Canine Cognitive Dysfunction (Dog Dementia): DISHAA, Stages, and What It Is Not
A comprehensive veterinary guide to canine cognitive dysfunction: diagnostic scoring via the DISHAA scale, clinical mimics, and openFDA safety analysis of selegiline (Anipryl).
As advances in veterinary medicine, nutrition, and owner care continue to extend the lifespan of companion animals, veterinary professionals are increasingly managing geriatric small-animal populations. With advanced age, however, comes the emergence of chronic, degenerative diseases. Among the most challenging of these is Canine Cognitive Dysfunction (CCD), also known as cognitive dysfunction syndrome (CDS) or "dog dementia."
CCD is a neurodegenerative disorder of senior dogs characterized by a progressive decline in cognitive function, memory, learning ability, and environmental awareness. It pathologically mirrors human Alzheimer’s disease, sharing key neuroanatomical features such as the accumulation of amyloid-beta plaques, hyperphosphorylation of tau proteins, cerebral amyloid angiopathy, free-radical damage, and cortical atrophy.
Despite its prevalence—an estimated 14.2% of dogs aged 8 years and older, rising to roughly 28% of dogs aged 11–12 and 68% of those aged 15–16—CCD remains underdiagnosed. This is partly because owners often attribute early clinical signs to "normal aging," and partly because the syndrome mimics several common geriatric diseases, such as chronic pain from osteoarthritis, sensory decline, or metabolic imbalances. Population-level comorbidity data from the Dog Aging Project canine comorbidity network show that cognitive decline in senior dogs frequently clusters with exactly these sensory and mobility problems, which is why an isolated "dementia" label is often incomplete.
This guide provides a comprehensive clinical reference for veterinarians and veterinary technicians diagnosing and managing canine cognitive dysfunction. It details the pathophysiological basis of the disease, outlines the DISHAA diagnostic and staging framework, provides a structured rule-out protocol for look-alike conditions, analyzes the real-world safety and efficacy profile of selegiline (Anipryl) using openFDA pharmacovigilance data, and details multimodal treatment and quality-of-life decisions.
Quick answer
Canine cognitive dysfunction (CCD) is diagnosed clinically using the DISHAA framework (Disorientation, Interactions, Sleep-wake cycles, House-soiling, Activity, Anxiety) to rule out primary pain, sensory loss, or metabolic issues. Treatment centers on environmental modification, antioxidants, and the FDA-approved drug selegiline (Anipryl). Analysis of 4,116 canine adverse event reports in the openFDA database reveals that the top reactions associated with selegiline are vomiting (10.91%), clinical ineffectiveness for cognitive dysfunction (10.67%), loss of effect (8.21%), diarrhoea (8.19%), and anorexia (7.87%). Death by euthanasia appeared as a reported reaction in 5.90% of cases and a "died" outcome in 8.38%—signals that reflect the advanced age of the treated population rather than direct drug toxicity.
What is the pathophysiology of Canine Cognitive Dysfunction?
Diagnosing and treating CCD requires a solid understanding of the neurodegenerative changes occurring within the geriatric canine brain. The brain is highly vulnerable to oxidative damage and metabolic stress, and as its compensatory mechanisms fail, several distinct pathological processes take hold:
1. Amyloid-Beta Accumulation
Similar to human Alzheimer's disease, the hallmark lesion of CCD is the deposition of amyloid-beta (Aβ) protein in the brain parenchyma and cerebral blood vessel walls. Aβ is derived from the abnormal cleavage of amyloid precursor protein (APP). In healthy brains, APP is processed into soluble fragments. In diseased brains, enzyme cleavage yields insoluble Aβ peptides (specifically Aβ1-42), which aggregate into diffuse and neuritic plaques.
These plaques accumulate primarily in the cerebral cortex and the hippocampus—the regions responsible for learning, memory, and executive function. The density of Aβ deposition correlates directly with the severity of cognitive decline; as plaque density increases, synaptic transmission is disrupted, and neuronal death ensues.
2. Free Radical Damage and Oxidative Stress
The canine brain consumes a disproportionate amount of oxygen relative to its mass and possesses high levels of polyunsaturated fatty acids, making it highly susceptible to lipid peroxidation and free-radical damage. As mitochondria age, they become less efficient, generating higher levels of reactive oxygen species (ROS).
Under normal conditions, endogenous antioxidants (such as superoxide dismutase, catalase, and glutathione) neutralize ROS. In senescent dogs, these antioxidant defenses are depleted, leading to cumulative damage to lipids, proteins, and nucleic acids within neurons. This oxidative stress accelerates neuronal apoptosis and fuels a chronic neuroinflammatory state.
3. Neuroinflammation and Microglial Activation
In addition to direct oxidative stress, neuroinflammation plays a central role in the progression of CCD. Microglia, the resident immune cells of the central nervous system, become chronically activated in response to the presence of Aβ plaques and cellular debris. In their activated state, microglia release pro-inflammatory cytokines—including interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α)—along with neurotoxic nitric oxide.
While initial microglial activation is protective, aimed at clearing abnormal protein aggregates, chronic activation results in bystander damage to healthy neurons and synapses, creating a self-sustaining cycle of neurodegeneration and brain atrophy.
4. Cerebrovascular Microbleeds and Hypoxia
Cerebral amyloid angiopathy—the deposition of Aβ within the walls of cerebral arterioles—weakens vessel walls and reduces elasticity. This leads to microvascular stenosis, thickening of the basement membrane, and the formation of microthrombi, resulting in chronic, localized cerebral hypoperfusion (hypoxia).
Additionally, microbleeds occur throughout the cerebral cortex. The chronic lack of oxygen and glucose damages astrocytes and microglia, impairing their ability to maintain the blood-brain barrier and clear cellular debris, which further exacerbates cognitive decline.
How do veterinarians use the DISHAA scale to diagnose dog dementia?
Because there is no definitive, non-invasive antemortem diagnostic test (such as a biomarker or imaging signature) that can confirm CCD in first-opinion practice, diagnosis is based on clinical signs, behavioral history, and the systematic exclusion of other medical conditions.
The primary clinical tool used to gather this history is the DISHAA scale, a structured questionnaire developed to quantify behavioral changes across six cognitive domains. According to a study published in PMC (PMC6943310), physical signs of canine cognitive dysfunction include changes in gait, posture, and neurological responses, which correlate with these behavioral domains:
1. Disorientation (D)
The dog displays spatial disorientation, staring blankly at walls, standing behind doors on the hinge side, or getting trapped in corners. Owners often report that the dog wanders aimlessly through the house or yard and fails to recognize familiar people, places, or commands that were previously well-established.
2. Interactions (I)
Social relationships change. The dog may become socially withdrawn, seeking isolation and showing little interest in greeting family members or guests. Alternatively, some dogs display hyper-attachment, exhibiting extreme clinginess, constant attention-seeking behavior, or developmental aggression and irritability due to confusion or fear.
3. Sleep-Wake Cycles (S)
circadian rhythm disruption is a highly disruptive sign. The dog sleeps excessively during the day but wakes during the night, pacing, whining, panting, and vocalizing. This sleep-wake cycle inversion represents a significant burden for owners, often resulting in household sleep deprivation.
4. House-soiling (H)
Loss of house-training occurs in a previously house-trained dog. The dog eliminates in the house without signaling its need to go outside. In many cases, the dog will urinate or defecate indoors immediately after returning from a prolonged walk, indicating a loss of the cognitive association with outdoor elimination.
5. Activity Changes (A)
Behavioral patterns alter. The dog may show aimless wandering, pacing, or repetitive, stereotyped activities (such as obsessive licking of surfaces or self-grooming). Conversely, there is often a general loss of purposeful activity, including a decreased interest in play, exploration, or retrieval tasks.
6. Anxiety (A)
Generalized anxiety and specific phobias develop or worsen. The dog may display severe separation anxiety when left alone, fear of noises (thunderstorms, fireworks), or acute panic in response to minor environmental changes, such as moving furniture or visiting a veterinary clinic.
Staging Cognitive Decline
To use the DISHAA scale effectively, clinicians ask owners to grade specific behaviors as "None," "Mild," "Moderate," or "Severe." The scores are then aggregated to classify the dog's cognitive state:
- Mild Cognitive Impairment (Score 1–7): Typically involves changes in a single domain, most commonly minor changes in sleep patterns or mild separation anxiety. The dog remains highly functional, and these signs are often missed by owners.
- Moderate Cognitive Dysfunction (Score 8–15): Changes are visible across multiple domains. The dog may show occasional disorientation (e.g., hesitating at the hinge side of a door) and altered social interactions. This is the optimal window for therapeutic intervention.
- Severe Cognitive Dysfunction (Score 16+): Multiple domains are severely affected. The dog displays frequent disorientation, significant sleep disruption, loss of house-training, and constant pacing or vocalization. Prognosis at this stage is guarded, and management shifts to palliative care and quality-of-life monitoring.
+--------------------------------------------------------------------------+
| DISHAA Scoring and Staging Registry |
+---------------+------------------------+---------------------------------+
| Score Range | Staging Classification | Primary Clinical Indicators |
+---------------+------------------------+---------------------------------+
| 0 | Normal Aging | No cognitive changes observed. |
| 1–7 | Mild Cognitive Decline | Minor changes in 1 category |
| | | (e.g., occasional night waking) |
| 8–15 | Moderate Dysfunction | Obvious changes in 2+ categories|
| | | (e.g., door hesitation, soiling)|
| 16+ | Severe Dysfunction | Severe changes across multiple |
| | | categories (wandering, panic) |
+---------------+------------------------+---------------------------------+
What look-alike conditions mimic canine cognitive dysfunction?
Before attributing a senior dog’s behavioral changes to CCD, the veterinary team must perform a thorough diagnostic workup to identify and treat look-alike conditions. Many chronic geriatric diseases produce signs that mimic or exacerbate cognitive decline:
[Behavioral Presentation] -> [Possible Mimic Condition] -> [Veterinary Diagnostic Pathway]
Pacing / Restlessness -> Osteoarthritis Pain -> Orthopedic exam, Radiographs, NSAID trial
Disorientation / Fear -> Sensory Loss (Eyes/Ears) -> Ophthalmic exam, Otoscopic exam
House-soiling -> Renal / Urinary Disease -> Urinalysis, Biochemistry, Urine Culture
Pacing / Panting -> Endocrine Disease -> ACTH stim, LDDST (Cushing's rule-out)
Lethargy / Withdrawal -> Hypothyroidism -> Thyroid panel (Free T4, TSH)
Circling / Seizures -> Intracranial Neoplasia -> Neurological exam, MRI brain scan
1. Osteoarthritis (OA) Pain
Pain is the most common mimic of CCD. A dog with chronic joint pain from osteoarthritis may display nighttime pacing, restlessness, whining, irritability, and withdrawal from family members—signs that map directly onto the DISHAA domains for Sleep-wake cycles, Interactions, and Activity.
Rule-out Pathway: Perform a detailed orthopedic examination, including joint palpation, range-of-motion testing, and observation of gait. Obtain radiographs of suspect joints.
If joint disease is identified, initiate a 2- to 3-week trial of a non-steroidal anti-inflammatory drug (NSAID) or a monoclonal antibody (such as bedinvetmab / Librela), along with appropriate analgesics. If the pacing and restlessness resolve during the pain-management trial, the primary issue is chronic pain, not primary cognitive decline.
2. Sensory Loss (Visual and Auditory Decline)
Nuclear sclerosis, cataracts, progressive retinal atrophy, and age-related hearing loss (presbycusis) can cause a dog to appear disoriented, bump into furniture, withdraw from social interactions, startle easily, or vocalize due to separation anxiety.
Rule-out Pathway: Perform a complete ophthalmic examination, including pupillary light reflexes, menace response, fundoscopy, and intraocular pressure measurement. Conduct an otoscopic exam and assess the dog’s response to auditory cues out of its line of sight. Visual aids or environmental stabilization (e.g., keeping furniture in fixed locations) can dramatically improve function if sensory decline is the primary driver.
3. Metabolic and Systemic Diseases
Geriatric dogs are prone to internal diseases that alter behavior:
- Urinary Tract Infections (UTIs), Urinary Incontinence, and Chronic Kidney Disease (CKD): These conditions cause polyuria, polydipsia, dysuria, or loss of sphincter control, leading to house-soiling that mimics cognitive decline.
- Hepatic Encephalopathy: Microvascular dysplasia or acquired shunts can lead to elevated blood ammonia levels, causing head pressing, staring into space, disorientation, and seizures.
- Endocrine Diseases (Hyperadrenocorticism/Cushing's and Hypothyroidism): Cushing's disease causes panting, pacing, polyuria, and polydipsia, which disrupt sleep. Hypothyroidism leads to profound lethargy, mental dullness, and social withdrawal.
Rule-out Pathway: Perform a complete urinalysis (including specific gravity, sediment chemistry, and urine culture/sensitivity), a serum biochemistry profile, and a complete blood count. If endocrine disease is suspected based on clinical signs and lab work, perform specific hormone testing (such as a Low-Dose Dexamethasone Suppression Test [LDDST] or an ACTH stimulation test for Cushing's, and a total T4, free T4, and TSH panel for hypothyroidism).
4. Intracranial Neoplasia (Brain Tumors)
Primary brain tumors, such as meningiomas or gliomas, are relatively common in geriatric dogs, particularly in brachycephalic breeds (for gliomas) and dolichocephalic breeds (for meningiomas). A brain tumor growing in the frontal lobe or cerebral cortex can cause circling, head pressing, staring into space, loss of training, and seizures, mimicking advanced CCD.
Rule-out Pathway: Conduct a complete neurological examination. Look for asymmetric deficits, cranial nerve abnormalities, or proprioceptive deficits that suggest focal intracranial disease rather than diffuse neurodegeneration. Advanced imaging, specifically magnetic resonance imaging (MRI) of the brain and cerebrospinal fluid (CSF) analysis, is required to rule out neoplasia or infectious/inflammatory encephalitis.
What are the real-world safety and efficacy profiles of selegiline (Anipryl)?
Currently, the only drug approved by the FDA for the control of clinical signs associated with canine cognitive dysfunction is selegiline hydrochloride, sold under the brand name Anipryl (underwritten and distributed by Zoetis).
Mechanism of Action
Selegiline is a synthetic monoamine oxidase inhibitor (MAOI). In dogs, it is highly selective for monoamine oxidase type B (MAO-B). MAO-B is the primary enzyme responsible for the catabolism of dopamine in the central nervous system.
By inhibiting MAO-B, selegiline increases dopamine concentrations within the synaptic cleft in the cerebral cortex and striatum. This enhancement of dopaminergic transmission improves cognitive processing, memory retrieval, and motor function.
Additionally, selegiline metabolizes into L-methamphetamine and L-amphetamine, which act as weak stimulants. The drug also exerts neuroprotective effects by reducing the oxidative stress associated with dopamine metabolism and enhancing the production of nerve growth factors.
Pharmacovigilance Data: Analyzing 4,116 openFDA Reports
To construct an objective safety and efficacy profile of selegiline in real-world clinical use, we analyzed 4,116 canine adverse event reports associated with selegiline within the openFDA database.
Clinicians must understand that because this dataset relies on passive surveillance (voluntary reporting by veterinarians and owners), the counts represent reported events and do not establish direct causality. However, they provide a valuable signal regarding the most common side effects and clinical failure rates encountered in practice.
+--------------------------------------------------------------------------+
| Canine Selegiline (Anipryl) Adverse Event Rates |
+------------------------------------+-------------------------------------+
| Total Canine Reports Analyzed | 4,116 |
+------------------------------------+-------------------------------------+
| Top Reported Reactions | |
| - Vomiting | 449 cases (10.91%) |
| - Clinical Ineffectiveness (CCD) | 439 cases (10.67%) |
| - Loss of Effect Over Time | 338 cases (8.21%) |
| - Diarrhea | 337 cases (8.19%) |
| - Anorexia / Appetite Loss | 324 cases (7.87%) |
| - Lack of Efficacy (NOS) | 311 cases (7.56%) |
| - Depression / Mental Dullness | 301 cases (7.31%) |
| - Restlessness | 262 cases (6.37%) |
| - Ineffectiveness (Cushing's) | 252 cases (6.12%) |
| - Death by Euthanasia (Reaction) | 243 cases (5.90%) |
| - Convulsions / Seizures | 231 cases (5.61%) |
| - Elevated Alkaline Phosphatase | 226 cases (5.49%) |
+------------------------------------+-------------------------------------+
| Reported Outcomes | |
| - Died (Natural Death) | 345 cases (8.38%) |
| - Outcome Unknown | 222 cases (5.39%) |
| - Ongoing | 99 cases (2.41%) |
| - Recovered / Returned to Normal | 45 cases (1.09%) |
| - Euthanized (Recorded Outcome) | 12 cases (0.29%) |
+------------------------------------+-------------------------------------+
Key Interpretations of the openFDA Signal
- Gastrointestinal Sensitivity: Vomiting (10.91%), diarrhea (8.19%), and anorexia (7.87%) represent the most common physiological adverse reactions. Veterinarians should counsel owners to monitor for gastrointestinal upset, particularly during the first two weeks of therapy. Administering the medication with a small amount of food can mitigate these effects.
- The Efficacy Challenge: Clinical ineffectiveness for cognitive dysfunction was reported in 10.67% of cases, and a distinct loss of effect over time was reported in 8.21%. Combined with "Lack of Efficacy - NOS" (7.56%), this indicates that a substantial proportion of treated dogs do not respond to selegiline, or they experience a recurrence of symptoms as the underlying neurodegenerative pathology progresses. Clinicians must manage owner expectations: selegiline is not a cure; it is a palliative therapy designed to slow cognitive decline and improve temporary quality of life.
- The Cushing's Context: The reporting of "Ineffective, Cushing's" in 6.12% of cases relates to the historical use of selegiline for pituitary-dependent hyperadrenocorticism (PDH). Because PDH is caused by a pituitary tumor, dopamine depletion in the hypothalamus was thought to play a role. However, clinical studies later demonstrated that selegiline is weakly effective for Cushing's compared to trilostane (Vetoryl), explaining the high number of ineffectiveness reports for this off-label indication.
- Hepatic Metabolism Considerations: Selegiline undergoes rapid hepatic metabolism via the cytochrome P450 enzyme system (specifically CYP2B11 and CYP3A in dogs) to produce its active metabolites (methamphetamine and amphetamine). Concurrent administration of cytochrome P450 inhibitors (such as ketoconazole or cimetidine) can decrease the clearance of selegiline, potentially increasing its systemic concentration and the risk of adverse neurological reactions like hyperactivity and restlessness.
- Mortality and Euthanasia: The reported natural death rate of 8.38% and the euthanasia reaction rate of 5.90% reflect the demographics of the treated population. Dogs receiving selegiline are geriatric, often with significant comorbidities. The high mortality signals are indicative of advanced age and the progression of concurrent terminal illnesses, rather than direct drug toxicity.
Drug Interactions and Safety Warnings: The Serotonin Syndrome Gate
Because selegiline is an MAOI, it alters monoamine levels throughout the central nervous system. Combining selegiline with other medications that increase serotonin levels can precipitate Serotonin Syndrome, a life-threatening veterinary emergency characterized by hyperthermia, tremors, rigidity, mental status changes, tachycardia, and death.
Strict Contraindications:
- Antidepressants and Behavior-Modifying Drugs: Do not administer selegiline concurrently with Selective Serotonin Reuptake Inhibitors (SSRIs) such as fluoxetine (Reconcile) or tricyclic antidepressants (TCAs) such as amitriptyline or clomipramine (Clomicalm).
- Trazodone: An extremely common sedative used in veterinary medicine for anxiety and clinic visits. Trazodone has serotonin agonist and reuptake inhibitor (SARI) properties. Combining trazodone with selegiline carries a high risk of serotonin syndrome and is strictly contraindicated.
- Analgesics: Do not combine with tramadol, which inhibits serotonin and norepinephrine reuptake.
- Other MAOIs: Do not use concurrently with amitraz (found in some tick collars and mange treatments).
Washout Periods: When transitioning a dog from an SSRI or TCA to selegiline, or vice versa, a strict washout period must be observed:
- Allow at least 14 days after discontinuing selegiline before starting any serotonergic drug.
- Allow at least 14 to 35 days (depending on the drug's half-life; e.g., 5 weeks for fluoxetine due to its active metabolite) after discontinuing an SSRI/TCA before starting selegiline.
How is canine cognitive dysfunction managed with nutrition and environment?
Managing CCD requires a multimodal approach that goes beyond drug therapy. Combining pharmacotherapy with nutritional support and environmental enrichment yields the best results in slowing cognitive decline:
1. Dietary Interventions
Specific commercial diets are formulated to support brain health in senior dogs:
- Purina Pro Plan Veterinary Diets NeuroCare: Formulated with 6.5% medium-chain triglycerides (MCTs). MCTs are rapidly absorbed and metabolized by the liver into ketone bodies, which cross the blood-brain barrier and serve as an alternative energy source for aging neurons that suffer from glucose hypometabolism.
- Hill’s Prescription Diet b/d: Rich in antioxidants (vitamins E and C, selenium, beta-carotene) and essential fatty acids (EPA and DHA) to combat oxidative damage, support cell membrane fluidity, and reduce neuroinflammation.
2. Environmental Enrichment
Mental stimulation is critical to maintaining synaptic plasticity:
- Encourage gentle play, introduce food-puzzle toys, and provide short, sniff-focused walks in new environments.
- Maintain a strict daily routine (feeding times, walk schedules, bedtime) to reduce anxiety and help orient dogs with sleep-wake cycle disturbances.
- Modify the home environment to support mobility and safety. Use nonslip rugs on hardwood floors to prevent slipping, block staircase areas with baby gates to prevent falls, and utilize nightlights to assist dogs with visual impairment during nighttime waking.
What are the decision rules for canine cognitive dysfunction quality of life and euthanasia?
As CCD reaches its final stages, the veterinary team’s role shifts from active treatment to assisting the owner with quality-of-life assessments and navigating the decision of when to pursue humane euthanasia. Because the diagnostic workups, neurologic imaging, and ongoing senior care that surround this stage are expensive, it is also worth understanding how pet insurance for senior dogs treats age limits, exclusions, and pre-existing cognitive signs—many owners first encounter these limits precisely when a CCD workup is underway.
Using Quantitative Quality-of-Life Scales
Rather than relying on subjective impressions, clinicians should encourage owners to use structured assessment tools, such as the HHHHHMM (HHHHHMM Quality of Life Scale) or the Canine Cognitive Dysfunction Quality of Life (CCD-QoL) questionnaire. These scales ask owners to score several parameters:
- Hurt: Is the dog's pain managed effectively?
- Hunger: Is the dog eating adequate amounts?
- Hydration: Is the dog drinking enough, or showing signs of dehydration?
- Hygiene: Can the dog keep itself clean? Does it lie in its own urine or feces due to house-soiling or mobility loss?
- Happiness: Does the dog interact with the family, wag its tail, or show interest in its environment?
- Mobility: Can the dog stand and walk independently?
- More Good Days than Bad Days: When bad days outnumber good days, quality of life has significantly deteriorated.
The Specific Burden of Advanced CCD
CCD presents a unique challenge for owners. Unlike dogs with physical illnesses (e.g., congestive heart failure or osteosarcoma) who may remain mentally present and affectionate, dogs with advanced CCD may lose the ability to recognize their owners, display constant pacing or vocalization that prevents the owner from sleeping, or exhibit severe separation anxiety.
This creates a high caregiver burden, often leading to sleep deprivation and emotional exhaustion for the family.
Veterinarians must address this caregiver burden during consultations. If a dog's anxiety and sleep-wake cycles cannot be managed with medication, and if the dog no longer displays signs of awareness or pleasure in its daily life, euthanasia is a humane option to prevent further distress for both the pet and the family.
Sources
- American Animal Hospital Association (AAHA). "2023 AAHA Senior Care Guidelines for Dogs and Cats." https://www.aaha.org/for-veterinary-professionals/aaha-guidelines/senior-care-guidelines/
- U.S. Food and Drug Administration. "Anipryl (Selegiline Hydrochloride) FDA CVM Approved Product Label & FOI Summary." NADA 141-080. https://www.fda.gov/
- National Institutes of Health. "Physical signs of canine cognitive dysfunction." PubMed Central. PMCID: PMC6943310. https://pmc.ncbi.nlm.nih.gov/articles/PMC6943310/
- Landsberg, G., et al. "Evaluation of cognitive dysfunction in geriatric dogs: a survey and diagnostic model." Journal of Veterinary Internal Medicine (2001). https://doi.org/10.1111/j.1939-1676.2001.tb02301.x
- Purina Institute. "Nutritional Intervention for Canine Cognitive Dysfunction: Medium-Chain Triglycerides." https://www.purinainstitute.com/
- DailyMed. "Anipryl (selegiline hydrochloride) tablet, prescribing information." https://dailymed.nlm.nih.gov/dailymed/
- U.S. Food and Drug Administration. "openFDA — Animal Drug Adverse Event API" (canine selegiline adverse-event reports analyzed for this article; passive pharmacovigilance data that does not establish causality or incidence). https://open.fda.gov/data/downloads/
