Chihuahua: knees, fontanelle and small size, what to anticipate
Published by Planète Pets · managing editor: Clément Lacaille · how our guides are written
The chihuahua is the smallest dog breed in the world, and its extreme miniaturisation comes with specific fragilities: the knees and, in some dogs, the skull. Knowing them means adopting with confidence and watching for the right signs. All our pointers are in the dog care and grooming section, with the full profile on the chihuahua page.
Contents · 4 sections
Patellar luxation, a very common condition
Patellar luxation is one of the most common orthopaedic disorders in the chihuahua. A study by Nilsson, Zanders and Malm, published in 2018 in The Veterinary Journal, measured a 23 % prevalence in a large screened population of Swedish chihuahuas, with heritability estimated between 0.25 and 0.46 depending on the calculation method (see the study). A gait that intermittently "skips," especially in a puppy, should be reported to the vet: early screening allows better planning of any future surgery.
The open fontanelle, or "molera"
Some chihuahuas are born with a skull fontanelle that never fully closes, known in the breed as a "molera." It is not automatically pathological, but it calls for extra care when handling the head, especially in puppyhood, and for choosing a harness over a collar to avoid any pressure on the neck.
What care budget to plan
Patellar luxation surgery is the most likely expense for this breed. Our guide to pet insurance for dogs helps you assess whether cover pays off, and our page on insuring a chihuahua spells out the orthopaedic cover to prioritise.
Frequently asked questions
Do all chihuahuas get patellar luxation?
No, but the risk is high: roughly one chihuahua in four is affected according to screening studies, making it a predisposition worth watching closely.
Is a molera dangerous?
Usually not, it shrinks with growth; but it does call for avoiding any impact or direct pressure on the puppy's skull.
Should a chihuahua be insured from an early age?
It's advisable: patellar luxation can appear within the first few months, and early cover avoids it being excluded as pre-existing.
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This guide is part of Planète Pets’s Dogs universe. Our advice is general in nature: for any health concern, your veterinarian remains the only reference.