Toy Poodle, Peking-ese, Shih Tzu, Small Terrier, Chihuahua & Pug.
250ml is the most cost effective option.

Weight: Upto 10KG
Recommended Daily Feeding Amount: Upto 5ml

How many days will a 100ml bottle last?
Maximum 20 days (Based on a 10kg dog) 0.45[ per day maximum.
How many days will a 250ml bottle last?
Maximum 50 days (based on a 10kg dog) 0.32p per day maxiumum.

Bulldog, Beagle, Large Terrier and Cocker Spaniel.
250/500ml are the most cost effective options.

Weight: Upto 11-20KG
Recommended Daily Feeding Amount: Upto 5-10ml

How many days will a 100ml bottle last?
10 - 20 days | 0.45p - 0.90p per day
How many days will a 250ml bottle last?
25 - 50 days | 0.32p - 0.64p per day
How many days will a 500ml bottle last?
50 days for a 20KG dog | 0.52p per day

Boxer, Setter and Dalmatian.
500ml / 1L are the most cost effective options.

Weight: Upto 21-30KG
Recommended Daily Feeding Amount: Upto 10 - 15ml

How many days will a 100ml bottle last?
6 - 10 days | 0.90p - £1.49 per day
How many days will a 250ml bottle last?
16 - 25 days | 0.64p - £1.00 per day
How many days will a 500ml bottle last?
33 - 50 days | 0.52p - 0.69p per day

Shepherd, Labrador and Retriever
1L is the most cost effective options.

Weight: Upto 31 - 40KG
Recommended Daily Feeding: 15 - 20ml

How many days will a 100ml bottle last?
15 - 16 days | £1.49 - £1.79 per day
How many days will a 250ml bottle last?
13 - 17 days | 0.94p - £1.22 per day

How many days will a 500ml bottle last?
23 - 33 days days | 0.79p - £1.04 per day

How many days will a 1L bottle last?
50 - 67 days | 0.61p - 0.82p per day

Great Dane, Newfoundland & Mastiff.
1L is the most cost effective options.

Weight: Over 40KG
Recommended Daily Feeding: 20ml plus 1ml every addional 2KG

How many days will a 250ml bottle last?
12 days or less depending on weight

How many days will a 500ml bottle last?
25 days or less depending on weight

How many days will a 1L bottle last?
50 days or less depending on weight