

Jepson, R. E., D. Brodbelt, et al. (2009). "Evaluation of predictors of the development of azotemia in cats." J Vet Intern Med 23(4): 806-13.

Chronic kidney disease (CKD) often afflicts geriatric cats, with prevalence rates of 15% reported. The important factors for development of CKD that could be monitored in cats are not known, and were investigated by these researchers. They followed healthy geriatric cats for 12 months (exams every six months), measuring various clinical parameters and correlated these with development of kidney disease. The study evaluated 118 client-owned cats with an average age of 13 years. All were neutered. Physical exams, blood pressure measurement, and blood and urine analyses were done on all cats. Thirty percent of the cats enrolled developed evidence of kidney disease (azotemia) during the study. Of the parameters measured, only two – increased levels of creatinine (including high normal levels) in the blood and detectable protein in the urine – correlated with development of kidney disease (as evidenced by azotemia). The authors concluded that measurement of protein in the urine is an inexpensive and easy way to monitor aging cats for development of CKD. [MK]
>> PubMed Abstract

Related articles:
King JN, Tasker S, Gunn-Moore DA, Strehlau G; BENRIC (benazepril in renal
insufficiency in cats) Study Group. Prognostic factors in cats with chronic kidney disease. J Vet Intern Med. 2007 Sep-Oct;21(5):906-16.
>> PubMed Abstract

Boyd LM, Langston C, Thompson K, Zivin K, Imanishi M. Survival in cats with
naturally occurring chronic kidney disease (2000-2002). J Vet Intern Med. 2008 Sep-Oct;22(5):1111-7.
>> PubMed Abstract

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Jepson, R. E., D. Brodbelt, et al. (2009). "Evaluation of predictors of the development of azotemia in cats." J Vet Intern Med 23(4): 806-13.

Chronic kidney disease (CKD) often afflicts geriatric cats, with prevalence rates of 15% reported. The important factors for development of CKD that could be monitored in cats are not known, and were investigated by these researchers. They followed healthy geriatric cats for 12 months (exams every six months), measuring various clinical parameters and correlated these with development of kidney disease. The study evaluated 118 client-owned cats with an average age of 13 years. All were neutered. Physical exams, blood pressure measurement, and blood and urine analyses were done on all cats. Thirty percent of the cats enrolled developed evidence of kidney disease (azotemia) during the study. Of the parameters measured, only two – increased levels of creatinine (including high normal levels) in the blood and detectable protein in the urine – correlated with development of kidney disease (as evidenced by azotemia). The authors concluded that measurement of protein in the urine is an inexpensive and easy way to monitor aging cats for development of CKD. [MK]
>> PubMed Abstract

Related articles:
King JN, Tasker S, Gunn-Moore DA, Strehlau G; BENRIC (benazepril in renal
insufficiency in cats) Study Group. Prognostic factors in cats with chronic kidney disease. J Vet Intern Med. 2007 Sep-Oct;21(5):906-16.
>> PubMed Abstract

Boyd LM, Langston C, Thompson K, Zivin K, Imanishi M. Survival in cats with
naturally occurring chronic kidney disease (2000-2002). J Vet Intern Med. 2008 Sep-Oct;22(5):1111-7.
>> PubMed Abstract

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Renal Dysplasia in a Norwegian Forest Cat

Aresu, L., R. Zanatta, et al. (2009). "Bilateral juvenile renal dysplasia in a Norwegian Forest Cat." J Feline Med Surg 11(4): 326-9.

Renal dysplasia is a kidney malformation made up of disorganized development of renal parenchyma due to abnormal differentiation. This condition leads to chronic renal failure in young animals. In addition to cats, renal dysplastic lesions have been found in dogs, cattle, horses, sheep, and humans. Renal dysplasia can be diagnosed only by histological examination of biopsy samples. The dysplasia can be unilateral or bilateral. In this case of a 5-month old Norwegian Forest cat, where the disease was bilateral, renal failure was the ultimate result. Kittens can often be clinically normal for extended periods of time; however, most of clinical signs are seen before 2 years of age. Feline renal dysplasia has been reported in fetal infections with panleukopenia virus. There are no reports of familial origins in feline renal dysplastic lesions. [VT]
>> PubMed Abstract

Related articles:
Greco, D. (2001). "Congenital and inherited renal disease of small animals." Vet Clin North Amer: Sm Anim Pract 31(2): 393-399.
>> PubMed Abstract

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Aresu, L., R. Zanatta, et al. (2009). "Bilateral juvenile renal dysplasia in a Norwegian Forest Cat." J Feline Med Surg 11(4): 326-9.

Renal dysplasia is a kidney malformation made up of disorganized development of renal parenchyma due to abnormal differentiation. This condition leads to chronic renal failure in young animals. In addition to cats, renal dysplastic lesions have been found in dogs, cattle, horses, sheep, and humans. Renal dysplasia can be diagnosed only by histological examination of biopsy samples. The dysplasia can be unilateral or bilateral. In this case of a 5-month old Norwegian Forest cat, where the disease was bilateral, renal failure was the ultimate result. Kittens can often be clinically normal for extended periods of time; however, most of clinical signs are seen before 2 years of age. Feline renal dysplasia has been reported in fetal infections with panleukopenia virus. There are no reports of familial origins in feline renal dysplastic lesions. [VT]
>> PubMed Abstract

Related articles:
Greco, D. (2001). "Congenital and inherited renal disease of small animals." Vet Clin North Amer: Sm Anim Pract 31(2): 393-399.
>> PubMed Abstract

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Survival of Cats with Kidney Disease

Boyd, L. M., C. Langston, et al. (2008). "Survival in Cats with Naturally Occurring Chronic Kidney Disease (2000-2002)." Journal of Veterinary Internal Medicine 22(5): 1111-1117.

Up to 20% of cats will be affected with chronic kidney disease (CKD) during their lifetime. The prevalence of CKD increases with age, so that almost 1/3 of cats over the age of 15 years are affected. The disease has unpredictable progression and variable presentation, making it difficult to perform long-term survival studies. The International Renal Interest Society (IRIS) has developed a classification scheme for CKD in dogs and cats that is often used in long-term studies. The purpose of this study was to determine the average survival time for a large populatoin of cats from a facility that sees both first and second opinion cases, and to determine if the IRIS stage at diagnosis and after correction of pre-renal azotemia are associated with survival time. The study population consisted of 211 client-owned cats enrolled between April 2000 and January 2002. Clinical characteristics, clinicopathologic data, and survival times were extracted from the medical records. Kaplan-Meier survival curves were performed to determine survival times. Median survival for cats in IRIS stage IIb at the time of diagnosis was 1,151 days, and was longer than survival in stage III (median 778 days) or stage IV (median 103 days). The researchers conclude that IRIS stage of CKD based on serum creatinine at the time of diagnosis is strongly predictive of survival in cats with naturally occurring CKD.
>> PubMed Abstract

Related articles:
Syme, H. M., P. J. Markwell, et al. (2006). "Survival of cats with naturally occurring chronic renal failure is related to severity of proteinuria." J Vet Intern Med 20(3): 528-35.
>> PubMed Abstract

Elliott, J., J. M. Rawlings, et al. (2000). "Survival of cats with naturally occurring chronic renal failure: effect of dietary management." J Small Anim Pract 41(6): 235-42.
>> PubMed Abstract

More on cat health: Winn Feline Foundation Library

Boyd, L. M., C. Langston, et al. (2008). "Survival in Cats with Naturally Occurring Chronic Kidney Disease (2000-2002)." Journal of Veterinary Internal Medicine 22(5): 1111-1117.

Up to 20% of cats will be affected with chronic kidney disease (CKD) during their lifetime. The prevalence of CKD increases with age, so that almost 1/3 of cats over the age of 15 years are affected. The disease has unpredictable progression and variable presentation, making it difficult to perform long-term survival studies. The International Renal Interest Society (IRIS) has developed a classification scheme for CKD in dogs and cats that is often used in long-term studies. The purpose of this study was to determine the average survival time for a large populatoin of cats from a facility that sees both first and second opinion cases, and to determine if the IRIS stage at diagnosis and after correction of pre-renal azotemia are associated with survival time. The study population consisted of 211 client-owned cats enrolled between April 2000 and January 2002. Clinical characteristics, clinicopathologic data, and survival times were extracted from the medical records. Kaplan-Meier survival curves were performed to determine survival times. Median survival for cats in IRIS stage IIb at the time of diagnosis was 1,151 days, and was longer than survival in stage III (median 778 days) or stage IV (median 103 days). The researchers conclude that IRIS stage of CKD based on serum creatinine at the time of diagnosis is strongly predictive of survival in cats with naturally occurring CKD.
>> PubMed Abstract

Related articles:
Syme, H. M., P. J. Markwell, et al. (2006). "Survival of cats with naturally occurring chronic renal failure is related to severity of proteinuria." J Vet Intern Med 20(3): 528-35.
>> PubMed Abstract

Elliott, J., J. M. Rawlings, et al. (2000). "Survival of cats with naturally occurring chronic renal failure: effect of dietary management." J Small Anim Pract 41(6): 235-42.
>> PubMed Abstract

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Diagnosis of Hyperthyroidism in Cats with Kidney Disease

Wakeling, J., K. Moore, et al. (2008). "Diagnosis of hyperthyroidism in cats with mild chronic kidney disease." Journal of Small Animal Practice 49(6): 287-294.


It is a well known phenomenon that hyperthyroid cats with concurrent non-thyroidal illness, such as chronic kidney disease (CKD), may have total thyroxine concentrations within the normal reference range. This causes a diagnostic dilemma. The objective of this study was to determine total thyroxine, free thyroxine and/or thyroid-stimulating hormone concentrations in cats with mild CKD. Three groups of cats were included: 16 cats with CKD and clinical signs compatible with hyperthyroidism but total thyroxine within the reference range (these cats were confirmed with hyperthyroidism at a later date); 20 cats with CKD and no signs of hyperthyroidism; 20 clinically healthy senior cats (over 8 years of age). Four of the 20 cats with CKD had free thyroxine concentrations that were borderline or high. Of the 16 cats with hyperthyroidism and CKD, free thyroxine was high in 15/16 cats and thyroid-stimulating hormone was low in all cats. The researchers conclude that the combined measurement of free thyroxine with total thyroxine or thyroid-stimulating hormone may be of merit in the diagnosis of hyperthyroidism in cats with chronic kidney disease.
>> PubMed abstract


Related articles:
Langston, C. E. and N. J. Reine (2006). "Hyperthyroidism and the kidney." Clin Tech Small Anim Pract 21(1): 17-21.
>> PubMed abstract


More on cat health: Winn Feline Foundation Library

Wakeling, J., K. Moore, et al. (2008). "Diagnosis of hyperthyroidism in cats with mild chronic kidney disease." Journal of Small Animal Practice 49(6): 287-294.


It is a well known phenomenon that hyperthyroid cats with concurrent non-thyroidal illness, such as chronic kidney disease (CKD), may have total thyroxine concentrations within the normal reference range. This causes a diagnostic dilemma. The objective of this study was to determine total thyroxine, free thyroxine and/or thyroid-stimulating hormone concentrations in cats with mild CKD. Three groups of cats were included: 16 cats with CKD and clinical signs compatible with hyperthyroidism but total thyroxine within the reference range (these cats were confirmed with hyperthyroidism at a later date); 20 cats with CKD and no signs of hyperthyroidism; 20 clinically healthy senior cats (over 8 years of age). Four of the 20 cats with CKD had free thyroxine concentrations that were borderline or high. Of the 16 cats with hyperthyroidism and CKD, free thyroxine was high in 15/16 cats and thyroid-stimulating hormone was low in all cats. The researchers conclude that the combined measurement of free thyroxine with total thyroxine or thyroid-stimulating hormone may be of merit in the diagnosis of hyperthyroidism in cats with chronic kidney disease.
>> PubMed abstract


Related articles:
Langston, C. E. and N. J. Reine (2006). "Hyperthyroidism and the kidney." Clin Tech Small Anim Pract 21(1): 17-21.
>> PubMed abstract


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Kidney Insufficiency After Treatment for Feline Hyperthyroidism

Riensche, M. R., T. K. Graves, et al. (2008). "An investigation of predictors of renal insufficiency following treatment of hyperthyroidism in cats." J Feline Med Surg 10(2): 160-6.

Renal insufficiency is a common finding in older cats, affecting about 30% of cats over age 15. Hyperthyroidism is the most common endocrine disorder in cats, and it appears to be increasing in incidence over time. Hyperthyroidism can mask underlying renal disease by causing an increase in the glomerular filtration rate (GFR). Treatment of hyperthyroidism leads to a decrease in GFR and an increase in blood urea nitrogen (BUN). Different treatments exist for hyperthyroidism in cats, including reversible (methimazole) and irreversible (thyroidectomy, radioiodine) options. The ability to predict which cats will develop renal insufficiency after treatment for hyperthyroidism would help guide treatment decisions. The purpose of this retrospective study was to determine if routine pre-treatment clinical data can be used to predict the development of overt renal insufficiency following treatment of feline hyperthyroidism. Medical records were reviewed for 39 nonazotemic cats undergoing treatment for hyperthyroidism at the College of Veterinary Medicine, University of Illinois. The records were reviewed for for signalment, clinical signs, and serum biochemical, hematologic and urinalysis findings before and after treatment for hyperthyroidism. Cats that developed renal insufficiency within 6 months after treatment (n=20) were compared to cats that did not (n=19). No significant differences could be detected between the groups with respect to the parameters measured. The study suggests that the results of routine pre-treatment clinical data cannot be used to predict renal function after treatment for hyperthyroidism, and that a trial of methimazole therapy is indicated before choosing irreversible treatment such as radioiodine.
>> PubMed abstract

Related articles:
Boag, A. K., R. Neiger, et al. (2007). "Changes in the glomerular filtration rate of 27 cats with hyperthyroidism after treatment with radioactive iodine." Vet Rec 161(21): 711-5.
>> PubMed abstract

More on cat health: Winn Feline Foundation Library

Riensche, M. R., T. K. Graves, et al. (2008). "An investigation of predictors of renal insufficiency following treatment of hyperthyroidism in cats." J Feline Med Surg 10(2): 160-6.

Renal insufficiency is a common finding in older cats, affecting about 30% of cats over age 15. Hyperthyroidism is the most common endocrine disorder in cats, and it appears to be increasing in incidence over time. Hyperthyroidism can mask underlying renal disease by causing an increase in the glomerular filtration rate (GFR). Treatment of hyperthyroidism leads to a decrease in GFR and an increase in blood urea nitrogen (BUN). Different treatments exist for hyperthyroidism in cats, including reversible (methimazole) and irreversible (thyroidectomy, radioiodine) options. The ability to predict which cats will develop renal insufficiency after treatment for hyperthyroidism would help guide treatment decisions. The purpose of this retrospective study was to determine if routine pre-treatment clinical data can be used to predict the development of overt renal insufficiency following treatment of feline hyperthyroidism. Medical records were reviewed for 39 nonazotemic cats undergoing treatment for hyperthyroidism at the College of Veterinary Medicine, University of Illinois. The records were reviewed for for signalment, clinical signs, and serum biochemical, hematologic and urinalysis findings before and after treatment for hyperthyroidism. Cats that developed renal insufficiency within 6 months after treatment (n=20) were compared to cats that did not (n=19). No significant differences could be detected between the groups with respect to the parameters measured. The study suggests that the results of routine pre-treatment clinical data cannot be used to predict renal function after treatment for hyperthyroidism, and that a trial of methimazole therapy is indicated before choosing irreversible treatment such as radioiodine.
>> PubMed abstract

Related articles:
Boag, A. K., R. Neiger, et al. (2007). "Changes in the glomerular filtration rate of 27 cats with hyperthyroidism after treatment with radioactive iodine." Vet Rec 161(21): 711-5.
>> PubMed abstract

More on cat health: Winn Feline Foundation Library

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