Information for Vets RABBITS: GERIATRICS AND CHRONIC DISEASE by Carolynn Harvey, DVM Goal: Prolong Quality Life Chronic illness in rabbits should be approached like chronic illness in other species. In each case it is important to decide what your treatment objectives will be. Are you trying to slow the course of the primary illness, to prevent or control secondary problems, or simply keep the patient as comfortable as possible for as long as possible. The mental/emotional reaction of the patient to its illness must be taken into account in designing a treatment plan. A bright, alert, hungry rabbit with severe vestibular disturbance needs to be approached differently from a vestibular rabbit who is depressed, won't eat, and isn't responding to his owner. Euthanasia is NOT the appropriate answer for all chronically ill rabbits - but may be the best choice in some circumstances. Chronic Infections 1. Snuffles/upper respiratory disease. Because they are obligate nose-breathers, rabbits are more affected by upper respiratory problems than dogs or cats. Antibiotics rarely affect a cure once an upper respiratory infection has become chronic, but they may effectively suppress symptoms. Patients who are functional and happy without antibiotic therapy may be treated only during exacerbations, until signs return to a comfortable level. Other patients become uncomfortable without continuous antibiotic therapy. Classic antibiotic resistance seems a less common reason for therapeutic failure than is the inability of an antibiotic to reach the sites of infection. Still, periodic reculture is recommended to make sure that resistance has not developed. Culture of nasal discharge is not representative. Cultures should be obtained from deep nasal swabs, usually requiring light sedation and causing the swab to be blood-tinged on withdrawal. Antibiotics which have been used long term in our practice include trimethoprim-sulfa, enrofloxacin, tetracycline, ciprofloxacin, chloramphenicol. Helpful ancillary therapies include ensuring sufficient hydration, nebulisation, keeping the nose and paws clean of exudates, keeping the rest of the rabbit groomed and clean. 2. Eye infections. Conjunctivitis deserves a thorough workup and appropriate therapy. Unfortunately, some cases fail to respond and become chronic. Chronic conjunctivitis or epiphora can cause pain, corneal damage or secondary dermatitis. Therapy should be directed at controlling these as far as possible. Periodic rechecks assess corneal health, tear duct patency, periocular tissues. Topical or systemic antibiotics may be used chronically or intermittently as needed. Tear duct flushing may help control infection. Periocular dermatitis secondary to chronic ocular discharge can be severe and painful. Topical protectants such as petroleum jelly or DesitinR may help limit irritation. Topical steroids should be used for short periods only, as systemic effects are seen with continued use. Cool herbal poultices have been useful in reducing inflammation. Sometimes clipping the hair from the area is useful. Deep ophthalmic infections always pose the danger of extension into the CNS. Despite this, we are slow to recommend enucleation, since some cases of endophthalmitis, iris abscess/granuloma, and anterior uveitis have responded over weeks or months to systemic and topical antibiotic therapy. Systemic chloramphenicol or quinolones achieve good levels in the eye and are good choices if culture is not available. Enucleation may be curative if the infection is completely contained within the globe, but if retrobulbar or periocular tissues are involved, enucleation is likely to be of limited value, except for pain control. 3. Urinary tract infection (UTI). UTI can be chronic and insidious and, in my experience carries a relatively high risk of septicaemia or renal damage in aged or debilitated rabbits. The infections are sometimes asymptomatic. DON'T RELY ON URINALYSIS to detect them. Urinalysis is not a very sensitive test for urinary tract infection in rabbits, perhaps because their abundant crystals obscure small numbers of white blood cells and bacteria. Culture is the best tool we have to screen for UTI, but false negatives occur with some regularity. Periodic urine culture is ideal in any rabbit with neurological deficits affecting the bladder, urine scald, chronic infection, or any other condition prediposing to UTI. Arthritis Arthritis may be difficult to distinguish from other causes of limited mobility. Additionally, septic and degenerative joint disease may be radiographically indistinguishable - both causing marked periosteal proliferation. Joint taps have been helpful in diagnosing some cases. In any case where pain is a limiting factor, analgesics may be appropriate. I am most familiar with aspirin. A dose of 100mg/kg has been published. I find that 165mg (1/2 of a 325 mg tablet) given orally twice a day usually provides relief for a 6-8lb rabbit. Because septic joints are hard to diagnose and because so many rabbits harbour subclinical infections elsewhere, long-term corticosteroid use is not recommended. Environmental changes help support arthritic rabbits and limit the complications of limited mobility. Specifically: 1. Provide easy access to food and water (e.g. piles of hay and greens, low-rimmed stable dishes, water bottle) 2. Provide soft absorbent surfaces; artificial sheepskin is ideal 3. Create a rimless litterbox 4. Provide ramps as needed 5. Exclude dampness and drafts, provide mild warmth if it seems to help Physical therapy and mild exercise can help retain flexibility. Chondroprotectives such as polysulfated glycosaminoglycans (CosequinR) have been used in rabbits, at doses extrapolated from dogs, with some anecdotal reports of improvement. Weight control is important. Overweight rabbits should lose weight gradually. Acupuncture and chiropractic treatment have been very helpful in some rabbits. Chronic Abscesses Sometimes appropriate medical and surgical options have been exhausted and our rabbits have chronic abscesses. The goal is then to minimise the impact of the abscess on the rabbit's overall health and happiness, and to protect other rabbits in the household. Chronic antibiotic therapy? Yes, if the abscess is poorly encapsulated and danger of spreading is high, if the rabbit is febrile, painful, or acts sick when antibiotics are withdrawn. (More concern about developing drug-resistant strains in multi-rabbit households). No, if the abscess is encapsulated and draining well to the outside. Should topical therapy be continued? It depends on how painful/stressful it is for the patient and owner, and whether it affects the course of the abscess. Possibly intermittent lancing/draining will suffice. Are chronic abscesses permanent? Usually, but not always. Occasionally an abscess present for years will finally dry up and disappear. Analgesics may be needed if abscesses affect limbs or oral cavity. I have used aspirin (40-100 mg/kg orally BID, and doses have been published for ibuprofen and other analgesics.1 Systemic consequences of chronic abscesses: Systemic consequences may be inapparent, or disastrous. Acute septicaemia and death may result without warning from a chronic abscess. More commonly, subclinical infections of lungs, kidneys, heart, etc. are present and are detected on post-mortem. Occasionally large, palpable intra-abdominal abscesses are formed. Rabbits can live happily with these for years, if they do not obstruct the GI tract or otherwise influence organ function. Dental Points Dental problems can be the reason for chronic poor-doing, for gradual weight loss or for sudden anorexia in an otherwise healthy geriatric rabbit. Rabbits over 5 years should have an oral exam every 6 to 12 months, or whenever signs pointing to oral cavity disease are seen (drooling, seeming hungry without eating, grinding teeth, pawing at mouth, change in food preferences). I use an otoscope and no sedation for preliminary evaluation. I also do a digital exam on cooperative patients over 5 pounds in weight. If I see or feel anything suspicious (excess saliva, pus, blood, ulcers, sharp points on teeth, fetid-smelling food material), I recommend an exam under anaesthesia. Anaesthetic protocols for dental exam 1. Ketamine 20 mg/kg + butorphanol 0.2 mg/kg + Robinul-V (glycopyrrolate) 0.05 ml/kg IM 2. 1:1 mixture of ketamine (100mg/ml) and diazepam (5mg/ml) given through a catheter (or just IV) to effect. Usually requires 0.1 to 0.2 cc/kg total. Can also use 2:1 ketamine:diazepam 3. Premed with butorphanol 0.2 mg/kg and Robinul-V (glycopyrrolate) 0.05 ml/kg IM, then mask intermittently with isoflurane Rabbits that have sharp buccal or lingual points on their cheek teeth usually respond dramatically to having them filed. Paresis/Paralysis Paresis/paralysis bring with them a host of secondary problems. If these are controlled, afflicted rabbits can live happily for years. Access to food and water is often overlooked. Shape, placement and stability of food and water bowls need to be altered to fit the individual patient. Supports (rolled towels work well) may be necessary to help recumbent rabbits eat. Hand-feeding of hay and greens is the key for some patients, while others may need to be syringe-fed. Rabbits with weakness or chronic jaw pain may take to spoon-feeding of softened pellets. Urine scald/faecal soiling can cause anything from mild discomfort to fever and systemic illness. It can also strain the rabbit-human bond as a wet, odorous rabbit is aesthetically displeasing, and the time required to care for him or her can be burdensome. Helping the committed owner set up a practical care plan may avert an unwanted, unnecessary euthanasia. 1. Clip (carefully!) hair from affected areas. Scissoring is not safe. 2. Use a mild surfactant rather than soap to loosen adhered feces (Nolvasan oticR has worked particularly well for us). 3. Consider diapering (using nappies) - works best on inactive rabbits. 4. Keep indoors to avoid myiasis. 5. Mental/emotional health - Place rabbit so that he or she can get plenty of attention or interaction. Putting a desk-level bunny corral in several rooms may make it easier to include the rabbit in family activities. 6. Topical therapy: Use steroid combinations only short term. Sitz-baths are useful if well tolerated. Avoid chilling or overheating. Discontinue if rabbit is unduly stressed or slow to recover. Aloe vera gel, other soothing preparations are helpful if inflammation is present. 7. Absorbent bedding - artificial sheepskin is ideal; also towels or diapers (nappies). 8. Systemic antibiotics only when fever and ulceration are present. 9. Monitor for urinary tract infections. Loss of litterbox training may be the first sign of paresis that the owner notices. While pursuing diagnosis and treatment, help the rabbit by providing rimless litterboxes or toilet areas, carrying the rabbit to the litterbox frequently. Assess whether incontinence, atonic bladder or urine retention play a part. Can try phenylpropanolamine (6-12 mg/rabbit PO BID), or bethanechol chloride (1.25 to 5 mg PO BID per rabbit) or possibly phenoxybenzamine as needed. Suggestions for Geriatric Health Maintenance Programme Tailor this to meet your patients' needs 1. Geriatric baseline workup: 5 years of age + 2. (CBC/Chemistry, urinalysis, whole body X-rays). Include titer for E. cuniculi, Tyzzer's? (mostly for herd health/database uses). Include Pasteurella titer? 3. Body weight check every 2 months (owner can follow) 4. Physical exam every 6 months 5. Blood panel CBC/Chem.: yearly. Follow up any abnormal values more often 6. Urinalysis: yearly 7. Urine culture: every 6 months in rabbits with any condition predisposing to UTI 8. Oral exam: yearly. Every 3-6 months in a rabbit with history of dental abnormalities or "points" 9. Diet/husbandry counselling at yearly exams References 1. Hillyer, E and Quesenberry, K, Ferrets, Rabbits, and Rodents, W.B. Saunders, 1997 APPENDIX: HOSPICE CARE HOW-TO From the U.S. House Rabbit Society Fosterer's Manual Chronically ill geriatric rabbits have lived for up to 4 years in HRS hospice care. The programme consists of providing physical comfort and mental satisfiers, under the following guidelines. Environment Provide a living space where there is plenty of daylight without direct sun. It should be conducive to social interaction and human attention, such as a busy office or study. Enclosure A fenced-in (8" high) table or desktop covered with a synthetic sheepskin rug (30" x 40") provides a comfortable, stimulating, and accessible living space. Padding and Props Use rolled towels or synthetic sheepskin rugs. A brick, rolled up in a rug, makes a sturdy support to prop up a crippled rabbit. Moral Support Adding a friend or keeping existing friends together provides comfort and motivation for the ailing rabbit and a sense of purpose for the "nurse" rabbit. Human Bonding Invalid bunnies form very strong bonds with their humans and adapt well to increased handling. Many are especially responsive to voices and can be kept happy with some good conversations. Feeding a Disabled Rabbit Access is the most important consideration in keeping crippled rabbits able to self-feed. For rabbits who are partially mobile, pellets can be fed in flat dishes, along with hay and fresh vegetables. Sipper tubes should be within easy reach. The general diet for severely disabled rabbits includes: moistened pellets, hay, fruit, and veggie treats. Many hospice rabbits are quite frail and are fed to keep weight on rather than take it off. Fruit Since fructose is easily digested in the rabbit's small intestine, it is unlikely to cause carbohydrate overload in the caecum and is a safe calorie source. Half a banana or apple daily seems to be well tolerated and can be especially useful for camouflaging medications. Hay Give handfuls. Even quadriplegic rabbits are able to nibble on enough hay to keep their GI tract working. Moistened Pellets Disabled rabbits do much better on moistened pellets than dry pellets, especially when water intake is poor. Moistened pellets keep up hydration and greatly reduce the need to give supplemental subcutaneous fluids. A single feeding for a 6 lb rabbit: Soak 2 (rounded) tbls pellets in 1/4 cup warm water Feed 3 times per day Hospice rabbits usually have chronic conditions rather than a critical illness and therefore do not require force- feedings by syringe. However they are often unable to feed themselves adequately, and they do require help. Use a teaspoon to form bite-size mounds for bunny to grab by mouth. Otherwise the moistened pellets flatten into the dish and can't be accessed. Syringe-Feeding If syringe-feeding is necessary, due to an acute illness, use 35cc feeding syringes. Mix a day's batch at a time: A half-cup pellets in 1 cup water, blended for at least 5 minutes at medium-high speed. This yields a smooth paste that can pass through the syringe. A 6 lb rabbit can consume about 50- 60cc at a feeding. Diapering a Disabled Rabbit The easiest way to prevent urine burn in crippled rabbits is with diapers (nappies). Moisture is absorbed into the diaper, minimising exposure to the flesh. Kind of Diapers Step one (or newborn) for rabbits under 8 lbs, step two for over 8 lbs. The best brands are generic store brands with good gripping tape. Diaper Modifications Large rabbits: Clip the diaper at the front of the curved leg area (about 1" at a 45-degree angle upwards) to make it curve around the knee for a better fit. Tail hole (optional): use scissors to poke a hole in the middle of the crotch area. Enlarge the slit with your fingers to about 2-21/2". Small rabbits: (under 4 lbs): Include a tail hole as above, but do not clip. Positioning Option 1. With his back toward you, dangle the rabbit from a table with his front paws on the edge of the table. Slip the diaper between his legs, then hold on to the corners of the diaper, suspending the bunny in a "hammock". Work the tail through the hole and wrap the diaper around the body tightly. A snug fit above the knee is crucial (or the diaper will come off). Option 2. Spread the open diaper on a table or counter. Holding bunny with his shoulders against your chest, lean over the table to position bunny over the diaper. Push tail through tail hole (if used) and pull the front and back sides of the diaper upward. A variation is to position bunny over an open diaper on your lap, then lean yourself and bunny backward until you can secure the diaper at the front. Step back from the table (or stand up if you are sitting) and, while holding the diaper loosely in place, let the bunny slide downwards to your knees. Hold on to the corners of the diaper so that bunny stays suspended in the hammock. This ensures a snug fit above the knees. Taping (either option). When wrapping the diaper around the body of a rabbit over 4lbs, the tape should overlap onto itself at the front. Under 4lbs, the tape should overlap completely beyond the tape area. Changing Bunnies can get by with three changes a day. One of the diapers will contain caecotropes which are filled with vitamins and protein and should be fed to the bunny. If you express the bladder every time the diaper is changed, the diaper will remain dry and can sometimes be re-used. Absorbent Bedding Undiapered rabbits are much more difficult to keep clean. 1. Keep fur/bedding dry by expressing bunny's bladder twice a day. 2. Remove caecotropes immediately (hand feed to bunny). Otherwise they smear into bedding or fur. 3. Keep a good supply of synthetic sheepskin rugs on hand for quick changes. On the other hand, if caecotropes have been removed and the bladder has been expressed and "marbles" have been swept up, a rug may last for 3 days before laundering is necessary. 4. If prompt excrement removal is impossible and moisture accumulates, change bedding and wash (spot clean) bunny daily. Cleaning a Disabled Rabbit Since crippled rabbits cannot clean themselves, they require daily hygienic care. This is not an overwhelming task once a routine is established. Spot Cleaning Chlorhexidine solution, such as Nolvasan Otic works well. Wet as small an area as possible. For redness or skin irritation, Neo-Predef powder (from the vet) is a really nice cure. Otherwise, try baby powder or cornstarch. Shower Bathe bunny's bottom with running water rather than a dip. The least stressful way is to use a rubber shower hose and a dish drainer. An inexpensive drugstore shower-hose works just fine. Use a flat-type dish drainer in the sink with a soft towel partially covering for bunny's upper half (towards you). Bunny's lower half is over the open drainer. With a warm gentle spray wash only the soiled areas. Towel-Dry When you're finished, pull the bunny's hindquarters up into the towel (that's already in the drainer). Wrap the tail in a paper towel and gently squeeze excess moisture. The other areas can be towel-dried. The advantage of this technique over dipping is that minimal areas are soaked, towel-drying is much easier, and it is a less stressful process. Mini-shower The shower method can be used without a drainer to spot wash and express the bladder at the same time. Holding the bunny over the sink, extend the hind legs upward so that the tail area is exposed to the spray. Spray-wash only the target. Blot the tail with a paper towel (as above), then finish drying with a cloth towel.