Owner Experiences in Treating Dogs and Cats Diagnosed With Diabetes Mellitus in the United States^S

Introduction

Diabetes is a common chronic illness in pets that requires continuing medical care and owner education to prevent complications and ensure a good quality of life. Successful treatment depends on close owner observation of clinical signs and periodic evaluation by a veterinarian.^1,2

The purpose of the current study was to expand the information available to veterinarians and the pet care industry by surveying owners of diabetic dogs and cats regarding their experiences, practices, and satisfaction in treating a pet with diabetes. In particular, the study authors sought to determine the treatments administered, owner and pet responses to insulin injections, owner experiences with control of clinical signs, methods of monitoring diabetic control, owner lifestyle changes resulting from caring for a diabetic pet, and the sources of information used by owners.

Materials and Methods

A website was created by the Office of Marketing and Communication at the University of Queensland and made available to the public as a link from websites related to feline and canine diabetes or companion animal health. All participants voluntarily answered the survey. This study had ethics approval from the School of Veterinary Science at the University of Queensland.

Survey forms were developed using traditional survey design techniques and were adapted for use on the Internet.³ Owners were asked to respond to 37 questions either by mutually exclusive responses or by choosing one or more answers that were the most appropriate (see Supplementary Table I). Some questions offered scaled responses. The survey was available online for 5 mo (from March 2008 through August 2008).

Results

A total of 834 participants located in United States completed the survey, including 224 dog owners (27%) and 610 cat owners (73%). Most dogs and cats (83%) were diagnosed with diabetes < 6 mo before survey completion. Only 30% of dogs and 12% of cats were diabetic for > 1 yr. Because of a low response rate from any single country outside the United States, all responses from outside the United States were excluded from analysis.

Significantly more dogs (97%) than cats (82%) were treated with insulin injections (P < .0001) as described in Table 1. The types of insulin used most commonly by dog and cat owners differed also differed (Table 2). Administration of insulin q 12 hr was most common in both species (87% of dogs and 73% of cats). Only one dog was treated with an oral hypoglycemic agent (which was combined with insulin) and two cats received hypoglycemic agents (with and without insulin) combined with a specific diet for diabetes (Tables 1, 2).

TABLE 1 Percent Distribution of the Treatments Used in Diabetic Dogs (n = 224) and Cats (n = 610)

*

Values were considered significantly different between cats and dogs (P < .05).

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TABLE 2 Percent Distribution of the Types of Insulin and Frequency of Administration Used for the Treatment of Diabetes in Dogs (n = 224) and Cats (n = 610)

*

Values were considered significantly different between cats and dogs (P < .05).

†

Ultralente insulin was no longer available at time of survey.

§

The results did not add up to 100% because 1.3% of dog owners and 7.5% of cat owners did not used insulin injections in their pets; 14.3% of dog owners and 6.4% of cat owners used another type of insulin in their pets; and 1.8% of dog owners and 1.3% of cat owners did not answer this question.

N/I, not included; PZI, protamine zinc insulin.

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At the beginning of treatment, over half the dog and cat owners were fearful of giving injections. At the time of survey completion, only 8% of owners considered fear a problem. Almost 90% of pets were reported to be calm when injections were administered. In only a minority of dogs (7%) and cats (2%) was their behavior described as stressed, frightened, or “angry.” The longer the pet had been diagnosed with diabetes, the calmer they were considered by the owners at the time of injection (ρ, 0.16; P < .0001). Most owners reported that the treatment their pet was receiving was easy to perform (dog owners, 77%; cat owners, 78%).

Nearly all cat owners (93%) changed their pet’s food after diagnosis, which was significantly (P < .0001) higher than the percentage of dog owners (79%). However, only 29.2% of cats and 34.7% of dogs were fed a food prescribed for management of diabetes (Table 1).

More dog (64%) than cat (52%) owners responding to the survey considered the treatment expensive (P < .003). Although all respondents were treating diabetic pets, anticipated reasons for other owners to decline treatment included cost of the treatment at home (82%), cost of veterinary visits (74%), inconvenience of complying with a schedule of daily injections (67%), fear of giving injections (66%), the anticipated reaction of the pet to injections (43%), inconvenience of frequent visits to the veterinarian (37%), inconvenience of complying with feeding schedule (32%), number of people in the household either available or willing to administer insulin (28%), and the need to change the diet (20%).

For diabetic pets diagnosed > 3 mo, more cat owners (43%) than dog owners (27%) had not visited their veterinarian for a recheck examination of their pet in the 3 mo prior to survey completion (P < .0001). In fact, 34% of dog owners and 35% of cat owners reported an average of less than one examination/mo. Specifically, 16% of dog owners and 12% of cat owners made an average of one visit/mo, and more dog owners (22%) than cat owners (9%) reported making two or more visits/mo to a veterinarian (P < .0001). Twenty-six percent of respondents owned newly diagnosed (< 3 mo) diabetic pets (38% of dogs, 21% of cats), and these owners did not contribute answers regarding monitoring frequency.

Methods of home monitoring of diabetes reported to be used by owners have been shown in Figure 1. Fifty-three percent of dog owners and 55% of cat owners used more than one method of home monitoring. Infrequent veterinary re-evaluations after the first 3 mo of diagnosis were associated with home blood glucose monitoring in cats (ρ, 0.40; P = .0003).

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The satisfaction of owners was positively correlated to using twice daily insulin injections (ρ, 0.28; P = 0.04) in cats. There was no correlation between the frequency of veterinary visits and the outcome (ρ, −0.05; P = 0.14). Dog and cat owners’ opinions concerning resolution of signs have been illustrated in Figure 2. The longer the pet was diagnosed with diabetes (excluding pets treated for < 3 mo), the lower the owner’s opinion of control of clinical signs (ρ, −0.33; P < .0001).

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Owners’ opinion about the treatment of diabetic pets were summarized in Table 3. After diagnosis, the most frequently used sources of information about diabetes were the Internet (37%) and their veterinarian (34%). Use of those resources was similar between dog and cat owners. Other sources included veterinary technicians or nurses (11%), brochures or magazines for pet owners (8%) and family or friends (7%). Many owners sought information from multiple sources.

TABLE 3 Owners’ Opinions About the Treatment of Diabetic Dogs (n = 224) and Cats (n = 610)

*

Values were considered significantly different between cats and dogs (P < .05).

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Discussion

Current insulin selection guidelines for cats recommend use of long-acting insulin, either glargine, detemir, or protamine zinc insulin (PZI).^4,5 The results of this survey indicate that 82% of cat owners use insulin, and glargine and PZI are the two most commonly used insulins, similar to the findings of Niessen et al. (2010) and Smith (2012).^6,7 In this survey, glargine (31%) was used equally as often as PZI (34%), whereas Niessen et al. (2010) reported that PZI was used more often (39%) than glargine (23%)⁶ Similarly, Smith et al. (2012) reported that 42% of veterinarians prescribed PZI and 27% prescribed glargine.⁷ Those differences in relative frequency of glargine use versus PZI might partly reflect the requirement in the United Kingdom to use a veterinary-licensed insulin as first-line therapy.⁶

Since the first report of glargine use in diabetic cats in 2004, glargine has became widely used in cats in both the United States and Europe.^8–12 That is likely because, although it is a human-use insulin and is not commercially marketed for veterinary use, its long duration of action is associated with high remission rates in cats.^10–12

Although lente and ultralente insulins have been used to treat diabetic cats, this survey indicated that they were used much less frequently than PZI or glargine, and ultralente was already no longer being manufactured at the time of our survey.¹³ The veterinary formulation of porcine insulin^b is considered a lente insulin, but was analyzed separately from human-use lente insulins. It was used by 10% of cat owners in the current study, which was less than the 19% reported by Niessen et al. (2010), likely because of regulatory requirements in the United Kingdom.⁶

The majority of cat owners (75%) administering insulin gave it q 12 hr (Table 2), similar to findings from Niessen et al. (2010).⁶ That was consistent with the published guidelines and with research showing that owners of newly diagnosed diabetic cats should expect to treat their pet q 12 hr with either glargine or PZI to provide better glycemic control and potentially increase the likelihood of remission.^{4,11,12,14–16} In fact, when glargine was used q 24 hr, remission rates were similar to lente insulin administered q 12 hr.¹⁶ All diabetic dogs require insulin treatment of control of hyperglycemia.² That was reflected in the current survey as 97% of owners of diabetic dogs reported administering insulin. Porcine lente insulin was most often used (41%), although neutral protamine Hagedorn was also commonly used (35%), consistent with the current guidelines for diabetic dogs.⁴ Different results were found in a similar study performed in Brazil that showed the majority of dogs received neutral protamine Hagedorn (89%), and only few dogs were treated with porcine lente insulin (5%).¹⁷ The efficacy of porcine lente insulin has been reported in dogs, and because it has an identical amino acid sequence to canine insulin, it was hypothesized that it might be the best insulin for diabetic dogs.^2,18

The overwhelming majority of dog owners (87%) participating in this survey reported using insulin q 12 hr (Table 2) as recommended by current guidelines.⁴ In contrast, Davison et al. (2005) found 78% of the diabetic dogs were receiving insulin only q 24 hr.¹⁹ The results of that earlier study from the United Kingdom might be influenced by the previous dosing recommendations for porcine lente, which was initially registered for use q 24 hr.

A good outcome was reported by most owners of diabetic dogs and cats in this study, with two-thirds of owners reporting either total resolution or good improvement of signs. Owners also reported feeling more attached to their pet than they did before diabetes was diagnosed.

The results showed the longer the pet had been diagnosed with diabetes, the calmer about injections they were considered by the owners. The process of accustoming owners to giving injections is likely important for the success of therapy, and this study suggests that veterinarians need to help pet owners overcome their initial fear considering that insulin is the mainstay of diabetes therapy.

Traditionally, it was recommended that a high-fiber, moderate carbohydrate diet be used for diabetic cats.²⁰ However, more recent publications recommend diets containing high protein and low carbohydrate.^4,20,21 In this study, most cat owners (93%) changed their cat’s diet after diagnosis; however, only one-third fed a diet prescribed for diabetes. It is difficult to compare the current results with those from Niessen et al. (2010), where 60% of cats received a special diabetic diet, which presumably could include a homemade high-protein, low-carbohydrate diet.⁶ Further investigation is required to determine whether the feeding practices identified in the current study represent use of nonprescription low-carbohydrate, high-protein diets, lack of owner education, or noncompliance for cost or other reasons. The only studies that have reported remission rates of > 80% in recently diagnosed diabetic cats all used high-protein diets with < 10% metabolizable energy from carbohydrate together with a long-acting insulin. Therefore, to optimize the probability of remission in diabetic cats, veterinarians and nutrition companies need to more effectively disseminate information that high-protein, low carbohydrate diets are associated with higher remission rates.^11,12,22

The current survey results show that although only 35% of dog owners changed their dog’s food to a prescribed diabetes diet, almost 80% made a food change after the diagnosis. Studies in diabetic dogs indicate that high-fiber diets might be associated with improved glycemic control.^23,24 Those studies, however, compared high-fiber with low-fiber diets without including a comparison with a typical diet formulated for canine adult maintenance with moderate fiber. Fleeman et al. (2009) showed that a traditional diabetes diet consisting of high-fiber, moderate carbohydrate, and moderate fat did not reduce insulin requirements or improve glycemic control when compared with a commercial, canned, canine adult maintenance diet with moderate-fiber, low-carbohydrate, and high-fat content.²⁵ It is interesting that only a minority of dog owners fed a prescription diabetes diet after diagnosis. The majority of dog owners changed to a nonprescription diet, although it is unknown if a low-carbohydrate diet was selected as used by Fleeman et al. (2009).²⁵

Even though most pet owners thought the treatment of diabetes was easy to perform and interfered very little with their daily life, they expressed concerns related to arranging care for their pets when they are traveling and the cost of the treatment. Similarly, Niessen et al. (2010) and Niessen et al. (2012) reported that factors such as boarding difficulties, diabetes-related costs, and difficulties leaving pet with friend/family most negatively impacted the quality of life of diabetic pet owners.^6,26

Veterinarians should be aware of owner concerns about cost and discuss various options of therapy with owners. This is particularly true for dogs where food costs are more substantial, remission is not a treatment goal, and maintenance diets result in similar glycemic control to prescription diet.²⁵

Considering that most pets in this survey had been diagnosed relatively recently, a surprisingly high percentage of owners of pets diagnosed > 3 mo had not taken their pet to the veterinarian for an examination in the preceding 3 mo. From the data available from this survey, the study authors were unable to discern the reason(s) for such infrequent initial veterinary monitoring. Possible reasons include lack of owner education, noncompliance due to cost, inconvenience, owner satisfaction with their pet’s progress, or use of home blood glucose monitoring, which was shown to be associated with fewer veterinary visits.

Some studies demonstrated that the majority of owners were able and willing to perform long-term monitoring of blood glucose concentrations of their pet.^1,27–29 According to limited data from one study, cats managed with home monitoring may have better glycemic control than those managed without it.¹ The current study results showed that home blood glucose monitoring was the most commonly used method of monitoring in cats (76%), which was also observed by Niessen et al. (2010).⁶ Home blood glucose monitoring but was used by only a minority of dog owners (30%). Use of home glucose monitoring has been increasing since the first reports on this topic and is particularly recommended for cats because of the spurious effects of stress on blood glucose concentrations.^29,30 Home blood glucose monitoring may help satisfy some of the quality of life concerns reported by Niessen et al. (2010) and Niessen et al. (2012).^6,26 In the current study, home blood glucose monitoring was associated with infrequent veterinary re-evaluations in cats. The infrequent veterinary monitoring by cat owners in the current survey may reflect the study findings that cat owners were more often performing home monitoring and/or were less satisfied with their veterinarians’ knowledge.

The authors of this study found no correlation between the frequency of veterinary visits and the owner-reported outcome; however, there was a correlation between positive outcome and home blood glucose monitoring in cats. The finding that frequency of veterinary visits was not positively associated with outcome was likely confounded by the negative association between home monitoring and reduced veterinary visits and that pets with poor control might be presented more frequently until good control is achieved. Of concern was that the longer the pet was diabetic, the poorer the resolution of signs and the fewer veterinary visits. That finding suggests that routine follow-up of long-term diabetic patients by veterinarians might be useful.

Although the majority of pet owners responding to this survey were aware before their pet was diagnosed that pets could get diabetes, few owners got that information from their veterinarian. After diagnosis, owners obtained information about diabetes from their veterinarian (34%) almost as often as from the Internet (37%). Given the ready access of clients to Internet-based information, there is a growing opportunity for veterinary practices to educate their clients through that medium, rather than relying only on face-to-face veterinary visits for client education.

The web-based format of the current study might have biased responses toward owners that are more likely to use the Internet as a source of information, potentially either younger or more technologically-advanced owners or owners that were more dedicated than typical owners. It is possible that the higher survey completion rates by cat owners compared with dog owners is because the treatment of canine diabetes has changed little in 30 yr, but there have been major recent advances in the management of feline diabetes. This has been associated with substantial improvements in outcomes for cats, with remission rates increasing from approximately 30 to > 60%.^11,12,16,22 Although the prevalence of diabetes in dogs and cats is similar, nearly three times as many cat owners as dog owners responded to the survey.³¹ Of those that did complete the survey, an equal proportion of dog and cat owners got their information from the Internet. However, cat owners were less often satisfied with their veterinarian’s knowledge and were more often performing home blood glucose monitoring. Only 47% of cat owners were satisfied with their veterinarian’s knowledge of diabetes, which may reflect owner access to the rapidly changing body of knowledge on the Internet. The high percentage of cat owners (76%) that performed home blood glucose monitoring may also reflect a more dedicated pet-owner population. Further investigation is required to better understand veterinarians’ reasons for prescribing specific insulin and dietary recommendations for diabetic pets. It is possible that lack of knowledge of current literature is responsible for some treatment recommendations.

Conclusion

The overall outcome of this survey provides useful information on the contemporary management of diabetes by pet owners in the United States, which may help veterinarians better counsel owners about treatment of their diabetic pets. Veterinarians should provide encouragement to owners to undertake treatment of newly diagnosed diabetic pets, given the increased attachment reported toward their pet after starting treatment, the level of satisfaction with treatment, and minimal problems associated with giving injections. Veterinarians also need to take into account the difficulties reported by owners when planning treatment (e.g., care of diabetic pets when owners travel). Despite the fact that the web-based format was considered a bias in this study, there are opportunities for veterinarians to use the Internet to provide information for owners, including advice on appropriate diets for diabetic pets and recommended frequency of veterinary visits.