Feline aldosterone-secreting adrenocortical tumour studies

Aldosterone-secreting adrenocortical tumours are uncommon neoplasms in cats, leading to the paraneoplastic condition of primary hyperaldosteronism. However, it is unknown how often these tumours cause multiple corticosteroid abnormalities.

Two recent studies looked at these endocrine abnormalities in cats with adrenal tumours. Langlois et al¹ performed a study to evaluate adrenal-derived corticosteroids in the blood samples of cats that had previously been submitted to a laboratory for measurement of aldosterone. A total of 297 cats were included in this retrospective study.

Progesterone and corticosterone concentrations were strongly correlated with each other, and were higher in cats with markedly increased aldosterone concentrations than cats with normal aldosterone concentrations. In total, 32% of cats with markedly high aldosterone also had markedly high progesterone concentrations. Cortisol was lower in cats with high aldosterone concentrations than those with normal aldosterone.

The authors noted that multiple corticosteroid abnormalities are found in some cats with hyperaldosteronism, and that the level of increases in progestorone and corticosterone is likely to be clinically relevant in some cases.

Harro et al² described a retrospective case series of 10 cats with multiple corticosteroid-secreting adrenocortical tumours. All 10 cats were found to have diabetes mellitus and clinicopathological features of hyperaldosteronism – for example, hypokalaemia.

All 10 cases had unilateral adrenal tumours identified on ultrasound examination, with the contralateral adrenal gland atrophied or not identified in five cases. Three out of four cats that underwent surgical adrenalectomy developed hypoadrenocorticism, but three cats had remission from their diabetes mellitus after adrenalectomy.

Two cats treated surgically survived more than one year, and two cats out of four cats treated medically survived more than one year. Two cats were not treated.

As with the previous study, the authors noted that multiple corticosteroid abnormalities can be found in cats with aldosterone secreting adrenal tumours – especially if diabetes mellitus is also present. Long-term survival can be achieved with medical and surgical therapy, but remission from diabetes mellitus was only observed after adrenalectomy.

Diagnosis and utility of assessing respiratory clinical signs

Examination and assessment of abnormal breathing patterns (ABPs) is part of the clinical assessment of a patient – especially one with respiratory signs. However, it is known that in humans there is only poor-to-moderate interclinician agreement when classifying ABPs.

Two papers by the same group looked at the diagnosis and utility of assessing respiratory clinical signs. The first study by Dominguez-Ruiz et al³ aimed to assess the interclinician agreement in the recognition of certain respiratory clinical signs in dogs and cats with ABPs.

Dogs and cats from three hospitals were evaluated each by three clinicians and the level of agreement between the clinicians’ assessments was analysed. A total of 115 dogs and 49 cats were included in the study.

Stertor, stridor, attenuation of heart and/or lung sounds and goose honking in dogs, and stertor and open-mouth breathing in cats, had a reasonable-to-good level of interobserver agreement.

A good level of agreement on assessment of respiratory rate also occurred. However, for most respiratory clinical signs, interobserver agreement was poor. A larger difference in clinical experience between the observers led to a lower agreement.

The authors recommended teaching and acquisition of clinical experience to improve the recognition of clinical respiratory signs.

The second paper by Dominguez-Ruiz et al⁴ aimed to explore the associations between respiratory signs and disease locations in dogs and cats with ABPs. Little evidence exists on the diagnostic value of respiratory signs in small animals.

As in the previous study, dogs presenting to three hospitals were assessed for respiratory signs, and they were included in the study if it was possible to localise their disease by investigations. The same population of 115 dogs and 49 cats were assessed. Inspiratory effort was found to be associated with extra-thoracic airway disease, with an odds ratio of 9.1, and expiratory effort with intra-thoracic airway disease, with an odds ratio of 6.5. Paradoxical breathing and muffled heart and lung sounds were associated with pleural disease.

Decreased nasal airflow and stertor were associated with naso-pharyngeal disease with an odds ratio of 26.2, and stridor with laryngeal or tracheal disease with an odds ratio of 39. All dogs with goose honking had tracheal involvement of their disease. Tracheal sensitivity was associated with bronchial disease and crackles were associated with pulmonary or bronchial disease, but the associations were weaker.

The authors concluded that certain respiratory signs aid in disease localisation, which can help target further diagnostic tests and treatments.

Prostatic artery embolisation to treat prostatic carcinoma

Prostatic carcinoma is a difficult neoplasm to treat, with limited success with chemotherapy, and often poor outcomes after surgery.

In a prospective cohort study, Culp et al⁵ described a procedure to treat this condition with prostatic artery embolisation. In total, 20 dogs with prostatic carcinoma were included in the study.

Before and after the procedure, dogs underwent ultrasound and CT examinations of the prostate, and owners completed questionnaires about their dogs’ clinical signs. Prostatic arterial embolisation was carried out under fluoroscopic guidance. The procedure was performed successfully in all 20 dogs.

Symptoms of tenesmus, stranguria and lethargy were significantly less common 30 days after the procedure compared to before. Median prostatic volume was reduced after the procedure, and all dogs had a reduction in prostatic volume.

The authors note that the procedure was associated with improved clinical signs and reduced prostatic volume in the short term. Longer-term evaluation of the procedure is needed to assess its impact on survival time.

Complications associated with CT angiography

Despite the apparent success of the previous study, CT angiography used to perform transarterial embolisation is associated with some risks.

Griffin et al⁶ described complications associated with this procedure. In the same week at one institution, three sequential patients suffered from suspected contrast-induced nephropathy after undergoing CT angiography to assist in transarterial embolisation.

One case was a 10-year-old, female, poodle-cross; one was a 13-year-old, male, mixed-breed dog; and one was a female cat. They were undergoing the procedure for treatment of prostatic carcinoma in one case and hepatocellular carcinoma in the other two cases.

Higher creatinine was observed after contrast administration. Patients were treated for acute kidney injury. After a median of 4 days, serum creatinine concentration began to improve, and within a median of 7 days (range 3 to 13 days) the concentration had returned to reference range levels. The authors note that contrast-induced nephropathy is a potential risk after CT angiography, but the prognosis appears to be excellent with appropriate care.

The COVID-19 pandemic led to many changes to people’s lifestyle – especially in countries with lockdowns that restricted movement.

Vučinić et al⁷ reported a study that determined the effect of a state of emergency with a curfew and restrictions on movement in Belgrade on the duration of walking time of owners with their dogs. The study was conducted in March and April 2020.

COVID-19 pandemic restrictions led to a decrease in duration of dog walks – 59% of dog owners walked their dogs more than 150 minutes per week before the pandemic, compared to 44% during the state of emergency.

Owner sex, age and income were associated with the magnitude of the effects of the pandemic on walking times. The authors noted that COVID-19 has changed the social structures and daily habits of households, which can affect the walking time of dogs and their owners.

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