In addition to non-agricultural sources of ammonia (NH₃), this chapter discusses emissions from domestic animals such as dogs and cats.

Ammonia emissions from pets are calculated for the first time and based on the methodological description of Sutton et al. (2000) ¹⁾and the Guidebook 2023 ²⁾. For the complete time series, the emissions are calculated as follows:

As there are no official statistics on pets in Germany, data of a representative survey of over 5.000 households conducted on behalf of the German Pet Food Association (Industrieverband Heimtierbedarf e.V., IVH, and the Zentralverband Zoologischer Fachbetriebe Deutschlands e.V., ZZF)³⁾ for the period 2012-2022 are applied.

The latest EMEP EEA Guidebook refers to European statistics. The figures for 2021 and 2022 are consistent with those in the publication mentioned above and according to the 2023 Guidebook only the main categories cats (39% by animal catory) and dogs (27% by animal catory) were considered.

Time series for the main animal categories of pets are obtained by the numbers of the survey for the years 2012 to 2022. Data for 1990 are estimated retrospectively using the number of households (see also https://www.destatis.de/DE/Themen/Gesellschaft-Umwelt/Bevoelkerung/Haushalte-Familien/Tabellen/1-3-privathaushalte-neuer-zeitvergleich.html) and the trend between 1991 and 2013 (+13.9%) is accounted for as a baseline for 1990 animal numbers.

The data for 1990 and 2012 are used to gapfill the missing animal numbers by linear interpolation.

The following table shows the estimated pet population over time:

Table 1: Animal numbers in 10⁶, as of 1990

For the calculation of ammonia emissions in this category, the mean (best estimate) of the emission factors given in Sutton et al. (2000) are used:

• EF_cats: 0.11 kg NH₃-N animal^-1 year^-1
• EF_dogs: 0.61 kg NH₃-N animal^-1 year^-1

The emission factors were converted to the amount of ammonia using the stoichiometric factor of 17/14.

The following figure shows the development of emissions for the pet-categories dogs (EM_dog) and cats (EM_cat).

In recent years, an increasing trend can be observed, resulting in a mean value (between 2020 to 2022) of NH₃ emissions of 9.92 kt/a or xx% of total national ammonia emissions reported for 2022. Especially since the Corona year 2020, more people have acquired pets such as dogs.

Figure 1: Ammonia emissions from pets

For pets the uncertainty of the animal numbers is assumed to be 5% (standard error), and hence 10% for half the 95% confidence interval, with normal distribution.

There is no information on the uncertainty of the emission factors. However, uncertainties are expected to be relatively high, as EF vary between different sources and the amount of ammonia volatilized is based on an assumption. Therefore, an uncertainty of 50% for half the 95-percent confidence-interval (normal distribution) is assumed.