5 Jul 2022
Ellie Mardell
Job Title
Image © punsayaporn / Adobe Stock
As veterinarians, the welfare of our patients should always be our prime consideration. Assessment and management of geriatric cats can be a very rewarding process, given the number and range of ways we can have a positive impact on the quality of life of elderly felids.
Whether through yearly health checks, vaccination appointments or senior clinics, monitoring of geriatric cats should be proactive, rather than waiting for a problem to present itself clinically.
Signs of disease are often subtle and easily missed in cats, but as increasing age brings an increased likelihood of disease development, carers must be particularly vigilant, and, prompted by us for information, recall where it may not automatically occur. History taking may differ a little from a standard health check appointment.
Information should be carefully gathered, with particular regard to the following.
An owner may or may not volunteer that their pet is “sleeping more”, assuming this to be a normal senescent change. As vets, we can immediately pick up that this could, in fact, be a sign of disease – particularly discomfort – but it is not just the activity level that should interest us. Questioning as to the variety of activities displayed will help alert to signs of musculoskeletal pain, such as that associated with arthritis.
Decreased grooming and stropping, difficulty using or avoidance of the litter tray, reduced ability or willingness to jump or climb, unwillingness to engage in play behaviour and resentment of handling may all suggest that the cat is experiencing orthopaedic pain. Conversely, an increase in activity levels or attention-seeking behaviour may raise suspicion for hyperthyroidism.
The timing of most active spells is also relevant. Cats that are withdrawn during the day, but restless and vocal at night, may have some degree of cognitive dysfunction, or hypertension, which we must assume is distressing for the cat.
Again, if they are successful in maintaining their cat’s caloric intake with a natural response of offering an ever-more varied diet, or frequently having to tempt their cat to eat, an owner may fail to appreciate that the cat’s behaviour is actually an indication of suboptimal health.
Older cats that are asking for food, but not eating what is offered, probably have some pathological reason for this.
This is a good time to ask about any teeth grinding while eating, or whether food is sometimes dropped from the mouth instead of swallowed, as this can often be a sign of abdominal pain or nausea if it is a new feature for this individual.
A cat that has started to use a litter tray instead of venturing out of doors may be withdrawing from any situation in which it feels more vulnerable, because a disease state is compromising its ability to readily defend itself.
Tenesmus is a non-specific sign, but can often indicate dehydration due to uncompensated polyuria; it may be more readily recognised than polyuria and polydipsia by many owners. Inappropriate elimination may indicate muscular weakness, causing an inability to climb into a litter tray, or urinary tract infection.
An owner may not mention an increase in vomiting frequency in a cat that has routinely vomited two or three times a month as they may not recognise potential significance.
However, an increase in vomiting frequency or change in the nature of the vomiting (for example, how long after eating, whereas previously emesis was only immediately after rapidly eating a meal) is likely to indicate the development or sudden progression of a pathological process that requires investigation and/or management.
It is time-consuming to gather this information, but some can be collected using a questionnaire that the owner completes prior to an appointment. This technique also ensures that no pertinent questions are inadvertently omitted.
Each vet will have their own system for ensuring a physical examination is complete, but the following points deserve comment.
Bodyweight remains the best objective assessment of food intake, and checking for weight loss is the easiest way to detect a hypermetabolic state in a polyphagic animal. Body condition score and muscle condition score should be evaluated.
Sarcopenia can be expected in any elderly animal, but the aim would be to minimise this, and to investigate excessive loss of body and particularly muscle condition. As a minimum, highly digestible, high-quality protein diets with pro-active supplementation of B12, L-carnitine, co-enzyme Q and probiotics may be a consideration, although evidence for many of these is scant. While obesity should be addressed in cats, to reduce risk of diabetes mellitus and to prevent exacerbation of OA, weight control is better achieved in early to mid-adulthood than in the geriatric phase of life. Weight loss in a patient whose deliberate weight reduction diet has been a failure for years is a sign of disease, but owners may assume it is due to eventual success.
While dental disease is not a common cause of a sudden appetite reduction, the experience of chronic dental pain is likely to negatively impact caloric intake over time. Of equal or greater concern is the welfare impact this has on the cat.
It is probably underestimated in a well-meaning attempt to reduce anaesthetic-related risk involved in dental treatment. However, it is worth noting that dental disease is recognised to be associated with progressive kidney disease (Finch et al, 2016) and a better response would be to adequately plan the procedure using a regime tailored to the elderly individual. This may include multimodal analgesia to lower the dose of each agent used, active warming and blood pressure monitoring with appropriate perioperative fluid therapy.
Whether to proactively check for a goitre in an asymptomatic cat is controversial. On the one hand, finding a goitre may raise suspicion for current or developing hyperthyroidism. On the other, non-functional goitres are common and finding one may promote unnecessary testing (Norsworthy et al, 2002).
The author would argue that the major benefit is to practise the technique, which is an acquired skill, so that goitres in hyperthyroid cats are readily detected.
Blood pressure should always be measured in a senior cat. Doppler devices are generally preferred, but some high-definition oscillometric machines can produce reliable results if the operator is familiar with them.
Untreated hypertension has potential for a severely detrimental effect on patient welfare, and it also prompts investigation for underlying disease processes – such as chronic kidney disease (CKD), hyperthyroidism or hyperaldosteronism – that may be showing few other signs.
One of the most cost-effective early tests in an elderly patient is urinalysis. It also provides valuable pre-anaesthetic information.
Submaximally concentrated urine triggers recommendation for serum biochemical testing, including renal parameters and calcium, to determine the cause. Renal proteinuria similarly leads to a search for a cause; blood pressure should certainly be checked if not undertaken previously.
Owners may be able to collect a urine sample at home with non-absorbable litter, rinsed dried lentils or aquarium gravel. Otherwise, cystocentesis is an easy technique to master. Urine culture should only be carried out on samples collected in this sterile manner.
It is of note that while studies have shown what was thought to be occult urinary tract infection (UTI) in certain disease states (hyperthyroidism, diabetes mellitus, CKD; Mayer-Roenne et al, 2007), it is possible that in many cases this is, in fact, asymptomatic bactiuria (Weese et al, 2019).
History taken to determine whether associated signs of UTI exist is essential when interpreting any positive urine culture. Where remaining uncertainty exists, a short course of narrow-spectrum antibiotics is a reasonable option.
Inevitably, older cats are more likely to present more than one condition requiring treatment. We should address diseases as they arise to maximise the chance of successful control and prevent a patient avoidably collecting comorbidities.
This is desirable as conflicting disease requirements and drug interactions can complicate treatment. Where possible, aims should be as follows:
Of course, it is not always realistic to achieve these goals; not all cats and owners will be in a suitable position for radioactive iodine or surgical thyroidectomy to be the preferred treatment recommendation. However, we should train ourselves to think in these terms as far as possible, and mould owners’ expectations accordingly.
A 15-year-old male, neutered, domestic shorthair presents with a five-year history of inflammatory enteropathy, managed with an antigen-restricted diet (chicken and rice commercial diet) and intermittent prednisolone treatment.
The cat has experienced recent weight loss, dropping from 4.5kg to 4kg over the preceding six months, as well as intermittent vomiting, diarrhoea and inappetence of three weeks’ duration. This has not resolved with current treatment of 1mg/kg prednisolone orally once daily.
The patient has a recent diagnosis of International Renal Interest Society (IRIS) Stage 2 chronic kidney disease (urine specific gravity 1.020; serum creatinine 220µmol/L [78-120]; urea 12.5mmol/L [5.9-10.6]). Hyperphosphataemia is 2.79mmol/L (1.45-2.62). Urine protein:creatinine ratio is 0.7 (acellular sediment). Urine culture is negative. Serum B12 is low-normal.
The remainder of the haematology and biochemistry – including total thyroxine, folate and feline pancreas-specific lipase – are within normal limits.
On observation, the cat has a stiff gait. Questioning reveals a history of difficulty jumping and reduced mobility. Physical examination supports a diagnosis of OA that is felt to be having a significant impact on the cat’s quality of life.
Systolic blood pressure (Doppler) has been approximately 200mmHg on several occasions.
The remainder of the physical examination is unremarkable.
Abdominal ultrasound showed bilateral, mild reduction in renal size with reduced corticomedullary definition; the renal pelvis was unremarkable. Mild diffuse small intestinal thickening existed (4mm; normal <2.8mm) with preservation of normal layering. No other abdominal abnormalities were identified.
In terms of a problem list with likely differentials:
Management priorities included:
First-line antihypertensives for cats are amlodipine (calcium channel antagonist) and telmisartan (angiotensin receptor blocker). Fluid therapy (intravenous, or even subcutaneous) may be a good idea in this patient prior to starting treatment.
Clinical experience with amlodipine suggests it has a powerful and rapid anti-hypertensive effect. Control of hypertension may be sufficient to reduce proteinuria to within the normal range. If not, benazepril (angiotensin-converting enzyme inhibitor) or telmisartan can be used alongside amlodipine, as long as hypotension does not occur (usually avoidable with dose titration).
Telmisartan treatment can often be used alone to both control blood pressure and reduce proteinuria.
Maropitant (NK1 receptor antagonist) is an effective way to control nausea and it has been shown to palliate vomiting when used in a chronic setting in cats with CKD (Quimby et al, 2015) and clinical experience suggests it is similarly effective in chronic gastrointestinal (GI) disease.
If caloric intake is insufficient despite this, mirtazapine could be used to stimulate appetite. Ideally, re-stabilising the GI disease may reduce reliance on such drugs for the time being, however.
NSAIDs are an effective treatment for OA, possessing both analgesic and anti-inflammatory properties – the latter helping to limit the generation of pain at the source site. In this patient, it may be possible to use them, if the GI disease can be stabilised sufficiently such that nausea is resolved, oral intake is sufficient to prevent dehydration and, of course, prednisolone can be ceased (probably in favour of another drug).
Stable, IRIS Stage 2 CKD is not a contraindication to NSAID use as long as the cat remains well hydrated (Gowan et al, 2011; Gowan et al, 2012; Gunew et al, 2008; King et al, 2016). It is also a good idea to start with a low dose, to guard against any GI side effects.
NSAIDs are still regarded with some suspicion in cats with CKD. Pets usually do not die from their disease – more commonly they are euthanised due to perceived poor quality of life. A well-intentioned avoidance of certain medications, due to fear that they may hasten disease, has potential to be self-defeating if it leads to premature euthanasia because of otherwise controllable discomfort.
However, other options are now available where NSAIDs are unsuitable. Frunevetmab (anti-nerve growth factor monoclonal antibody) is effective in controlling pain caused by OA (Gruen et al, 2021) and the drug appears safe in CKD, at least in the early stages. Off-licence use of other analgesics such as gabapentin, tramadol or amantadine may also be considered.
Omega-3 fatty acid supplementation would also be expected to be beneficial for joint pain and inflammation (Lascelles et al, 2010) and early studies focusing on the benefits of renal diets also suggested that this supplement is involved in the successful lengthening of lifespan seen with renal diets (Plantigra et al, 2005).
Finally, some environmental changes will benefit this patient. Critical resources (food, water, resting places, hiding places and litter trays) must be easily accessible. This is achieved by providing resources at a lower height, providing steps and slopes or using low-sided litter trays. Comfortable bedding should be provided, and assistance with grooming and care of claws (to prevent excessive growth) is ideal if well tolerated.
Anecdotal evidence suggests that vitamin B12 supplementation is indicated, even though serum B12 is within the normal range – presumably because low-normal values are do not adequately overcome any impairment of transport at the cellular level. B12 is a benign treatment, and options are available for supplementation depending on owner and patient preference; either oral powder (packaged in capsules) or parenteral hydroxycobalamin (off-licence).
Additional treatment for this cat’s intestinal disease could include chlorambucil (off licence), given that it is recognised as a powerful adjunct to treatment of both severe IBD and small cell lymphoma. Side effects are uncommon, but occasionally cats do experience nausea and haematological monitoring is mandatory, as bone marrow suppression – although very uncommon – can be marked and prolonged.
Budesonide (off licence) may be a consideration if the introduction of chlorambucil is unsuccessful in controlling the disease sufficiently to allow cessation of prednisolone, in a cat where NSAIDs are required. Systemic effects of budesonide should be minimal, but a slightly increased risk of GI ulceration may exist with this drug.
Given the long-term success seen with the chicken and rice diet, this should probably be continued in the first instance. A phosphate binder such as chitosan/calcium carbonate could be added to achieve phosphate control. Other options, useful wherever hypercalcaemia is a potential concern, are lanthanum or sevelamer, but there are no specific veterinary preparations of these available.
Once the cat is sufficiently stable, with a good appetite and vomiting and diarrhoea controlled, the gradual introduction of a renal diet could be considered. An appealing option may be a prescription “multifunction” diet, designed to cater for more than one disease process.
Adequate fluid intake should be ensured, by offering a canned/sachet diet where possible, plus additional meat or fish stock. Specially designed sachets of food, with a high water content akin to a soup, are available and specifically designed to increase fluid intake.
This complex patient gives us a good example of how to approach a cat with numerous disease conditions to be managed. Priorities have to be made and each condition approached in a step-wise fashion.
In reality, it may have been impossible to introduce all of the suggested strategies listed here. As long as dehydration, pain, nausea and confusion are addressed, the most important aspects of our job have been achieved.
