Feline Pica

Key Points

Pica (Including Wool-Sucking)

Some reports indicate that chewing or sucking of woolly items is commonest in early-weaned oriental breed cats, that continue to display suckling behaviour but transfer it to clothing and bedding. Typically the first sign is that the cat chews the owner’s clothes whilst being held. These cats usually stop ‘wool-sucking’ before the age of 6 months The precise reason for this delay in weaning from oral suckling behaviour is not understood but such juvenile behaviour is not considered to be compulsive and does not necessarily lead into adult 'compulsion'.

Genuinely compulsive pica in adult cats usually begins at maturity and can involve various different materials including fabric, wool, rubber and cardboard. Usually the cats show a specific preference for a material but this may generalise or change over time especially if the owner attempts to stop the cat from chewing the items that it currently favours. Wool is often the first target with progression from that to cotton and synthetics over time.

The behaviour may be restricted to chewing or mouthing the material, but can involve ingestion. The risk this presents depends upon the type of material being swallowed. The motivation to swallow objects is different from that in the dog. Dogs swallow food items as a means of carrying them between locations. They will then regurgitate the undigested food to eat or bury. Dogs often learn to swallow non-food items that they have stolen when the owner approaches to try to take them away. Cats do not do this, and are also less inclined to steal and retain objects as a means of gaining attention. However, cats with existing attachment problems, especially oriental breeds, may steal and chew objects to get attention.

Diagnosis

Wool-sucking is characterised by rhythmic repetitive mouthing and sucking of woolly objects and has therefore been classed by many authors as a compulsive disorder. Other possible explanations for the behaviour include a possible miswiring within the hypothalamic region of the brain which leads to errors in the detection of potential prey items and the redirection of hunting responses onto unsuitable items such as fabric. Cats with pica consistently choose to chew and swallow the same kind of non-food items, rather than simply engaging in oral investigation of a range of different items and materials, which is relatively normal in immature cats.

Differentials

There are a number of differentials for compulsive pica or wool-sucking, including:

• Repetitive chewing to relieve oral pain.
• Consumption of non-food items to induce vomiting [which can also occur repeatedly if a previous foreign body remains lodged in the stomach].
• Stealing and chewing objects as a means of getting attention from the owner.
• Cats with severe CNS pathology or senility may sometimes attempt to eat non-food items because they may perceive them as food.
• Conditions causing polyphagia may encourage cats to investigate and consume borderline non-food items.

Cats with pica should be thoroughly medically investigated before commencing a behavioural investigation.

Treatment

Young cats that wool-suck before the age of 6 months will probably stop spontaneously, but should be given alternative safe objects to chew. Food that is chewy may help to redirect the behaviour. Hide-based dog chews tend to be too hard for cats and have little flavour but they can be adapted by soaking them in hot water until the hide becomes softer. It may then be flavoured to make it appealing, using a few drops of fish sauce used for oriental cooking. The pieces must be sufficiently large that they cannot be swallowed whole. Other alternatives include dental hygiene dried cat food, which comes in large pieces, or meat jerky sold for human consumption.

The same diversionary tactic can be tried with adult-onset cases of pica and the texture of the chewing substitute should be matched to the cat’s existing preference. These cats should also be provided with general environmental enrichment and any specific underlying environmental or social stressors should be dealt with. Psychoactive medication may be used, with SRI and SSRI drugs producing significant improvement in both juvenile post-weaning and adult-onset cases of pica, although the mode of action of the drug in the two conditions may be different. Clomipramine should be given at an initial lower dose, rising to a higher dose if there is insufficient response after 4-6 weeks.

Drug therapy should be continued until a period of 6-8 weeks without pica has elapsed, and the cat is chewing the alternatives provided.

Treatment Summary - Pica

• Investigate and treat underlying social or environmental maintaining factors.
• Provide environmental enrichment to use up the cat’s time and activity budget: activity feeding, play, increased access to height, and a range of additional toys and feeding sites.
• Provide substitute to chew and consider feeding a chewy dental diet.
• Psychoactive medication; Clomipramine, or Fluoxetine are first choices.

Prognosis

Cats with pica represent a serious risk to themselves, as ingested material may cause gastrointestinal obstruction. Withdrawal of successful therapy may cause further potentially life-threatening bouts of pica, so the aim is to maintain a stable and low-stress environment compatible with producing the minimum amount of abnormal behaviour. In some cases long-term medication may be needed.