Geriatric clinics in practice- Part 1
As animals age a variety of changes occur which makes the management of elderly animals both interesting and, at times, challenging. Two main types of change occur concurrently:
Aging changes that typically occur in tissues are predictable and progressive and they ultimately result in decreased organ reserve and impaired functionality but, by themselves, aging changes do not cause disease. Some of the typical aging changes are listed in Table 1 and the combined effects of these result in altered neuroendocrine function, reduced ability of the animal to respond to stress (such as the metabolism and elimination of drugs), and reduced ability to mount a robust immune response if exposed to pathogenic agents; wound healing may also be impaired.
In addition to aging changes, elderly animals often have concurrent age-related diseases, many of which can be subclinical for many weeks, months or even years before signs become obvious to the owner or clinician (Table 2). A good example is mitral regurgitation secondary to endocardiosis in dogs. With advancing age the severity of the lesions on the atrio-ventricular valve(s) progresses (Figure 1) and one study found that 58% of dogs had severe disease by the age of 9 years (1). As the lesions progress regurgitation gets worse, reducing ejection volume and, in an attempt to maintain cardiac output, homeostatic mechanisms kick-in, including stimulation of the renin-angiotensin-aldosterone system and the sympathetic nervous system. Therefore although a murmur can be heard on auscultation, the underlying disease is masked, and it can take years before the condition decompensates; medical intervention is usually reserved until the dog shows clinical signs of heart failure. However, reduced cardiac output results in decreased blood supply to all organs resulting in local hypoxia, and impaired venous return results in congestion with consequential decreased removal of waste products from tissues. Essentially dogs in heart failure have impaired multiple organ function (Figure 2).
The possibility of age-related diseases needs to be considered at all times as their presence alters the way that the animal should be managed; for example changes in exercise pattern - from long to short walks - might be recommended for dogs with osteoarthritis, and dietary changes may be advisable; the introduction of a weight loss program is needed for obese animals; and drug selection may need to be modified or the dose rate or interval of dosing changed if an animal has hepatic or renal disease.
Aims of Screening
Pet owners often do not recognize the importance of signs that are commonly present in animals with age-related diseases, such as increased thirst, weight loss, exercise intolerance and excess weight (2), and they do not report them to the attending veterinarian. It is therefore important to educate clients on what they should look for, and to screen their animals for unrecognized signs. The aims of screening elderly animals are multiple:
1. To detect signs of age-related disease, thus allowing both early diagnosis and early intervention. Early intervention can have several key end-points:
• Remove pain
• Increase the likelihood of successful treatment
• Improve quality of life • Delay progression of the condition
• Prolong lifespan
2. To identify risk factors in the animals lifestyle such as inappropriate feeding practices.
3. To obtain baseline physiological values or blood biochemistry/ hematology values for the animal which can be used for comparison with tests performed at a later date.
4. As a benefit to the practice by:
• Strengthening client-practice bonding
• Meeting client expectations for quality life-time care for their pet
• Generating additional revenue
Geriatric screening programs
It may be appropriate to question if geriatric screening should be optional or mandatory. Routine screening can be optional but, in my opinion, screening of elderly patients should be mandatory in some circumstances:
1. Prior to general anesthesia.
2. Prior to the administration of drugs with a narrow therapeutic index, especially some frequently used drugs including NSAIDs, ACE inhibitors, acetyl-promazine, medetomidine and dexmedetomidine.
Over the years I have been involved with several different formats for running a geriatric clinic in first opinion practices:
• Format 1. The clinic is promoted as a premium service clients are charged a relatively high fee to include the cost of examination, a full panel of blood serology and hematology, urine tests, fecal examination, blood pressure monitoring, chest radiographs, electrocardiogram, intraocular pressure measurements, etc. Some practices run such programs successfully but, whilst this type of screening provides the most information, in my experience the uptake rate by clients is poor.
• Format 2. The clinic is promoted as a special service with clinician/nurse time charged at normal consultation rates and all tests done are charged at normal rates. This format is successful but in my experience the uptake is relatively low.
• Format 3. A free consultation (history and physical examination) and urinalysis is offered with any additional tests or investigations charged at normal rates. In my experience this is the most successful protocol with the highest uptake. If clients are invited to attend by a cold mailshot the uptake can be 18% (3); however if invited personally by practice staff most clients will agree to attend.
The most important part of a geriatric screen is the acquisition of a detailed history and the findings of a good physical examination. The longer I allow clients to talk the more useful information I obtain, and sometimes a key issue will take 20-30 minutes to be mentioned. I prefer not to view previous clinical records until after I have examined the animal and there are 3 stages to history taking:
1. Firstly, an open question asking what changes the owner has noticed as their pet has aged.
2. Secondly, a basic fact-finding history including details about lifestyle, exercise, feeding, drinking and toileting. This elicits details about vaccination status and preventative medicines (e.g. endo- and ecto-parasiticides) that the owner uses, concurrent medications that the animal is taking, and previous illnesses that the animal may have had.
3. Finally I take a detailed prompted history covering all body systems.
Many practices may delegate their geriatric screening to veterinary nurses/technicians, and they can play an important part in running a program; however, as the objective of screening an animal is to identify signs of common age-related diseases it is necessary that a qualified veterinarian performs a full physical examination that includes the following:
1. Ophthalmoscopy assessment
2. Neurological examination
3. Cardiorespiratory examination
4. Palpation of the abdomen
5. Otoscopy examination
6. Rectal examination (for male dogs)
7. Musculoskeletal evaluation
Of course nurses can be involved in other parts of the screening process, including some of the history taking, weighing the animal, urinalysis, blood testing, etc, but most nurses will not have the clinical knowledge to explore in-depth signs that may be described during the history taking and this is best done by a veterinarian.
Come back next week for Part 2 covering diagnostic test!
1. Whitney JC. Observations on the effect of age on the severity of heart valve lesions in the dog. J Small Anim Pract 1974;15:511-522.
2. Davies M. Internet users’ perception of the importance of signs commonly seen in old animals with age-related diseases. Vet Rec 2011;169:584. (DOI:10.1136/vr.d5512).
3. Davies M. Geriatric screening in first opinion veterinary practice – results of 45 dogs. J Small Anim Pract (in press).
4. Alef M, von Praun F, Oechtering G. Is routine pre-anaesthetic haematological and biochemical screening justified in dogs? Vet Anesth and Analg 2008;35:132-140.
5. Archer J. Interpretation of laboratory data. In: Villiers E, Blackwood L, eds. Manual of Canine and Feline Clinical Pathology, 2nd ed. Gloucester; BSAVA, 2005;18.
6. Galena HJ. Complications occurring from diagnostic venipuncture. J Fam Pract 1992;34:582-584.
7. Lifelines - Official newsletter of the Kansas State University School of Veterinary Medicine 2010;5:(6). www.vet.k-state.edu/depts/development/ lifelines/1006.htm#radiographs. Accessed 28 October 2011.
8. Joubert KE. Pre-anesthetic screening of geriatric dogs. J S Afr Vet Ass 2007;78(1):31-5.
This article was previously published in 2012.
Veterinary Manual. http://www.merckmanuals.com professional/geriatrics.html Accessed 21.10.2011.
Davies M. Canine and Feline Geriatrics. 1996. Oxford. Blackwells.
Hoskins JD. Geriatrics and gerontology of the dog and cat, 2nd Ed. 2004. Philadelphia. W.B Saunders Co.