Transient Third-Degree Atrioventricular Block in a Dog with Addisonian Crisis

A 3-year-old spayed male mixed-breed Labrador presented to the Emergency and Critical Care Unit with lethargy, loss of appetite, vomiting, a recent history of presyncopal episodes, and severe exercise intolerance. On admission, the patient had bradycardia, low blood pressure, and mild abdominal pain. Serum biochemistry information revealed severe hyperkalemia, hyponatremia, hypoglycemia, and mildly increased liver and kidney parameters. Upon taking these findings into consideration, hypoadrenocorticism was suspected, and a basal cortisol level was determined; it was below 1.0 µg/dL. Upon examination with ultrasound, we observed that the size of the adrenal glands was considerably reduced. Due to the bradycardia, a complete cardiologic examination consisting of 5 min of six-lead electrocardiography and echocardiography (ECG) was performed. Six-lead ECG revealed a complete atrio-ventricular block with an atrial rate of 140 bpm and a ventricular rate of 60 bpm. The PQ interval was variable, without any evidence of atrio-ventricular conduction. Treatment for hyperkalemia was initiated immediately after admission, followed by dexamethasone sodium phosphate administration, which led to an improvement in the patient's general condition, and the normalization of the ECG readings, after 24 h of therapy. Afterward, prednisolone (0.5 mg/kg/24 h p.o.) and desoxycorticosterone pivalate (2.2 mg/kg s.c.) were administered. This case shows that a third-degree atrioventricular block might be a reversible problem in dogs with hypoadrecorticism that can be managed with specific treatment for this disorder, without requiring pacemaker implantation.

Ultrasonographic adrenal gland changes in dogs with Cushing's syndrome with a low-dose dexamethasone suppression test result consistent with partial suppression or escape pattern

Background

Cushing's syndrome (CS) in dogs is mainly caused by pituitary-dependent (PDH) or adrenal-dependent (ADH) hypercortisolism. Result of the low-dose-dexamethasone suppression test (LDDST) with partial suppression (PSP) or escape pattern (EP) are indicative of PDH. No data concerning the ultrasonographic characteristics of the adrenal glands from dogs with these patterns exists.

Objective

To describe ultrasonographic appearance of adrenal glands in dogs with CS, with a LDDS test result consistent with PSP or EP.

Animals

Forty-nine client owned dogs with a diagnosis CS with a PSP or EP in the LDDST.

Methods

Retrospective evaluation of ultrasonographic adrenal gland size, shape and echogenicity. The dorsoventral thickness ratio (DVTR) and dorsoventral thickness difference ratio (DVTDR) was calculated.

Results

PSP and EP occurred in 42.9 and 57.1% of all LDDST. The median maximum width of the left adrenal gland was 0.71 cm (IQR, 0.24 cm) and of the right 0.75 cm (IQR, 0.19 cm) in all dogs and there was no difference between both patterns. There was a significant correlation between adrenal gland width and weight (left adrenal gland p = 0.002, right adrenal gland p = 0.017). In 9/49 dogs (18.4%), an adrenal asymmetry with a DVTDR >0.3 was present. In 7 of these 9 dogs, follow-up was available indicating presence of PDH.

Conclusions and clinical importance

Based on follow up, PSP and EP of the LDDST were very supportive of PDH. Bilaterally symmetric adrenomegaly is a characteristic finding in dogs with PDH, however the size of adrenal gland width in this cohort was smaller than previously reported. Adrenal asymmetry was noted in approximately 20%.

Can neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios be used as markers for hypercortisolism in dogs?

Changes in neutrophil-to-lymphocite ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been identified in dogs with hypercortisolism (HC), but, no studies have investigated the changes in these inflammatory biomarkers as cost-effective and available parameters for the diagnosis and management of HC. This study was performed to evaluate whether NLR and PLR could be used as biomarkers for the diagnosis and treatment response in dogs with HC. This retrospective study included 67 dogs with HC, 58 dogs with non-adrenal illness (NAI), and 39 healthy dogs. NLR and PLR were compared among the three groups. Cut-off values of NLR and PLR for HC screening and percent change in biomarkers for assessing treatment response were evaluated. In addition, the NLR and PLR were compared before and after trilostane treatment. NLR and PLR were significantly higher in the HC group than in the NAI and healthy groups. The NLR cut-off value of 4.227 had a sensitivity of 67.16% and specificity of 65.52%, and the PLR cut-off value of 285.0 had a sensitivity of 56.72% and specificity of 70.69% for differentiating between dogs with HC and those with NAI, respectively. Furthermore, a significant decline in NLR was observed after treatment in the well-controlled HC group. The cutoff value of percent change in NLR to identify well-controlled HC was -7.570%; sensitivity and specificity were 100% and 63.64%, respectively. Therefore, NLR and PLR might be used cautiously as supportive biomarkers for HC diagnosis, and NLR could be a potential monitoring tool in assessing the treatment response of HC in dogs.

The use of ultrasonographic adrenal dimensions and the adrenal dimension-to-aorta ratio in the diagnosis of benign and malignant adrenal diseases in dogs

Background and Aim

Ultrasound (US) is a useful tool for detecting adrenal abnormalities. However, a definite reference range differentiating normal and diseased adrenal glands in dogs of varying body sizes is still lacking. The organ dimension-to-aorta (Ao) ratio of the dogs is correlated with their body weight (BW). Therefore, this study aimed to investigate the adrenal dimensions, including adrenal pole thickness and adrenal length, as well as the adrenal dimension-to-Ao ratio, to differentiate between dogs with normal, benign lesions such as pituitary-dependent hyperadrenocorticism (PDH) and malignant invasive adrenal tumors.

Materials and Methods

The medical records and US images of 39 dogs that were either normal (normal) (n = 15) or affected by PDH (n = 15) or malignant invasive adrenal tumors (tumor) (n = 9) were retrieved in this study. All the dogs had a transabdominal US on the sagittal plane. The adrenal dimensions and luminal Ao diameter at the peak of the systolic phase were recorded. The average adrenal dimensions, including the adrenal dimension-to-Ao ratio, were compared among the groups.

Results

Most of the dogs in each group were small-breed dogs with comparable ages, BW, and Ao values. Both adrenal dimensions and the adrenal dimension-to-Ao ratio were significantly lower in the normal group than in the PDH and tumor groups. To differentiate the PDH group from the tumor group, adrenal dimensions of pole thickness and length were more appropriate than the adrenal dimension-to-Ao ratio.

Conclusion

Adrenal dimensions and the adrenal dimension-to-Ao ratio can be used to diagnose adrenal diseases. However, in small-breed dogs, adrenal dimensions are suitable for differentiating PDH from tumor groups. Further research is required with a larger sample size and a wider range of canine body sizes.

ACVR and ECVDI Consensus Statement for the Standardization of the Abdominal Ultrasound Examination

This consensus statement is designed to provide a standard of care document and describes the ACVR and ECVDI definition for performing a standard abdominal ultrasound examination in dogs and cats. The ACVR and ECVDI define a standard abdominal ultrasonographic examination as a complete exam of the abdominal organs which is appropriately documented. The consensus statement intends to provide guidance to veterinary sonographers and veterinarians for the performance and documentation of high-quality diagnostic ultrasound examination. The document may also serve as a teaching aid for veterinary students, veterinarians, and residents in diagnostic imaging who seek proficiency in diagnostic ultrasound. Finally, it may serve an additional role in educating the public as to what a high-quality abdominal ultrasound examination should entail.

Inverse relationship between eosinophil profiles and serum glucose concentration in dogs with naturally occurring hypercortisolism

Hyperglycemia and eosinopenia are well-known characteristics of hypercortisolism (HC) in humans, however, their association in dogs with HC has rarely been reported. This study aimed to evaluate the association between eosinophils and serum fasting glucose concentration in dogs with HC. Forty-seven dogs with HC and 43 dogs with non-adrenal illness were included. In this retrospective cohort study, the complete blood count, blood chemistry profile, and pre- and post-adrenocorticotropic hormone (ACTH) cortisol concentrations were analyzed. Significant differences were found in neutrophil, monocyte, eosinophil, and platelet counts; eosinophil percentage; neutrophil-to-lymphocyte ratio; aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyl transferase activities (P < 0.05) between the groups. In dogs with HC, the eosinophil percentage was inversely correlated with fasting blood glucose (r = -0.3515, P = 0.0154) and post-ACTH cortisol concentrations (r = -0.6509, P < 0.0001). The neutrophil-to-lymphocyte ratio was inversely correlated with the eosinophil percentage (r = -0.4573, P = 0.0012) and count (r = -0.3688, P = 0.0108), but positively correlated with the fasting blood glucose level (r = 0.3888, P = 0.0069). Such correlations were not identified in dogs with non-adrenal illness. A multivariate analysis showed that only eosinophil percentage was associated with the presence of hyperglycemia in dogs with HC (odds ratio = 2.100, 95% confidence interval = 1.051-4.199, P = 0.0360). Therefore, eosinopenia induced by excess cortisol might be associated with altered glucose metabolism in dogs with HC. A better understanding of this correlation could be valuable to predict and prevent the complications of HC.

Diagnosis of canine spontaneous hypoadrenocorticism

Hypoadrenocorticism is characterized by a reduction in mineralocorticoid and/or glucocorticoid production by the adrenal glands. Several subtypes have been described with different clinical and clinicopathological consequences. Most affected dogs have vague and non-specific signs that precede an eventual life-threatening crisis. This review aims to appraise classification, the available data on epidemiology and the clinical and laboratory features of naturally occurring canine hypoadrenocorticism.

Canine hypoadrenocorticism is a relatively uncommon endocrine disease that can present with a wide variety of clinical signs resulting from cortisol or aldosterone deficiency or both. Hypoadrenocorticism should be considered in all dogs with severe illness and typical electrolyte abnormalities but also in those with waxing and waning clinical signs. Multiple clinical and laboratory features are suggestive of the disease and should prompt evaluation of adrenal function. The ACTH stimulation test is the best test for diagnosing hypoadrenocorticism but, in those cases without the typical presentation, evaluation of aldosterone secretory capacity and endogenous ACTH concentrations should be performed to distinguish primary from secondary disease. In this review we discuss the pathophysiology of the disease, the clinical signs and laboratory features that should raise suspicion of hypoadrenocorticism and the performance of the different diagnostic tests.

Adrenal Gland Ultrasonographic Measurements and Plasma Hormone Concentrations in Clinically Healthy Newborn Thoroughbred and Standardbred Foals

Simple Summary

The hypothalamic–pituitary–adrenal axis regulates many physiologic and metabolic functions and plays a central role in the inflammatory response to illness. Clinically, hypothalamic–pituitary–adrenal axis function can be evaluated by combined assessment of adrenal hormones, adrenocorticotropin plasma concentrations and ultrasonographic examination of the adrenal glands in other species. Multiple individual variables have been demonstrated to affect ultrasonographic measurements of adrenal glands in several species. Ultrasonographic measurements of the adrenal glands and plasma concentration of adrenocorticotropin, cortisol, dehydroepiandrosterone, progesterone, aldosterone and adrenocorticotropin/adrenal hormone ratios were assessed and compared between Thoroughbred and Standardbred healthy neonatal foals. The effect of age, weight and sex on ultrasonographic measurements of the adrenal glands was also investigated. The width of whole adrenal glands and the medulla differed significantly between Thoroughbreds and Standardbreds. Cortisol and adrenocorticotropin were, respectively, higher and lower in Thoroughbreds than in Standardbreds. The cortisol/dehydroepiandrosterone ratio was higher in Thoroughbreds than in Standardbreds. The results of this study provide reference ranges for healthy neonatal Thoroughbred and Standardbred foals and suggest the presence of breed-related differences in ultrasonographic measurements, plasmatic cortisol and adrenocorticotropin concentrations. The higher cortisol/dehydroepiandrosterone ratio of Thoroughbred foals may suggest a different response to stress and environmental stimulation between the two breeds.

Abstract

Adrenal hormones, ACTH plasma concentrations and the ultrasonographic evaluation of the adrenal glands are considered complementary in clinical evaluations of the hypothalamic–pituitary–adrenal (HPA) axis function in several species. In dogs, age, size and weight have a significant effect on the ultrasonographic size of the adrenal glands. In neonatal foals, ultrasonographic evaluation and measurements of the adrenal glands have been demonstrated to be reliable; however, the effect of individual variables on ultrasonographic features has not been investigated, and the clinical usefulness of adrenal gland ultrasonography is still not known. The aims of this study were: (i) to provide and compare adrenal glands ultrasound measurements in healthy newborn Thoroughbred and Standardbred foals, and assess any effect of age, weight and sex on them; (ii) to assess and compare ACTH and steroid hormone concentrations in healthy neonatal foals of the two breeds. Venous blood samples and ultrasonographic images of the adrenal glands were collected from 10 healthy neonatal Thoroughbred and 10 healthy neonatal Standardbred foals. Ultrasonographic measurements of the adrenal glands were obtained and adrenocorticotropin (ACTH), cortisol, dehydroepiandrosterone (DHEA), progesterone (P4) and aldosterone plasma concentrations were assessed. The ACTH/cortisol, ACTH/progesterone, ACTH/aldosterone, ACTH/DHEA and cortisol/DHEA ratios were calculated. A significant positive correlation was found between the height of the right adrenal gland and the foal’s weight; the width of the right and left adrenal gland and the medulla was significantly lower in Thoroughbreds than in Standardbreds. Cortisol and ACTH plasma concentrations were significantly higher and lower, respectively, in Thoroughbreds compared with Standardbreds. The cortisol/DHEA ratio was significantly higher in Thoroughbreds. This study provides reference ranges for neonatal Thoroughbred and Standardbred foals, and suggests the presence of breed-related differences in ultrasonographic adrenal gland measurements, plasmatic cortisol and ACTH concentrations. The higher cortisol/DHEA ratio detected in Thoroughbred foals could suggest a different response to environmental stimulation in the two breeds.

Ultrasound evaluation of adrenal gland size in clinically healthy dogs and in dogs with hyperadrenocorticism

BACKGROUND

Precise reference intervals of adrenal gland thickness are required for detection of adrenomegaly in dogs with hyperadrenocorticism (HAC).

METHODS

Eighty-six clinically healthy dogs were prospectively included, and 91 dogs with untreated HAC were retrospectively evaluated. Dorso-ventral adrenal gland thickness was ultrasonographically measured on the sagittal plane. Dogs were classified into four body weight categories, and those with HAC were also ultrasonographically classified as consistent with pituitary-dependent HAC (PDH), adrenal-dependent HAC (FAT), equivocal adrenal asymmetry (EAA), or normal adrenal thickness.

RESULTS

The upper limits for left adrenal gland in clinically healthy dogs were 5.1 mm (≥2.5-5 kg), 5.5 mm (>5-10 kg), 6.4 mm (>10-20 kg), and 7.3 mm (>20-40 kg), and for right adrenal gland the upper limits were 5.3 mm (≥2.5-5 kg), 6.8 mm (>5-10 kg), 7.5 mm (>10-20 kg), and 8.7 mm (>20-40 kg). The sensitivity of ultrasound to detect adrenomegaly in dogs with HAC was 95.6%. Most dogs with HAC (56.0%) had ultrasound findings consistent with either PDH or FAT; however, EAA was commonly occurring in 39.6% of dogs with HAC.

CONCLUSIONS

The sensitivity of ultrasonography to detect adrenomegaly in dogs with HAC is high when using four weight categories. EAA is common in dogs with HAC.

Ultrasonography of Normal Adrenal Glands in Adult Holstein-Friesian Cows: A Pilot Study

Ultrasonographic reference values for the adrenal glands of cattle have not been reported to date. Adrenal glands can be affected by different pathologies, such as hyperplasia, neoplasia and atrophy (either primary or secondary). The present findings indicate that the right adrenal gland can be easily characterized by transabdominal ultrasound in adult Holstein-Friesian cows, with no apparent influence of age or weight. The right adrenal gland (mean length 3.86 ± 1.39 cm; and mean thickness 1.39 ± 0.26 cm) was consistently and mainly located in the 12th intercostal space. The left adrenal gland was more difficult to locate due to its more medial position, and to the presence of gas in the gastrointestinal tract, so it could not be visualized in most animals (18/25). Its mean length was 3.72 ± 0.95 cm, and mean thickness was 1.36 ± 0.33 cm, in the sagittal section. This is the first report of the ultrasonographic appearance of the adrenal glands of cows and of the corresponding reference preliminary values.

Ultrasonographic measurement of adrenal gland-to-aorta ratio as a method of estimating adrenal size in dogs

BACKGROUND

Adrenal size has been used as the principal criterion for differentiating a normal gland from adrenal hyperplasia. The objectives of this study were to establish an ultrasonographic measurement of adrenal gland-to-aorta (adrenal/Ao) ratio to estimate the adrenal size and to assess the effects of bodyweight, age and sex on the adrenal/Ao ratio in non-adrenal gland disease dogs.

METHODS

Two hundred and thirty-four dogs (120 entire females and 114 entire males) considered non-adrenal gland disease were included in this study. Dogs were allocated into three bodyweight categories (<10 kg, 10-20 kg and >20 kg), and four age groups (<1 year, 1-5 years, 5-10 years and >10 years old). Measurements of the maximal thickness of caudal pole of both adrenal glands and the aortic luminal diameter in sagittal plane were performed on the ultrasonographic images. Three different ratios were calculated for each dog.

RESULTS

Sex and age did not influence on the adrenal/Ao ratio. There were differences (P<0.05) between the three dog sizes for adrenal/Ao ratio, being the highest value for small size and the lowest value for large size.

CONCLUSIONS

In this study, only bodyweight influences the ultrasound measurement of the adrenal/Ao ratio in non-adrenal gland disease dogs.

Investigation of adrenal and thyroid gland dysfunction in dogs with ultrasonographic diagnosis of gallbladder mucocele formation

Gallbladder mucocele formation is an emerging disease in dogs characterized by increased secretion of condensed granules of gel-forming mucin by the gallbladder epithelium and formation of an abnormally thick mucus that can culminate in obstruction of the bile duct or rupture of the gallbladder. The disease is associated with a high morbidity and mortality and its pathogenesis is unknown. Affected dogs have a significantly increased likelihood of concurrent diagnosis of hyperadrenocorticism, hypothyroidism, and hyperlipidemia. Whether these endocrinopathies represent coincidental primary disease processes that exacerbate gallbladder mucocele formation in predisposed dogs or reflect a concurrent disruption of endocrine and lipid metabolism is unclear. In this study, we investigated a hypothesis that dogs with gallbladder mucocele formation would have a high prevalence of occult and atypical abnormalities in adrenal cortical and thyroid gland function that would suggest the presence of endocrine disruption and provide deeper insight into disease pathogenesis. We performed a case-control study of dogs with and without ultrasonographic diagnosis of gallbladder mucocele formation and profiled adrenal cortical function using a quantitative mass spectrometry-based assay of serum adrenal-origin steroids before and after administration of synthetic cosyntropin. We simultaneously profiled serum thyroid hormone concentrations and evaluated iodine sufficiency by measurement of urine iodine:creatinine ratios (UICR). The studies were complemented by histological examination of archival thyroid tissue and measurements of thyroid gland organic iodine from dogs with gallbladder mucocele formation and control dogs. Dogs with gallbladder mucocele formation demonstrated an exaggerated cortisol response to adrenal stimulation with cosyntropin. A prevalence of 10% of dogs with gallbladder mucocele formation met laboratory-based criteria for suspect or definitive diagnosis of hyperadrenocorticism. A significantly greater number of dogs with gallbladder mucocele formation had basal serum dehydroepiandrosterone (DHEAS) increases compared to control dogs. A high percentage of dogs with gallbladder mucocele formation (26%) met laboratory-based criteria for diagnosis of hypothyroidism, but lacked detection of anti-thyroglobulin antibodies. Dogs with gallbladder mucocele formation had significantly higher UICRs than control dogs. Examination of thyroid tissue from an unrelated group of dogs with gallbladder mucocele formation did not demonstrate histological evidence of thyroiditis or significant differences in content of organic iodine. These findings suggest that dogs with gallbladder mucocele formation have a greater capacity for cortisol synthesis and pinpoint DHEAS elevations as a potential clue to the underlying pathogenesis of the disease. A high prevalence of thyroid dysfunction with absent evidence for autoimmune thyroiditis suggest a disrupted thyroid hormone metabolism in dogs with gallbladder mucocele formation although an influence of non-thyroidal illness cannot be excluded. High UICR in dogs with gallbladder mucocele formation is of undetermined significance, but of interest for further study.

The interpretive contribution of the baseline serum cortisol concentration of the ACTH stimulation test in the diagnosis of pituitary dependent hyperadrenocorticism in dogs

Background

Current recommendation for performing the ACTH stimulation test (ACTHST) for diagnosis of hyperadrenocorticism (HAC) advocates the collection of baseline serum cortisol concentration (BC), but no references for interpretation of its results exist.

Objective

Evaluate the contribution of BC of the ACTHST to the diagnosis of HAC.

Animals

Fifty‐four dogs were evaluated for suspected HAC at a referral hospital.

Methods

Records of dogs that had been evaluated by ACTHST for suspected HAC were reviewed. Receiver operator characteristics (ROC) analyses were used to assess the performance of BC, post‐stimulation serum cortisol concentrations (PC), post‐to‐baseline cortisol concentration difference (DeltaC) and quotient (RatioC) for the diagnosis of HAC by comparing the area under the ROC curve (AUC) of PC to each of the other tests.

Results

The AUC of PC (95% confidence interval [CI]: 0.92; 95% CI, 0.81‐0.98) was significantly higher than AUCs of BC (0.70; 95% CI, 0.56‐0.82; P = .01) and RatioC (0.55; 95% CI, 0.41‐0.69; P < .001), and was not significantly different from AUC of DeltaC (0.86; 95% CI, 0.74‐0.94; P = .09). An optimal cutoff value of 683 nmol/L (24.8 μg/dL) for PC yielded a sensitivity of 86% and a specificity of 94%, respectively, and a cutoff value of 718 nmol/L (26.0 μg/dL) yielded a specificity of 100% with of 81% sensitivity for the diagnosis of pituitary‐dependent HAC.

Conclusion and Clinical Importance

The PC had good discriminatory ability for the diagnosis of HAC. It was comparable to DeltaC, whereas BC and RatioC were ineffective. Current recommendations to collect samples for BC appear redundant.

The effect of recumbency position on the ultrasound measurement of the canine adrenal gland in non-adrenal gland illness

Abdominal ultrasound is frequently used to assess the canine adrenal gland (AG) and subjective and objective features of normal AGs have been described. The effect of the dogs’ recumbency position on the accuracy of AG measurement acquisition is not known. This prospective study, performed in dogs with non-adrenal illness, compared ultrasonographic AG measurements made in dogs placed in dorsal recumbency with those made in left or right lateral recumbency. AG length, height and width measurements made in the longitudinal image plane, and height and width measurements from the transverse image plane were assessed. The level and limits of agreement between the dorsal and lateral recumbency for each of the measurements were determined using the Bland–Altman analysis. The measurement with the best agreement between the dorsal and lateral recumbency was the caudal pole thickness (CPT) from the longitudinal image plane. Agreement between lateral and dorsal recumbency was poorer for the measurements derived from the transverse image plane and poorest for measurements of AG length in the longitudinal plane. This study demonstrates that there is some difference in the measurements acquired in dorsal compared with lateral recumbency; however, the difference is small for the CPT from the longitudinal plane. This finding suggests that the CPT from the longitudinal image plane is the most reliable measurement in terms of agreement between dorsal and lateral recumbency in dogs with non-AG illness.

Intrinsic factors, adrenal gland morphology, and disease burden in captive cheetahs (Acinonyx jubatus) in South Africa

Adrenal gland weight (AW) and corticomedullary ratio (ACMR) are used as indicators of stress in animals. Captive cheetahs (Acinonyx jubatus) have higher ACMRs than free-ranging ones and stress has been linked to gastritis, amyloidosis, glomerulosclerosis, and myocardial fibrosis. We reviewed age, sex, body weight (BW), kidney weight (KW), and left AW and ACMR with necropsy findings in 51 South African captive cheetahs. Eleven common histopathologic lesions were counted for each animal as measure of its disease burden. Adrenal corticomedullary hyperplasia was significantly correlated with left AW and ACMR. Males had significantly higher AWs than females; other parameters showed no difference between the sexes. Disease burden, gastritis, and myocardial fibrosis were moderately correlated with adrenal morphology supporting prior evidence that gastritis and myocardial fibrosis are linked to stress. Glomerulosclerosis was not correlated with adrenal morphology and neither kidney nor liver amyloidosis contributed significantly to variation in AW or ACMR on multivariate analyses. Interstitial nephritis showed much stronger correlations with kidney and liver amyloidosis than gastritis. All three adrenal parameters were correlated with age; age was the only significant variable affecting ACMR on the multivariate analyses; and disease burden as well as systemic amyloidosis and kidney disease (except for fibrosis) showed moderate correlations with age. Age may, therefore, be important in the pathogenesis of disease in captive cheetahs, particularly of amyloidosis and kidney disease. None of the intrinsic measurements or adrenal parameters were sufficiently closely linked to disease to be used as ante-mortem proxies for disease burden or specific diseases. Zoo Biol. 36:40-49, 2017. © 2016 Wiley Periodicals, Inc.