Feline Hyperthyroidism: Signs, Diagnosis, and Treatment

Feline hyperthyroidism is the most common endocrine disorder in middle‑aged and senior cats, with a prevalence of approximately 2.4% in the general feline population and 8.7% among cats aged 10 years or older [1]. This condition results from the excessive production and secretion of thyroid hormones (thyroxine, T4, and triiodothyronine, T3) by a benign adenomatous hyperplasia, rarely carcinoma, of the thyroid gland. If left untreated, hyperthyroidism can lead to severe weight loss, hypertensive damage to the eyes and kidneys, high-output heart failure, and a variety of neurological signs. Early recognition, accurate diagnosis, and appropriate therapy are essential for optimising both survival and quality of life.

This article provides a detailed overview of the clinical signs, diagnostic approach, treatment options, and long‑term management of feline hyperthyroidism, drawing on recent peer‑reviewed literature and established veterinary guidelines. We also highlight red‑flag signs that should prompt an immediate visit to your veterinary surgeon.

Quick Q&A

Question: What are the earliest signs of hyperthyroidism in cats?

Answer: The earliest signs often include unexplained weight loss despite a ravenous appetite, increased thirst and urination, restlessness or hyperactivity, and a poor hair coat. Some cats also develop vomiting or diarrhoea. If you notice any of these changes in your cat, especially if it is over eight years of age, a veterinary check‑up and a blood test for thyroxine concentration is strongly recommended.

Clinical Signs: Recognising the Red Flags

Hyperthyroidism accelerates the cat’s metabolism, causing a constellation of systemic signs. Owners and veterinary clinicians must be vigilant for the following “red‑flag” changes that warrant immediate investigation:

• Weight loss despite polydipsia (increased eating) – a cardinal sign; affected cats often beg for food yet lose muscle mass.
• Polyuria and polydipsia (PU/PD) – increased urine output and thirst, sometimes mimicking kidney disease or diabetes mellitus.
• Hyperactivity, restlessness or irritability – the cat may seem “wired”, vocalise more, or display aggression.
• Tachycardia and heart murmur – elevated heart rate (>220 beats per minute) and a systolic murmur are common; severe cases may lead to gallop rhythms or congestive heart failure.
• Gastrointestinal signs – vomiting, diarrhoea (or soft stools) and occasional tenesmus.
• Poor hair coat – alopecia, matted fur, excessive shedding, or “moth‑eaten” appearance.
• Cervical ventroflexion – a weak, dropped head posture may signal hypokalaemic myopathy, which can occur secondary to hyperthyroidism [25].
• Paroxysmal dyskinesia – episodic involuntary movements, tremors, or ataxia that resolve when thyroid function normalises, a recently recognised manifestation [13].
• Hypertrophic cardiomyopathy phenotype (HCMP) – up to 80% of hyperthyroid cats show echocardiographic changes, including concentric left ventricular hypertrophy, left atrial enlargement, and sometimes a restrictive cardiomyopathy phenotype [10][18]. These changes may partially reverse with effective treatment.

When to see a veterinarian immediately: any cat showing difficulty breathing, sudden paralysis or severe pain in a hindlimb (suggesting arterial thromboembolism), collapse, seizures, or signs of hypertensive crisis (blindness, dilated pupils) needs emergency care. Hyperthyroidism is a risk factor for arterial thromboembolism, even in cats without advanced heart disease [7][8].

Causes and Risk Factors

The precise aetiology of feline hyperthyroidism remains incompletely understood, but current evidence points to a multifactorial origin involving environmental, dietary, and genetic factors.

• Age and breed: The condition is strongly age‑dependent; rarely seen in cats younger than 6 years, with median age at diagnosis around 12 years [3]. No strong breed predisposition exists, but some studies suggest Persian and Siamese cats may have a lower risk.
• Iodine and dietary factors: Consumption of canned cat food with high iodine content and certain preservatives (e.g., BHA/BHT) has been implicated, though definitive causal links are not established.
• Endocrine‑disrupting chemicals (EDCs): Recent investigations found higher urinary levels of phthalates and parabens in hyperthyroid cats compared to healthy controls, suggesting that chemicals from household products, cat litter, or flea treatments may contribute to thyroid dysregulation [9]. Silicone passive sampler tags worn by cats have also detected higher concentrations of fragrances and plasticizers in hyperthyroid individuals [23].
• Indoor lifestyle and canned food: Most hyperthyroid cats are indoor‑dwelling and consume a diet largely of canned food, but controlled studies have not consistently identified a single causal agent.

Despite these associations, hyperthyroidism in cats is not generally considered preventable. Regular wellness screening and a high index of suspicion are the best tools for early detection.

Diagnosing Feline Hyperthyroidism

Diagnosis relies on a combination of clinical examination, baseline biochemistry, and specific thyroid testing. The goal is to confirm excess thyroid hormone production, assess for concurrent disease (especially chronic kidney disease and heart disease), and stage the thyroid pathology.

1. Serum Total Thyroxine (TT4) Measurement

Measurement of serum total thyroxine (TT4) is the first‑line diagnostic test. A single TT4 concentration above the reference interval (typically >40‑50 nmol/L or >3‑4 µg/dL) is highly suggestive of hyperthyroidism. However, up to 10% of cats with early or mild hyperthyroidism may have a TT4 within the upper reference range because of fluctuation or concurrent non‑thyroidal illness [20][28]. In these ambiguous cases, additional testing is indicated.

New point‑of‑care assays for TT4 (e.g., Vcheck T4) provide rapid results with good precision and a high negative predictive value, making them useful for ruling out hyperthyroidism in screening contexts [39].

2. Free T4 (fT4) and Thyroid-Stimulating Hormone (TSH)

Measurement of free T4 by equilibrium dialysis (fT4) can be helpful when TT4 is borderline. Suppression of TSH is an even more specific indicator of hyperthyroidism. The bulk acoustic wave TSH assay (TSH‑BAW) offers high specificity and fewer false positives in cats with non‑thyroidal illness compared to older chemiluminescent assays [20].

3. Reverse T3 (rT3)

Total reverse T3 (rT3), the “inactivated” metabolite of T4, is significantly elevated in hyperthyroid cats and provides excellent diagnostic accuracy (sensitivity 1.0, specificity 0.968 at a cut‑off >0.75 nmol/L) [28]. However, this test is not yet widely available in practice.

4. Thyroid Scintigraphy

Scintigraphy with technetium‑99m pertechnetate is the gold‑standard anatomical and functional imaging technique. It identifies the location, extent, and functional activity of hyperfunctioning thyroid tissue, helping differentiate unilateral from bilateral disease and detecting ectopic thyroid tissue or carcinoma. In a large Argentinian cohort, 38% of cats had bilateral asymmetric involvement, 31% unilateral disease, and 5.6% had features suggestive of carcinoma [3]. Scintigraphy is recommended before definitive treatment with radioiodine (RAI) to plan the dose and anticipate potential complications [30].

5. Renal Assessment: Creatinine and SDMA

Hyperthyroidism increases glomerular filtration rate (GFR), which can mask underlying chronic kidney disease (CKD). After treatment, GFR falls, and previously undetected azotaemia may appear.

Both creatinine and symmetric dimethylarginine (SDMA) are used to assess renal function. However, SDMA can be discordant with GFR in hyperthyroid cats; it may be elevated by non‑renal factors such as hyperthyroidism itself or inflammation [2][15]. Using a higher SDMA cut‑off (≥18 µg/dL) improves specificity for detecting true GFR reduction in senior cats [2]. Additionally, the SDMA level does not reliably predict which cats will become azotaemic after treatment [15][24]. More recent work suggests that urinary asymmetric dimethylarginine (ADMA) may be a more accurate predictor of post‑RAI azotaemia [32].

6. Additional Baseline Tests

A complete blood count, biochemistry panel (including creatinine, urea, phosphorus, and potassium), urinalysis with specific gravity and protein:creatinine ratio, blood pressure measurement, and echocardiography are essential before initiating therapy. Electrocardiography may identify sinus tachycardia, atrial fibrillation, or left ventricular hypertrophy.

Treatment Options

Four major treatment modalities are available: medical management with anti‑thyroid drugs, surgical thyroidectomy, radioiodine therapy (RAI), and dietary management with an iodine‑restricted prescription diet. Each has advantages and limitations; the choice depends on the cat’s age, comorbidities, owner compliance, and access to specialised facilities.

1. Medical Management (Anti‑thyroid Drugs: Thiamazole/Methimazole, Carbimazole)

Thiamazole (methimazole) is the most commonly used oral medication. It blocks thyroid hormone synthesis without destroying thyroid tissue. The starting dose is usually 1.25‑2.5 mg twice daily. A predictive algorithm based on baseline TT4 and creatinine concentrations can help determine whether a cat is likely to require ≤5 mg or >5 mg total daily dose to achieve euthyroidism [11].

Advantages: Non‑invasive, reversible, and suitable for temporary stabilisation or long‑term management in cats that cannot undergo RAI or surgery.

Side effects: About 15‑20% of cats develop adverse effects, including vomiting, anorexia, lethargy, facial excoriation (pruritic dermatitis), and, rarely, serious haematological reactions such as agranulocytosis, anaemia, or thrombocytopenia [37]. Regular monitoring (blood counts and biochemistry) is mandatory, especially in the first 3‑4 months of treatment.

2. Radioiodine Therapy (RAI, 131I)

RAI is the gold‑standard definitive treatment. A single injection of radioactive iodine selectively destroys hyperfunctioning thyroid tissue while sparing normal tissue. Success rates exceed 90‑95% for cats with benign adenomatous disease.

Advantages: Curative, no need for lifelong medication, minimal side effects. The majority of cats become euthyroid within 1‑3 months.

Considerations: RAI requires hospitalisation for a period (variable by jurisdiction). Recent studies suggest that release criteria may be overly conservative; many cats can be discharged the same day with negligible radiation exposure to owners [5]. However, iatrogenic hypothyroidism occurs in 6‑23% of treated cats, especially those with pre‑existing renal compromise or bilateral disease [30][38]. Hypothyroidism, when it occurs, can be managed with levothyroxine supplementation, which has been shown to improve survival in non‑azotaemic cats [38].

Owner satisfaction with RAI is very high, and health‑related quality of life (HRQoL) improves significantly in treated cats, regardless of whether they become euthyroid or hypothyroid [27][29][33].

3. Surgical Thyroidectomy

Unilateral or bilateral surgical removal of affected thyroid lobes is curative. It requires general anaesthesia, which can be risky for cats with compromised cardiac function. Possible complications include hypoparathyroidism (with resulting hypocalcaemia), laryngeal paralysis, and Horner’s syndrome. Preoperative stabilisation with thiamazole is recommended to reduce anaesthetic risk.

4. Dietary Management (Iodine‑Restricted Prescription Diets)

Iodine‑restricted diets (e.g., Hill’s y/d, Royal Canin Feline Veterinary Diet Thyroid Control) limit the availability of dietary iodine, suppressing thyroid hormone synthesis. This option is convenient and non‑invasive.

Limitations: Cats must eat the diet exclusively (no other food or treats) for life. Adherence can be challenging in multi‑cat households or finicky cats. In a quality‑of‑life study, dietary management was associated with lower owner‑reported HRQoL and was less favoured than RAI [33]. The diet is not recommended for cats with concurrent CKD or other conditions requiring specific nutritional support.

Monitoring and Home Care

Whether you choose medical management, RAI, surgery, or diet, ongoing veterinary monitoring is essential:

• Thyroid status: Re‑check TT4 (and TSH if available) 2‑4 weeks after starting or changing therapy, then every 3‑6 months after stabilisation.
• Renal function: Monitor creatinine, SDMA, and urine specific gravity. Post‑treatment azotaemia is a risk, particularly in cats with pre‑existing renal compromise. SDMA levels may not climb as quickly as creatinine, and interpreting discordant results requires clinical judgment [2][15].
• Blood pressure: Hypertension should be managed with amlodipine if systolic blood pressure exceeds 160‑170 mmHg.
• Echocardiography: Repeat imaging 6‑12 months after normalisation of thyroid hormones to assess reversal of hypertrophy and monitor for residual or newly unmasked primary hypertrophic cardiomyopathy [10][18].
• Quality of life: Validated owner‑based instruments (e.g., HyperthyroidismQoL‑cat) are available to track function and well‑being [27][33].

Home Care Tips

• Administer oral medication consistently with food to reduce gastrointestinal upset.
• Provide fresh water ad libitum and a quiet, stress‑reduced environment.
• If using an iodine‑restricted diet, enforce strict dietary control and avoid treats.
• Watch for signs of hypothyroidism (lethargy, weight gain, hair loss, bradycardia) after RAI or surgery. If noted, prompt veterinary re‑evaluation and possible levothyroxine therapy are needed.
• Keep a log of body weight and appetite changes.

Frequently Asked Questions

What are the first signs of feline hyperthyroidism?

The earliest and most common signs are weight loss despite a good or increased appetite, increased thirst and urination, hyperactivity, and a scruffy coat. Vomiting and diarrhoea may also occur. In senior cats, any of these changes should prompt a blood test for thyroxine.

Is hyperthyroidism in cats fatal?

If left untreated, hyperthyroidism can lead to fatal complications: high‑output heart failure, arterial thromboembolism (a saddle thrombus), hypertensive retinopathy, progressive kidney damage, and metabolic derangements. With appropriate treatment, the prognosis is excellent; most cats live many more years with normal quality of life.

Can feline hyperthyroidism be cured?

Yes, definitive treatments such as radioiodine therapy or bilateral thyroidectomy can cure the condition. Medical therapy and dietary management control the disease but require lifelong attention and do not eliminate the underlying thyroid adenoma.

What is the best treatment for hyperthyroidism in cats?

The “best” treatment depends on the individual cat. Radioiodine (RAI) is considered the gold standard for cats without significant concurrent disease and is associated with the highest owner satisfaction and best quality‑of‑life outcomes [27][33]. Medical therapy with thiamazole is a good option for cats that are poor candidates for RAI or surgery, but it requires diligent administration and monitoring.

How long does a cat live after being diagnosed with hyperthyroidism?

Survival depends on the cat’s age, renal function, heart status, and chosen treatment. With successful radioiodine therapy, the median survival of euthyroid non‑azotaemic cats exceeds 4 years (around 1600 days) [38]. Medical management also provides good long‑term outcomes, especially if renal and cardiac disease are well managed. Iatrogenic hypothyroidism after RAI should be recognised and supplemented to maintain survival advantage [38].

Can hyperthyroidism cause heart disease in cats?

Yes, hyperthyroidism frequently induces a hypertrophic cardiomyopathy phenotype (HCMP), often with left ventricular concentric hypertrophy, diastolic dysfunction, and left atrial enlargement. In a recent study, 64% of hyperthyroid cats exhibited HCMP, and 14% had a restrictive cardiomyopathy phenotype [10]. These changes are often reversible once euthyroidism is restored, but long‑standing disease may cause permanent myocardial injury [26].

Is kidney disease a concern in treated hyperthyroid cats?

Absolutely. Hyperthyroidism masks chronic kidney disease by increasing GFR. After successful treatment, GFR declines, and previously undetected azotaemia can appear. Pre‑treatment assessment of creatinine, SDMA, and urinalysis is critical. If azotaemia develops, the management of CKD must be initiated while maintaining euthyroidism; close collaboration with a veterinary internist is recommended.

References

[1] de Carvalho MLP, Caragelasco DS, Librais GNM, et al. Endocrine diseases in Brazilian small‑animal hospitals and referral caseloads: A systematic review and meta‑analysis of proportions. Open Vet J. 2026. [PMID: 42375456]

[2] Hardy L, Hibbert A, Tasker S, et al. Longitudinal evaluation of discordant symmetric dimethylarginine and creatinine as markers of glomerular filtration rate in radioiodine‑treated hyperthyroid cats. J Feline Med Surg. 2026. [PMID: 42359893]

[3] García JD, Devoto C, Miceli DD. Qualitative and quantitative assessment of thyroid scintigraphy in 536 hyperthyroid cats from Argentina. Domest Anim Endocrinol. 2026. [PMID: 42172728]

[4] (CPD module) . Free CPD module on feline hyperthyroidism. Vet Rec. 2026. [PMID: 42138493]

[5] Davila AR, Wang WH. Evaluating feline release criteria following 131I therapy for hyperthyroidism. Health Phys. 2026. [PMID: 42133591]

[6] Nijveldt E, Yildiz V, Schober KE. Echocardiographic evaluation of aortic root size in cats with hypertrophic cardiomyopathy. J Vet Med Sci. 2026. [PMID: 42036317]

[7] Blunschi F, Riwers J, Jaresova T, et al. Tongue infarction in suspected lingual artery thromboembolism in a cat with hypertrophic cardiomyopathy. JFMS Open Rep. 2026. [PMID: 41978704]

[8] Jalilian M, Pahlevaninezhad N, Yazdanjoo Z, et al. Hypertrophic cardiomyopathy in cats: clinical prevalence, risk factors, and outcomes of arterial thromboembolism in a referral population in Tehran, Iran (2020-2024). BMC Vet Res. 2026. [PMID: 41888795]

[9] Ziv-Gal A, Mahoney M, Lopez-Villalobos N, et al. Investigating changes in serum metabolome and urinary endocrine disrupting chemicals in cats with hyperthyroidism. Vet Res Commun. 2026. [PMID: 41870785]

[10] Foulex P, Reslinger B, Kurtz M, et al. Hypertrophic cardiomyopathy is not the sole echocardiographic phenotype associated with hyperthyroidism in cats: a retrospective study in 147 cats (2005-2025). J Vet Intern Med. 2026. [PMID: 41742580]

[11] Tang PK, Lötter N, Geddes RF, et al. A predictive algorithm for the optimal daily dosage of thiamazole to control cats with hyperthyroidism. J Vet Intern Med. 2026. [PMID: 41742559]

[12] Tallaksen JM, Reinhart JM, Lopez-Villalobos N, et al. Subclinical bacteriuria and pyuria in companion animals without signs of lower urinary tract disease: prevalence and associations in a prospective cross‑sectional study using multimodal analytics. J Vet Intern Med. 2026. [PMID: 41742555]

[13] Espinosa J, Espadas I, Karpozilou A, et al. Paroxysmal dyskinesia associated with hyperthyroidism in 7 cats: a novel manifestation of a metabolic encephalopathy. J Vet Intern Med. 2026. [PMID: 41742482]

[14] Niessen SJM, Shiel R, Wehner A, et al. Agreeing Language in Veterinary Endocrinology (ALIVE): Hypothyroidism, Hyperthyroidism, (Euglycaemic) Diabetic Ketosis/Ketoacidosis, and Diabetic Remission – A Modified Delphi‑Method‑Based System to Create Consensus Definitions. Vet Sci. 2026. [PMID: 41600691]

[15] Cox SE, Tarrant EL, Williams TL. Changes in serum symmetric dimethylarginine concentrations after treatment of feline hyperthyroidism with antithyroid medications. J Feline Med Surg. 2026. [PMID: 41566222]

[16] Smith A, Dobson EJ, McCallum KE, et al. Investigation of the association between serum amyloid A concentrations and proteinuria in cats. J Feline Med Surg. 2026. [PMID: 41510759]

[17] Zhou HY, Deng SS, Wei SY, et al. Publisher Correction: Effects of effective antithyroid therapy on adiposity and skeletal muscle in patients with hyperthyroidism across gender and age groups. Eur Rev Med Pharmacol Sci. 2025. [PMID: 41489243]

[18] van Zuiden B, Santarelli G, Galac S, et al. Cardiac Abnormalities in Feline Hyperthyroidism. Vet Sci. 2025. [PMID: 41472095]

[19] Bent N, Kearns S, Mouser P, et al. Primary portal vein hypoplasia in cats: clinical findings, diagnosis and outcomes in five cases. J Feline Med Surg. 2026. [PMID: 41395787]

[20] Brassard C, DeMonaco SM, Wilkinson AR, et al. Comparison of thyrotropin concentrations measured by bulk acoustic wave technology and chemiluminescence in hyperthyroid cats and cats with non‑thyroidal illness. J Feline Med Surg. 2026. [PMID: 41222090]

[21] Shin D, Chae Y, Yun T, et al. Change in insulin‑like growth factor type 1 concentration after radioactive iodine treatment in cats with hyperthyroidism. J Feline Med Surg. 2025. [PMID: 41170923]

[22] Deutsch J, Finch N, Kästner S, et al. Randomised clinical trial comparing intramuscular alfaxalone and butorphanol sedation with or without midazolam in hyperthyroid cats. J Feline Med Surg. 2025. [PMID: 41017067]

[23] Nelson IM, Vazquez JH, Poutasse CM, et al. Unraveling the environmental links to feline hyperthyroidism: Insights from silicone passive samplers. Environ Res. 2025. [PMID: 40972849]

[24] Menzel AP, Schaub S, Güssow A, et al. [Evaluation of predictors of chronic kidney disease in hyperthyroid cats following radioiodine treatment – a pilot study]. Tierarztl Prax Ausg K Kleintiere Heimtiere. 2025. [PMID: 40897180]

[25] Karpozilou A, De Stefani A, Liatis T. Cervical ventroflexion in cats: 86 cases (2003-2024). J Feline Med Surg. 2025. [PMID: 40692342]

[26] Janus‑Ziółkowska I, Bubak J, Tursi M, et al. Molecular Cardiac Changes in Feline Hyperthyroidism and Hypertrophic Cardiomyopathy: Focus on Desmin, Calreticulin, and Interleukin-10 Expression. Animals (Basel). 2025. [PMID: 40564271]

[27] Blunschi F, Muthmann S, Bauer N, et al. Comparison of the Changes in Quality‑of‑Life of Cats with Hyperthyroidism Treated with Radioiodine or Antithyroid Drugs – A Preliminary Study. Vet Sci. 2025. [PMID: 40559809]

[28] Wiesner NR, Zeugswetter FK, Hildebrand A, et al. Reverse triiodothyronine concentrations in hyperthyroid, healthy, and azotemic cats determined by ultra‑performance liquid chromatography‑tandem mass spectrometry. Domest Anim Endocrinol. 2025. [PMID: 40513454]

[29] Muthmann S, Tiefenbrunner JL, Blunschi F, et al. Owners’ Experience and Satisfaction with Radioiodine Treatment in Hyperthyroid Cats – A Prospective Questionnaire Study. Vet Sci. 2025. [PMID: 40431551]

[30] Stammeleer L, Xifra P, Serrano SI, et al. Thyroid Scintigraphy Findings in 234 Hyperthyroid Cats Before and After Radioiodine Treatment. Animals (Basel). 2025. [PMID: 40427371]

[31] Schreiber N, Prisco F, Kipar A, et al. Valvular mitral stenosis in adult cats: knowledge gained from the clinical and pathological workup of 18 cases. J Vet Cardiol. 2025. [PMID: 40286346]

[32] Vanden Broecke E, Stammeleer L, Stock E, et al. Efficacy of Urine Asymmetric Dimethylarginine Concentration to Predict Azotemia in Hyperthyroid Cats After Radio‑Iodine Treatment. J Vet Intern Med. 2025. [PMID: 40271736]

[33] Muthmann S, Schofield I, Kersting M, et al. Influence of Owner Personality and Other Owner‑, Cat‑ and Treatment‑Related Factors on the Perception of Quality of Life in Cats With Hyperthyroidism. J Vet Intern Med. 2025. [PMID: 40231815]

[34] Ruane E, Odatzoglou P, Wong H, et al. Primary hyperparathyroidism in a domestic shorthair cat following I(131) radioiodine therapy. J Small Anim Pract. 2025. [PMID: 40169934]

[35] Cattaneo G, Kingsbury EJ, McCallum KE, et al. Association of Serum Symmetric Dimethylarginine Concentrations and Inflammation in Cats. J Vet Intern Med. 2025. [PMID: 40008808]

[36] Leuthard FN, Carranza Valencia A, Wenger M, et al. Screening for naturally occurring hypothyroidism in adult cats: A prospective multi‑center study in Central Europe. Schweiz Arch Tierheilkd. 2025. [PMID: 39943853]

[37] Mastrangelo C. Adverse side effects, including agranulocytosis and anemia, from methimazole treatment of a hyperthyroid cat. Can Vet J. 2025. [PMID: 39898169]

[38] Cox SE, Wakeling J, Hall T, et al. Survival of radioiodine treated hyperthyroid cats that are euthyroid and hypothyroid after treatment, and effect of levothyroxine supplementation on survival time of cats with iatrogenic hypothyroidism. J Vet Intern Med. 2025. [PMID: 39831449]

[39] Spada E, Perego R, Baggiani L, et al. Evaluation of a point‑of‑care test for quantitative determination of total thyroxine in feline serum. J Feline Med Surg. 2025. [PMID: 39781578]

[40] Guse B, Langenstein J, Bauer N, et al. Signalment, clinicopathological findings, management practices and comorbidities in cats with diabetes mellitus in Germany: cross‑sectional study of 144 cases. J Feline Med Surg. 2025. [PMID: 39772828]