Chihuahua (Long and Short Coat)
The Chihuahua is the smallest of the dog breeds. He is a dog you can take anywhere because of his size and an ideal lap dog. Despite his small size the Chihuahua thinks he is a big dog and will give a loud warning if strangers approach the house. He will adapt to most types of home. Like all dogs he needs daily exercise and should be treated as a dog and not as a toy. The long coated version will need regular grooming more than once a week.
Inbreeding Coefficient - COI
(Should be as low as possible)
The UK Kennel Club breed average COI is 5.8% (smooth coat) 4.0% (long coat) - see 'A Beginners Guide to COI'
Effective Population Size - EPS81.05 (smooth coat) and 175.96 (long coat)
EPS is a measure of how many individuals are contributing genetically to a breed population. It is a measure of the size of the gene pool in a breed. Lower than 100 is considered critical by conservationists and below 50 brings a breed close to extinction. For more information see the Kennel Club article.
Health and Welfare Problems due to Conformation
(Body shape and physical characteristics)
- Skeletal fragility due to extreme miniaturisation.
- Hydrocephalus possibly due to head shape/size (fluid causes pressure on the brain, chronic pain and loss of brain function – treatment is often not effective)
- The merle coat colour is associated with deafness. The Kennel Club bans registration of Chihuahua puppies with a Merle parent.
Chiari malformation/Syringomyelia (CMSM) MRI scheme (neurological disease caused by a malformation of the occipital bone and leading to the formation of fluid filled pockets within the spinal cord). Can cause life long pain.
Estimated Breeding Values (EBVs) are now available for Hip Dysplasia and Elbow Dysplasia:
DNA Tests Available
- Pyruvate kinase deficiency (a key enzyme deficiency which shortens the lifespan of red blood cells, leading to haemolytic anaemia)
- Merle gene
Unofficial (Breed Club) Schemes
Ask the breeder to show you the certificates for the above tests/screening for both parents. If any of the above tests have not been considered necessary by the breeder (and there may be good reasons), ask her to explain why.
Other Diseases Reported
(For which there are currently no genetic or screening tests for sire or dam)
- Hydrocephalus (water on the brain)
- Heart disease: Myxomatous degeneration of the mitral valve; Pulmonic stenosis (narrowing of the pulmonary valve)
- Patellar luxation (dislocated kneecap)
- Atopy (hypersensitivity to pollens and other protein particles – causes intense itching)
- Tracheal collapse (collapse of breathing tube)
- Cancer (skin melanoma)
- Retained temporary dentition
- Atlantoaxial subluxation (instabilty of the cervical spine – neck – causing injury to the spinal cord and pain)
- Necrotising leucoencephalitis (inflammation of the brain, often fatal) (autoimmune disease)
- Myasthenia gravis (autoimmune disease) (neuromuscular disease causign weakness)
- Corneal dystrophy (eye disease)
- Urolithiasis (stone formation in urinary system)
- Dystocia (difficulty giving birth)
- Narcolepsy (sudden episodes of complete collapse, sleepiness)
- Legg-Calve-Perthe disease (disease of the head of the femur causing pain and disability)
- Haemophilia (blood clotting disease)
Ask the breeder about the medical history of the parents, grandparents and great grandparents. Consider carefully whether to purchase a puppy if some of these or other diseases are in the family line.
Ask about the breeder’s policy in cases of serious genetic diseases occurring to your puppy in later life. Good breeders will request to be informed of such events in order to improve future breeding decisions. Some breeders will also agree to contribute towards medical costs or refund purchase price.
You are strongly advised to buy from a breeder who uses (or is prepared to use) the RSPCA / BVA AWF Puppy Contract and Puppy Information Pack (PIP): www.puppycontract.org.uk
You are also advised to buy from a breeder who follows the Dog Breeding Reform Group’s (DBRG) Standard for Dog Breeding: