Naturally Occurring Adrenocortical Insufficiency--An Epidemiological Study Based on a Swedish-Insured Dog Population of 525,028 Dogs

European Network for Optimization of Veterinary Antimicrobial Therapy (ENOVAT) Guidelines for Antimicrobial Use in Canine Acute Diarrhoea

Acute diarrhoea is a common presentation in dogs, and a common reason for antimicrobial prescription and nutraceutical use. This evidence-based guideline provides recommendations for antimicrobial and probiotic treatment of canine acute diarrhoea (CAD). A multidisciplinary panel developed the recommendations by adhering to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. The opinions of stakeholders (general veterinary practitioners and dog owners) were collected and incorporated to ensure the applicability of this guideline. Four strong recommendations informed by high certainty evidence, and three conditional recommendations informed by very low or low certainty evidence, were drafted by the panel, along with an ungraded section on diagnostic work-up of dogs with acute diarrhoea. The ENOVAT guidelines initiative encourages national or regional guideline makers to use the evidence presented in this document, and the supporting systematic review, to draft national or local guidance documents.

The epidemiology of osteochondrosis in an insured Swedish dog population

Osteochondrosis (OC) is a focal disturbance of endochondral ossification due to a failure of blood supply to the epiphyseal growth cartilage. In dogs, OC most commonly affects the shoulder joint, followed by the elbow, tarsal, and stifle joints. The condition is associated with clinical signs such as lameness and pain and the prognosis varies depending on the affected joint. Most epidemiologic studies of OC in dogs were performed over 20 years ago, and updated estimates of disease incidence are lacking. Therefore, the objectives of this study were to provide population-based estimates of the incidence rate, cause-specific mortality rate, and age at diagnosis of appendicular OC (AOC, including OC of the shoulder, elbow, stifle, and tarsal joints) and stifle and tarsal OC separately, using data from Agria Djurförsäkring in Sweden (2011-2016). Further, the study aimed to evaluate the risk of OC in subgroups divided by breed and sex and describe previous, concurrent, and subsequent diagnoses of the affected joint in dogs with stifle or tarsal joint OC. The study population included just over 600,000 dogs, of which 685 were affected by AOC. Stifle joint OC (n = 113) was more common than tarsal joint OC (n = 80). The incidence rate of AOC was 3.77 (95% confidence interval (CI): 3.49-4.07) cases per 10,000 dog-years at risk, while the incidence rate of stifle and joint tarsal OC was 0.64 (95% CI: 0.53-0.77) and 0.43 (95% CI: 0.34-0.54) cases per 10,000 dog-years at risk, respectively. All breeds at increased risk of AOC were large or giant, and male dogs had an increased risk of AOC compared to female dogs (RR 1.76, 95% CI: 1.50-2.07, p < 0.001). The median age at first diagnosis during the study period was 0.74 (0.32-11.5) years for AOC, 2.62 (0.45-8.82) years for stifle joint OC, and 0.73 (0.35-7.35) years for tarsal joint OC. Of the dogs with stifle or tarsal joint OC, 30.2% and 15.0% had a previous diagnosis of stifle/tarsal joint pain or other unspecific clinical signs, respectively, and 13.8% of the dogs with stifle joint OC suffered subsequent cruciate ligament rupture. Osteochondrosis was the most common reason for euthanasia in the affected dogs. In total, 77 dogs were euthanised due to AOC during the study period.

Hypothalamic-pituitary-adrenal axis recovery after intermediate-acting glucocorticoid treatment in client-owned dogs

BACKGROUND

In dogs, duration of hypothalamic-pituitary-adrenal (HPA) axis suppression after systemic glucocorticoid treatment is reported to vary from a few days to up to 7 weeks after glucocorticoid discontinuation. These data are derived mainly from experimental studies in healthy dogs and not from animals with spontaneous disease.

HYPOTHESIS AND OBJECTIVE

To determine the timeline for recovery of the HPA axis in a group of ill dogs treated with intermediate-acting glucocorticoids (IAGCs).

ANIMALS

Twenty client-owned dogs that received IAGC for at least 1 week.

METHODS

Single-center prospective observational study. An ACTH stimulation test, endogenous ACTH concentration, serum biochemistry profile, and urinalysis were performed at T0 (2-6 days after IAGC discontinuation) and then every 2 weeks (eg, T1, T2, T3) until HPA axis recovery was documented (post-ACTH cortisol concentration > 6 μg/dL).

RESULTS

The median time of HPA axis recovery was 3 days (range, 2-133 days). Eleven of 20 dogs showed recovery of the HPA axis at T0, 6/20 at T1, and 1 dog each at T2, T5, and T9. Dose and duration of treatment were not correlated with timing of HPA axis recovery. Activities of ALT and ALP were significantly correlated with the post-ACTH cortisol concentration (rs = -0.34, P = .03; rs = -0.31, P = .05). Endogenous ACTH concentration was significantly correlated with pre (r = 0.72; P < .0001) and post-ACTH cortisol concentrations (r = 0.35; P = .02). The timing of HPA axis recovery of the dogs undergoing an alternate-day tapering dose was not different compared to dogs that did not (3.5 vs 3 days, P = .89).

CONCLUSION AND CLINICAL IMPORTANCE

Most dogs experienced HPA axis recovery within a few days after IAGC discontinuation. However, 2/20 dogs required >8 weeks.

Prevalence of eunatremic, eukalemic hypoadrenocorticism in dogs with signs of chronic gastrointestinal disease and risk of misdiagnosis after previous glucocorticoid administration

BACKGROUND

Dogs with eunatremic, eukalemic hypoadrenocorticism (EEH) typically show signs of chronic gastrointestinal disease (CGD). Previous glucocorticoid administration (PGA) can give false-positive results on the ACTH stimulation test (ACTHst).

HYPOTHESIS/OBJECTIVES

To determine the prevalence of EEH in dogs with signs of CGD, and to identify clinical and clinicopathological features for EEH and PGA.

ANIMALS

One hundred twelve dogs with CGD (101 non-PGA and 11 PGA), 20 dogs with EEH.

METHODS

Multicenter prospective cohort study. Basal serum cortisol (BSC) concentration was measured in dogs with signs of CGD. When BSC was <2 μg/dL and in PGA dogs, ACTHst plus measurement of endogenous ACTH (eACTH) were performed. Records of dogs with EEH from 2009 to 2021 were reviewed.

RESULTS

The BSC concentration was <2 μg/dL in 48/101 (47.5%) non-PGA and in 9/11 (82%) PGA dogs. EEH was diagnosed in 1/112 dog (prevalence 0.9%; 95% CI, 0.1%-4.8%); the ACTHst provided false-positive results in 2/11 PGA dogs. PGA dogs showed lower C-reactive protein-to-haptoglobin ratio (median 0.01, range 0.003-0.08; P = .01), and higher haptoglobin (140, 26-285 mg/dL; P = .002) than non-PGA dogs (0.04, 0.007-1.5; 38.5, 1-246 mg/dL, respectively). eACTH was higher (P = .03) in EEH (396, 5->1250 pg/mL) than in non-PGA dogs (13.5, 7.3-46.6 pg/mL). Cortisol-to-ACTH ratio was lower (P < .0001 and P = .01, respectively) in EEH (0.002, 0.0002-0.2) than in non-PGA (0.1, 0.02-0.2) and PGA dogs (0.1, 0.02-0.2).

CONCLUSIONS AND CLINICAL IMPORTANCE

The prevalence of EEH in dogs with signs of CGD was lower than previously reported. The clinical and clinicopathological features herein identified could increase the index of suspicion for EEH or PGA in dogs with an unclear history of glucocorticoid administration.

The epidemiology of patellar luxation in an insured Swedish dog population

Patellar luxation (PL) is a common orthopaedic condition in dogs. This study aimed to evaluate the incidence and cause-specific mortality rate, age at diagnosis, and risk factors for medial PL (MPL), lateral PL (LPL), and bidirectional PL (BPL). Other diagnoses in dogs with PL were also explored. The study population included just over 600,000 dogs insured by Agria Pet Insurance in Sweden (2011-2016). There were 2726 dogs with PL. Medial patellar luxation affected 90 % of the dogs with PL, followed by LPL (5.9 %), BPL (2.4 %), and unspecified PL (1.6 %). The median age at first diagnosis during the study period was 2.8 years for MPL, 2.7 years for LPL, and 1.5 years for BPL. In total, 168 (6.2 %) of the dogs with PL had cruciate ligament rupture. There were substantial breed-specific differences in the risk of PL: almost all breeds at increased risk of MPL were small-sized, while several of the breeds at increased risk of LPL were large-sized. The breeds at high risk of BPL varied in size. Females had an increased risk of MPL (RR 1.2, 95 % CI: 1.1-1.3, p < 0.001) and a decreased risk of LPL (RR 0.72, 95 % CI: 0.51-1.0, p = 0.042) compared to males. In total, 116 dogs were euthanised due to PL and the breeds with the highest risk of PL-related euthanasia were the Pyrenean mountain dog, Dogue de Bordeaux, and German pinscher. The median age for PL-related euthanasia was 2.2 years.

A case-control survey study of environmental risk factors for primary hypoadrenocorticism in dogs

BACKGROUND

Primary hypoadrenocorticism in dogs is thought to be multifactorial with roles for both genetic and environmental factors. The contributions of environmental factors remain unexplored.

OBJECTIVE

Identify environmental and lifestyle exposures associated with primary hypoadrenocorticism in 2 dog breeds with high risk of developing the disease.

ANIMALS

Animals were not used in this study. Owners of Standard Poodles (STPDs) and Portuguese water dogs (POWDs) participated in a survey.

METHODS

Retrospective case-control study. Dog owners were invited to participate in an online survey through convenience sampling. Questions regarded the demographics, health histories, and indoor/outdoor environments in which their dogs live and play. Responses for dogs with primary hypoadrenocorticism were compared to those without the disease using univariate and multivariate logistic regression models.

RESULTS

Five thousand forty-seven responses (358 cases, 4689 controls) met initial inclusion criteria. Significant associations with modest effect size were found for community type, ingestion of canned food, and use of lawn fertilizer in some analysis models. Reproductive (spay/neuter) status exhibited the strongest association with high effect size across all models with adjusted odds ratio (OR) 2.5 (95% confidence interval [CI], 1.4-4.5; P = .003) for spayed females and 6.0 (95% CI, 2.6-13.9; P < .001) for neutered males.

CONCLUSIONS AND CLINICAL IMPORTANCE

The large effect size for reproductive status reflects its high potential clinical relevance, whereas modest effect sizes for other environmental variables suggest lower potential clinical relevance. These findings are associations and do not necessarily imply causation. Before any actionable recommendations are warranted, additional evidence regarding biological mechanisms is needed.

[Polyendocrine syndromes in dogs]

The autoimmune polyendocrine syndrome (APS) refers to a combination of autoimmune endocrine disorders. It is rarely described in dogs. The most common combinations are hypoadrenocorticism and hypothyroidism, followed by diabetes mellitus, and less often hypoparathyroidism and orchitis. The diagnosis of the APS is based on the diagnosis of each endocrinopathy, as is the therapy, which involves the substitution of deficient hormones. If a patient was previously stable under treatment and is showing further signs (e.g. polyuria, polydipsia, or weight loss), the development of additional endocrinopathies like hypoadrenocorticism or diabetes mellitus should be considered. The diagnosis of the initially diagnosed endocrinopathy should also be critically questioned. This article summarizes some cases of our own animal hospital and selected cases published in the available literature.

A qualitative analysis of the impact of canine hypoadrenocorticism on the quality of life of owners

BACKGROUND

Canine hypoadrenocorticism is a rare chronic disease, which demands intense dog-owner interaction, as its treatment requires to be individualised. The aim of this study was a qualitative analysis of the challenges owners face when dealing with the disease, especially regarding its management and how this affects quality of life. By promoting an online discussion between owners, we transcribed and summarised their experiential knowledge in dealing with the disease.

METHODS

Owners were recruited for the online seminars via social media. After a theoretical introduction, participants were free to share experiences and ask questions. The recorded events were retrospectively analysed.

RESULTS

Twenty-four owners of 22 Addisonian dogs took part in four events. Owners felt most "traumatised" when experiencing their dog's acute adrenal crisis. The initial adjustment phase and distinguishing the non-specific symptoms of hypoadrenocorticism from those of other diseases were also challenging. Overall, owners were well informed on the disease and committed to its long-term adjustment.

CONCLUSIONS

Adrenal crisis and the initial adjustment phase may be more burdening to owners than expected. Understanding what their clients' concerns are, can help veterinarians provide better care and reduce the negative impacts of canine hypoadrenocorticism. Promoting peer to peer support, as well as providing a framework for participative communication might also help.

Prevalence of hypercalcemia in primary hypoadrenocorticism in dogs: Multicenter, retrospective study

BACKGROUND

Hypoadrenocorticism is an important differential for hypercalcemia. The etiology of hypercalcemia in hypoadrenocorticism in dogs is unclear.

OBJECTIVE

To review the prevalence of hypercalcemia and use statistical models to identify clinical, demographic, and biochemical variables associated with hypercalcemia in dogs with primary hypoadrenocorticism.

ANIMALS

One hundred ten dogs with primary hypoadrenocorticism; 107 with recorded total calcium (TCa), 43 recorded ionized calcium (iCa).

METHODS

Multicenter retrospective observational study at 4 UK referral hospitals. Univariable logistic regression analyses were performed to assess the association between independent variables of signalment, hypoadrenocorticism type (glucocorticoid only deficient hypoadrenocorticism [GHoC] vs glucocorticoid and mineralocorticoid deficient hypoadrenocorticism [GMHoC]), clinicopathological variables and hypercalcemia. Hypercalcemia was defined as elevated TCa, an elevated iCa, or both elevated TCa and iCa (Model 1) or as elevated iCa (Model 2).

RESULTS

Overall prevalence of hypercalcemia was 34.5% (38/110). The odds of hypercalcemia (Model 1) were increased (P < .05) in dogs with GMHoC ([vs GHoC], OR [odds ratio] = 3.86, 95% confidence interval [CI] 1.105-13.463), higher serum creatinine (OR = 1.512, 95% CI 1.041-2.197), and higher serum albumin (OR = 4.187, 95% CI 1.744-10.048). The odds of ionized hypercalcemia (Model 2) were increased (P < .05) with reduced serum potassium concentration (OR = 0.401, 95% CI 0.184-0.876) and younger age (OR = 0.737, 95% CI 0.558-0.974).

CONCLUSIONS AND CLINICAL IMPORTANCE

This study identified several key clinical and biochemical variables associated with hypercalcemia in dogs with primary hypoadrenocorticism. These findings aid understanding of the pathophysiology and etiology of hypercalcemia in dogs with primary hypoadrenocorticism.

Diagnostic predictivity of transtubular potassium gradient for primary hypoadrenocorticism in hyperkalemic dogs: a cross-sectional study

OBJECTIVES

Transtubular potassium gradient has never been evaluated in the diagnosis of primary hypoadrenocorticism in dogs. The objective of this study is to evaluate the diagnostic utility of transtubular potassium gradient for the diagnosis of primary hypoadrenocorticism in dogs with serum K+  > 5.5 mol/L.

MATERIALS AND METHODS

Cross-sectional study including dogs with primary hypoadrenocorticism and dogs with other disease. Differences in signalment and laboratory parameters between groups were assessed by binary logistic regression modelling. Variables significantly associated with primary hypoadrenocorticism were evaluated for their diagnostic accuracy of this condition by receiver operator characteristic curve analysis and by multivariable logistic regression analysis, respectively.

RESULTS

Dogs with primary hypoadrenocorticism (n=39) were significantly younger than hyperkalemic dogs without primary hypoadrenocorticism (n=41). Moreover they had higher serum and urinary concentrations of Na+ and Na+ :K+ , but lower transtubular potassium gradient than hyperkalemic dogs without hypoadrenocorticism. Serum Na+ (sNa+ ) had the highest diagnostic accuracy (area under the curve [AUC]: 0.87, 95% confidence interval, 0.78 to 0.96), followed by the transtubular potassium gradient (AUC: 0.81, 0.72 to 0.91), however the accuracy of the two AUCs was not statistically different. The transtubular potassium gradient-sNa+ additive index (i.e. transtubular potassium gradient+sNa+ /10) had a greater accuracy (AUC: 0.88, 0.79 to 0.94) than transtubular potassium gradient or sNa+ , although it was not statistically superior to the latter. The multivariable logistic regression model showed that transtubular potassium gradient (adjusted odds ratio [aOR]: 0.51, 0.3 to 0.84), sNa+ (aOR: 0.86, 0.78 to 0.95) and spayed female (aOR: 24.96, 2.32 to 267.66) were associated with primary hypoadrenocorticism.

CLINICAL SIGNIFICANCE

Transtubular potassium gradient-sNa+ additive index can contribute to decision-making on diagnosis of primary hypoadrenocorticism in dogs presenting with hyperkalaemia.

Morbidity of insured Swedish cats between 2011 and 2016: Comparing disease risk in domestic crosses and purebreds

BACKGROUND

Sources of population-based cat health information are scarce. The objective of this study was to determine disease frequency in cats using pet insurance data to inform health promotion efforts.

METHODS

A descriptive analysis of cats insured with Agria Pet Insurance in Sweden (2011-2016) was performed. Incidence rates of broad disease categories were calculated based on veterinary care events and an exact denominator consisting of cat-years-at-risk. Rate ratios were calculated, comparing domestic crosses to all purebreds and specific purebreds to all other purebreds combined.

RESULTS

The study included over 1.6 million cat-years-at-risk (78.5% were domestic crosses), 18 breeds and 24 disease categories. The most common disease categories causing morbidity in purebreds were digestive, whole body, injury, urinary lower, skin and female reproduction. Purebreds had the highest relative risk (compared to domestics crosses) in the female reproduction, heart, operation complication, respiratory lower and immunological disease categories.

LIMITATIONS

There are typical limitations of secondary data, but they do not negate the overall value of such a large dataset.

CONCLUSION

This study demonstrates how pet insurance data can be used to find breed-specific differences in the incidence of various disease categories in cats. This may be of importance for breeders, cat owners, veterinarians and researchers.

Banking on a new understanding: translational opportunities from veterinary biobanks

Current advances in geroscience are due in part to the discovery of biomarkers with high predictive ability in short-lived laboratory animals such as flies and mice. These model species, however, do not always adequately reflect human physiology and disease, highlighting the need for a more comprehensive and relevant model of human aging. Domestic dogs offer a solution to this obstacle, as they share many aspects not only of the physiological and pathological trajectories of their human counterpart, but also of their environment. Furthermore, they age at a considerably faster rate. Studying aging in the companion dog provides an opportunity to better understand the biological and environmental determinants of healthy lifespan in our pets, and to translate those findings to human aging. Biobanking, the systematic collection, processing, storage, and distribution of biological material and associated data has contributed to basic, clinical, and translational research by streamlining the management of high-quality biospecimens for biomarker discovery and validation. In this review, we discuss how veterinary biobanks can support research on aging, particularly when integrated into large-scale longitudinal studies. As an example of this concept, we introduce the Dog Aging Project Biobank.

Successful use of a benchtop fluorescent enzyme immunoassay analyzer to measure serum cortisol concentration as a screening test for hypoadrenocorticism in dogs

OBJECTIVE

To assess the diagnostic performance of a benchtop fluorescent enzyme immunoassay analyzer (AIA-360; Tosoh Bioscience Inc) for the measurement of serum cortisol concentration as a screening test for hypoadrenocorticism in dogs.

ANIMALS

173 client-owned dogs (20 with hypoadrenocorticism and 153 with nonadrenal illness).

PROCEDURES

Medical records of all dogs that underwent an ACTH stimulation test between June 2015 and October 2019 were reviewed retrospectively. Dogs were excluded if the ACTH stimulation test was performed on the basis of a suspicion of hypercortisolism, serum cortisol concentrations were measured using an analyzer other than the one assessed in the present study, or dogs had received medication known to affect the pituitary-adrenal axis in the 4 weeks1,2 preceding ACTH stimulation testing. The diagnostic performance of the benchtop analyzer was evaluated by calculating sensitivity, specificity, and likelihood ratios at various cutoff points.

RESULTS

Serum resting cortisol cutoff point concentrations of 0.8 μg/dL (22 nmol/L), 1 μg/dL (28 nmol/L), and 2 μg/dL (55 nmol/L) had a sensitivity of 100%. An optimal serum resting cortisol cutoff point of 0.58 μg/dL (16 nmol/L) had a sensitivity, specificity, and positive and negative likelihood ratios of 100%, 97%, and 30.6 and 0.0, respectively.

CLINICAL RELEVANCE

Findings indicated that previously derived cutoff points could be used with excellent sensitivity to exclude hypoadrenocorticism in this population of dogs when serum cortisol concentration was measured with the evaluated benchtop analyzer. An ACTH stimulation test may need to only be performed to diagnose hypoadrenocorticism if resting serum cortisol concentration is ≤ 0.58 μg/dL when measured with the evaluated benchtop analyzer.

Evaluation of a machine learning tool to screen for hypoadrenocorticism in dogs presenting to a teaching hospital

BACKGROUND

Dogs with hypoadrenocorticism (HA) have clinical signs and clinicopathologic abnormalities that can be mistaken as other diseases. In dogs with a differential diagnosis of HA, a machine learning model (MLM) has been validated to discriminate between HA and other diseases. This MLM has not been evaluated as a screening tool for a broader group of dogs.

HYPOTHESIS

An MLM can accurately screen dogs for HA.

ANIMALS

Dogs (n = 1025) examined at a veterinary hospital.

METHODS

Dogs that presented to a tertiary referral hospital that had a CBC and serum chemistry panel were enrolled. A trained MLM was applied to clinicopathologic data and in dogs that were MLM positive for HA, diagnosis was confirmed by measurement of serum cortisol.

RESULTS

Twelve dogs were MLM positive for HA and had further cortisol testing. Five had HA confirmed (true positive), 4 of which were treated for mineralocorticoid and glucocorticoid deficiency, and 1 was treated for glucocorticoid deficiency alone. Three MLM positive dogs had baseline cortisol ≤2 μg/dL but were euthanized or administered glucocorticoid treatment without confirming the diagnosis with an ACTH-stimulation test (classified as "undetermined"), and in 4, HA was ruled out (false positives). The positive likelihood ratio of the MLM was 145 to 254. All dogs diagnosed with HA by attending clinicians tested positive by the MLM.

CONCLUSIONS AND CLINICAL IMPORTANCE

This MLM can robustly predict HA status when indiscriminately screening all dogs with blood work. In this group of dogs with a low prevalence of HA, the false positive rates were clinically acceptable.

Effect of long-term management of hypoadrenocorticism on the quality of life of affected dogs and their owners

BACKGROUND

The treatment of canine adrenal insufficiency consists of hormone substitution and requires high owner compliance and intense human-dog interaction. This might affect the quality of life (QoL) of owners and their pets. The aim of the study was to evaluate the impact of hypoadrenocorticism and its treatment on the QoL of dogs and their owners.

METHODS

Owners completed a web-based survey that contained items concerning signalment, owner QoL, dog QoL and long-term therapy.

RESULTS

Three hundred and twenty-two owners participated. Most owners feared an adrenal crisis. Approximately half of the participants reported that the bond between them and their pet increased after diagnosis. Although many participants felt that their own QoL was not affected by their dog's disease, worries about costs and leaving their dog unsupervised were frequently reported. Half of the study participants increased their dog's glucocorticoid doses when a stressful situation was foreseeable ('boosting' of therapy). Some administered hydrocortisone, mostly switched from prednisolone, resulting in a reduction in side effects.

CONCLUSIONS

Special attention should be given to glucocorticoid therapy and owner's QoL. The overall worry of an adrenal crisis might increase caregivers' burden, reducing their overall QoL. Hydrocortisone might be a safe alternative to prednisolone, but further research is necessary to evaluate its long-term efficacy and safety in dogs.

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.

Evaluation of resting cortisol concentration testing in dogs with chronic gastrointestinal signs

Background

Resting cortisol concentrations are routinely measured in dogs with chronic gastrointestinal signs to rule out hypoadrenocorticism based on a concentration >2 μg/dL (>55 nmol/L).

Hypothesis/Objectives

To assess the cross‐sectional prevalence of hypoadrenocorticism in a group of dogs with chronic gastrointestinal signs presented to a referral internal medicine service.

Animals

Two‐hundred and eighty‐two client‐owned dogs with chronic gastrointestinal signs and with resting cortisol concentration testing performed.

Methods

Retrospective review of medical records (final diagnosis, resting cortisol concentration, and adenocorticotropic hormone [ACTH] stimulation test results) of a referral population of dogs between May 2013 and September 2017.

Results

Resting cortisol concentration was <2 μg/dL (<55 nmol/L) in 79 patients (28%). Repeated resting cortisol concentration measurements were performed in 28 dogs, and in 8, resting cortisol concentrations remained <2 μg/dL (<55 nmol/L). Post‐ACTH cortisol concentration was <2 μg/dL (<55 nmol/L) in 1 dog, consistent with a diagnosis of hypoadrenocorticism and giving a prevalence estimate of hypoadrenocorticism in this population of dogs of 0.3% (95% confidence interval [95CI], 0.03‐1.5%). In 19 dogs with an initial resting cortisol concentration <2 μg/dL (<55 nmol/L), hypoadrenocorticism was excluded based on a repeat resting cortisol concentration >2 μg/dL (>55 nmol/L). Overall, the most common diagnosis was chronic primary inflammatory enteropathy (176/282, 62.4%), followed by extragastrointestinal neoplasia (17/282, 6%), protein‐losing enteropathy, pancreatitis and megaesophagus (10/282, 3.5% each).

Conclusions and Clinical Importance

Although dogs with hypoadrenocorticism can present with chronic gastrointestinal signs, it was the final diagnosis in only 1 of 282 dogs presenting to a referral internal medicine service for signs of chronic enteropathy. Repeated resting cortisol concentration may be considered as a test to try and exclude hypoadrenocorticism.

Use of Deoxycorticosterone Pivalate by Veterinarians: A Western European Survey

This study aims to gather knowledge about the use of deoxycorticosterone pivalate (DOCP) by Western European Veterinarians (WEV) in dogs with typical hypoadrenocorticism. An observational cross-sectional study was conducted using an online survey, translated into four languages and disseminated to veterinary affiliates and mailing lists in six countries of Western Continental Europe. Respondents were tasked to share their therapeutic approach to hypoadrenocorticism, whether they preferred DOCP or fludrocortisone and the specific practical use of DOCP. One-hundred and eighty-four responses were included. Of these, 79.9% indicated that they preferred prescribing DOCP over fludrocortisone as a first-line treatment for mineralocorticoid supplementation. A total of 154 respondents had used DOCP at least once. Eighty percent of those who reported their initial dosage prescribed 2.2 mg/kg. After starting DOCP, 68.2% of the respondents assess electrolytes 10 and 25 days after administration following manufacturer instructions. In stable dogs, electrolytes are monitored quarterly, monthly, semi-annually, and annually by 44.2%, 34.4%, 16.9%, and 4.6% of respondents respectively. When treatment adjustment is required, 53% prefer to reduce dosage while 47% increase the interval between doses. Overall, DOCP is the preferred mineralocorticoid supplementation among WEV. Reported variability underlies the need to investigate the best strategies for DOCP use and therapeutic adjustments.

The epidemiology of cruciate ligament rupture in an insured Swedish dog population

Cruciate ligament rupture (CLR) is a common orthopedic disorder in dogs. The study objectives were to evaluate incidence rate (IR), cause-specific mortality rate (CSMR) and risk factors for CLR in insured dogs. A single cohort study of dogs insured in Agria Pet Insurance in Sweden (2011–2016) was performed. Age at diagnosis, IR, CSMR and relative risk (RR) for CLR was calculated overall and per breed. The cohort included just over 600,000 dogs. The IR of CLR was 23.8 (95% confidence interval, 23.1–24.6) cases per 10,000 DYAR. The breeds with highest RR of CLR were Boerboel and Dogo Canario, while the breeds with lowest RR were Standard Dachshund and Miniature Pinscher. Dogue de Bordeaux had highest RR of euthanasia due to CLR. The median age at veterinary care claim for CLR was 7.1 (range 0.3–16.0) years and 6.6 (0.3–12) years at life insurance settlement. Large and giant breeds were generally diagnosed and euthanized due to CLR at a younger age compared to smaller breeds. The majority of the breeds with increased RR of CLR diagnosis and CLR-related euthanasia were large or giant. A pattern of increasing size and decreasing age at diagnosis/CLR-related euthanasia was observed.

The epidemiology of stifle joint disease in an insured Swedish dog population

BACKGROUND

Stifle joint diseases (SJD) are common in dogs and include a variety of diagnoses. The objective of the study was to provide an overview of the epidemiology of SJD in insured dogs.

METHODS

An historical single cohort study of dogs insured in Agria Pet Insurance (2011-2016) in Sweden was performed. Incidence and relative risk (RR) of SJD was calculated for the whole dog population and for subgroups divided by breed, breed group and sex.

RESULTS

The study population included almost 600,000 insured dogs (>1.7 million dog-years). Ninety-three different stifle joint diagnoses were reported in 9624 dogs, and the most common were cruciate ligament rupture and patellar luxation. The incidence of SJD was 55.4 cases per 10,000 dog-years at risk. Bulldog and boerboel had the highest RR of SJD. The breeds that accounted for the highest proportion of all SJD claimed dogs were mixed breed and Labrador retriever. Female dogs had a slightly increased RR compared with male dogs (RR 1.06, p = 0.006). The incidence increased yearly during the observation period.

CONCLUSION

The study demonstrates breed-specific differences in incidence of SJD in dogs, which may be of importance for breeders, dog owners and veterinarians.

Hypoadrenocorticism in dogs under UK primary veterinary care: frequency, clinical approaches and risk factors

Objectives

To estimate the frequency, clinical approaches and risk factors of hypoadrenocorticism in dogs under UK primary veterinary care.

Materials and Methods

Dogs diagnosed with hypoadrenocorticism were identified from the UK VetCompass™ programme by searching anonymised electronic patient records. Pre‐existing and newly diagnosed cases of disease during 2016 were included. Cases were further sub‐categorised as having a laboratory‐confirmed or presumed diagnosis of hypoadrenocorticism based on the information recorded in the electronic patient records. Descriptive data were manually extracted. Multivariable logistic regression methods were used to identify demographic risk factors.

Results

There were 177 hypoadrenocorticism cases identified from 905,543 dogs in 2016; 72 laboratory‐confirmed and 105 presumed. The 1‐year period prevalence for hypoadrenocorticism in all dogs was 0.06% (95% confidence interval: 0.05‐0.07%). The most common presenting clinical signs in laboratory‐confirmed dogs were lethargy (51/66, 77.3%), anorexia (48/66, 66.7%) and vomiting (48/66, 66.7%). Hyperkalaemia was reported in 47 of 53 (88.7%), hyponatraemia in 46 of 53 (86.8%). Median sodium: potassium ratio was 19.00 (interquartile range: 16.20‐20.60). Breed, age, neuter status and insurance status were associated with a laboratory‐confirmed diagnosis of hypoadrenocorticism. No sex association with hypoadrenocorticism was observed in the multivariable model. The standard poodle had 51.38 times the odds (95% CI: 14.49‐182.18) of hypoadrenocorticism compared with crossbreeds. The labradoodle and West Highland white terrier also had increased odds.

Clinical Significance

This is the first epidemiological study to report on hypoadrenocorticism in dogs within the UK primary‐care population. These results provide benchmark data of current veterinary activity relating to hypoadrenocorticism in primary‐care practices.

Genetic characterization of Addison's disease in Bearded Collies

BACKGROUND

Primary hypoadrenocorticism (or Addison's disease, AD) is an autoimmune disease that results in destruction of the adrenal cortex and consequent adrenal insufficiency. The disease has been described in purebred and mixed breed dogs, although some breeds, including the Bearded Collie, are at increased risk for AD. Candidate gene approaches have yielded few associations that appear to be breed-specific. A single other genome-wide association study reported no significant regions of association for AD in Standard Poodles. The present study aimed to identify genomic regions of association for canine AD in Bearded Collies.

RESULTS

Our study consists of the first genome-wide association analysis to identify a genome-wide significant region of association with canine AD (CFA18). Peaks of suggestive association were also noted on chromosomes 11, 16 and 29. Logistic regression analysis supported an additive effect of risk genotypes at these smaller effect loci on the probability of disease associated with carrying a risk genotype on CFA18. Potential candidate genes involved in adrenal steroidogenesis, regulation of immune responses and/or inflammation were identified within the associated regions of chromosomes 11 and 16. The gene-poor regions of chromosomes 18 and 29 may, however, harbor regulatory sequences that can modulate gene expression and contribute to disease susceptibility.

CONCLUSION

Our findings support the polygenic and complex nature of canine AD and identified a strongly associated locus on CFA18 that, when combined with three other smaller effect loci, was predictive of disease. The results offer progress in the identification of susceptibility loci for canine AD in the Bearded Collie. Further studies are needed to confirm association with the suggested candidate genes and identify actual causative mutations involved with AD susceptibility in this breed.

Randomised clinical non-inferiority trial comparing two formulations of desoxycortone pivalate for the treatment of canine primary hypoadrenocorticism

BACKGROUND

This clinical trial compared two formulations of desoxycortone pivalate (DOCP) for treating the mineralocorticoid deficit in dogs with primary hypoadrenocorticism (PH).

METHODS

At veterinary clinics in the USA and France, dogs with PH (n=152) were randomised (3:1) to receive approximately monthly treatments with either the test product, Zycortal (Dechra), administered subcutaneously (n=113), or the control product, Percorten-V (Novartis Animal Health), administered intramuscularly (n=39), both at an initial dose of 2.2 mg/kg DOCP. Treatment administrators were unblinded; veterinarians assessing clinical signs were blinded; owners were blinded until at least day 90, the primary end point. Veterinarians assessed treatment outcome based on all of the following: clinical signs; sodium concentrations; potassium concentrations. Dogs received concurrent glucocorticoid therapy throughout the trial. Non-inferiority was assessed using a generalised linear mixed model to compare success rates between groups.

RESULTS

Success rates at day 90 were similar between groups (per-protocol population at day 90: Zycortal 87/101, 86.2 per cent, Percorten-V 29/34, 85.1 per cent). Zycortal was non-inferior to Percorten-V as the upper limit of the 95 per cent CI for the difference between groups was 13.6 per cent. Polydipsia and polyuria were the most common clinical observations.

CONCLUSION

Both products, in combination with glucocorticoid therapy, were safe and effective in treating PH.

Prevalence and characterization of hypoadrenocorticism in dogs with signs of chronic gastrointestinal disease: A multicenter study

Background

Dogs with hypoadrenocorticism (HA) frequently show signs of gastrointestinal disease (SGD). The prevalence of dogs presented for chronic SGD with HA is unknown.

Objectives

The aims of this study were to determine the prevalence of HA in dogs with chronic SGD and to identify clinical and laboratory variables for HA in this population.

Animals

One hundred fifty‐one dogs with chronic SGD.

Methods

In this multicentered prevalence study a standardized workup was performed in prospectively enrolled dogs with SGD > 3 weeks duration. Basal serum cortisol concentration was measured in every dog with ACTH stimulation test (ACTHST) if basal serum cortisol concentration was <3 μg/dL.

Results

Basal serum cortisol concentration was <3 μg/dL in 80/151 (53%) dogs, <2 μg/dL in 42/151 (28%) dogs, and < 1 μg/dL in 9/151 (6%) dogs. In 6/151 dogs HA was diagnosed based on ACTHST (stimulated serum cortisol concentration < 2 μg/dL), a prevalence of 4%. There was no difference in history, physical examination, and laboratory variables between dogs with HA and those with other causes of chronic SGD. In 4/6 dogs with HA, there was melena or hematochezia indicating gastrointestinal blood loss. Hyperkalemia, hyponatremia, or both was not observed in any dog.

Conclusion and Clinical Importance

The prevalence of HA among dogs with chronic SGD is higher than in the general population. Based on these results, testing adrenal function should be performed as a standard screening test in dogs with chronic SGD to differentiate between HA and chronic enteropathies.

A case of canine hypoadrenocorticism needing blood transfusion for severe acute anemia due to gastrointestinal hemorrhage

A 3-year-old male Rottweiler presented with the chief complaint of recurrent vomiting, diarrhea, hypothermia, and lethargy. Hypovolemic shock was noted with abnormal electrolytes (Na/K ratio, 27.9) and anemia (hematocrit, 17.3%). Since the hematocrit was 49.2% four days earlier when the primary veterinarian examined the dog, acute anemia was diagnosed. Melena was observed on the next day. The general condition and hydration improved with treatment, and an adrenocorticotropic hormone stimulation test identified hypoadrenocorticism. However, the hematocrit decreased further to 9%, necessitating blood transfusion. The cause of severe acute anemia was thought to be gastrointestinal hemorrhage. It should be noted that hypoadrenocorticism can lead to potentially fatal anemia with gastrointestinal tract bleeding, and blood transfusion may be required.

A Review of the Impact of Neuter Status on Expression of Inherited Conditions in Dogs

Gonadectomy is an important reproductive management tool employed in many countries, and is highly prevalent in the US with an estimated 85% of dogs being neutered. Despite the societal benefits in pet population control, negative associations between neuter status, and health conditions have been reported in recent years. Most particularly observed are the consequences of early age neutering. Knowing that different physiological systems rely upon gonadal steroids during development and physiological maintenance, studies have been undertaken to assess the impact of neuter status on multiple body and organ systems. For some inherited conditions, neutering is associated with an increased risk of expression. Neutering has also been associated with altered metabolism and a predisposition for weight gain in dogs, which may confound the detected risk association between neutering and disease expression. This review summarizes the effects of neutering on cancer, orthopedic, and immune disorders in the dog and also explores the potentially exacerbating factor of body weight.

Retrospective evaluation of the severity of and prognosis associated with potassium abnormalities in dogs and cats presenting to an emergency room (January 2014-August 2015): 2441 cases

OBJECTIVE

To determine the severity, concurrent clinical signs, and disease processes associated with potassium abnormalities in dogs and cats presenting to a veterinary emergency department and associated mortality.

DESIGN

Retrospective and descriptive study over 20 months.

SETTING

University teaching hospital.

ANIMALS

1916 dog and 525 cat visits.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Medical records from patients with a potassium concentration measured within 24 hours of admission were identified. Hypokalemia and hyperkalemia were defined as a potassium concentration <3.5 mmol/L [3.5 mEq/L] and >5 mmol/L [5 mEq/L], respectively. Associated disease processes and pathophysiologic risk factors for potassium abnormalities were reviewed for moderate to severe potassium abnormalities (<3 mmol/L or ≥6 mmol/L) [<3 mEq/L or ≥6 mEq/L]. Mortality associated with normokalemia, mild, and moderate to severe dyskalemia were evaluated. Overall prevalence of abnormal potassium concentration was 27% in dogs and 40% in cats. Moderate to severe hypokalemia and hyperkalemia were present in 3% of dogs and 8% of cats, and 2% of dogs and 7% of cats, respectively. Moderate to severe hypokalemia was most commonly associated with gastrointestinal disease (48% of dogs and 44% of cats) while moderate to severe hyperkalemia was most commonly associated with urinary tract disease (60% of dogs and 97% of cats). Dogs with hypokalemia and dogs and cats with hyperkalemia (P < 0.001) had significantly greater mortality than those with normokalemia. Dogs with mild hypokalemia and mild hyperkalemia (P < 0.0001) had higher mortality than dogs with normokalemia, but this was not found in cats.

CONCLUSIONS

Dyskalemia was common in this population and was associated with greater mortality. Moderate to severe potassium abnormalities were uncommon in this population and occurred most frequently in animals with gastrointestinal and urinary tract disease.

Breed susceptibility for common surgically treated orthopaedic diseases in 12 dog breeds

Background

A retrospective case–control study was conducted to estimate breed predisposition for common orthopaedic conditions in 12 popular dog breeds in Norway and Sweden. Orthopaedic conditions investigated were elbow dysplasia (ED); cranial cruciate ligament disease (CCLD); medial patellar luxation (MPL); and fractures of the radius and ulna. Dogs surgically treated for the conditions above at the Swedish and Norwegian University Animal Hospitals between the years 2011 and 2015 were compared with a geographically adjusted control group calculated from the national ID-registries. Logistic regression analyses (stratified for clinic and combined) were used to calculate odds ratios (OR) and 95% confidence intervals. Mixed breed dogs were used as reference.

Results

Breeds found at-risk for ED were the Labrador retriever (OR = 5.73), the Rottweiler (OR = 5.63), the German shepherd dog (OR = 3.31) and the Staffordshire bull terrier (OR = 3.08). The Chihuahua was the only breed where an increased risk for MPL (OR = 2.80) was identified. While the Rottweiler was the only breed predisposed for CCLD (OR = 3.96), the results were conflicting for the Labrador retriever (OR = 0.44 in Sweden, 2.85 in Norway); the overall risk was identical to mixed-breed dogs.

Conclusions

Most results are in concordance with earlier studies. However, an increased risk of CCLD was not identified for the Labrador retriever, the Staffordshire bull terrier was found to have an increased risk of ED and some country-specific differences were noted. These results highlight the importance of utilising large caseloads and appropriate control groups when breed susceptibility is reported.

Electronic supplementary material

The online version of this article (10.1186/s13028-019-0454-4) contains supplementary material, which is available to authorized users.

DLA class II haplotypes show sex-specific associations with primary hypoadrenocorticism in Standard Poodle dogs

Addison's disease (AD) is a life-threatening endocrine disorder that occurs spontaneously in both humans and dogs. Associations between MHC class II genes and AD have been shown in several human studies. Our goal was to identify MHC class II associations with AD in a large population of Standard Poodles, a breed highly predisposed to AD. We sequenced exon 2 of the class II genes DLA-DRB1, DLA-DQA1, and DLA-DQB1 in 110 affected and 101 unaffected Standard Poodles and tested for association with AD. After correcting for population structure, two haplotypes were found to confer risk of developing AD in a sex-specific manner: DLA-DRB1*015:01-DQA1*006:01-DQB1*023:01 in males (x²p = 0.03, OR 2.1) and DLA-DRB1*009:01-DQA1*001:01-DQB1*008:01:1 in females (x²p = 0.02, OR 8.43). Sex-specific associations have been previously described in human populations, but this is the first report of this kind in dogs. Consistent with findings in other studies, we found the DLA-DQA1*006:01 allele (x²p = 0.04) to be associated with AD in males independent of haplotype. In females, the haplotype DLA-DRB1*009:01-DQA1*001:01-DQB1*008:01:1 confers a very high risk for developing AD, although its frequency was rare (9 of 124 females) in our study population. Further studies are warranted to validate the findings of this exploratory dataset and to assess the usefulness of this haplotype as a risk marker for AD in female Standard Poodles. Our results highlight the importance of evaluating MHC class II disease associations in large populations, and accounting for both biological sex and population structure.

DLA class II risk haplotypes for autoimmune diseases in the bearded collie offer insight to autoimmunity signatures across dog breeds

BACKGROUND

Primary hypoadrenocorticism (Addison's disease, AD) and symmetrical lupoid onychodystrophy (SLO) are two clinical conditions with an autoimmune etiology that occur in multiple dog breeds. In man, autoimmunity is associated with polymorphisms in immune-related genes that result in a reduced threshold for, or defective regulation of, T cell activation. The major histocompatibility complex (MHC) class II genes encode molecules that participate in these functions, and polymorphisms within these genes have been associated with autoimmune conditions in dogs and humans. Bearded collies have a relatively high prevalence of autoimmune diseases, particularly AD and SLO. Our study assessed the relationship between particular MHC (dog leukocyte antigen, DLA) class II haplotypes and the two autoimmune diseases most common in this breed. Moreover, five unrelated breeds at increased risk for AD were studied for comparative purposes and analyzed in the context of extant literature.

RESULTS

A single DLA class II three-locus haplotype, determined by sequence-based typing, was associated with increased risk for AD (DLA-DRB1*009:01/DQA1*001:01/DQB1*008:02) in bearded collies. Comparative analysis with the five additional breeds showed limited allele sharing, with DQA1*001:01 and DQB1*002:01 being the only alleles observed in all breeds. A distinct three-locus risk haplotype (DLA-DRB1*001:01/DQA1*001:01/DQB1*002:01) was associated with AD in the West Highland white terrier and Leonberger. Two different risk haplotypes were associated with increased risk for SLO in the bearded collie (DLA-DRB1*018:01/DQA1*001:01/DQB1*002:01 and DLA-DRB1*018:01/DQA1*001:01/ DQB1*008:02).

CONCLUSION

Two-locus DQ haplotypes composed of DLA-DQA1*001:01 in association with DLA-DQB1*002:01 or DLA-DQB1*008:02 make up the four risk haplotypes identified in the present study and are also found in other risk haplotypes previously associated with diabetes mellitus and hypothyroidism across different dog breeds. Our findings build upon previously published data to suggest that this two-locus (DQ) model serves as a good indicator for susceptibility to multiple organ-specific autoimmune diseases in the canine population. However, it is also clear that additional loci are necessary for actual disease expression. Investigation of affected and unaffected dogs carrying these predisposing DQ haplotype signatures may allow for the identification of those additional genetic components that determine autoimmune disease expression and organ specificity.

Management of hypoadrenocorticism (Addison's disease) in dogs

Hypoadrenocorticism (HOAC; Addison’s disease) is an endocrine condition seen in small animal practice. Dogs with this disease can present in a variety of ways from acute hypovolemic collapse to vague, chronic, waxing, and waning clinical signs. In the most common form of this disease, animals have both mineralocorticoid and glucocorticoid deficiency, resulting in hyponatremia and hyperkalemia, and signs of cortisol deficiency. The etiology may be immune-mediated destruction of the adrenal cortex, drug-induced adrenocortical necrosis (mitotane), enzyme inhibition (trilostane), or infiltrative processes such as neoplastic or fungal disease. Much less commonly, dogs have signs of cortisol deficiency, but no electrolyte changes. This is referred to as atypical HOAC. The veterinarian needs to have a clinical suspicion for HOAC to make a diagnosis in a timely manner. Treatment of dogs with an acute presentation prioritizes correcting the hypovolemia, hyperkalemia, acidosis, and hypoglycemia. Fluid therapy addresses most of these issues, but other directed therapies may be required in the most severe cases. For chronic management, all patients with Addison’s disease will require replacement of glucocorticoids (usually prednisone), and most patients require replacement of mineralocorticoids with either desoxycorticosterone pivalate or fludrocortisone. Atypical Addisonians do not require mineralocorticoid supplementation, but electrolytes should be monitored in case the need arises in the future. The prognosis for dogs treated for HOAC promptly and appropriately is excellent; most patients die from other diseases. However, if the diagnosis is missed, patients may die as a consequence of HOAC. Thus, knowledge of the hallmarks of Addison’s disease is imperative.

Gonadectomy effects on the risk of immune disorders in the dog: a retrospective study

BACKGROUND

Gonadectomy is one of the most common procedures performed on dogs in the United States. Neutering has been shown to reduce the risk for some diseases although recent reports suggest increased prevalence for structural disorders and some neoplasias. The relation between neuter status and autoimmune diseases has not been explored. This study evaluated the prevalence and risk of atopic dermatitis (ATOP), autoimmune hemolytic anemia (AIHA), canine myasthenia gravis (CMG), colitis (COL), hypoadrenocorticism (ADD), hypothyroidism (HYPO), immune-mediated polyarthritis (IMPA), immune-mediated thrombocytopenia (ITP), inflammatory bowel disease (IBD), lupus erythematosus (LUP), and pemphigus complex (PEMC), for intact females, intact males, neutered females, and neutered males. Pyometra (PYO) was evaluated as a control condition.

RESULTS

Patient records (90,090) from the William R. Pritchard Veterinary Medical Teaching Hospital at the University of California, Davis from 1995 to 2010 were analyzed in order to determine the risk of immune-mediated disease relative to neuter status in dogs. Neutered dogs had a significantly greater risk of ATOP, AIHA, ADD, HYPO, ITP, and IBD than intact dogs with neutered females being at greater risk than neutered males for all but AIHA and ADD. Neutered females, but not males, had a significantly greater risk of LUP than intact females. Pyometra was a greater risk for intact females.

CONCLUSIONS

The data underscore the importance of sex steroids on immune function emphasizing a role of these hormones on tissue self-recognition. Neutering is critically important for population control, reduction of reproductive disorders, and offers convenience for owners. Despite these advantages, the analyses of the present study suggest that neutering is associated with increased risk for certain autoimmune disorders and underscore the need for owners to consult with their veterinary practitioner prior to neutering to evaluate possible benefits and risks associated with such a procedure.

Evaluation of the genetic basis of primary hypoadrenocorticism in Standard Poodles using SNP array genotyping and whole-genome sequencing

Primary hypoadrenocorticism, also known as Addison's disease, is an autoimmune disorder leading to the destruction of the adrenal cortex and subsequent loss of glucocorticoid and mineralocorticoid hormones. The disease is prevalent in Standard Poodles and is believed to be highly heritable in the breed. Using genotypes derived from the Illumina Canine HD SNP array, we performed a genome-wide association study of 133 carefully phenotyped Standard Poodles (61 affected, 72 unaffected) and found no markers significantly associated with the disease. We also sequenced the entire genomes of 20 Standard Poodles (13 affected, 7 unaffected) and analyzed the data to identify common variants (including SNPs, indels, structural variants, and copy number variants) across affected dogs and variants segregating within a single pedigree of highly affected dogs. We identified several candidate genes that may be fixed in both Standard Poodles and a small population of dogs of related breeds. Further studies are required to confirm these findings more broadly, as well as additional gene-mapping efforts aimed at fully understanding the genetic basis of what is likely a complex inherited disorder.

Evaluation of artificial selection in Standard Poodles using whole-genome sequencing

Identifying regions of artificial selection within dog breeds may provide insights into genetic variation that underlies breed-specific traits or diseases-particularly if these traits or disease predispositions are fixed within a breed. In this study, we searched for runs of homozygosity (ROH) and calculated the d _i statistic (which is based upon F _ST) to identify regions of artificial selection in Standard Poodles using high-coverage, whole-genome sequencing data of 15 Standard Poodles and 49 dogs across seven other breeds. We identified consensus ROH regions ≥1 Mb in length and common to at least ten Standard Poodles covering 0.6 % of the genome, and d _i regions that most distinguish Standard Poodles from other breeds covering 3.7 % of the genome. Within these regions, we identified enriched gene pathways related to olfaction, digestion, and taste, as well as pathways related to adrenal hormone biosynthesis, T cell function, and protein ubiquitination that could contribute to the pathogenesis of some Poodle-prevalent autoimmune diseases. We also validated variants related to hair coat and skull morphology that have previously been identified as being under selective pressure in Poodles, and flagged additional polymorphisms in genes such as ITGA2B, CBX4, and TNXB that may represent strong candidates for other common Poodle disorders.