Breeding Biewer Terriers

Complete Guide for Responsible Breeders

Breeding biewer terriers presents unique challenges that set this breed apart from other toy companions. As one of the newest AKC-recognized breeds (admitted in 2021), the Biewer Terrier's limited genetic diversity, mandatory tri-color pattern, and complex health profile demand meticulous planning and DNA testing. This guide provides comprehensive data on reproductive expectations, required health clearances, color genetics, and the economic realities of breeding this rare and distinctive toy terrier.

Breed Overview

The Biewer Terrier originated in Germany in 1984 when Werner and Gertrud Biewer produced the first tri-colored puppy through a rare recessive piebald gene mutation in their Yorkshire Terrier breeding program. Initially called "Biewer Yorkshire Terrier à la Pom Pon," the breed developed independently through selective breeding for the distinctive tricolor pattern that distinguishes it from its solid-colored Yorkshire Terrier ancestor.

American fanciers began importing Biewer Terriers from Germany in 2002. After genetic studies by Mars Veterinary confirmed the Biewer Terrier as genetically distinct from the Yorkshire Terrier, the breed was admitted to the AKC Foundation Stock Service in 2014. Full AKC recognition came in January 2021, making the Biewer Terrier the 197th AKC-recognized breed.

Currently ranked 77th in AKC popularity with registrations steadily increasing, the Biewer Terrier is classified in the Toy Group. The breed's sole purpose is companionship—the standard explicitly states its "only purpose in life is to love and be loved." The parent club, the Biewer Terrier Club of America (BTCA), maintains the breed standard and coordinates with AKC on health and breeding initiatives.

As a recently established breed with a small foundation population, Biewer Terrier breeders face the challenge of maintaining genetic diversity while preserving breed type. The average coefficient of inbreeding (COI) currently sits at 25%, significantly higher than the recommended target of under 5%.

Breed Standard Summary for Breeders

The Biewer Terrier is an elegant, longhaired tri-colored toy terrier standing 7-11 inches at the shoulder and weighing 4-8 pounds at maturity. Unlike the Yorkshire Terrier, the Biewer Terrier's tri-color pattern is a breed-defining characteristic, not an optional color variety. The standard disqualifies solid colors, bi-color patterns, and any dog over 8 pounds.

Key structural priorities for breeding stock:

Head and expression: The Biewer Terrier must maintain a terrier head type with small, V-shaped, erect ears set not too far apart. The eyes should be medium-sized, dark, and almond-shaped—round, prominent eyes that lack terrier expression are a serious fault. The muzzle is medium length with a scissors bite. The standard disqualifies overshot or undershot bites and any missing pigment on the nose, eye rims, or lips.

Body proportions: The breed presents a compact, well-balanced silhouette. The topline must be level—a roached or swayed back is a serious fault. The tail is set on high and carried gaily (not curled over the back), creating a balanced picture. Tail carriage is an important breed characteristic; a tail set too low or carried incorrectly affects the overall impression.

Coat: The Biewer Terrier's coat is one of its defining features. Hair should be fine, straight, and silky—never cottony, woolly, or coarse in texture. The coat falls fairly evenly down each side of the body, parting naturally from the head to the tail. Heavy, coarse coat texture is a serious fault. The hair on the head is long, either tied with a single bow in the center or parted down the middle and tied with two bows.

Size: Proper size is critical. The standard specifies 4-8 pounds as the acceptable weight range, with disqualification for any dog exceeding 8 pounds. Height ranges from 7-11 inches at the shoulder. Maintaining size while preserving bone and substance requires careful selection—toy breeds often face pressure toward extremes in either direction.

Disqualifications that eliminate dogs from breeding consideration:

• Weight over 8 pounds
• Solid color or bi-color coat pattern (tri-color is mandatory)
• Missing pigment on nose, eye rims, or lips
• Overshot or undershot bite

Breeders must balance multiple priorities: maintaining proper tri-color genetics, silky coat texture, correct size, level topline, terrier expression, and sound temperament. The breed standard emphasizes that the Biewer Terrier's whimsical, loyal companion temperament is as important as physical conformation.

Biewer Terrier Reproductive Profile

The Biewer Terrier's reproductive profile reflects the challenges common to toy breeds, with small litter sizes and elevated whelping complication rates. Understanding these patterns is essential for breeding program planning and financial projections.

Litter size: Biewer Terriers average 3.5 puppies per litter, with a typical range of 2-5 puppies. Litters of 1-2 puppies occur in approximately 25% of breedings, while litters of 4-5 puppies represent about 42% of whelps. Litters of 6 puppies are rare (under 3% frequency). The small litter size significantly impacts breeding program economics and puppy availability.

C-section rate: Approximately 35% of Biewer Terrier litters are delivered via cesarean section, higher than many toy breeds but lower than brachycephalic breeds. Natural whelping is the norm when conditions are favorable, but breeders must be prepared for emergency intervention. Common indications for C-section include dystocia due to the dam's small pelvis, primary uterine inertia (weak contractions), single-puppy syndrome with an oversized pup, or failure to progress after two or more hours of active labor.

Small litter sizes paradoxically increase the risk of oversized puppies—a litter of 1-2 puppies may result in individual pups that are too large for safe vaginal delivery. For this reason, progesterone timing and close whelping supervision are critical.

Fertility considerations: Several factors affect Biewer Terrier fertility. The breed's limited genetic diversity and high average COI can impact reproductive success. Some dogs experience occasional difficulty with natural breeding due to small size or temperament incompatibility, making artificial insemination a practical alternative for accessing quality genetics at a distance.

The female's fertile window in toy breeds is typically short—24-48 hours—making progesterone testing essential for optimal breeding timing. Mistiming the breeding is a common cause of small litters or failed breedings.

Artificial insemination: Natural breeding is preferred when dogs are compatible in size and temperament. Fresh-chilled AI is commonly used for accessing quality studs at a distance, with success rates of 60-80%. Frozen semen can be used with transcervical insemination (TCI) when necessary, achieving up to 80% success rates. The breed's small size can make surgical AI challenging, but TCI provides an effective alternative with lower risk.

Breeders working to reduce COI often need to import semen from European or distant U.S. lines, making proficiency with fresh-chilled and frozen AI protocols necessary for long-term breeding program success.

Breeding Age and Timeline

Biewer Terriers typically experience their first heat cycle between 7-12 months of age, though some females may cycle as early as 6 months or as late as 14 months. Early heats are common in toy breeds, but responsible breeders wait for physical and mental maturity before breeding.

Recommended first breeding age:

• Females: 18-24 months (after the second or third heat cycle)
• Males: 12-18 months

Waiting until 18 months minimum for females ensures the dam has completed her growth and achieved mature bone development. This timing also allows completion of all OFA health certifications, which cannot be submitted until 12 months of age. Many Biewer Terrier breeders prefer waiting until 24 months to assess full coat development and adult structure before making final breeding decisions.

Health testing timeline: The Orthopedic Foundation for Animals (OFA) requires dogs to be at least 12 months old for patellar luxation evaluation. ACVO eye examinations can be performed at any age but should be completed annually. DNA testing through Embark or similar providers can be performed as early as 8 weeks but is typically done at 6-12 months when breeding prospects are identified.

Schedule all health testing to be completed before 18 months so results are available when the female reaches breeding age. This prevents delays and allows time to address any unexpected findings.

Breeding frequency and retirement: Biewer Terrier females should not be bred on consecutive heat cycles. The recommended practice is to breed no more than once per year, allowing the dam's body to fully recover between litters. Given the small litter size and physical demands of pregnancy and lactation, adequate recovery time is essential.

Maximum recommended litters per female is 5 lifetime litters, with retirement by age 6-8 years. Some breeders retire females earlier if they've had difficult whelps, small litters, or show signs of declining vigor. Males can remain active longer, typically until 8-10 years, provided they maintain health and fertility.

Complete breeding timeline:

1. 6-12 months: Identify breeding prospects, begin socialization and training
2. 12 months: Complete OFA patellar luxation evaluation, submit DNA testing
3. 12-18 months: Complete annual ACVO eye examination
4. 18-24 months: Female reaches recommended breeding age
5. Day 1 of heat: Begin progesterone testing every 2-3 days
6. Breeding day: Based on progesterone levels (typically 5-10 ng/mL)
7. Day 28-30: Ultrasound confirms pregnancy
8. Day 58-63: Whelping (average gestation 63 days)
9. 8 weeks: Puppies ready for evaluation and placement
10. 10-12 weeks: Preferred go-home age for toy breeds

Required Health Testing

The Biewer Terrier CHIC (Canine Health Information Center) program requires two health clearances: an annual ACVO eye examination and an OFA patellar luxation evaluation. While these represent the minimum CHIC requirements, responsible breeders pursue additional testing to screen for the breed's known hereditary conditions.

CHIC-required testing:

ACVO Eye Examination (annual, $65): A board-certified veterinary ophthalmologist examines the dog for hereditary eye diseases including Primary Lens Luxation (PLL), Progressive Retinal Atrophy (PRA-prcd), cataracts, corneal dystrophy, entropion, and distichiasis. The Biewer Terrier has documented cases of both PLL and PRA-prcd, making annual eye examinations essential. Results are submitted to OFA and remain valid for 12 months.

Patellar Luxation Evaluation (one-time, $50): An OFA-certified veterinarian or veterinary specialist physically examines the stifle joint to grade patellar luxation from Normal (no luxation) through Grade I (mild), Grade II (moderate), Grade III (severe), to Grade IV (permanent luxation). Toy breeds have a 30-40% incidence of patellar luxation. Only dogs with Normal or Grade I ratings should be considered for breeding, and Grade I dogs should only be bred to Normal partners with excellent patellar structure.

Strongly recommended additional testing:

Embark Breeder Package ($199): This comprehensive DNA panel screens for over 200 genetic health conditions, including multiple conditions documented in Biewer Terriers. The panel identifies:

• Primary Lens Luxation (PLL) - autosomal recessive
• Progressive Retinal Atrophy, PRCD (PRA-prcd) - autosomal recessive
• Chondrodystrophy and IVDD risk (CDDY) - autosomal dominant
• Degenerative Myelopathy (DM) - autosomal recessive
• Portosystemic shunt risk markers
• Hemophilia B (Factor IX Deficiency) - X-linked recessive
• White Shaker Syndrome risk markers

The Embark panel also provides coefficient of inbreeding (COI) calculations and heterozygosity scores, critical tools for managing genetic diversity in this breed. Many Biewer Terrier breeders consider the Embark panel non-negotiable due to the breed's multiple DNA-testable conditions.

Cardiac Examination ($75): A veterinary cardiologist performs auscultation and may use echocardiography to screen for congenital heart defects and patent ductus arteriosus (PDA). While not CHIC-required, cardiac issues occasionally occur in toy breeds.

Bile Acids Test ($150): This blood test screens for portosystemic shunt (liver shunt), a condition with higher prevalence in toy breeds. The test measures bile acid levels before and after eating; elevated post-prandial bile acids suggest abnormal blood flow bypassing the liver. Early detection allows for medical management or surgical correction.

Total estimated health testing cost per breeding dog: $539 for comprehensive screening (CHIC requirements plus Embark, cardiac, and bile acids testing). This investment in health testing is essential for producing healthy puppies and maintaining breed viability.

Where to obtain testing:

• ACVO eye exams: Locate a board-certified veterinary ophthalmologist through acvo.org
• OFA patellar luxation: Any OFA-certified veterinarian can perform the evaluation
• Embark DNA testing: Order directly from embarkvet.com
• Cardiac and bile acids: Veterinary specialists or general practitioners

Breeders should maintain detailed health testing records and submit all results to OFA for public database inclusion. Transparency in health testing builds buyer confidence and contributes to breed-wide health data.

Hereditary Health Conditions

The Biewer Terrier inherits health predispositions from its Yorkshire Terrier ancestry while facing additional challenges from its small foundation population. Understanding the breed's hereditary conditions, their inheritance modes, and available testing options is fundamental to making sound breeding decisions.

Primary Lens Luxation (PLL) - 15% prevalence, autosomal recessive, DNA test available

Primary Lens Luxation occurs when zonular fibers that hold the lens in place fail, causing the lens to dislocate from its normal position. Affected dogs experience eye pain, corneal edema, secondary glaucoma, and vision loss. Age of onset is typically 3-8 years.

The condition is autosomal recessive, meaning dogs must inherit two copies of the mutated gene to develop the disease. Dogs with one copy (carriers) are clinically normal but can produce affected puppies if bred to another carrier or affected dog. The Embark panel tests for the PLL mutation. Breeding recommendations: Never breed two carriers together. Carrier-to-clear breedings produce 50% carriers and 50% clear puppies, allowing the carrier dog's other qualities to be preserved while avoiding affected offspring.

Progressive Retinal Atrophy, PRCD (PRA-prcd) - 10% prevalence, autosomal recessive, DNA test available

PRA-prcd causes progressive degeneration of the retina, beginning with night blindness and eventually leading to complete vision loss. Initial signs appear at 3-5 years, with blindness developing over 1-2 years. Affected dogs show dilated pupils and a reflective eye appearance in photos.

Like PLL, PRA-prcd follows autosomal recessive inheritance. The Embark panel identifies the PRCD mutation. The same breeding guidelines apply: avoid carrier-to-carrier matings. Since both PLL and PRA-prcd are recessive, DNA testing allows breeders to work with carriers safely while prioritizing genetic diversity and other health traits.

Chondrodystrophy (CDDY) and Intervertebral Disc Disease (IVDD) - 25% prevalence, autosomal dominant with incomplete penetrance, DNA test available

The CDDY mutation causes shortened limbs and premature intervertebral disc degeneration, increasing risk for disc herniation. Dogs with even one copy of the CDDY mutation have elevated IVDD risk. Clinical signs include back pain, weakness, and paralysis, typically appearing between 3-7 years.

Unlike the recessive conditions above, CDDY is autosomal dominant—one copy increases risk. The Embark panel detects CDDY status. Breeding strategy is more complex because incomplete penetrance means not all dogs with the mutation develop clinical disease. Some breeders avoid using dogs with even one CDDY copy, while others accept one-copy dogs with excellent structure and no family history of disc disease. This requires case-by-case evaluation balancing genetic diversity against health risk.

Patellar Luxation - 35% prevalence, polygenic inheritance, no DNA test available

Patellar luxation—the kneecap slipping out of its normal groove—is one of the most common orthopedic conditions in toy breeds, affecting Biewer Terriers at rates comparable to the Brussels Griffon. Severity ranges from Grade I (mild, intermittent) to Grade IV (permanent dislocation). Dogs show intermittent lameness, a skipping gait, or chronic pain.

Inheritance is polygenic (multiple genes), making it impossible to predict from DNA testing. Physical OFA examination is the only assessment method. Select breeding stock with Normal or Grade I ratings and excellent patellar conformation through multiple generations. Because prevalence reaches 30-40% in toy breeds, breeders must actively select against luxation to make progress.

Degenerative Myelopathy (DM) - 5% prevalence, autosomal recessive with incomplete penetrance, DNA test available

DM causes progressive hind limb weakness, ataxia, and eventual paralysis, typically with onset at 8-14 years. The condition is caused by mutations in the SOD1 gene. While autosomal recessive, many dogs with two copies of the mutation never develop clinical disease (incomplete penetrance), likely due to protective genetic or environmental factors.

The Embark panel tests for DM. Because onset is late and penetrance incomplete, many breeders are less restrictive about breeding DM carriers, prioritizing younger-onset conditions like PLL and PRA-prcd. However, breeding two at-risk dogs together should be avoided.

Portosystemic Shunt (Liver Shunt) - 8% prevalence, polygenic inheritance, no DNA test available

Portosystemic shunt is a congenital vascular abnormality where blood bypasses the liver, leading to toxin buildup. Affected puppies fail to thrive, show neurological signs after eating (hepatic encephalopathy), and may have seizures. Signs typically appear at 4-12 months.

Diagnosis requires bile acids testing or liver imaging. No DNA test exists, but certain genetic markers may indicate increased risk. Avoid breeding dogs that have produced shunt-affected puppies or have a family history of shunts. The condition's prevalence is higher in toy breeds generally, making vigilance important.

White Shaker Syndrome - 2% prevalence, unknown inheritance (possibly autoimmune)

This condition causes generalized tremors affecting the entire body, especially when excited. Onset is 6 months to 3 years. Most dogs respond well to corticosteroid treatment. The exact cause and inheritance pattern are unknown but may involve immune-mediated inflammation of the central nervous system.

Hemophilia B (Factor IX Deficiency) - 1% prevalence, X-linked recessive, DNA test available

Hemophilia B is a blood clotting disorder causing prolonged bleeding after injury or surgery. The condition is X-linked recessive, meaning males need only one copy of the mutated gene to be affected, while females need two copies. Female carriers are typically unaffected but can produce affected male puppies.

The Embark panel tests for Hemophilia B. Affected males and carrier females should not be used for breeding. Because inheritance is X-linked, careful tracking of female carrier status is essential.

Breeding strategy summary: The Biewer Terrier's multiple hereditary conditions require comprehensive DNA testing and careful genetic management. Embark testing identifies carrier status for PLL, PRA-prcd, CDDY, DM, and Hemophilia B, allowing breeders to avoid producing affected puppies while preserving genetic diversity. For polygenic conditions like patellar luxation and portosystemic shunt, selection based on phenotype and family history is essential. Given the breed's high average COI, breeders must balance health testing results against the need to maintain genetic diversity—eliminating all carriers from breeding programs would further constrict the gene pool.

The Yorkshire Terrier shares several of these conditions (PLL, PRA-prcd, patellar luxation), reflecting the Biewer Terrier's genetic origins. Comparing health data between the two breeds can provide insights into inheritance patterns and breeding strategies.

Color and Coat Genetics

The Biewer Terrier's tri-color pattern is the breed's most distinctive feature and a mandatory requirement in the standard. Unlike many breeds where color is secondary to structure and temperament, Biewer Terrier breeders must master color genetics to produce correct puppies and avoid disqualifying patterns.

Mandatory tri-color pattern: The AKC standard requires three colors in the coat: white plus two other colors (black, blue, chocolate, or gold/cream). Acceptable color combinations are:

• Black, White, and Gold
• Blue, White, and Gold
• Chocolate, White, and Gold
• Cream and White

Disqualifying colors: Solid colors (all black, all white, all gold) and bi-color patterns (only two colors present) are disqualified from the show ring and should not be bred. The absence of white in the coat disqualifies the dog from breeding consideration.

Genetic loci involved:

The Biewer Terrier's coloration results from the interaction of multiple genes:

A (Agouti) locus: Determines tan point distribution. Biewer Terriers must be homozygous for tan points (at/at) to express the characteristic tan/gold markings on the face, legs, and chest.

B (Brown) locus: Controls eumelanin color. Black (B/-) is dominant; chocolate (b/b) is recessive. Chocolate Biewer Terriers are genetically black dogs with brown dilution at the B locus.

D (Dilution) locus: Controls intensity of eumelanin. Dense color (D/-) is dominant; blue dilution (d/d) is recessive. Blue Biewer Terriers are genetically black dogs with dilution at the D locus, producing a gray-blue color.

E (Extension) locus: Allows eumelanin expression. Biewer Terriers must allow black/chocolate expression (E/-).

K (Dominant Black) locus: Must be ky/ky (recessive) to allow tan points to show. Dominant black (KB) would mask the tan point pattern.

S (Spotting/Piebald) locus: This is the critical locus that distinguishes Biewer Terriers from Yorkshire Terriers. The piebald gene creates white areas in the coat. Biewer Terriers are typically s/sp (parti) or sp/sp (piebald), producing significant white markings. Yorkshire Terriers are S/S (solid), with no white.

RALY gene: Controls progressive graying or clearing of the coat over time. This gene influences whether pigmented areas lighten with age.

Breeding for tri-color: To produce tri-color puppies with proper white distribution, both parents must carry piebald genetics (at least one sp allele). Breeding two solid-colored dogs (S/S × S/S) cannot produce tri-color puppies. Breeding a tri-color to a solid may produce tri-color puppies if the solid dog is a hidden carrier (S/sp), but this is uncommon.

The complexity of Biewer Terrier color genetics is rated "high" because multiple loci interact to produce the correct phenotype. Small changes in any locus can produce disqualifying colors or patterns.

Health-linked color concerns: Blue (dilute) Biewer Terriers may rarely develop Color Dilution Alopecia (CDA), a condition causing hair loss in diluted areas. CDA is more common in breeds with d/d genotypes. While not prevalent in Biewer Terriers, breeders should monitor blue dogs for coat quality issues.

Available DNA tests: Companies like Embark, Wisdom Panel, and Animal Genetics offer coat color panels that identify genotypes at the A, B, D, E, K, and S loci. These tests help breeders predict puppy colors and avoid producing disqualifying patterns.

Color breeding predictions: DNA testing both parents allows breeders to predict puppy color outcomes with high accuracy. For example:

• Black tri-color (B/B, D/D) × Black tri-color (B/B, D/D) = 100% black tri-color puppies
• Black tri-color (B/b, D/D) × Chocolate tri-color (b/b, D/D) = 50% black tri-color, 50% chocolate tri-color
• Black tri-color (B/B, D/d) × Blue tri-color (B/B, d/d) = 50% black tri-color, 50% blue tri-color

Understanding these patterns prevents surprises and ensures all puppies meet the standard's color requirements. Breeders should DNA test all breeding stock for coat color genetics to make informed pairing decisions.

Selecting Biewer Terrier Breeding Stock

Selecting superior breeding stock requires evaluating conformation, temperament, health testing, and genetic diversity. The Biewer Terrier's small population and high COI make selection particularly challenging—breeders must balance multiple priorities without further constricting the gene pool.

Conformation priorities:

Tri-color pattern with proper distribution (Importance: 10/10): This is non-negotiable. The dog must exhibit a correct tri-color pattern with white distribution that aligns with the standard. Excessive white beyond permitted areas is a serious fault. The pattern should create an aesthetically pleasing, balanced appearance.

Silky coat texture and quality (Importance: 9/10): Coat texture distinguishes an outstanding Biewer Terrier from a mediocre one. The coat must be fine, straight, and silky—never cottony, woolly, or coarse. When you run your fingers through the coat, it should feel smooth and fluid. Heavy, coarse coat is a serious fault and difficult to correct in a breeding program.

Terrier expression with small V-shaped ears (Importance: 8/10): The Biewer Terrier should project a keen, intelligent terrier expression. Eyes should be medium-sized, dark, and almond-shaped—not round or prominent. Ears must be small, V-shaped, and erect. Loss of terrier expression (round eyes, soft expression) detracts from breed type.

Size within standard - 4-8 pounds (Importance: 10/10): Proper size is a disqualifiable trait. Dogs over 8 pounds cannot be shown or bred. Select breeding stock in the middle of the range (5-7 pounds) to reduce the risk of oversized puppies. Breeding two dogs at the upper limit (7-8 pounds) increases the likelihood of producing puppies that exceed the standard.

Level topline and balanced proportions (Importance: 7/10): The topline should be level in motion and at rest. Roached or swayed backs are serious faults. The dog should present a compact, balanced outline with proper proportions.

Tail carriage (Importance: 6/10): The tail should be set high and carried gaily, contributing to the overall balanced picture. Low tail set or a tail curled over the back detracts from the correct silhouette.

Temperament (Importance: 10/10): The Biewer Terrier is a companion breed—temperament is paramount. Breeding stock must be friendly, outgoing, confident, and stable. The standard describes the breed as "whimsical" but not nervous or aggressive. Avoid timid, reactive, or aggressive dogs. Temperament issues are difficult to breed out and incompatible with the breed's purpose.

Overall balance (Importance: 8/10): The sum of the parts should create a harmonious, elegant toy terrier. Breeding stock should be sound in movement and well-balanced in proportion.

Common faults to select against:

• Round, prominent eyes lacking terrier expression
• Low tail set or improper tail carriage
• Heavy, coarse coat texture
• Excessive white beyond permitted areas
• Roached or swayed topline
• Incorrect color pattern (bi-color or solid)
• Oversize (over 8 pounds)
• Poor temperament (timid, nervous, aggressive)

Temperament evaluation: Test breeding prospects in multiple environments. Introduce them to strangers, children, other dogs, and novel situations. Evaluate their recovery time from startling stimuli. A confident Biewer Terrier approaches new experiences with curiosity rather than fear. Avoid breeding dogs that show excessive fear, aggression, or inability to settle.

Health testing priorities: All breeding stock must complete CHIC requirements (annual ACVO eye examination, OFA patellar luxation evaluation). Embark DNA testing is strongly recommended to identify carrier status for PLL, PRA-prcd, CDDY, DM, and Hemophilia B. Cardiac evaluation and bile acids testing screen for additional congenital conditions.

Genetic diversity and COI management: The Biewer Terrier's average COI of 25% is alarmingly high—the recommended target is under 5%. Breeders must prioritize genetic diversity to ensure the breed's long-term viability. Use Embark's COI calculator to estimate the COI of a proposed breeding before proceeding. Select pairings that reduce COI while maintaining breed type and health.

In practice, this means:

• Avoid breeding closely related dogs (parent-offspring, sibling-sibling, half-sibling matings)
• Seek outcross pedigrees with minimal common ancestors in 5-generation pedigrees
• Import genetics from European or distant U.S. lines when possible
• Accept carrier status for recessive conditions when necessary to preserve genetic diversity
• Balance health, conformation, and diversity—perfection in all areas is impossible with a small gene pool

Stud selection: Stud fees for Biewer Terriers range from $500-$1,500 depending on the dog's show record, health testing, and proven production. When selecting a stud, prioritize:

1. Comprehensive health testing (CHIC plus Embark)
2. Complementary pedigree (low COI with your female)
3. Strengths that complement your female's weaknesses
4. Proven production of quality puppies (if the dog has been bred)
5. Excellent temperament and breed type

Avoid the temptation to breed to the "popular sire" if it increases COI excessively. Overuse of popular sires accelerates genetic bottlenecks.

Show vs. breeding quality: Not all structurally sound, health-tested dogs are suitable for breeding. Breeding quality dogs should be excellent examples of the breed standard with minimal faults. Show quality dogs are outstanding specimens capable of finishing championships. Pet quality dogs may have minor faults (incorrect ear set, slightly oversized, non-standard color) that disqualify them from breeding programs but make wonderful companions.

Whelping and Neonatal Care

Biewer Terrier whelping requires vigilance and preparedness. While natural whelping is the most common method, the breed's 35% C-section rate means breeders must recognize when intervention is necessary and have an emergency plan in place.

Natural whelping: When conditions are favorable—appropriate puppy size, strong uterine contractions, and normal dam anatomy—Biewer Terriers whelp naturally. Natural whelping should progress with puppies delivered at intervals of 30 minutes to 2 hours. Prepare a whelping box in a quiet, temperature-controlled area. Assemble supplies including clean towels, bulb syringe, dental floss for clamping cords, iodine for cord dipping, heating pad, and scale for weighing puppies.

Breed-specific whelping complications:

• Dystocia due to small pelvis or disproportionately large puppies: Toy breeds have a higher rate of dystocia (difficult birth) because the dam's pelvis is small relative to puppy size. Monitor labor closely and consult a veterinarian if no puppy appears within 2 hours of active contractions or if the dam shows signs of distress.
• Primary uterine inertia (weak contractions): Some Biewer Terrier dams experience weak or absent contractions, preventing natural delivery. If labor does not progress or contractions are weak, veterinary intervention with oxytocin or calcium may be attempted. If ineffective, C-section is necessary.
• Single-puppy syndrome with oversized pup: Litters of 1-2 puppies allow individual puppies to grow excessively large, making natural delivery impossible. Radiographs or ultrasound late in pregnancy can assess puppy size.
• Failure to progress after 2+ hours of active labor: If the dam has been actively contracting for 2+ hours without producing a puppy, transport to a veterinary hospital immediately. Prolonged labor increases the risk of fetal distress and maternal exhaustion.

C-section rate and planning: With a 35% C-section rate, breeders should have a relationship with a veterinary hospital that offers 24-hour emergency care. Know the location, contact number, and estimated cost of an emergency C-section (typically $1,500-$2,500) before the breeding occurs. Many breeders elect to have their veterinarian on standby during whelping for immediate consultation.

Planned C-sections may be recommended for dams with a history of dystocia, single-puppy pregnancies, or known pelvic abnormalities. Timing a planned C-section requires progesterone monitoring in late pregnancy to ensure fetal maturity.

Average birth weight: Biewer Terrier puppies are tiny at birth:

• Males: 3.5-4.5 ounces (approximately 0.25 pounds)
• Females: 3.0-4.0 ounces (approximately 0.22 pounds)

Puppies should gain weight steadily from birth. Weigh each puppy immediately after birth and twice daily for the first two weeks to monitor growth.

Daily weight gain target: Healthy puppies should gain 5-10% of birth weight per day, equivalent to 0.15-0.3 ounces daily in the first week. A puppy born at 4 ounces should weigh approximately 4.3-4.4 ounces by 24 hours and 5.5-6 ounces by one week. Puppies that fail to gain weight or lose weight are at risk for fading puppy syndrome and require immediate intervention (supplemental feeding, veterinary exam).

Neonatal care: Maintain the whelping box temperature at 85-90°F for the first week, gradually reducing to 80°F by week two and 75°F by week four. Puppies cannot regulate their body temperature initially and are vulnerable to hypothermia.

Monitor puppies for signs of fading puppy syndrome: lethargy, failure to nurse, crying persistently, low body temperature, or weight loss. Fading puppies require immediate veterinary care and may need tube feeding, subcutaneous fluids, and glucose supplementation.

Dewclaw removal, tail docking, ear cropping: The Biewer Terrier breed does not practice dewclaw removal, tail docking, or ear cropping. Puppies are left natural.

Dam care: Provide the dam with unlimited access to high-quality puppy food and fresh water during lactation. Nursing dams may require 2-4 times their normal food intake to support milk production. Monitor the dam for signs of mastitis (hot, swollen mammary glands), metritis (uterine infection), or eclampsia (calcium deficiency causing tremors or seizures). Eclampsia is more common in toy breeds and requires emergency veterinary treatment with IV calcium.

Puppy Development Milestones

Biewer Terrier puppies grow rapidly during the first 12 weeks, progressing from tiny neonates to active, social companions. Understanding developmental milestones allows breeders to provide age-appropriate socialization and make informed decisions about puppy placement.

Week-by-week growth:

• Birth: Males average 0.25 pounds (4 ounces), females 0.22 pounds (3.5 ounces)
• Week 1: Puppies double birth weight, reaching 0.35 pounds (males) and 0.31 pounds (females)
• Week 2: Eyes open around day 10-14; puppies begin to hear. Weight: 0.5 pounds (males), 0.44 pounds (females)
• Week 3: Puppies begin walking unsteadily. Teeth start erupting. Weight: 0.7 pounds (males), 0.63 pounds (females)
• Week 4: Weaning begins. Introduce softened puppy food. Weight: 0.9 pounds (males), 0.81 pounds (females)
• Week 5: Puppies become increasingly active and playful. Weight: 1.1 pounds (males), 1.0 pounds (females)
• Week 6: Fully mobile, eating solid food, beginning socialization with people and littermates. Weight: 1.4 pounds (males), 1.25 pounds (females)
• Week 7: Peak socialization period. Introduce novel experiences. Weight: 1.7 pounds (males), 1.5 pounds (females)
• Week 8: Traditional go-home age for many breeds, though toy breeds benefit from additional time with the litter. Structural evaluation can begin. Weight: 2.0 pounds (males), 1.75 pounds (females)
• Week 10: Continuing socialization. Weight: 2.6 pounds (males), 2.25 pounds (females)
• Week 12: Preferred go-home age for toy breeds. Puppies are better developed and more resilient. Weight: 3.2 pounds (males), 2.75 pounds (females)

Weaning: Begin the weaning process gradually at 4-5 weeks by offering softened puppy food. Most puppies transition fully to solid food by 6-7 weeks but continue to nurse occasionally for comfort. Complete weaning occurs naturally by 7-8 weeks.

Go-home age: While 8 weeks is the legal minimum age for puppy placement in most jurisdictions, many Biewer Terrier breeders prefer to keep puppies until 10-12 weeks. Toy breed puppies are tiny and vulnerable at 8 weeks (2 pounds or less). Waiting until 10-12 weeks allows puppies to develop additional size, coordination, and resilience, improving their ability to adapt to new homes.

At 12 weeks, puppies weigh 2.75-3.2 pounds—still small but more robust than at 8 weeks. The extra time with littermates enhances socialization and bite inhibition learning. Many buyers appreciate the additional maturity and prefer to wait for a more developed puppy.

Adult size achievement: Biewer Terriers reach adult size at 9-12 months, though some individuals continue filling out until 18 months. Final adult weight ranges from 4-8 pounds, with most adults settling in the 5-7 pound range.

Structural evaluation timing: Breeders evaluating puppies for show potential should perform initial assessments at 8-10 weeks when proportions and structure are evident. However, coat color continues to develop and change through 4-6 months as the RALY gene influences progressive graying. Final evaluations for color and coat quality should wait until at least 4-6 months.

Socialization window: The critical socialization period for puppies is 3-14 weeks. During this time, puppies are maximally receptive to new experiences and form lasting impressions. Breeders should expose puppies to:

• Handling by multiple people (men, women, children)
• Novel sounds (vacuum, doorbell, TV, music)
• Various surfaces (grass, carpet, tile, gravel)
• Gentle play with littermates
• Car rides
• Crate training introduction

Positive experiences during the socialization window create confident, well-adjusted adults. Lack of socialization can result in fearful, reactive dogs.

Fear periods: Puppies experience fear periods around 8-10 weeks and again at 6-14 months when they may suddenly become wary of previously accepted stimuli. During fear periods, avoid overwhelming experiences and provide reassurance. Do not coddle fearful behavior, but expose puppies gently to the feared stimulus paired with positive rewards.

Biewer Terrier Breeding Economics

Breeding Biewer Terriers is rarely profitable when all costs are accounted for. The breed's small litter size (3.5 puppies average), elevated C-section rate, and substantial health testing requirements create a challenging economic reality. Understanding the true costs allows breeders to set realistic expectations and price puppies appropriately.

Pre-breeding costs:

Health testing per breeding dog: $539

• ACVO eye examination (annual): $65
• Patellar luxation (OFA, one-time): $50
• Embark Breeder Package: $199
• Cardiac examination: $75
• Bile acids test: $150

Both the stud and dam should be fully health tested, representing $1,078 in health testing costs per breeding. Many breeders absorb stud dog health testing costs, but responsible stud owners provide proof of health clearances.

Stud fee: $800 (average for a health-tested, titled stud)

Stud fees range from $500-$1,500 depending on the dog's accomplishments and reputation. Some breeders use their own stud (avoiding stud fees) but sacrifice genetic diversity. Using outside studs often requires fresh-chilled AI, adding collection and shipping fees ($200-$400).

Breeding and pregnancy costs:

Progesterone testing: $200

Progesterone testing determines optimal breeding timing. Tests cost $50-$100 each, with multiple tests needed throughout the heat cycle (typically 3-5 tests). Proper timing maximizes litter size and conception rates.

Prenatal veterinary care: $350

• Confirmation ultrasound (day 28-30): $75-$150
• Radiographs for puppy count (day 55-58): $100-$200
• Prenatal checkup: $75-$100

Whelping costs:

Natural whelping: $300 (supplies, emergency readiness)

Whelping supplies include a whelping box, heating pad, scales, clean towels, puppy milk replacer, feeding tubes, and miscellaneous supplies. Even when whelping occurs naturally, breeders should be prepared for emergencies.

C-section: $1,800 (average emergency C-section cost)

Emergency C-sections typically cost $1,500-$2,500 depending on geographic location and time of day (after-hours fees are higher). With a 35% C-section rate, breeders must budget for this possibility. Planned C-sections may cost slightly less ($1,200-$1,800) but still represent a significant expense.

For financial planning, breeders should assume a C-section is likely and budget accordingly. Expecting natural whelping and being surprised by a $2,000 C-section bill can be financially devastating.

Puppy-rearing costs (per puppy): $175

• Veterinary exam, first vaccines, deworming: $75
• Microchip: $25
• AKC registration: $35
• Food (dam and puppies through 12 weeks): calculated per litter
• Miscellaneous (toys, bedding, cleaning supplies): $40

For a typical litter of 3.5 puppies, puppy vet costs total approximately $613.

Food and supplements: $250 (dam during pregnancy/lactation plus puppies through 12 weeks)

The dam requires increased food intake during lactation (2-4x normal consumption). Puppies eat increasing amounts as they grow. High-quality puppy food is essential for proper development.

Registration costs: $200 (AKC litter registration plus individual puppy registrations)

Total investment per litter:

Best-case scenario (natural whelping, 4 puppies):

• Health testing (dam): $539
• Stud fee: $800
• Progesterone testing: $200
• Prenatal care: $350
• Whelping (natural): $300
• Puppy vet care (4 puppies): $700
• Food: $250
• Registration: $200
• Total cost: $3,339

Worst-case scenario (C-section, 2 puppies):

• Health testing (dam): $539
• Stud fee: $800
• Progesterone testing: $200
• Prenatal care: $350
• Whelping (C-section): $1,800
• Puppy vet care (2 puppies): $350
• Food: $250
• Registration: $200
• Total cost: $4,489

Average scenario (natural whelping, 3.5 puppies rounded to 4 for calculation):

• Total cost: $3,252

Revenue:

Average puppy prices:

• Pet quality: $2,500
• Show quality: $5,000

Most litters include a mix of pet and show prospects. A typical litter of 3.5 puppies might include 2 pet-quality puppies and 1-2 show prospects.

Average litter revenue (3.5 puppies): $8,750

• Assumes a mix of pet and show pricing averaging $2,500 per puppy

Net analysis:

Best-case scenario (natural whelping, 4 puppies at $2,500 each):

• Revenue: $10,000
• Costs: $3,339
• Net: +$6,661

Average scenario (natural whelping, 3.5 puppies at $2,500 average):

• Revenue: $8,750
• Costs: $3,252
• Net: +$5,498

Worst-case scenario (C-section, 2 puppies at $2,500 each):

• Revenue: $5,000
• Costs: $4,489
• Net: +$511

These calculations assume natural whelping or a single C-section and do not account for:

• Lost income from the breeder's time (whelping, puppy care, socialization, buyer communications)
• Marketing expenses (website, advertising, professional photos)
• Show expenses for the dam (entries, travel, handler fees)
• Emergency veterinary care for the dam or puppies
• Stud dog health testing and titling costs
• Facility maintenance and utilities

When these hidden costs are included, profit margins shrink significantly or disappear entirely. Many responsible breeders break even or operate at a loss, viewing breeding as a passion rather than a business.

Is breeding Biewer Terriers profitable? For hobbyist breeders producing 1-2 litters per year with comprehensive health testing and ethical practices, breeding is rarely profitable. The small litter size limits revenue while fixed costs (health testing, stud fees, whelping) remain constant. Breeders who cut corners (skipping health testing, using substandard facilities, selling puppies young) may achieve higher margins but do so at the expense of puppy welfare and breed health.

Ethical breeding is a labor of love, not a reliable income stream. Breeders should pursue the breed because they are passionate about improving the Biewer Terrier, not because they expect financial gain.

Breeder Resources

Successful Biewer Terrier breeders rely on a network of support from the parent club, regional organizations, and breed mentors. These resources provide education, networking opportunities, and guidance on health, genetics, and conformation.

Parent club: Biewer Terrier Club of America (BTCA)

The BTCA is the AKC-recognized parent club for the breed. The club maintains the breed standard, coordinates health initiatives, hosts specialty shows, and provides breeder education. Membership offers access to breeder directories, mentorship programs, and the latest breed health research. Website: https://biewerterrierclubofamerica.org/

Regional clubs: Several regional Biewer Terrier clubs have formed across the United States, offering local meetups, training classes, and conformation matches. Contact the BTCA for information on regional clubs in your area.

AKC Breeder Programs:

AKC Breeder of Merit: This program recognizes breeders who demonstrate a commitment to health testing, continuing education, and breed improvement. Requirements include health testing all breeding stock per CHIC recommendations, producing AKC-registered litters, and earning AKC titles on dogs. Breeder of Merit status increases buyer confidence and demonstrates dedication to responsible breeding.

AKC Bred with H.E.A.R.T. (Health, Education, Accountability, Responsibility, Tradition): This program highlights AKC's commitment to responsible breeding practices. Breeders pledge to health test, provide support to puppy buyers, and comply with AKC regulations. Participation is free and provides marketing benefits through the AKC Marketplace.

Recommended books:

"The Official Standard of the Biewer Terrier" (BTCA): Essential reading for anyone breeding or showing Biewer Terriers. The official standard provides detailed guidance on correct conformation, color, and temperament.

"AKC's Guide to Responsible Dog Breeding": A comprehensive resource covering breeding fundamentals, genetics, whelping, puppy care, and ethical practices. Suitable for new breeders or experienced breeders expanding to a new breed.

"Book of the Yorkshire Terrier" by Joan Gordon and Janet Bennett: Although focused on the parent breed, this book provides valuable insights into coat care, structure, and genetics applicable to Biewer Terriers.

Online communities:

Biewer Terrier Club of America Facebook Group: An active community of breeders, owners, and enthusiasts sharing photos, health information, and breeding advice. A valuable resource for connecting with experienced Biewer Terrier breeders.

Biewer Terrier Owners and Breeders (Facebook): A public group for discussions about training, health, and breeding. Members include both pet owners and breeders.

AKC Breeder Community forums: AKC offers forums for breeders to discuss topics ranging from health testing to marketing puppies. While not breed-specific, the community includes experienced mentors across all breeds.

Finding a mentor: New Biewer Terrier breeders should seek mentorship from established breeders with proven track records. A good mentor provides guidance on health testing interpretation, breeding decisions, whelping support, and navigating the challenges of a new breed. Attend BTCA specialty shows, introduce yourself to exhibitors, and ask questions. Most breeders are willing to share knowledge with genuinely interested newcomers.

Frequently Asked Questions

How many puppies do Biewer Terriers typically have?

Biewer Terriers average 3.5 puppies per litter, with a typical range of 2-5 puppies. Approximately 25% of litters consist of 1-2 puppies, while 42% have 4-5 puppies. Litters of 6 puppies are rare (under 3%). The small litter size is consistent with toy breeds and significantly impacts breeding program economics.

Do Biewer Terriers need C-sections?

Approximately 35% of Biewer Terrier litters are delivered via cesarean section due to dystocia, primary uterine inertia, oversized puppies, or failure to progress. While natural whelping is more common (65%), breeders must be prepared for emergency surgical intervention. Factors increasing C-section risk include small litter size (single-puppy syndrome), first-time mothers, and prolonged labor. Maintaining a relationship with a 24-hour veterinary hospital is essential.

What health tests are required for breeding Biewer Terriers?

The CHIC program requires two tests: an annual ACVO eye examination ($65) and an OFA patellar luxation evaluation ($50). Responsible breeders add the Embark Breeder Package ($199) to screen for PLL, PRA-prcd, CDDY/IVDD, DM, Hemophilia B, and over 200 other genetic conditions. Cardiac examination ($75) and bile acids testing for liver shunt ($150) are also recommended. Total comprehensive testing costs approximately $539 per breeding dog.

How much does it cost to breed Biewer Terriers?

The average cost per litter is $3,252, including health testing ($539), stud fee ($800), progesterone testing ($200), prenatal vet care ($350), natural whelping supplies ($300), puppy vet care for 3.5 puppies ($613), food ($250), and registration ($200). If a C-section is needed, costs increase by $1,500, raising the total to approximately $4,750. These figures do not include the breeder's time, marketing expenses, or facility costs.

At what age can you breed a Biewer Terrier?

Females should be bred no earlier than 18-24 months (after the second or third heat cycle) to ensure physical and mental maturity. Males can be used for stud service at 12-18 months. Biewer Terriers typically experience their first heat at 7-12 months, but breeding at the first heat is not recommended. All health testing (OFA patellar luxation, ACVO eye exam, Embark DNA panel) should be completed before breeding.

How much do Biewer Terrier puppies cost?

Pet-quality Biewer Terrier puppies typically cost $2,500, while show-quality puppies with breeding potential range from $4,000-$6,000 (averaging $5,000). Prices vary based on the breeder's reputation, the parents' titles and health testing, coat quality, color, and geographic location. Puppies from champion bloodlines with comprehensive health testing command higher prices.

What are the most common health problems in Biewer Terriers?

The most common hereditary conditions in Biewer Terriers include patellar luxation (35% prevalence), CDDY/IVDD (25%), Primary Lens Luxation (15%), PRA-prcd (10%), and portosystemic shunt (8%). Less common conditions include Degenerative Myelopathy, White Shaker Syndrome, and Hemophilia B. DNA testing through Embark identifies carrier status for PLL, PRA-prcd, CDDY, DM, and Hemophilia B, allowing breeders to make informed decisions and avoid producing affected puppies.

Is breeding Biewer Terriers profitable?

Breeding Biewer Terriers ethically is rarely profitable due to small litter sizes, high health testing costs, and significant whelping expenses. An average litter (3.5 puppies, natural whelping) generates approximately $8,750 in revenue against $3,252 in costs, yielding a net of $5,498 before accounting for the breeder's time, marketing, and facility expenses. A C-section litter of 2 puppies may net only $511. When all hidden costs are included, most hobbyist breeders break even or operate at a loss. Ethical breeding is a passion project, not a reliable business.

What is the difference between a Biewer Terrier and a Yorkshire Terrier?

The Biewer Terrier originated from Yorkshire Terriers but is now recognized as a genetically distinct breed. The primary difference is the mandatory tri-color pattern in Biewer Terriers (white plus two other colors) caused by the piebald gene, while Yorkshire Terriers are solid-colored (blue and tan). Biewer Terriers are slightly larger on average (4-8 pounds vs. Yorkshire Terrier's 4-7 pounds) and have a whimsical, companion-focused temperament emphasized more strongly in the Biewer standard. Both breeds share similar coat texture and terrier expression.

How do you breed for the tri-color pattern in Biewer Terriers?

The tri-color pattern requires specific genetics at multiple loci: tan points (at/at) at the A locus, non-dominant black (ky/ky) at the K locus, and piebald (s/sp or sp/sp) at the S locus. Both parents must carry at least one piebald allele to produce tri-color puppies. DNA testing both parents for coat color genetics allows breeders to predict puppy colors accurately. Breeding two solid-colored dogs (S/S) cannot produce tri-color offspring. The complexity of Biewer Terrier color genetics is rated "high" due to the interaction of multiple genes.

What is COI and why is it important for Biewer Terrier breeding?

The coefficient of inbreeding (COI) measures the probability that an individual inherited identical gene copies from both parents due to common ancestors. The Biewer Terrier's average COI is 25%—very high for a breed—due to the small foundation population. High COI increases the risk of inherited diseases and reduces genetic diversity. The target COI for Biewer Terriers is under 5%, though achieving this is challenging. Breeders should use Embark's COI calculator to evaluate proposed breedings and prioritize pairings that reduce COI while maintaining health and conformation.

How long should Biewer Terrier puppies stay with the breeder?

While 8 weeks is the legal minimum in most jurisdictions, many Biewer Terrier breeders keep puppies until 10-12 weeks. At 8 weeks, puppies weigh only 1.75-2 pounds and are still very tiny and vulnerable. Waiting until 10-12 weeks allows puppies to reach 2.25-3.2 pounds, improving their resilience and ability to adapt to new homes. The extra time with littermates also enhances socialization and bite inhibition learning. Most buyers appreciate the additional maturity.