Collie: The Loyal, Elegant Scottish Herding Dog
Everything you need to know about the Collie — from temperament to health, training to care.
Collie Coat Varieties
Trait
| Trait | Rough Collie | Smooth Collie | Key Difference |
|---|---|---|---|
| Coat | Long, abundant, harsh outer coat | Short, hard, dense | Only coat length differs |
| Grooming | 2–3 times weekly brushing, daily during shedding | Weekly brushing | Rough needs more grooming |
| Shedding | Heavy seasonal shedding | Moderate shedding | Rough sheds more visibly |
| Temperament | Same — loyal, intelligent, sensitive | Same — loyal, intelligent, sensitive | Identical temperament |
| Exercise | 45–60 min daily | 45–60 min daily | Same exercise needs |
| Heat Tolerance | Poor — thick coat retains heat | Better — short coat | Smooth handles heat better |
Collie Care Essentials
| Brush 2–3 times weekly — daily during seasonal shedding (Rough Collie) | |
| Moderate exercise: 45–60 min daily walks plus mental stimulation | |
| Positive reinforcement only — sensitive breed shuts down with harsh methods | |
| Early socialization — natural reserve with strangers | |
| Check for MDR1 drug sensitivity — affects up to 70% of Collies | |
| Eye screening for Collie Eye Anomaly (CEA) — genetic condition | |
| Use ivermectin or certain drugs without MDR1 testing — can be fatal | |
| Shave a Rough Collie — double coat protects from heat AND cold |
MDR1 drug sensitivity affects up to 70% of Collies. This genetic mutation makes them dangerously sensitive to common drugs including ivermectin (heartworm prevention), loperamide (Imodium), and certain chemotherapy and anesthesia drugs. A simple DNA test identifies affected dogs. Test before ANY medication.
Collie Eye Anomaly (CEA) is a genetic condition affecting Collies. It ranges from mild (no vision impact) to severe (retinal detachment and blindness). All Collie puppies should be examined by a veterinary ophthalmologist at 6–8 weeks. DNA testing identifies carriers. Reputable breeders test all breeding stock.
The Rough Collie -- the elegant, flowing-coated dog made globally famous by the fictional Lassie -- is a Scottish herding breed that combines remarkable intelligence, gentle sensitivity, and a devotion to family that many owners describe as unmatched. Males weigh 60 to 75 pounds; females 50 to 65 pounds. The Rough Collie is calm and trainable in the right household, but the breed carries several significant heritable health concerns -- particularly the MDR1/ABCB1 drug sensitivity mutation that makes some Collies severely reactive to medications that are perfectly safe in most other dogs. Every Collie owner must know about this before any veterinary treatment.
MDR1/ABCB1 mutation: the drug sensitivity every Collie owner must know
The MDR1 gene encodes a protein (P-glycoprotein) that pumps certain drugs out of brain cells, preventing toxic accumulation in the central nervous system. Approximately 70% of Rough Collies carry one or two copies of a deletion mutation in this gene. Homozygous affected dogs (two copies of the mutation) have severely reduced P-glycoprotein function; heterozygous dogs (one copy) have intermediate function. Drugs that accumulate to toxic levels in affected dogs include: ivermectin (at the high doses used for mange, not the heartworm prevention dose), milbemycin, moxidectin, loperamide (Imodium -- this is sold over the counter and available in every pharmacy), butorphanol, vincristine, doxorubicin, and several other common medications. Toxicity signs: neurological collapse, disorientation, tremors, coma. A dog that appears "strangely sensitive" to sedatives or shows neurological signs after a routine dewormer should be tested for MDR1 status immediately. DNA testing through Washington State University's College of Veterinary Medicine or commercial services like Embark confirms status. MDR1 status must be communicated to every veterinarian who treats the dog.
Collie Eye Anomaly
Collie Eye Anomaly (CEA) is a developmental defect of the choroid (the vascular layer behind the retina) present in 70 to 97% of Rough and Smooth Collies globally. Severity ranges enormously: most affected Collies have choroidal hypoplasia only (a pale area visible on ophthalmoscopy that is non-progressive and causes minimal or no visual impairment) to colobomas (holes in the tissue layers) and retinal detachment (causing significant vision impairment or blindness). DNA testing identifies CEA carriers; dogs with two normal copies (clear) cannot produce affected offspring. Breeders performing CEA DNA testing can eliminate the disease from their lines within one generation. Ophthalmoscopic examination by a board-certified veterinary ophthalmologist at 6 to 8 weeks of age, before the "go normal" period when affected areas are temporarily camouflaged by normal pigment development, is the standard phenotypic screening approach.
Temperament: sensitive, loyal, trainable
Collies are known for their emotional attunement to their families. They are sensitive to conflict, tone of voice, and emotional atmosphere in a way that makes them easy partners for positive reinforcement training but poor candidates for harsh correction methods. They are typically gentle with children, get along with other animals, and make watchful but not aggressive family dogs. They do bark -- the Collie voice is used readily for alerting and communication, which can become a nuisance in apartments or suburban neighborhoods where stimulation is constant. Early training to a reliable quiet cue reduces this significantly.
The coat: beautiful but demanding
The Rough Collie's flowing double coat requires substantial time investment: thorough brushing at least twice weekly with a pin brush and metal comb, more frequently during the twice-yearly shedding season. The undercoat tangles around the outer coat if neglected, forming mats that must be carefully worked out. The mane (ruff around the neck) and backs of the rear legs ("britches") are the primary mat-prone areas. The Smooth Collie variety (a separate variety in AKC, considered a separate breed in some countries) has a short, dense, easy-maintenance coat and the same temperament.
Sources: Mealey KL "Multidrug resistance gene" JAVMA 2004; Collie Health Foundation genetics resources; OFA CEA statistics; AKC Collie Club of America health committee; Merck Veterinary Manual -- MDR1 toxicity.