Rabbit Dental Disease Flashcards
What is PSADD and what are the contributory factors?
- PSADD - Progressive syndrome of acquired dental disease
- The shape, structure and position of the teeth change during this progressive syndrome of acquired dental disease (PSADD). PSADD underlies many common
- There are many theories about the aetiology of PSADD and opinions differ about the role and importance of age, gender, breed, genetic disposition, husbandry and diet. There is general agreement that rabbits that consume a lot of hay, grass and natural vegetation are seldom affected, whereas PSADD is extremely common in rabbits housed indoors in houses, sheds and hutches, and fed on muesli-type mixes. Inadequate dental wear and metabolic bone disease are the two most popular explanations for this syndrome.
Why has the incidence of dental disease in rabbits gone up since the introduction of muesli-type rabbit foods? List the common constituents of these diets.
The high incidence of dental disease in rabbits has coincided with the introduction of muesli-type rabbit foods, the ingredients of which are shown below, and include extruded nuggets (A and B), pellets (C), maize (D), wheat (E), beans (F), peas (G) and hay (H). The calcium content of many of the components of these mixtures is well below the level of 0·6 to 1 per cent that is required for calcification of bone (the calcium requirement for calcification of the teeth has not been determined). The most palatable parts of muesli mixes are the flaked maize and peas, which have very low calcium content and a highly inverse calcium to phosphorus ratio. Preferential selection of these ingredients provides a severely calcium deficient diet. Muesli-type mixes are not suitable as rabbit food. As well as being potentially deficient in calcium and vitamin D, these diets are low in indigestible fibre and a high in carbohydrate content, so they are fattening
What are some early signs of progressive syndrome of acquired dental disease?
- Reluctance to eat hay and other hard foods
- Epiphora
- Horizontal ridges on the incisors
- Palpable swellings along the ventral border of the mandible associated with the elongated roots of the cheek teeth
- Uneven wear on the cheek teeth
What are some dietary recommendations for rabbits showing early signs of dental disease?
- Exclude mixed, muesli-type rabbit food altogether
- Offer freely available, fresh, good-quality hay or dried grass, even though the rabbit may not appear to eat much of it
- Offer small amounts of pelleted or extruded food only once a day. Depending on the animal’s size, one to two tablespoonfuls per rabbit is sufficient. Dried food can be excluded altogether, especially if the rabbit is overweight and eats plenty of hay and a variety of leafy green plants
- Offer a wide variety of leafy green plants and vegetables at least twice daily
- Foods that are low in indigestible fibre (eg, apples, pears, bananas, carrots and other root vegetables) should only be fed in moderation as they can be fattening and cause soft caecotrophs
- If possible, allow the rabbit to graze outside as much as possible and lie in the sun
- Chocolate and yogurt drops, biscuits, bread, and sugary cereal treats should not be fed to rabbits
What do you understand by the term epiphora? What is the relationship between this condition and dental disease in rabbits?
- Epiphora: excessive watering of the eye
- Epiphora is a common sign of early PSADD and is due to elongation of the maxillary incisor constricting the nasolacrimal duct as it curls around the apex of the tooth. Blockage of the nasolacrimal duct causes tears to overflow down the face
What do you understand by the term dacryocystitis? What is the relationship between this condition and dental disease in rabbits?
- Dacryocystitis: is an infection of the lacrimal sac, secondary to obstruction of the nasolacrimal duct at the junction of lacrimal sac
- Dacryocystitis is defined as infection of the lacrimal sac. Once the nasolacrimal duct is blocked, secondary infection easily sets into the lacrimal sac, which fills with pus. Pus also fills the blocked nasolacrimal duct, which becomes increasingly dilated. It then leaks from the infected lacrimal sac, out of the punctum lacrimale into the conjunctival sac and overflows down the face. Dermatitis, conjunctivitis, keratoconjunctivitis, keratitis and even panophthalmitis can be the result. In many cases, erosion of the duct and the surrounding bony canal occurs so the duct drains into the nasal passages. Treatment of dacryocystitis is aimed at controlling infection and removing purulent material from the nasolacrimal duct, the conjunctival sac and surrounding tissues. Analgesia is required, especially if the cornea or deeper structures of the eye are infected. Systemic and topical antibiotics are indicated. Flushing purulent material out of the nasolacrimal duct is an essential part of treatment
What are some problems with rabbit jaw abscesses?
- Abscesses in rabbits tend to be slow growing and relatively painless. Resorption of water from pus results in thick, caseous material within the abscess cavity. Antibiotics cannot penetrate the pus or the cavity because of poor vascularity. Abscesses have a thick fibrous capsule that may be so rigid that it does not collapse even if it is opened and the pus is removed. Residual microorganisms lead to renewal of inflammation in the space within the capsule and recrudescence of the abscess. Periapical infection of diseased or damaged teeth is the most common cause of jaw abscesses. However, primary bacterial infection is unlikely to result in a jaw abscess in rabbits. Penetrating injuries from fight wounds, foreign bodies or sharp points on the crowns of the teeth can also cause abscesses by introducing infection into the subcutaneous tissues
What are the most common type of jaw abscess in rabbits?
What can they result from?
- Periapical abscesses are the most common type of jaw abscess and are usually associated with the progressive syndrome of acquired dental disease (PSADD); however, they can occur in rabbits with good dentition. Periapical abscesses can result from a fractured tooth or from splinters that gain access to the periodontal space, especially the incisors, when rabbits are gnawing or chewing wood. Foreign bodies, such as seeds, blades of hay and awns, are more likely to become wedged between the teeth in rabbits with PSADD due to widening interdental spaces.
Removing all the infected tissue and administering antibiotics are not the only factors that affect the outcome of treatment of jaw abscesses. Other factors that affect the prognosis include the cause of the abscess - how is this a prognostic indicator?
Cause of the abscess. Abscesses caused by penetrating wounds to the soft tissue due to elongated crowns are cured more easily than periapical infections;
Removing all the infected tissue and administering antibiotics are not the only factors that affect the outcome of treatment of jaw abscesses. Other factors that affect the prognosis include the dondition of the teeth on the opposite side of the mouth - how is this a prognostic indicator?
Condition of the teeth on the opposite side of the mouth. If these teeth are healthy and the rabbit can eat on that side, extensive surgery can be performed on the affected side without causing eating difficulties;
Removing all the infected tissue and administering antibiotics are not the only factors that affect the outcome of treatment of jaw abscesses. Other factors that affect the prognosis include the stage of dental disease - how is this a prognostic indicator?
Stage of dental disease. The prognosis for rabbits with normal teeth or those that are still growing is different from rabbits in the advanced stages of PSADD when the teeth have stopped growing. In the early stages overgrowth of the opposing teeth can cause problems, although a single tooth can be removed without repercussions;
Removing all the infected tissue and administering antibiotics are not the only factors that affect the outcome of treatment of jaw abscesses. Other factors that affect the prognosis include the site of periapical infection - how is this a prognostic indicator?
Site of periapical infection. Removal of infected teeth requires surgical access to their apices and the apices of the caudal cheek teeth are more inaccessible than those of the rostral teeth. The apices of the caudal maxillary cheek teeth are in the orbit under the glands of the eye, while those of the caudal mandibular cheek teeth are beneath the masseter muscle. In some rabbits, the apex of the small sixth mandibular cheek tooth penetrates the medial aspect of the mandible, which is very difficult to access;
Removing all the infected tissue and administering antibiotics are not the only factors that affect the outcome of treatment of jaw abscesses. Other factors that affect the prognosis include the nature of the rabbit - how is this a prognostic indicator?
Nature of the rabbit. Rabbits that eat well and are amenable to handling are more likely to do well than fractious, nervous rabbits. It is easier to clean and dress an abscess wound thoroughly if the rabbit does not struggle
Removing all the infected tissue and administering antibiotics are not the only factors that affect the outcome of treatment of jaw abscesses. Other factors that affect the prognosis include the standar of post-operative care - how is this a prognostic indicator?
Standard of postoperative care. A high standard of nursing care is required to prevent postoperative complications, such as gut stasis, which can be fatal. A quiet, secluded environment with tempting food, familiar bedding and litter material reduces stress and increases the chances of recovery. Good-quality hay is essential. Tempting leafy plants, such as grass, dandelions, kale or spring cabbage, encourage rabbits to eat. Syringe feeding up to four times a day may be necessary. Effective analgesia is essential. The wound will need cleaning and topical treatment applied at least twice daily. Effective analgesia and antibacterial therapy are required
Removing all the infected tissue and administering antibiotics are not the only factors that affect the outcome of treatment of jaw abscesses. Other factors that affect the prognosis include owner compliance - how is this a prognostic indicator?
Owner compliance. Repeated anaesthetics and surgery may be required and owners may need to give injections or clean and dress the wound at home. An understanding, willing owner can make a big difference to the prognosis.
