Clinical findings, diagnostic test results, and treatment outcome in cats with spontaneous hyperadrenocorticism: 30 cases

Ultrasonographic measurements of the normal adrenal glands in guinea pigs (Cavia Porcellus)

Hyperadrenocorticism is an uncommon but important endocrine disease in guinea pigs, but due to its subtle clinical signs and the limited information in veterinary literature, it can be underdiagnosed or misdiagnosed. Ultrasound of the adrenal glands in patients with suspected hyperadrenocorticism can help in identifying adrenomegaly. The purpose of this prospective study was to identify ultrasonographic adrenal gland dimensions in presumed healthy guinea pigs using the same standardized method described for dogs and cats. A conscious ultrasound scan was conducted on twenty client-owned, presumed healthy guinea pigs, and their adrenal glands were measured. A possible correlation between adrenal dimensions with age, sex, and body weight was investigated. The mean length, cranial and caudal pole thickness for the left and right adrenal glands were, respectively, 12.64 ± 2.11 mm and 11.55 ± 1.52 mm; 4.83 mm ± 1.03 mm and 4.69 ± 1.34 mm; 4.8 ± 1.23 mm and 4.04 ± 0.75 mm. The thickness of the left caudal pole was significantly higher than the right (P = 0.02). A significant positive correlation was found between the length of the left adrenal gland and both age (r = 0.46; P = .03) and weight (r = 0.59; P = .01). Statistical correlation between the thickness of each cranial and caudal pole, with age, sex, or weight, was not found. The dimensions provided could prove a useful tool in the clinical evaluation of guinea pigs with suspected hyperadrenocorticism.

Hypersomatotropism and Other Causes of Insulin Resistance in Cats

True insulin resistance should be differentiated from management-related difficulties (eg, short insulin duration, inappropriate insulin injection, inappropriate storage). Hypersomatotropism (HST) is the number one cause of insulin resistance in cats, with hypercortisolism (HC) occupying a more distant second place. Serum insulinlike growth factor-1 is adequate for screening for HST, and screening at the time of diagnosis, regardless of presence of insulin resistance, is advocated. Treatment of either disease centers on removal of the overactive endocrine gland (hypophysectomy, adrenalectomy) or inhibition of the pituitary or adrenal glands by using drugs such as trilostane (HC), pasireotide (HST, HC) or cabergoline (HST, HC).

Pathophysiology of Prediabetes, Diabetes, and Diabetic Remission in Cats

Diabetes mellitus (DM) has a heterogenous cause, and the exact pathogenesis differs between patients. Most diabetic cats have a cause similar to human type 2 DM but, in some, DM is associated with underlying conditions, such as hypersomatotropism, hyperadrenocorticism, or administration of diabetogenic drugs. Predisposing factors for feline DM include obesity, reduced physical activity, male sex, and increasing age. Gluco(lipo)toxicity and genetic predisposition also likely play roles in pathogenesis. Prediabetes cannot be accurately diagnosed in cats at the current time. Diabetic cats can enter remission, but relapses are common, as these cats might have ongoing, abnormal glucose homeostasis.

Skin fragility in a cat presenting with pituitary-dependent hyperadrenocorticism

Case summary

A case of skin fragility in an 8-year-old domestic shorthair cat with pituitary-dependent hyperadrenocorticism is described. The cat was referred to the Feline Centre at Langford Small Animal Hospital with a 2-month history of multiple skin wounds with no known traumatic aetiology. A low-dose dexamethasone suppression test was performed before referral, which was consistent with hyperadrenocorticism. On presentation, the cat had multiple cutaneous lacerations and patchy areas of alopecia. CT was performed, which revealed a pituitary mass most consistent with pituitary-dependent hyperadrenocorticism. Treatment with oral trilostane (Vetoryl; Dechra) was commenced and clinical improvement was observed; however, further extensive skin lesions as a consequence of her skin fragility resulted in euthanasia.

Relevance and novel information

Hyperadrenocorticism is an uncommon endocrinopathy of cats; however, it is an important differential for skin thinning and non-healing wounds. Skin fragility remains an important factor in the consideration of appropriate treatment protocols and ongoing quality of life in these patients.

Ultrasonographic Detected Adrenomegaly in Clinically Ill Cats: A Retrospective Study

This retrospective study aimed to assess the prevalence of ultrasonographic detected adrenomegaly in clinically ill cats, evaluating the final established diagnosis, describe adrenal ultrasound findings and if the adrenomegaly was suspected or incidental. Abdominal ultrasonography reports of cats presenting to a veterinary teaching hospital between October 2018 and February 2021 were retrospectively reviewed. Cats showing adrenomegaly (one or both glands having a dorsoventral axis >4.8 mm) were selected and medical records respectively evaluated. Nine-hundred and eighty-three ultrasonographical reports were selected, of which, 68 (7%) disclosed adrenomegaly. European/Domestic Short-Hair (62/68; 91%) male (44/68; 65%) castrated (35/44; 80%) cats were overrepresented. Adrenomegaly was an incidental finding in 62/68 (91%) cats while in 6/68 (9%) it was identified in the context of investigating a potential adrenal disease. Concerning established diagnosis, chronic kidney disease was overrepresented (25/68; 37%), followed by endocrinopathies (20/68; 29%). Adrenomegaly was bilateral in 53% (36/68) of cases. In unilateral cases (32/68; 47%), it was more prevalent on the left side (23/32; 72%), with a normal-sized contralateral adrenal gland. Left adrenal demonstrated a larger size and a tendency to oval shape. This study assesses the prevalence of adrenomegaly in clinically ill cats, reinforcing it can be an incidental ultrasound finding.

2022 Update of the Consensus on the Rational Use of Antithrombotics and Thrombolytics in Veterinary Critical Care (CURATIVE) Domain 1- Defining populations at risk

OBJECTIVES

To expand the number of conditions and interventions explored for their associations with thrombosis in the veterinary literature and to provide the basis for prescribing recommendations.

DESIGN

A population exposure comparison outcome format was used to represent patient, exposure, comparison, and outcome. Population Exposure Comparison Outcome questions were distributed to worksheet authors who performed comprehensive searches, summarized the evidence, and created guideline recommendations that were reviewed by domain chairs. The revised guidelines then underwent the Delphi survey process to reach consensus on the final guidelines. Diseases evaluated in this iteration included heartworm disease (dogs and cats), immune-mediated hemolytic anemia (cats), protein-losing nephropathy (cats), protein-losing enteropathy (dogs and cats), sepsis (cats), hyperadrenocorticism (cats), liver disease (dogs), congenital portosystemic shunts (dogs and cats) and the following interventions: IV catheters (dogs and cats), arterial catheters (dogs and cats), vascular access ports (dogs and cats), extracorporeal circuits (dogs and cats) and transvenous pacemakers (dogs and cats).

RESULTS

Of the diseases evaluated in this iteration, a high risk for thrombosis was defined as heartworm disease or protein-losing enteropathy. Low risk for thrombosis was defined as dogs with liver disease, cats with immune-mediated hemolytic anemia, protein-losing nephropathy, sepsis, or hyperadrenocorticism.

CONCLUSIONS

Associations with thrombosis are outlined for various conditions and interventions and provide the basis for management recommendations. Numerous knowledge gaps were identified that represent opportunities for future studies.

Is methylprednisolone acetate-related insulin resistance preventable in cats?

Methylprednisolone acetate (MPA) is often prescribed to cats despite being recognized eventually as diabetogenic. To assess MPA-related insulin resistance and evaluate the efficacy of metformin or an obesity and diabetes mellitus (O&D) adjuvant diet as protective factors, a randomized clinical trial was conducted with 28 owned cats undergoing glucocorticoid therapy. A single MPA dose of 20 mg intramuscularly was administered to each cat. Controls (n=10) received only MPA. In the diet group (n=9), replacement of their habitual diet by ad-libitum feeding of a feline commercial O&D diet (Equilíbrio O&D, Total Alimentos ADM) was made. In the metformin group (n=9), metformin chlorhydrate 25mg/cat PO/q24h was administered for 30 days. All patients were clinically evaluated at baseline (T0), day 15 (T15), and day 30 (T30) and blood draw for complete blood count, serum biochemistry, and determination of insulin concentrations. Fasting Insulin Sensitivity Index (SI), Amended Insulin to Glucose Ratio (AIGR), Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), and Homeostatic Model Assessment of beta-cell function (HOMA-B) were calculated based on fasting glycemia and insulinemia. All groups showed significantly higher levels (p < 0.05) of neutrophils, albumin, glucose, cholesterol, triglycerides, and serum insulin at T15. Patients in the metformin group showed also higher SI, AIGR, and HOMA-IR results at T15. Also, at T15, reduced levels (p < 0.05) of eosinophils, lymphocytes, and creatinine were documented in all groups. An MPA single dose induced changes in insulin sensitivity in cats; however, neither metformin nor O&D feeding used in this study was effective as protective factors against MPA-related insulin resistance.

Successful treatment of feline hyperadrenocorticism with pituitary macroadenoma using radiation therapy: a case study

A 10-year-old castrated male cat showing behavioral (irritation, prowling, and tumbling) and cutaneous abnormalities such as dermal fragility was diagnosed as hyperadrenocorticism with pituitary macroadenoma, concurrent with insulin dependent diabetes mellitus. Pituitary enlargement (18.0 mm) was observed during magnetic resonance imaging. High endogenous adrenocorticotropic hormone levels (>2,500 pg/ml) were also observed. Although trilostane treatment (5–10 mg/head, daily) was commenced, the clinical signs did not disappear. Insulin and trilostane treatment were discontinued on day 86 after first day of radiation therapy (4 Gy/12 fractions). After radiation therapy, a decreased pituitary tumor size (10.7 mm) was observed on day 301; neurological and dermatological signs exhibited remission. Radiation therapy is the treatment of choice for feline hyperadrenocorticism with pituitary macroadenoma with neurological signs.

Diabetes mellitus remission in a cat with hyperadrenocorticism after cabergoline treatment

Case summary

A 7-year-old spayed female domestic shorthair cat weighing 5 kg was referred with polyuria, polydipsia, lethargy, abdominal distension and dermatologic abnormalities. Diabetes mellitus was diagnosed and treatment was started with a diet for diabetic cats and insulin glargine (1 IU q12h SC). Hyperadrenocorticism (HAC) was suspected and diagnosed based on clinical signs, increased urinary cortisol:creatinine ratio, lack of suppression on low-dose dexamethasone suppression test and abdominal ultrasonography demonstrating bilateral adrenal enlargement. Oral cabergoline (10 μg/kg every other day) was initiated. After the second administration of cabergoline, the cat suffered from clinical hypoglycemia and no longer required insulin. One month after insulin withdrawal, blood work and urine analysis results showed normoglycemia, a normal serum fructosamine concentration (244 μmol/l) and normal urine analysis without glycosuria. Diabetic remission persisted until its death 7 months later. In addition, cabergoline treatment was associated with improvement in clinical signs such as lethargy, seborrhea, alopecia and abdominal distension.

Relevance and novel information

To our knowledge, this is the first reported case of the use of cabergoline in a cat with HAC, as well as the first reported case of diabetic remission in a cat with HAC after cabergoline treatment. Cabergoline could be an alternative treatment for diabetic cats with pituitary-dependent HAC. Further work should focus on different protocols with greater number of cases.

Feline Pituitary Adenomas: Correlation of Histologic and Immunohistochemical Characteristics With Clinical Findings and Case Outcome

Pituitary glands from 141 feline autopsy cases were reviewed histologically. Adenoma and hyperplasia were the most common lesions at 13 cases each. Pituitary adenoma was more likely than hyperplasia to be associated with clinical evidence of endocrinopathy or an intracranial mass (P < .001). A histochemical and immunohistochemical panel was applied to 44 autopsy- or hypophysectomy-derived pituitary adenomas in 43 cats from 2 diagnostic laboratories. Adenomas were differentiated from hyperplasia by the presence of disrupted reticulin fibers. One cat had a double (somatotroph and melanotroph) adenoma. Twenty somatotroph adenomas consisted of periodic acid-Schiff (PAS)-negative acidophils that expressed growth hormone; 16/20 had hypersomatotropism; 17/20 had diabetes mellitus. Eleven melanotroph adenomas consisted of PAS-positive basophils or chromophobes that expressed melanocyte-stimulating and adrenocorticotrophic hormones; 5/11 had hypercortisolism; 6/11 had diabetes mellitus. Eleven gonadotroph adenomas consisted of PAS-negative chromophobes that expressed follicle-stimulating and/or luteinizing hormones. Two thyrotroph adenomas consisted of PAS-negative basophils or chromophobes that expressed thyroid-stimulating hormone. Pituitary-dependent disease was not recognized in cats with gonadotroph or thyrotroph adenomas. The Ki-67 proliferation index in hypophysectomy specimens was lower in somatotroph than in melanotroph adenomas. Fourteen cats with hypophysectomy-treated somatotroph or melanotroph adenoma had an 899-day median survival time versus 173 days in 17 nonsurgical cases. After adjusting for age, adenoma size and type, hypophysectomized cats had an overall better survival time than nonsurgical cases (P = .029). The study results underscore the value of hypophysectomy and trophic hormone immunohistochemistry in the treatment and classification of feline pituitary adenomas.

Feline plasma adrenocorticotropic hormone: validation of a chemiluminescent assay and concentrations in cats with hypercortisolism, primary hypoadrenocorticism and other diseases

OBJECTIVES

The aims of this study were to validate a commercially available chemiluminescent assay for measurement of feline plasma adrenocorticotropic hormone concentration (ACTH), to determine the normal reference interval (RI) of plasma ACTH in healthy cats, to assess plasma ACTH in cats with naturally occurring hypercortisolism (HC), primary hypoadrenocorticism (PH) and other diseases (OD), and to evaluate the effect of aprotinin on plasma ACTH degradation.

METHODS

Forty healthy cats, 10 with HC, 11 with PH and 30 with OD, were included. The chemiluminescent enzyme immunometric assay was evaluated by measurement of intra-assay precision, interassay precision and linearity. The RI for plasma ACTH in healthy cats was established using robust methods. Plasma ACTH of samples collected with and without aprotinin, stored at 4°C and assayed over a 6-day period, was measured.

RESULTS

The intra-assay coefficients of variance (CVs) ranged from 2.7% to 4.3% and interassay CVs from 3.3% to 10.7%. Dilution studies showed excellent accuracy (R2 >0.99). The RI for plasma ACTH in healthy cats was 32-370 pg/ml. Plasma ACTH was not significantly different between healthy cats and the OD group. Cats with pituitary-dependent hypercortisolism (PDH) and PH had significantly higher plasma ACTH than the other groups. Plasma ACTH did not show significant differences when samples collected with and without aprotinin were compared.

CONCLUSIONS AND RELEVANCE

The Immulite chemiluminescent assay is a valid technique for measuring plasma ACTH in cats and the RI of plasma ACTH is quite wide. Owing to the low overlap between healthy or OD cats and cats with HC or PH, the measurement of plasma ACTH appears to be useful and should be included in the diagnostic work-up when HC or PH are suspected. Furthermore, the measurement of plasma ACTH may be an accurate test for differentiating PDH from adrenal-dependent hypercortisolism.

Pituitary tumour types in dogs and cats

Pituitary tumours are common in dogs and are being increasingly recognized in cats. Pituitary tumours are usually classified as adenomas and should only be classified as carcinomas when there is evidence of metastatic spread of the tumour, which is rare. Despite the benign nature of most pituitary tumours, they can still compress or invade neighbouring tissues. Pituitary tumours can be functional (hormonally active) or non-functional (hormonally silent). The aim of this review was to provide an overview of the different pituitary tumour types in dogs and cats that have been reported in the literature. In dogs, the most common pituitary tumour type is the corticotroph adenoma, which can cause pituitary-dependent hypercortisolism. In cats, the most common pituitary tumour is the somatotroph adenoma, which can cause hypersomatotropism, and the second-most common is the corticotroph adenoma. A lactotroph adenoma has been described in one dog, while gonadotroph, thyrotroph and null cell adenomas have not been described in dogs or cats. Hormonally silent adenomas are likely underdiagnosed because they do not result in an endocrine syndrome. Tools used to classify pituitary tumours in humans, particularly immunohistochemistry for lineage-specific transcription factors, are likely to be useful to classify canine and feline pituitary tumours of unknown origin. Future studies are required to better understand the full range of pituitary adenoma pathology in dogs and cats and to determine whether certain adenoma subtypes behave more aggressively than others. Currently, the mechanisms that underlie pituitary tumorigenesis in dogs and cats are still largely unknown. A better understanding of the molecular background of these tumours could help to identify improved pituitary-targeted therapeutics.

Feline comorbidities: Recognition, diagnosis and management of the cushingoid diabetic

PRACTICAL RELEVANCE

Diabetes mellitus (DM) is a common feline endocrinopathy, and is often driven by underlying insulin resistance with associated pancreatic beta (β)-cell dysfunction. Although spontaneous hyperadrenocorticism (HAC) with hypercortisolemia (hypercortisolism) is relatively uncommon in cats, it is a well-established cause of insulin resistance and is routinely associated with DM in this species.

CLINICAL CHALLENGES

Many of the clinical signs associated with feline HAC are subtle and may be attributed to concurrent DM or the aging process. Failure to recognize HAC in the diabetic cat can impact patient wellbeing and predispose the patient to progressive compromise. Unfortunately, it can be difficult to establish a diagnosis of HAC, as test results may be influenced by poor diabetic regulation, and protocols are different to those used in canine patients. Treatment options depend on the underlying cause, and often require careful, ongoing assessment and modulation of both adrenal function and insulin requirements. However, various approaches have been shown to either improve glycemic control in cats with sustained insulin dependence, or facilitate diabetic remission.

EVIDENCE BASE

This review summarizes the current literature on feline HAC, with a particular focus on cats with concurrent DM. The clinical findings that suggest HAC are discussed, along with an outline of diagnostic options and their limitations. Published outcomes for various medical options, surgical procedures and radiation therapy are provided. The authors also share their thoughts on the safe and effective management of cats with HAC and DM, with an emphasis on the anticipation and recognition of changing insulin requirements.

Feline abdominal ultrasonography: what's normal? what's abnormal? The adrenal glands

PRACTICAL RELEVANCE

Abdominal ultrasound plays a vital role in the diagnostic work-up of many cats presenting to general and specialist practitioners. Ultrasound examination of the adrenal glands can provide important information pertaining to several conditions including hyperaldosteronism and hyperadrenocorticism.

CLINICAL CHALLENGES

Despite ultrasonography being a commonly used modality, many practitioners are not comfortable performing an ultrasound examination or interpreting the resulting images. Even for the experienced ultrasonographer, differentiating between incidental findings, such as adrenal mineralisation, and clinically significant pathological changes can be challenging.

AIM

This review, part of an occasional series on feline abdominal ultrasonography, discusses the ultrasonographic examination of the normal and diseased adrenal glands. Aimed at general practitioners who wish to improve their knowledge of and confidence in feline abdominal ultrasound, this review is accompanied by high-resolution images and videos available online as supplementary material.

EQUIPMENT

Ultrasound facilities are readily available to most practitioners, although the use of ultrasonography as a diagnostic tool is highly dependent on operator experience.

EVIDENCE BASE

Information provided in this article is drawn from the published literature and the author's own clinical experience.

Hepatopatia esteroidal em gatas após terapia com prednisolona: aspectos laboratoriais, tomográficos e histopatológicos

RESUMO Glicocorticoides são amplamente utilizados na clínica de pequenos animais, entretanto seu uso contínuo pode causar efeitos colaterais. Os gatos são considerados menos susceptíveis a esses efeitos do que outras espécies, mas existem poucos trabalhos abordando os efeitos adversos em felinos. O objetivo deste estudo foi avaliar possíveis alterações laboratoriais, histopatológicas e do grau de atenuação radiográfica do parênquima hepático de gatas submetidas à terapia com prednisolona. Um ensaio clínico foi realizado em quatro gatas hígidas, as quais receberam prednisolona, por via oral, na dose de 3mg/kg, durante 60 dias consecutivos. Nos achados histopatológicos após 60 dias de tratamento, observou-se desorganização dos cordões de hepatócitos e degeneração vacuolar, além de necrose de hepatócitos, porém não foram observados sinais de fibrose no parênquima hepático. Os dados da tomografia computadorizada demonstram aumento do grau de atenuação do parênquima hepático a partir do 30º dia da administração de prednisolona, que persistiu até o final do experimento. No presente estudo, foi possível caracterizar a existência de hepatopatia esteroidal em gatos em estágios precoces da terapia com prednisolona.

Hypertension: Why Is It Critical?

Hypertension is a common problem, particularly in older cats. Hypertension secondary to a concurrent disease is the most common form of hypertension in cats, particularly in association with chronic kidney disease or hyperthyroidism. However, idiopathic hypertension may account for up to 24% of cases. Any form of persistent hypertension risks target organ damage (TOD), therefore measurement of blood pressure is vital in at-risk cats to identify occult hypertension before TOD occurs. This article addresses when and how to perform blood pressure measurement in cats, TOD that has been documented in this species, and our evidence basis for treating hypertension.

CT characterisation of feline adrenal glands

OBJECTIVES

The objectives of this study were to describe the CT characteristics of the adrenal glands in healthy cats, to provide normal reference biometry for adrenal gland size and attenuation values, and to investigate the association with age, sex, laterality and body weight.

METHODS

Retrospective evaluation of 30 CT studies of healthy adult cats recruited from September 2013 to July 2015 was performed. Healthy cats >1 year of age were included based on the absence of clinical signs, unremarkable physical examination, normal results of the complete blood count, biochemical profile, feline immunodeficiency virus, feline leukaemia virus and Bartonella species infection tests. The relationship between gland biometry (size and attenuation values) and the age, sex, laterality and body weight of cats were tested by two-way ANOVA. The intraclass correlation coefficient was assessed and mean, SD, range and reference interval provided.

RESULTS

Twenty-seven cats were included. Bilobed, arrowhead and oval adrenal gland shape patterns were recognised, the first being most common. No statistically significant differences were observed between the biometric parameters (length, height and attenuation values) and age, sex, laterality or body weight of the cats. Regarding the width of the adrenal glands, there was a statistically significant effect of sex and laterality. The length (11.6 ± 2.1 mm) and height (6.1 ± 1.3 mm) were the most consistent biometrical parameters to describe adrenal glands.

CONCLUSIONS AND RELEVANCE

Adrenal gland shape, size and attenuation CT data of healthy feline patients are provided in this study, as well as normal reference intervals for morphometric characterisation based on adrenal length and height.

Hypercholesterolemia and hypertriglyceridemia as biochemical markers of disease in companion rabbits

BACKGROUND

Inflammation has important effects on lipid metabolism, but the relationship between hyperlipidemia, inflammation, and disease remains unknown in rabbits. While rabbits are sensitive to dietary hypercholesterolemia, the etiology of hyperlipidemia when fed non-atherogenic diets is uncertain.

OBJECTIVES

This study aimed to determine the association between hypercholesterolemia and patient characteristics, diseases, and select CBC and biochemistry analytes in rabbits, and to measure plasma lipoprotein lipid fractions in rabbits with inflammatory and other diseases.

METHODS

Complete blood count and plasma biochemistry data, including total cholesterol concentrations, were evaluated in 531 companion rabbits. Lipoprotein cholesterol fractions (non-high-density lipoprotein cholesterol [non-HDLc] and high-density lipoprotein [HDLc]) and triglycerides were measured using a colorimetric enzymatic assay in archived plasma from a subset of 267 rabbits. Rabbits were categorized by age, sex, spay/neuter status, breed, diet status (fed atherogenic dietary components or not), the organ system affected by disease, and the pathologic process.

RESULTS

Cholesterol was associated with fibrinogen (P = 0.01), globulins (P < 0.01), and heterophil (P < 0.01) concentrations. Adjusting for diet, rabbits with severe infection or sepsis (odds ratio [OR] = 13.25, 95% CI = 5.83-30.12), renal failure (OR = 14.42, 95% CI = 5.69-36.54), and hepatopathy (OR = 8.55, 95% CI = 3.55-20.62) had increased risks of hypercholesterolemia. Increased non-HDLc and triglyceride concentrations were also associated with these three disease states (P < 0.05).

CONCLUSIONS

Hyperlipidemia is associated with biochemical and CBC markers of inflammation, and with severe infection or sepsis, renal failure, and hepatopathy. Independent of diet, increased cholesterol, non-HDLc, and triglycerides are indicators of disease in companion rabbits.

ACVIM consensus statement: Guidelines for the identification, evaluation, and management of systemic hypertension in dogs and cats

An update to the 2007 American College of Veterinary Internal Medicine (ACVIM) consensus statement on the identification, evaluation, and management of systemic hypertension in dogs and cats was presented at the 2017 ACVIM Forum in National Harbor, MD. The updated consensus statement is presented here. The consensus statement aims to provide guidance on appropriate diagnosis and treatment of hypertension in dogs and cats.

Measurement of the normal feline pituitary gland in brachycephalic and mesocephalic cats

Objectives The purpose of this study was to determine differences in normal feline pituitary dimensions in brachycephalic and mesocephalic cats as a basis for establishing cryohypophysectomy in cats. Methods Measurements were performed on sagittal T2-weighted and transverse post-gadolinium T1-weighted or T1 3D fast field echo-weighted MRI images. A total of 32 brachycephalic and 27 mesocephalic cats were examined. Inter-observer reproducibility was assessed by t-test and Bland-Altman analysis. Results The cats were 0.6-15.9 years of age with a body weight range of 1.84-6.60 kg. For brachycephalic cats, the mean pituitary gland sagittal height was 2.15 ± 0.15 mm, pituitary gland transverse height was 2.42 ± 0.21 mm, pituitary gland transverse width was 4.44 ± 0.27 mm and pituitary gland sagittal length was 3.14 ± 0.30 mm. In mesocephalic cats, the pituitary gland dimensions were 2.94 ± 0.16 mm, 3.09 ± 0.26 mm, 4.73 ± 0.31 mm and 4.88 ± 0.30 mm for pituitary gland sagittal height, transverse height, transverse width and sagittal length, respectively. There was a highly significant correlation between brachycephalic and mesocephalic cats and pituitary gland height and length ( P <0.0001), respectively. Sex also had an effect on pituitary gland measurements. Neutering status had no significant effect on hypophyseal measurements. Age had a significant influence on pituitary gland height, width and length in the brachycephalic population. Inter-observer reproducibility was good to excellent. Conclusions and relevance The different pituitary measurements in brachycephalic and mesocephalic cats has to be considered if surgery comes into question. There are ranges in pituitary gland sizes, even among the mesocephalic cat population. Thus, exact measuring of the pituitary gland is crucial before any surgical intervention.

Diabetes mellitus remission in a cat with pituitary-dependent hyperadrenocorticism after trilostane treatment

Case summary

An 8-year-old male neutered Persian cat was presented with polyuria, polydipsia, polyphagia and muscle weakness associated with a 7 month history of diabetes mellitus (DM). The cat had initially been treated with neutral protamine Hagedorn (NPH) insulin 2 U q12h, followed by porcine lente insulin 2 U q12h and, most recently, 3 U glargine insulin q12h, without improvement of clinical signs. The cat also suffered from concurrent symmetrical bilateral alopecia of thorax and forelimbs, abdominal distension and lethargy. Hyperadrenocorticism (HAC), specifically pituitary-dependent HAC, was suspected and confirmed through abdominal ultrasonography demonstrating bilateral adrenal enlargement, and a low-dose dexamethasone suppression test using 0.1 mg/kg dexamethasone intravenously. Trilostane treatment (initially 10 mg/cat PO q24h then increased to 10 mg/cat PO q12h) was started and insulin sensitivity gradually improved, ultimately leading to diabetic remission after an increased in trilostane dose to 13mg/cat PO q12h, 14 months after the DM diagnosis and 7 months after the initiation of trilostane therapy.

Relevance and novel information

DM in cats with HAC is a difficult combination of diseases to treat. To our knowledge this is the first reported case of diabetic remission in a feline patient with HAC as a result of treatment with trilostane. Further work should focus on whether fine-tuning of trilostane-treatment protocols in cats with concurrent DM and HAC could lead to a higher proportion of diabetic remissions in this patient group.

Comparative occurrence of diabetes in canine, feline, and few wild animals and their association with pancreatic diseases and ketoacidosis with therapeutic approach

Diabetes mellitus (DM) is a chronic metabolic disorder in which blood glucose level raises that can result in severe complications. However, the incidence increased mostly by obesity, pregnancy, persistent corpus luteum, and diestrus phase in humans and animals. This review has focused on addressing the possible understanding and pathogenesis of spontaneous DM in canine, feline, and few wild animals. Furthermore, pancreatic associated disorders, diabetic ketoacidosis, hormonal and drug interaction with diabetes, and herbal remedies associated with DM are elucidated. Bibliographic search for the present review was done using PubMed, Scopus, and Google Scholar for articles on concurrent DM in small and wild animals. Persistent corpus luteal and pseudopregnancy in female dogs generate gestational DM (GDM). GDM can also be caused by extensive use of drugs/hormones such as glucocorticosteroids. Although many similarities are present between diabetic cats and diabetic humans which present islet amyloidosis, there was a progressive loss of β- and α-cells and the normal number of δ-cells. The most prominent similarity is the occurrence of islet amyloidosis in all cases of diabetic cat and over 90% of human non-insulin dependent DM Type-2. Acute pancreatic necrosis (APN) occurs due to predisposing factors such as insulin antagonism, insulin resistance, alteration in glucose tolerance, obesity, hyperadrenocorticism, and persistent usage of glucocorticoids, as these play a vital role in the progression of APN. To manage such conditions, it is important to deal with the etiological agent, risk factors, diagnosis of diabetes, and hormonal and drug interaction along with its termination with suitable therapy (herbal) protocols. It should be noted that the protocols used for the diagnosis and treatment of human DM are not appropriate for animals. Further investigations regarding diabetic conditions of pets and wild animals are required, which will benefit the health status of all animals health worldwide.

2018 AAHA Diabetes Management Guidelines for Dogs and Cats*

Diabetes mellitus (DM) is a common disease encountered in canine and feline medicine. The 2018 AAHA Diabetes Management Guidelines for Dogs and Cats revise and update earlier guidelines published in 2010. The 2018 guidelines retain much of the information in the earlier guidelines that continues to be applicable in clinical practice, along with new information that represents current expert opinion on controlling DM. An essential aspect of successful DM management is to ensure that the owner of a diabetic dog or cat is capable of administering insulin, recognizing the clinical signs of inadequately managed DM, and monitoring blood glucose levels at home, although this is ideal but not mandatory; all topics that are reviewed in the guidelines. Insulin therapy is the mainstay of treatment for clinical DM. The guidelines provide recommendations for using each insulin formulation currently available for use in dogs and cats, the choice of which is generally based on efficacy and duration of effect in the respective species. Also discussed are non-insulin therapeutic medications and dietary management. These treatment modalities, along with insulin therapy, give the practitioner an assortment of options for decreasing the clinical signs of DM while avoiding hypoglycemia, the two conditions that represent the definition of a controlled diabetic. The guidelines review identifying and monitoring patients at risk for developing DM, which are important for avoiding unnecessary insulin therapy in patients with transient hyperglycemia or mildly elevated blood glucose.

Peculiarities of feline hyperadrenocorticism: Update on diagnosis and treatment

Practical relevance: Hyperadrenocorticism (HAC) is a relatively uncommon endocrinopathy of older cats, with a mean age at diagnosis of 10 years. In addition to pituitary-dependent and adrenal-dependent hypercortisolism, clinical signs of HAC can result from adrenal sex steroid-producing tumours. Clinical challenges: While HAC in cats has many similarities to canine HAC, there are key differences in presentation, diagnosis and response to therapy. Most, but not all, cats with HAC have concurrent diabetes mellitus, which is often insulin resistant. Up to a third of cats with HAC have extreme skin fragility and are at high risk of debilitating iatrogenic skin tears during diagnostic or therapeutic interventions. Infections of the skin and nail beds, and urinary, respiratory and gastrointestinal tract, secondary to cortisol-induced immune suppression, are also common. Cats respond differently to dogs to adrenal function tests including adrenocorticotropic hormone (ACTH) stimulation and dexamethasone suppression tests; a 10-fold higher dose of dexamethasone is recommended in cats to screen for HAC. Curative treatment options include adrenalectomy or transsphenoidal hypophysectomy. Radiation or medical treatment may improve clinical signs. The response to mitotane therapy is poor. While trilostane is the medical treatment of choice based on retrospective studies, investigations into the pharmacokinetics of this drug in cats are lacking. Global importance: Feline HAC occurs worldwide and is not associated with any purebreed predisposition. Although uncommon, adrenal sex steroid-producing tumours have a higher prevalence in cats than in dogs. Evidence base: The information in this review is drawn from over 180 reported cases of feline HAC. Reports investigating clinical presentation, clinicopathological findings and treatment outcomes are observational, retrospective multiple case series (EBM grade III) or single case reports (EBM grade IV). While most endocrine testing studies for diagnosis are cohort controlled analytical studies (EBM grade III), prospective, randomised, placebo-controlled studies have been performed (EBM grade I).

Concurrent hyperadrenocorticism and diabetes mellitus in dogs

Hyperadrenocorticism (HAC) and diabetes mellitus (DM) are two diseases that can occur concurrently in dogs. The objective of this study was to evaluate the coexistence of HAC and DM, and the risk factors involved that could contribute to the development of DM in dogs with HAC. A total of 235 dogs with HAC were studied and, according to their fasting glycemia, they were divided into three groups: <5.6mmol/L, between 5.6 and 10.08mmol/L and >10.08mmol/L. The following parameters were evaluated: age, gender, cause of HAC, body condition, glycemia, total cholesterol, triglycerides, urinary cortisol:creatinin ratio (UCCR) and survival time. A 13.61% concurrence of HAC and DM was observed. Dogs with a fasting glycemia >5.6mmol/L, with dislipemia, with Pituitary-Dependent Hyperadrenocorticism, UCCR >100×10^-6 and non-castrated females showed a higher risk of developing DM. The development of DM in dogs with HAC reduces the survival time.

Epidemiology of Diabetes Mellitus among 193,435 Cats Attending Primary-Care Veterinary Practices in England

BACKGROUND

Diabetes mellitus (DM) is a common endocrine disease of cats. The prevalence of DM in cats in England is not well-defined.

HYPOTHESIS/OBJECTIVES

To estimate the prevalence and identify risk factors for DM in a large population of cats attending primary-care practices.

ANIMALS

A cohort of 193,563 cats in the VetCompass Programme attending 118 primary-care practices in England.

METHODS

Cross-sectional analysis of cohort clinical data. Data were extracted covering September 1st 2009 and August 31st 2014. Period prevalence of DM was calculated. Associations between risk factors and DM were assessed using logistic regression modelling.

RESULTS

Of 1,128 DM cases were identified among 194,563 cats (period prevalence 0.58%; 95% confidence interval [CI] 0.54-0.61). Multivariable modelling indicated that Tonkinese (OR 4.1; 95% CI 1.8-9.6; P = .001), Norwegian Forest (odds ratio [OR] 3.5; 95% CI 1.3-9.6; P = .001) and Burmese (OR 3.0; 95% CI 2.0-4.4; P < .001) cats had increased odds of DM compared with crossbred cats. DM odds increased as bodyweight categories increased above 4 kg (P < .001), as cats aged beyond 6 years old (P < .001) and in insured cats (OR 2.0; 95% CI 1.6-2.4; P < .001) but sex was not significantly associated with DM.

CONCLUSIONS AND CLINICAL IMPORTANCE

Diabetes mellitus is an important component of the primary-care practice caseload with 1-in-200 cats affected. An increased risk of DM in certain cat breeds supports a genetic predisposition. These results can guide future research and preventative healthcare.

Hypochloremia in cats - prevalence and associated diseases

OBJECTIVE

To describe the prevalence and possible causes of hypochloremia in the local hospital cat population.

MATERIAL AND METHODS

Retrospective study consisting of two parts. Data were collected from the local electronic medical records database using the search terms "chloride" and "cats" (part A), and "blood gas analysis" and "cats" (part B). The medical records of the hypochloremic cats were then reviewed to determine prior treatment or infusions and to identify major underlying disease processes. Part A included an age and gender matched non-hypochloremic control group, whereas in part B acid-base status was assessed.

RESULTS

Hypochloremia was detected in 367 (27%) of 1363 blood samples. The application of a correction formula to adjust for free water changes decreased the number of hypochloremic cats to 253 (19%). Only a minority had received glucocorticoids or loop diuretics and the prevalence of vomiting was 44%. Common associated disorders were gastrointestinal and respiratory diseases, as well as azotemia and diabetes mellitus. Polyuria/polydipsia, dehydration, prednisolone or furosemide pretreatment, azotemia and diabetes mellitus increased, whereas fluid therapy and the diagnosis of neoplasia decreased the prevalence of hypochloremia. An inverse correlation was found between corrected chloride and standardized base excess (rs = -0.597, p = 0.001) as well as anion gap (rs = -0.4, p = 0.026). 99% of the hypochloremic cats had derangements of acid-base balance.

CONCLUSION

Hypochloremia is a common electrolyte disorder in the local cat population. The correction formula is necessary to adjust for changes in plasma osmolality. Although associated with metabolic alkalosis, most of the hypochloremic cats have a normal or decreased pH. The inverse correlation of chloride and anion gap als well as the high proportion of azotemic or diabetic animals support the concept of compensatory acidosis induced hypochloremia.

CLINICAL RELEVANCE

Hypochloremia should prompt the clinician to performe blood-gas analysis. Diabetes mellitus (especially ketoacidosis) and renal disease should be included in current algorithms for the evaluation of hypochloremic patients.

Cutaneous asthenia (Ehlers-Danlos-like syndrome) of Burmese cats

OF CASES

A 6-month-old Burmese kitten developed focal skin lesions following a routine ovariohysterectomy. These were eventually attributed to the patient struggling during catheter placement and induction of anaesthesia. The lesions were caused by fluid extravasation in the subcutis and ischaemic necrosis of the overlying dermis, giving rise to an eschar-like appearance. Such lesions have been seen previously in Burmese cats with cutaneous asthenia and it is thought that they arise due to poor collagenous support for dermal blood vessels. An increased skin extensibility index (>23%) supported a diagnosis of cutaneous asthenia (Ehlers-Danlos-like syndrome), which has been reported as an inherited condition of Burmese cats in Australia, New Zealand and Europe. An additional Burmese cat with cutaneous asthenia is presented in detail, with lifetime follow-up and further salient observations by the owner, a veterinarian. Photographs of three other affected Burmese cats are provided to illustrate the range of presentations encountered with this condition. All five affected cats were presented with eschars, atrophic alopecia and increased skin extensibility, while one cat also had skin ulcers. Routine histopathological examination, including use of special stains such as trichrome, was unhelpful in establishing the diagnosis.

CLINICAL REVIEW

The clinical features of this genetic disease of Burmese cats are reviewed, especially in relation to the postulated 'vasculopathy' that gives rise to characteristic skin lesions. Long term management of this condition is discussed briefly.