House soiling represents approximately 40% of cases seen at behavior referral practices.1,2 Most soiling cases involve urine only although some cats soil with urine and stools and fewer with stools only.1 In one study 63% of soiling was litter box aversion (toileting) and 15.5% urine marking.1 Persian, Siamese and Burmese type were reported to have highest soiling with urine, Siamese and Burmese greater spraying and Persians highest urine and stool soiling.2,3
Marking is a form of social communication. Marking may be sexual or reactional and may be stimulated by arousal or a change in the cat’s environment. Targets include plants, furniture, boundaries and exits. Less commonly cats that soil on horizontal surfaces may also be marking. In most cases, the cat backs up to a vertical surface and directs a small stream of urine toward an object or surface. Typical posturing includes standing, treading with back legs, with tail elevated and quivering. Cats that spray generally still use their litter for elimination. Although sexually intact males are most likely to mark the problem is more common in neutered males than spayed females
Most horizontal house soiling is due to avoidance of the box, litter, or location, or a preference for substrates or locations other than the box. Cats usually assume a squatting posture and may dig or scratch after elimination. For cats that intermittently use the litter box, the history can provide insight as to what might be leading to avoidance (e.g., cleaning, aversive events, social conflict, surface preferences). Households with urine spraying compared to households with toileting cats had higher fecal glucorticoid levels in both treatment cats and controls, but no differences between cats in the same household.3
Medical conditions can cause or contribute to both toileting and marking. In a recent case-controlled study medical problems including renal insufficiency, cystitis, and lithiasis had similar frequency in toileting and spraying cats (39%). Cats living in the household with soiling cat but not the spraying cat were more likely so have medical problems.4
Increased frequency or volume of urine, loss of control, pollakiuria, or discomfort during elimination (e.g., vocalization, running from the box) might indicate a medical cause. Systemic diseases, neurological disorders including cognitive dysfunction and pain may contribute to soiling by altering hormonal states, increasing anxiety, or altering mobility. In spraying cats with evidence of masculinization such as penile barbs or tomcat odor, rule out hormonal disorders arising from a retained testicle, extratesticular tissue or a Sertoli cell tumor. Through history or video if available determine if the cat is marking or toileting. In some households, both problems co-exist. Cats that mark near external walls, windows, and doorways may be responding to outdoor stimuli. Cats that mark household objects, owner possessions, visitors clothing, or those of the family dog may be stressed or anxious in their social relationships or with their home environment.
In one study, environmental management alone (i.e., enzymatic cleansers, increasing the number of litter boxes to the number of cats plus one; cleaning the box daily; changing the box weekly and ceasing punishment) led to improvement in a number of cats that were vertically marking.5 For toileting focus on litter box management including increasing size, cleaning more frequently, adding additional boxes, and identifying the preferred substrate, box type and location. Where there are sources of underlying anxiety or conflict, that contribute to litter avoidance, interstitial cystitis or marking medication might be indicated.
For a comprehensive review, see www.catvets.com/guidelines/practice-guidelines/house-soiling
1. Environmental management
Ensure that all of the cats behavioral needs are adequately met and that there are sufficient resources and opportunities for comfort and security (bedding, perches) to prevent and avoid social conflict. (www.catvets.com, https://indoorpet.osu.edu). Manage the environment to prevent access to triggers or to prevent access to the areas being marked. For cats that mark in specific locations an indoor marking site might be considered.
2. Behavior modification
For marking related to social anxiety with people, stressors should be identified, unpleasant interactions avoided (including any punishment) and relationships improved with reward-based training and desensitization and counterconditioning. For social conflict between cats, identify and avoid triggers, increase availability of resources, place a bell on the aggressor, separate at times and in situations where problems might arise and improve relationships with desensitization and counter-conditioning.
3. Medication is often necessary to reduce the cat’s level of arousal or anxiety. As no psychotropic drugs are currently licensed for cats except clomipramine for urine marking in Australia, drugs should be dispensed with informed owner consent and with ongoing veterinary monitoring and oversight.
Selective Serotonin Reuptake Inhibitors (SSRI) and Tricyclic Antidepressants (TCA)
i) Fluoxetine and clomipramine are similarly effective in reducing or controlling urine marking.7 Other SSRIs, such as paroxetine, and TCAs, such as amitriptyline, are also an option; however, their efficacy has not been evaluated. While improvement may be seen within the first week, 8 weeks or longer might be needed to achieve maximal control.8 Once there has been a cessation for 2 months, the dose might be gradually decreased. However, long-term therapy is often necessary and recurrence is likely unless sufficient modifications have been made to manage the environment and modify behavior.
ii) Benzodiazepines may be effective as an alternative option particularly for the “victim cat” with intraspecific social conflict. Benzodiazepines might also be considered for as needed use for situational anxiety. Since diazepam has been associated with rare reports of fatal hepatopathies, lorazepam and oxazepam may be safer options as they have no active intermediate metabolites.
iii) Buspirone has been shown to reduce urine spraying with a lower relapse rate than diazepam on withdrawal.
iv) Gabapentin might be a consideration for situational use as well as for ongoing use particularly when neuropathic pain might be contributing.
v) Progestins have been shown to improve marking in 50% of neutered males; however, due to high risk of adverse effects including diabetes, immune suppression, and breast tumors their use should be avoided or limited to refractory cases.
vi) For both the stress and pain associated with interstitial cystitis, the use of a serotonin norepinephrine reuptake inhibitor, venlafaxine might be considered in refractory cases.
vii) Natural options might also be used as an alternative to, or in conjunction with drug therapy including feline F3 facial pheromone (Feliway®), Feliway Multi-Cat® for marking related to intercat social conflict, l-theanine, alpha-casozepine, a combination of Magnolia, phellodendron, l-theanine, and whey protein (Solliquin®, Nutramax) or diets supplemented with alpha-casozepine and tryptophan.
In a meta-analysis of 10 studies that evaluated drug and pheromone use for urine marking, there was a significant (p<0.001) association between the use of any intervention and the number of cats that ceased or were reduced by at least 90%. The greatest effect was achieved with fluoxetine and clomipramine.7
When there are compliance issues with oral dosing, compounding and transdermal dosing might be considered. However, with compounding there are concerns about homogeneity, bioavailability, and stability while transdermal use has not demonstrated sufficient absorption or bioavailablity, particularly with TCAs and SSRIs. However, in one study comparing buspirone at 1 mg/kg orally to 4 mg/kg transdermally for 5 weeks, a significant improvement was seen in both groups.8
Table 1. Drug doses for marking in cats
0.125–0.25 mg/cat prn to bid
0.125–0. 25 mg/cat prn to tid
0.2–0.5 mg/kg prn to bid
5–30 mg/kg prn to tid
2.5–10 mg/cat q 24 h
0.25–1 mg/kg q 24 h
0.25–1. 5 mg/kg q 24 h
0.25–1.5 mg/kg q 24 h
0.5–1 mg/kg sid to bid
0.5–2.0 mg/kg daily
1. Amat M, Ruiz de la Torre JL, Fatjo J, et al. Potential risk factors associated with feline behavior problems. Appl Anim Behav Sci. 2009; 121, 134–39
2. Wassink-van der Schot AA, Day C, Morton JM, et al. Risk factors for behavior problems in cats presented to an Australian companion animal clinic. J Vet Behav. 2016; 14, 34–40
3. Ramos D, Reche-Junior A, Mills D, et al. Are cats with houseoiling problems stressed? A case-controlled comparison of faecal glucocorticoid levels in urine spraying and toileting cats. Lisbon, Portugal, In: Mills ed. Proc 9th IVBM Conference, 2013, PSI Animal, 113–114
4. Ramos D, Reche-Junior A, Mills DS, et al. A closer look at the health of cats showing urinary house-soiling (periuria): a case-control study 2018. J Fel Med Surg. https://doi. org/10.1177/1098612X18801034
5. Pryor PA, Hart BL, Bain MJ, et al. Causes of urine marking in cats and effects of environmental management on frequency of marking. JAVMA. 2001;219:1709–1713.
6. Mills DS, Redgate SE, Landsberg GM. A meta-analysis of studies of treatments for feline urine spraying. PloS ONE. 6(4): e18448. doi:10.1371/journal.pone.0018448, 2011.
7. Hart BL, Cliff KD, Tynes VV, et al. Control of urine marking by use of long-term treatment with fluoxetine or clomipramine in cats. JAVMA. 2005; 226, 378–382
8. Chavez G, Pardo P, Ubilla MJ, et al. Effects on behavioural variables of oral versus transdermal administration in cats displaying urine marking. J Appl Anim Res. 2016; 44, 454–57.