does not always mean that the pet will develop disease.
In most instances, genotypic testing is used as a health screen rather than a disease screen.
Phenotypic testing can confirm a diagnosis, but typically later in the course of disease.
Veterinary teams need to be able to effectively counsel clients as how a combination of genotypic and phenotypic testing can help deliver excellent healthcare across a pet's lifespan.
Abbreviation
DNA Deoxyribonucleic acid
Recommended Reading
1 Ackerman, L. (2011). The Genetic Connection, 2e. Lakewood, CO: AAHA Press.
2 Ackerman, L. (2019). An introduction to pet‐specific care. EC Vet. Sci. 4 (1): 1–3.
3 Ackerman, L. (ed.) (2020). Pet‐specific care. In: Five‐Minute Veterinary Practice Management Consult, 3e, 260–263. Ames, IA: Wiley.
4 Ackerman, L. (2020). Proactive Pet Parenting: Anticipating pet health problems before they happen. Problem Free Publishing.
5 American Animal Hospital Association‐American Veterinary Medical Association Preventive Health Guidelines Task Force (2011). J. Am. Vet. Med. Assoc. 239 (5): 625–629.
6 Bell, J., Cavanagh, K., Tilley, L., and Smith, F. (2012). Veterinary Medical Guide to Dog and Cat Breeds. Jackson Hole, WY: Teton NewMedia.
7 Companion Animal Parasite Council. www.capcvet.org
8 Partners for Healthy Pets. www.partnersforhealthypets.org
9 Shaffer, L.G., Geretshlaeger, A., Ramirez, C.J. et al. (2019). Quality assurance checklist and additional considerations for canine clinical genetic testing laboratories: a follow‐up to the published standards and guidelines. Hum. Genet. 138: 501–508.
10 Stull, J.W., Shelby, J.A., Bonnett, B.N. et al. (2018). Barriers and next steps to providing a spectrum of effective health care to companion animals. J. Am. Vet. Med. Assoc. 253 (11): 1386–1389.
3.12 Orthopedic Screening
Jason C. Nicholas, BVETMED (Hons)
Independent Consultant, Author and Speaker, Co-founder, Preventive Vet, Portland, OR, USA
3.12.1 Summary
From congenital and early‐onset conditions, such as angular limb deformities (ALD), luxating patella (LP), and hip dysplasia (HD), to developmental conditions that show up later in life, like degenerative joint disease (DJD) and osteoarthritis (OA), orthopedic conditions can cause significant pain, dysfunction, and secondary complications in our canine and feline patients. Such conditions can also cause emotional distress, logistical complications, and financial strain for our clients. Proactive screening and early client education and intervention are crucial to help avoid or mitigate the problems associated with orthopedic conditions both for our patients and our clients.
On the other hand, a reactive approach typically results in affected patients suffering unnecessarily until such time that their owners recognize a problem and present their pet for evaluation. By this point, treatment options may be more limited or prognosis for the best level of return to function and good quality of life (QOL) may already be reduced.
Orthopedic conditions in cats and dogs can be more common than many people realize and they can often have a significant negative impact on the comfort and QOL of affected animals. Orthopedic conditions can cause a host of problems, both for the affected pet and also for their people. Associated problems can include:
pain (potentially with a resulting change in behavior, including development of aggression and noise aversions)
loss of normal function and range of motion (ROM)
forced early retirement for a working dog
difficulty getting into/out of owner's vehicle
difficulty getting on/off owner's bed
difficulty navigating stairs within/outside owner's home
decreased jumping ability for cats
trouble accessing litter boxes for cats (with resulting inappropriate toileting)
overall decreased QOL
damage to the bond between the affected pet and their people.
Earlier detection and intervention can help improve the QOL for affected pets and their people. Since many pet owners don't appreciate the prevalence of orthopedic conditions in cats and dogs, and many don't pick up on the earliest signs of such conditions, veterinary teams must be proactive in educating clients and encouraging early and appropriate screening for orthopedic issues to help advocate for and provide the best comfort and care for our patients.
3.12.2 Congenital and Acquired Orthopedic Conditions Can Be Common
3.12.2.1 Canine Hip Dysplasia (HD)
Data from the Orthopedic Foundation for Animals (OFA) puts the likelihood of canine HD at 18.3–21.2% for Rottweilers, 20.1–20.5% for German shepherd dogs, 15.5–19.9% for golden retrievers, and 8.5–12.0% for labrador retrievers [1]. (Bulldogs had the highest prevalence of HD according to OFA data, at 65.9–71.2%!)
3.12.2.2 Canine Elbow Dysplasia (ED)
OFA data also show high prevalence of ED in certain dog breeds: chow chows (48.6%), Rottweilers (38.9%), German shepherd dogs (19.1%), and golden retrievers (11.4%) [1].
3.12.2.3 Canine Osteoarthritis (OA)
In a OA screening study done on dogs undergoing dental prophylaxis, it was found that 68% had radiographic evidence of OA in at least one joint (many had more than one joint affected) [2]. It was also found in this study that 71% of the owners of the dogs that were found to have radiographic OA weren't appreciating any clinical signs of their dog's OA [2].
3.12.2.4 Feline Osteoarthritis (OA)
In one study, radiographic evidence of OA was present in approximately 30% of cats over 8 years old [3]. Another study found that 90% of cats over 12 years old had radiographic evidence of DJD [4].
3.12.3 Diagnostic Methods for Screening for Orthopedic Disease and Risk Factors
While radiographs are a central modality of orthopedic disease screening, they aren't the only diagnostic testing method to use when looking for orthopedic problems in patients.
3.12.3.1 Pain Assessment Questionnaires
Validated pet owner questionnaires exist that can help increase a clinician's index of suspicion for orthopedic (or other painful) disease in pets. When orthopedic disease is anticipated or suspected based upon breed, age, activity level, or other factors,